While working on my other scripts to deal with gdb headers, I noticed
that some files were missing include guards. I wrote a script to add
the missing ones, but found that using the obvious names for the
guards ran into clashes -- for example, gdb/nat/linux-nat.h used
"LINUX_NAT_H", but this was also the script's choice for
gdb/linux-nat.h.
So, I changed the script to normalize all include guards in gdb. This
patch is the result.
As usual the script is available here:
https://github.com/tromey/gdb-refactoring-scripts
Tested by rebuilding; I also ran it through "Fedora-x86_64-m64" on the
buildbot.
gdb/ChangeLog
2019-02-07 Tom Tromey <tom@tromey.com>
* yy-remap.h: Add include guard.
* xtensa-tdep.h: Add include guard.
* xcoffread.h: Rename include guard.
* varobj-iter.h: Add include guard.
* tui/tui.h: Rename include guard.
* tui/tui-winsource.h: Rename include guard.
* tui/tui-wingeneral.h: Rename include guard.
* tui/tui-windata.h: Rename include guard.
* tui/tui-win.h: Rename include guard.
* tui/tui-stack.h: Rename include guard.
* tui/tui-source.h: Rename include guard.
* tui/tui-regs.h: Rename include guard.
* tui/tui-out.h: Rename include guard.
* tui/tui-layout.h: Rename include guard.
* tui/tui-io.h: Rename include guard.
* tui/tui-hooks.h: Rename include guard.
* tui/tui-file.h: Rename include guard.
* tui/tui-disasm.h: Rename include guard.
* tui/tui-data.h: Rename include guard.
* tui/tui-command.h: Rename include guard.
* tic6x-tdep.h: Add include guard.
* target/waitstatus.h: Rename include guard.
* target/wait.h: Rename include guard.
* target/target.h: Rename include guard.
* target/resume.h: Rename include guard.
* target-float.h: Rename include guard.
* stabsread.h: Add include guard.
* rs6000-tdep.h: Add include guard.
* riscv-fbsd-tdep.h: Add include guard.
* regformats/regdef.h: Rename include guard.
* record.h: Rename include guard.
* python/python.h: Rename include guard.
* python/python-internal.h: Rename include guard.
* python/py-stopevent.h: Rename include guard.
* python/py-ref.h: Rename include guard.
* python/py-record.h: Rename include guard.
* python/py-record-full.h: Rename include guard.
* python/py-record-btrace.h: Rename include guard.
* python/py-instruction.h: Rename include guard.
* python/py-events.h: Rename include guard.
* python/py-event.h: Rename include guard.
* procfs.h: Add include guard.
* proc-utils.h: Add include guard.
* p-lang.h: Add include guard.
* or1k-tdep.h: Rename include guard.
* observable.h: Rename include guard.
* nto-tdep.h: Rename include guard.
* nat/x86-linux.h: Rename include guard.
* nat/x86-linux-dregs.h: Rename include guard.
* nat/x86-gcc-cpuid.h: Add include guard.
* nat/x86-dregs.h: Rename include guard.
* nat/x86-cpuid.h: Rename include guard.
* nat/ppc-linux.h: Rename include guard.
* nat/mips-linux-watch.h: Rename include guard.
* nat/linux-waitpid.h: Rename include guard.
* nat/linux-ptrace.h: Rename include guard.
* nat/linux-procfs.h: Rename include guard.
* nat/linux-osdata.h: Rename include guard.
* nat/linux-nat.h: Rename include guard.
* nat/linux-namespaces.h: Rename include guard.
* nat/linux-btrace.h: Rename include guard.
* nat/glibc_thread_db.h: Rename include guard.
* nat/gdb_thread_db.h: Rename include guard.
* nat/gdb_ptrace.h: Rename include guard.
* nat/fork-inferior.h: Rename include guard.
* nat/amd64-linux-siginfo.h: Rename include guard.
* nat/aarch64-sve-linux-sigcontext.h: Rename include guard.
* nat/aarch64-sve-linux-ptrace.h: Rename include guard.
* nat/aarch64-linux.h: Rename include guard.
* nat/aarch64-linux-hw-point.h: Rename include guard.
* mn10300-tdep.h: Add include guard.
* mips-linux-tdep.h: Add include guard.
* mi/mi-parse.h: Rename include guard.
* mi/mi-out.h: Rename include guard.
* mi/mi-main.h: Rename include guard.
* mi/mi-interp.h: Rename include guard.
* mi/mi-getopt.h: Rename include guard.
* mi/mi-console.h: Rename include guard.
* mi/mi-common.h: Rename include guard.
* mi/mi-cmds.h: Rename include guard.
* mi/mi-cmd-break.h: Rename include guard.
* m2-lang.h: Add include guard.
* location.h: Rename include guard.
* linux-record.h: Rename include guard.
* linux-nat.h: Add include guard.
* linux-fork.h: Add include guard.
* i386-darwin-tdep.h: Rename include guard.
* hppa-linux-offsets.h: Add include guard.
* guile/guile.h: Rename include guard.
* guile/guile-internal.h: Rename include guard.
* gnu-nat.h: Rename include guard.
* gdb-stabs.h: Rename include guard.
* frv-tdep.h: Add include guard.
* f-lang.h: Add include guard.
* event-loop.h: Add include guard.
* darwin-nat.h: Rename include guard.
* cp-abi.h: Rename include guard.
* config/sparc/nm-sol2.h: Rename include guard.
* config/nm-nto.h: Rename include guard.
* config/nm-linux.h: Add include guard.
* config/i386/nm-i386gnu.h: Rename include guard.
* config/djgpp/nl_types.h: Rename include guard.
* config/djgpp/langinfo.h: Rename include guard.
* compile/gcc-cp-plugin.h: Add include guard.
* compile/gcc-c-plugin.h: Add include guard.
* compile/compile.h: Rename include guard.
* compile/compile-object-run.h: Rename include guard.
* compile/compile-object-load.h: Rename include guard.
* compile/compile-internal.h: Rename include guard.
* compile/compile-cplus.h: Rename include guard.
* compile/compile-c.h: Rename include guard.
* common/xml-utils.h: Rename include guard.
* common/x86-xstate.h: Rename include guard.
* common/version.h: Rename include guard.
* common/vec.h: Rename include guard.
* common/tdesc.h: Rename include guard.
* common/selftest.h: Rename include guard.
* common/scoped_restore.h: Rename include guard.
* common/scoped_mmap.h: Rename include guard.
* common/scoped_fd.h: Rename include guard.
* common/safe-iterator.h: Rename include guard.
* common/run-time-clock.h: Rename include guard.
* common/refcounted-object.h: Rename include guard.
* common/queue.h: Rename include guard.
* common/ptid.h: Rename include guard.
* common/print-utils.h: Rename include guard.
* common/preprocessor.h: Rename include guard.
* common/pathstuff.h: Rename include guard.
* common/observable.h: Rename include guard.
* common/netstuff.h: Rename include guard.
* common/job-control.h: Rename include guard.
* common/host-defs.h: Rename include guard.
* common/gdb_wait.h: Rename include guard.
* common/gdb_vecs.h: Rename include guard.
* common/gdb_unlinker.h: Rename include guard.
* common/gdb_unique_ptr.h: Rename include guard.
* common/gdb_tilde_expand.h: Rename include guard.
* common/gdb_sys_time.h: Rename include guard.
* common/gdb_string_view.h: Rename include guard.
* common/gdb_splay_tree.h: Rename include guard.
* common/gdb_setjmp.h: Rename include guard.
* common/gdb_ref_ptr.h: Rename include guard.
* common/gdb_optional.h: Rename include guard.
* common/gdb_locale.h: Rename include guard.
* common/gdb_assert.h: Rename include guard.
* common/filtered-iterator.h: Rename include guard.
* common/filestuff.h: Rename include guard.
* common/fileio.h: Rename include guard.
* common/environ.h: Rename include guard.
* common/common-utils.h: Rename include guard.
* common/common-types.h: Rename include guard.
* common/common-regcache.h: Rename include guard.
* common/common-inferior.h: Rename include guard.
* common/common-gdbthread.h: Rename include guard.
* common/common-exceptions.h: Rename include guard.
* common/common-defs.h: Rename include guard.
* common/common-debug.h: Rename include guard.
* common/cleanups.h: Rename include guard.
* common/buffer.h: Rename include guard.
* common/btrace-common.h: Rename include guard.
* common/break-common.h: Rename include guard.
* cli/cli-utils.h: Rename include guard.
* cli/cli-style.h: Rename include guard.
* cli/cli-setshow.h: Rename include guard.
* cli/cli-script.h: Rename include guard.
* cli/cli-interp.h: Rename include guard.
* cli/cli-decode.h: Rename include guard.
* cli/cli-cmds.h: Rename include guard.
* charset-list.h: Add include guard.
* buildsym-legacy.h: Rename include guard.
* bfin-tdep.h: Add include guard.
* ax.h: Rename include guard.
* arm-linux-tdep.h: Add include guard.
* arm-fbsd-tdep.h: Add include guard.
* arch/xtensa.h: Rename include guard.
* arch/tic6x.h: Add include guard.
* arch/i386.h: Add include guard.
* arch/arm.h: Rename include guard.
* arch/arm-linux.h: Rename include guard.
* arch/arm-get-next-pcs.h: Rename include guard.
* arch/amd64.h: Add include guard.
* arch/aarch64-insn.h: Rename include guard.
* arch-utils.h: Rename include guard.
* annotate.h: Add include guard.
* amd64-darwin-tdep.h: Rename include guard.
* aarch64-linux-tdep.h: Add include guard.
* aarch64-fbsd-tdep.h: Add include guard.
* aarch32-linux-nat.h: Add include guard.
gdb/gdbserver/ChangeLog
2019-02-07 Tom Tromey <tom@tromey.com>
* x86-tdesc.h: Rename include guard.
* x86-low.h: Add include guard.
* wincecompat.h: Rename include guard.
* win32-low.h: Add include guard.
* utils.h: Rename include guard.
* tracepoint.h: Rename include guard.
* tdesc.h: Rename include guard.
* target.h: Rename include guard.
* server.h: Rename include guard.
* remote-utils.h: Rename include guard.
* regcache.h: Rename include guard.
* nto-low.h: Rename include guard.
* notif.h: Add include guard.
* mem-break.h: Rename include guard.
* lynx-low.h: Add include guard.
* linux-x86-tdesc.h: Add include guard.
* linux-s390-tdesc.h: Add include guard.
* linux-ppc-tdesc-init.h: Add include guard.
* linux-low.h: Add include guard.
* linux-aarch64-tdesc.h: Add include guard.
* linux-aarch32-low.h: Add include guard.
* inferiors.h: Rename include guard.
* i387-fp.h: Rename include guard.
* hostio.h: Rename include guard.
* gdbthread.h: Rename include guard.
* gdb_proc_service.h: Rename include guard.
* event-loop.h: Rename include guard.
* dll.h: Rename include guard.
* debug.h: Rename include guard.
* ax.h: Rename include guard.
This commit applies all changes made after running the gdb/copyright.py
script.
Note that one file was flagged by the script, due to an invalid
copyright header
(gdb/unittests/basic_string_view/element_access/char/empty.cc).
As the file was copied from GCC's libstdc++-v3 testsuite, this commit
leaves this file untouched for the time being; a patch to fix the header
was sent to gcc-patches first.
gdb/ChangeLog:
Update copyright year range in all GDB files.
This adds some basic type alignment support to gdb. It changes struct
type to store the alignment, and updates dwarf2read.c to handle
DW_AT_alignment. It also adds a new gdbarch method and updates
i386-tdep.c.
None of this new functionality is used anywhere yet, so tests will
wait until the next patch.
2018-04-30 Tom Tromey <tom@tromey.com>
* i386-tdep.c (i386_type_align): New function.
(i386_gdbarch_init): Update.
* gdbarch.sh (type_align): New method.
* gdbarch.c, gdbarch.h: Rebuild.
* arch-utils.h (default_type_align): Declare.
* arch-utils.c (default_type_align): New function.
* gdbtypes.h (TYPE_ALIGN_BITS): New define.
(struct type) <align_log2>: New field.
<instance_flags>: Now a bitfield.
(TYPE_RAW_ALIGN): New macro.
(type_align, type_raw_align, set_type_align): Declare.
* gdbtypes.c (type_align, type_raw_align, set_type_align): New
functions.
* dwarf2read.c (quirk_rust_enum): Set type alignment.
(get_alignment, maybe_set_alignment): New functions.
(read_structure_type, read_enumeration_type, read_array_type)
(read_set_type, read_tag_pointer_type, read_tag_reference_type)
(read_subrange_type, read_base_type): Set type alignment.
With version 7.3 GCC supports new options
-mindirect-branch=<choice>
-mfunction-return=<choice>
The choices are:
keep behaves as before
thunk jumps through a thunk
thunk-external jumps through an external thunk
thunk-inline jumps through an inlined thunk
For thunk and thunk-external, GDB would, on a call to the thunk, step into
the thunk and then resume to its caller assuming that this is an
undebuggable function. On a return thunk, GDB would stop inside the
thunk.
Make GDB step through such thunks instead.
Before:
Temporary breakpoint 1, main ()
at gdb.base/step-indirect-call-thunk.c:37
37 x = apply (inc, 41);
(gdb) s
apply (op=0x80483e6 <inc>, x=41)
at gdb.base/step-indirect-call-thunk.c:29
29 return op (x);
(gdb)
30 }
After:
Temporary breakpoint 1, main ()
at gdb.base/step-indirect-call-thunk.c:37
37 x = apply (inc, 41);
(gdb) s
apply (op=0x80483e6 <inc>, x=41)
at gdb.base/step-indirect-call-thunk.c:29
29 return op (x);
(gdb)
inc (x=41) at gdb.base/step-indirect-call-thunk.c:23
23 return x + 1;
This is independent of the step-mode. In order to step into the thunk,
you would need to use stepi.
When stepping over an indirect call thunk, GDB would first step through
the thunk, then recognize that it stepped into a sub-routine and resume to
the caller (of the thunk). Not sure whether this is worth optimizing.
Thunk detection is implemented via gdbarch. I implemented the methods for
IA. Other architectures may run into unexpected fails.
The tests assume a fixed number of instruction steps to reach a thunk.
This depends on the compiler as well as the architecture. They may need
adjustments when we add support for more architectures. Or we can simply
drop those tests that cover being able to step into thunks using
instruction stepping.
When using an older GCC, the tests will fail to build and will be reported
as untested:
Running .../gdb.base/step-indirect-call-thunk.exp ...
gdb compile failed, \
gcc: error: unrecognized command line option '-mindirect-branch=thunk'
gcc: error: unrecognized command line option '-mfunction-return=thunk'
=== gdb Summary ===
# of untested testcases 1
gdb/
* infrun.c (process_event_stop_test): Call
gdbarch_in_indirect_branch_thunk.
* gdbarch.sh (in_indirect_branch_thunk): New.
* gdbarch.c: Regenerated.
* gdbarch.h: Regenerated.
* x86-tdep.h: New.
* x86-tdep.c: New.
* Makefile.in (ALL_TARGET_OBS): Add x86-tdep.o.
(HFILES_NO_SRCDIR): Add x86-tdep.h.
(ALLDEPFILES): Add x86-tdep.c.
* arch-utils.h (default_in_indirect_branch_thunk): New.
* arch-utils.c (default_in_indirect_branch_thunk): New.
* i386-tdep: Include x86-tdep.h.
(i386_in_indirect_branch_thunk): New.
(i386_elf_init_abi): Set in_indirect_branch_thunk gdbarch
function.
* amd64-tdep: Include x86-tdep.h.
(amd64_in_indirect_branch_thunk): New.
(amd64_init_abi): Set in_indirect_branch_thunk gdbarch function.
testsuite/
* gdb.base/step-indirect-call-thunk.exp: New.
* gdb.base/step-indirect-call-thunk.c: New.
* gdb.reverse/step-indirect-call-thunk.exp: New.
* gdb.reverse/step-indirect-call-thunk.c: New.
This changes the gdbarch fast_tracepoint_valid_at method to use a
std::string as its out parameter, and then updates all the uses. This
allows removing a cleanup from breakpoint.c.
Regression tested by the buildbot.
ChangeLog
2018-02-24 Tom Tromey <tom@tromey.com>
* i386-tdep.c (i386_fast_tracepoint_valid_at): "msg" now a
std::string.
* gdbarch.sh (fast_tracepoint_valid_at): Change "msg" to a
std::string*.
* gdbarch.c: Rebuild.
* gdbarch.h: Rebuild.
* breakpoint.c (check_fast_tracepoint_sals): Use std::string.
* arch-utils.h (default_fast_tracepoint_valid_at): Update.
* arch-utils.c (default_fast_tracepoint_valid_at): "msg" now a
std::string*.
PR 21555 is caused by the exception during the prologue analysis when re-set
a breakpoint.
(gdb) bt
#0 memory_error_message (err=TARGET_XFER_E_IO, gdbarch=0x153db50, memaddr=93824992233232) at ../../binutils-gdb/gdb/corefile.c:192
#1 0x00000000005718ed in memory_error (err=TARGET_XFER_E_IO, memaddr=memaddr@entry=93824992233232) at ../../binutils-gdb/gdb/corefile.c:220
#2 0x00000000005719d6 in read_memory_object (object=object@entry=TARGET_OBJECT_CODE_MEMORY, memaddr=93824992233232, memaddr@entry=1, myaddr=myaddr@entry=0x7fffffffd0a0 "P\333S\001", len=len@entry=1) at ../../binutils-gdb/gdb/corefile.c:259
#3 0x0000000000571c6e in read_code (len=1, myaddr=0x7fffffffd0a0 "P\333S\001", memaddr=<optimized out>) at ../../binutils-gdb/gdb/corefile.c:287
#4 read_code_unsigned_integer (memaddr=memaddr@entry=93824992233232, len=len@entry=1, byte_order=byte_order@entry=BFD_ENDIAN_LITTLE) at ../../binutils-gdb/gdb/corefile.c:362
#5 0x000000000041d4a0 in amd64_analyze_prologue (gdbarch=gdbarch@entry=0x153db50, pc=pc@entry=93824992233232, current_pc=current_pc@entry=18446744073709551615, cache=cache@entry=0x7fffffffd1e0) at ../../binutils-gdb/gdb/amd64-tdep.c:2310
#6 0x000000000041e404 in amd64_skip_prologue (gdbarch=0x153db50, start_pc=93824992233232) at ../../binutils-gdb/gdb/amd64-tdep.c:2459
#7 0x000000000067bfb0 in skip_prologue_sal (sal=sal@entry=0x7fffffffd4e0) at ../../binutils-gdb/gdb/symtab.c:3628
#8 0x000000000067c4d8 in find_function_start_sal (sym=sym@entry=0x1549960, funfirstline=1) at ../../binutils-gdb/gdb/symtab.c:3501
#9 0x000000000060999d in symbol_to_sal (result=result@entry=0x7fffffffd5f0, funfirstline=<optimized out>, sym=sym@entry=0x1549960) at ../../binutils-gdb/gdb/linespec.c:3860
....
#16 0x000000000054b733 in location_to_sals (b=b@entry=0x15792d0, location=0x157c230, search_pspace=search_pspace@entry=0x1148120, found=found@entry=0x7fffffffdc64) at ../../binutils-gdb/gdb/breakpoint.c:14211
#17 0x000000000054c1f5 in breakpoint_re_set_default (b=0x15792d0) at ../../binutils-gdb/gdb/breakpoint.c:14301
#18 0x00000000005412a9 in breakpoint_re_set_one (bint=bint@entry=0x15792d0) at ../../binutils-gdb/gdb/breakpoint.c:14412
This problem can be fixed by
- either each prologue analyzer doesn't throw exception,
- or catch the exception thrown from gdbarch_skip_prologue,
I choose the latter because the former needs to fix *every* prologue
analyzer to not throw exception.
This error can be reproduced by changing reread.exp. The test reread.exp
has already test that breakpoint can be reset correctly after the
executable is re-read. This patch extends this test by compiling test c
file with and without -fPIE.
(gdb) run ^M
The program being debugged has been started already.^M
Start it from the beginning? (y or n) y^M
x86_64/gdb/testsuite/outputs/gdb.base/reread/reread' has changed; re-reading symbols.
Error in re-setting breakpoint 1: Cannot access memory at address 0x555555554790^M
Error in re-setting breakpoint 2: Cannot access memory at address 0x555555554790^M
Starting program: /scratch/yao/gdb/build-git/x86_64/gdb/testsuite/outputs/gdb.base/reread/reread ^M
This is foo^M
[Inferior 1 (process 27720) exited normally]^M
(gdb) FAIL: gdb.base/reread.exp: opts= "-fPIE" "ldflags=-pie" : run to foo() second time (the program exited)
This patch doesn't re-indent the code, to keep the patch simple.
gdb:
2017-07-25 Yao Qi <yao.qi@linaro.org>
PR gdb/21555
* arch-utils.c (gdbarch_skip_prologue_noexcept): New function.
* arch-utils.h (gdbarch_skip_prologue_noexcept): Declare.
* infrun.c: Include arch-utils.h
(handle_step_into_function): Call gdbarch_skip_prologue_noexcept.
(handle_step_into_function_backward): Likewise.
* symtab.c (skip_prologue_sal): Likewise.
gdb/testsuite:
2017-07-25 Yao Qi <yao.qi@linaro.org>
PR gdb/21555
* gdb.base/reread.exp: Wrap the whole test with two kinds of
compilation flags, with -fPIE and without -fPIE.
The displaced_step_free_closure gdbarch hook allows architectures to
free data they might have allocated to complete a displaced step.
However, all architectures using that hook use the
simple_displaced_step_free_closure provided in arch-utils.{c,h}, which
does a simple xfree. We can remove it and do an xfree directly instead
of calling the hook.
gdb/ChangeLog:
* gdbarch.sh (displaced_step_free_closure): Remove.
* gdbarch.h, gdbarch.c: Re-generate.
* aarch64-linux-tdep.c (aarch64_linux_init_abi): Don't set
displaced_step_free_closure.
* amd64-linux-tdep.c (amd64_linux_init_abi_common): Likewise.
* arm-linux-tdep.c (arm_linux_init_abi): Likewise.
* i386-linux-tdep.c (i386_linux_init_abi): Likewise.
* rs6000-aix-tdep.c (rs6000_aix_init_osabi): Likewise.
* rs6000-tdep.c (rs6000_gdbarch_init): Likewise.
* s390-linux-tdep.c (s390_gdbarch_init): Likewise.
* arch-utils.h (simple_displaced_step_free_closure): Remove.
* arch-utils.c (simple_displaced_step_free_closure): Remove.
* infrun.c (displaced_step_clear): Call xfree instead of
gdbarch_displaced_step_free_closure.
Recently a feature called "return address signing" has been added to GCC to
prevent stack smash stack on AArch64. For details please refer:
https://gcc.gnu.org/ml/gcc-patches/2017-01/msg00376.html
GDB needs to be aware of this feature so it can restore the original return
address which is critical for unwinding.
On compiler side, whenever return address, i.e. LR register, is mangled or
restored by hardware instruction, compiler is expected to generate a
DW_CFA_AARCH64_negate_ra_state to toggle return address signing status.
DW_CFA_AARCH64_negate_ra_state is using the same CFI number and
therefore need to be multiplexed with DW_CFA_GNU_window_save which was designed
for SPARC.
A new gdbarch method "execute_dwarf_cfa_vendor_op" is introduced by this patch.
It's parameters has been restricted to those only needed by SPARC and AArch64
for multiplexing DW_CFA_GNU_window_save which is a CFI operation takes none
operand. Should any further DWARF CFI operation want to be multiplexed in the
future, the parameter list can be extended. Below is the current function
prototype.
typedef int (gdbarch_execute_dwarf_cfa_vendor_op_ftype)
(struct gdbarch *gdbarch, gdb_byte op, struct dwarf2_frame_state *fs);
DW_CFA_GNU_window_save support for SPARC is migrated to this new gdbarch
method by this patch.
gdb/
* gdbarch.sh: New gdbarch method execute_dwarf_cfa_vendor_op.
* gdbarch.c: Regenerated.
* gdbarch.h: Regenerated.
* dwarf2-frame.c (dwarf2_frame_state_alloc_regs): Made the
visibility external.
(execute_cfa_program): Call execute_dwarf_cfa_vendor_op for CFI
between DW_CFA_lo_user and DW_CFA_high_user inclusive.
(enum cfa_how_kind): Move to ...
(struct dwarf2_frame_state_reg_info): Likewise.
(struct dwarf2_frame_state): Likewise.
* dwarf2-frame.h: ... here.
(dwarf2_frame_state_alloc_regs): New declaration.
* sparc-tdep.c (sparc_execute_dwarf_cfa_vendor_op): New function.
(sparc32_gdbarch_init): Register execute_dwarf_cfa_vendor_op hook.
This applies the second part of GDB's End of Year Procedure, which
updates the copyright year range in all of GDB's files.
gdb/ChangeLog:
Update copyright year range in all GDB files.
Both of them are used in conversion. We can remove them since the
conversion is done.
There are many architectures only have one breakpoint instruction,
so their gdbarch methods breakpoint_kind_from_pc and
sw_breakpoint_from_kind look very similar. Instead of macro, we
use template "template <size_t, const gdb_byte *> struct bp_manipulation"
for these architectures. In order to use template, I also change
breakpoint instruction of type "static const gdb_byte[]" to
"constexpr gdb_byte[]", and rename them to ARCH_break_insn.
gdb:
2016-11-03 Yao Qi <yao.qi@linaro.org>
Pedro Alves <palves@redhat.com>
* aarch64-tdep.c (aarch64_default_breakpoint): Change it to
constexpr. Don't use GDBARCH_BREAKPOINT_MANIPULATION.
(aarch64_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* alpha-tdep.c (break_insn): Rename to alpha_break_insn.
Don't use GDBARCH_BREAKPOINT_MANIPULATION.
(alpha_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* arc-tdep.c (arc_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* arch-utils.h (GDBARCH_BREAKPOINT_MANIPULATION): Remove.
(struct bp_manipulation): New.
(SET_GDBARCH_BREAKPOINT_MANIPULATION): Remove.
(struct bp_manipulation_endian): New.
(BP_MANIPULATION): New.
(BP_MANIPULATION_ENDIAN): New.
* arm-tdep.c (arm_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* avr-tdep.c (avr_break_insn): Change it constexpr.
(avr_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* bfin-tdep.c (bfin_gdbarch_init): Likewise.
* cris-tdep.c (cris_gdbarch_init): Likewise.
* frv-tdep.c (breakpoint): Rename it to frv_break_insn, and
change its type to constexpr. Don't use
GDBARCH_BREAKPOINT_MANIPULATION.
(frv_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* ft32-tdep.c (breakpoint): Rename it to ft32_break_insn and
change its type to constexpr. Don't use
GDBARCH_BREAKPOINT_MANIPULATION.
(ft32_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* h8300-tdep.c (breakpoint): Rename it to h8300_break_insn.
Don't use GDBARCH_BREAKPOINT_MANIPULATION.
(h8300_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* hppa-tdep.c (breakpoint): Rename it to h8300_break_insn.
Don't use GDBARCH_BREAKPOINT_MANIPULATION.
(hppa_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* i386-tdep.c (break_insn): Rename it to i386_break_insn.
Don't use GDBARCH_BREAKPOINT_MANIPULATION.
(i386_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* iq2000-tdep.c (iq2000_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* lm32-tdep.c (breakpoint): Rename it to lm32_break_insn and
change its type to constexpr. Don't use
GDBARCH_BREAKPOINT_MANIPULATION.
(lm32_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* m32c-tdep.c (break_insn): Rename it to m32c_break_insn and change
its type to constexpr. Don't use GDBARCH_BREAKPOINT_MANIPULATION.
(m32c_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* m32r-tdep.c (m32r_gdbarch_init): Likewise.
* m68hc11-tdep.c (breakpoint): Rename it to m68hc11_break_insn and
change its type to constexpr. Don't use GDBARCH_BREAKPOINT_MANIPULATION.
(m68hc11_gdbarch_init): Don't use SET_GDBARCH_BREAKPOINT_MANIPULATION.
* m68k-tdep.c (break_insn): Rename it to m68k_break_insn and change
its type to constexpr. Don't use GDBARCH_BREAKPOINT_MANIPULATION.
(m68k_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* m88k-tdep.c (break_insn): Rename it to m88k_break_insn and change
its type to constexpr. Don't use GDBARCH_BREAKPOINT_MANIPULATION.
(m88k_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* mep-tdep.c (breakpoint): Rename it to mep_break_insn and change
its type to constexpr. Don't use GDBARCH_BREAKPOINT_MANIPULATION.
(mep_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* microblaze-tdep.c (break_insn): Rename it to
microblaze_break_insn and change its type to constexpr. Don't use
GDBARCH_BREAKPOINT_MANIPULATION.
(microblaze_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* mips-tdep.c (mips_gdbarch_init): Likewise.
* mn10300-tdep.c (breakpoint): Rename it to mn10300_break_insn and
change its type to constexpr. Don't use
GDBARCH_BREAKPOINT_MANIPULATION.
(mn10300_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* moxie-tdep.c (breakpoint): Rename it to moxie_break_insn and
change its type to constexpr. Don't use
GDBARCH_BREAKPOINT_MANIPULATION.
(moxie_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* msp430-tdep.c (breakpoint): Rename it to msp430_break_insn
and change its type to constexpr. Don't use
GDBARCH_BREAKPOINT_MANIPULATION.
(msp430_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* mt-tdep.c (mt_gdbarch_init): Likewise.
* nds32-tdep.c (break_insn): Rename it to nds32_break_insn
and change its type to constexpr. Don't use
GDBARCH_BREAKPOINT_MANIPULATION.
(nds32_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* nios2-tdep.c (nios2_gdbarch_init): Likewise.
* rl78-tdep.c (breakpoint): Rename it to rl78_break_ins
and change its type to rl78_break_insn. Don't use
GDBARCH_BREAKPOINT_MANIPULATION.
(rl78_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* rs6000-tdep.c (big_breakpoint): Change its type to
constexpr.
(little_breakpoint): Likewise.
Don't use GDBARCH_BREAKPOINT_MANIPULATION_ENDIAN.
(rs6000_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* rx-tdep.c (breakpoint): Rename it to rx_break_insn and
change its type to constexpr. Don't use
GDBARCH_BREAKPOINT_MANIPULATION.
(rx_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* s390-linux-tdep.c (breakpoint): Rename it to s390_break_insn
and change its type to constexpr. Don't use
GDBARCH_BREAKPOINT_MANIPULATION
(s390_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* score-tdep.c (score_gdbarch_init): Likewise.
* sh-tdep.c (sh_gdbarch_init): Likewise.
* sh64-tdep.c (sh64_gdbarch_init): Likewise.
* sparc-tdep.c (break_insn): Rename it to sparc_break_insn
and change its type to constexpr. Don't use
GDBARCH_BREAKPOINT_MANIPULATION.
(sparc32_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* spu-tdep.c (breakpoint): Rename it to spu_break_insn and change
its type to constexpr. Don't use
GDBARCH_BREAKPOINT_MANIPULATION.
(spu_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* tic6x-tdep.c (tic6x_gdbarch_init): Likewise.
* tilegx-tdep.c (breakpoint): Rename it to tilegx_break_insn
and change its type to constexpr. Don't use
GDBARCH_BREAKPOINT_MANIPULATION.
(tilegx_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* v850-tdep.c (v850_gdbarch_init): Likewise.
* vax-tdep.c (break_insn): Rename it to vax_break_insn and
change its type to constexpr.
Don't use GDBARCH_BREAKPOINT_MANIPULATION.
(vax_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* xstormy16-tdep.c (breakpoint): Rename it to
xstormy16_break_insn and change its type to constexpr.
Don't use GDBARCH_BREAKPOINT_MANIPULATION.
(xstormy16_gdbarch_init): Don't use
SET_GDBARCH_BREAKPOINT_MANIPULATION.
* xtensa-tdep.c (xtensa_gdbarch_init): Likewise.
This patch adds a new gdbarch method breakpoint_kind_from_current_state
for single step breakpoint, and uses it in breakpoint_kind.
gdb:
2016-11-03 Yao Qi <yao.qi@linaro.org>
* arch-utils.c (default_breakpoint_kind_from_current_state):
New function.
* arch-utils.h (default_breakpoint_kind_from_current_state):
Declare.
* arm-tdep.c (arm_breakpoint_kind_from_current_state): New
function.
(arm_gdbarch_init): Call
set_gdbarch_breakpoint_kind_from_current_state.
* breakpoint.c (breakpoint_kind): Call
gdbarch_breakpoint_kind_from_current_state for single step
breakpoint. Update comments.
* gdbarch.sh (breakpoint_kind_from_current_state): New.
* gdbarch.c, gdbarch.h: Regenerate.
This patch adds two gdbarch methods breakpoint_kind_from_pc and
sw_breakpoint_from_kind, and uses target_info.placed_size as "kind"
of the breakpoint. This patch updates the usages of
target_info.placed_size.
The "kind" of a breakpoint is determined by gdbarch rather than
target, so we have gdbarch method breakpoint_kind_from_pc, and we
should set target_info.placed_size out of each implementation of
target to_insert_breakpoint. In this way, each target doesn't have
to set target_info.placed_size any more.
This patch also sets target_info.placed_address before
target_insert_breakpoint too, so that target to_insert_breakpoint
can use it, see record_full_insert_breakpoint.
Before we call target_insert_breakpoint, we set
target_info.placed_address and target_info.placed_size like this,
CORE_ADDR addr = bl->target_info.reqstd_address;
bl->target_info.placed_size = gdbarch_breakpoint_kind_from_pc (bl->gdbarch, &addr);
bl->target_info.placed_address = addr;
return target_insert_breakpoint (bl->gdbarch, &bl->target_info);
target_insert_breakpoint may fail, but it doesn't matter to the "kind"
and "placed_address" of a breakpoint. They should be determined by
gdbarch.
gdb:
2016-11-03 Yao Qi <yao.qi@linaro.org>
* arch-utils.h (GDBARCH_BREAKPOINT_MANIPULATION): Define
breakpoint_kind_from_pc and sw_breakpoint_from_kind.
(GDBARCH_BREAKPOINT_MANIPULATION_ENDIAN): Likewise.
(SET_GDBARCH_BREAKPOINT_MANIPULATION): Call
set_gdbarch_breakpoint_kind_from_pc and
set_gdbarch_sw_breakpoint_from_kind.
* arm-tdep.c: Add comments.
* bfin-tdep.c: Likewise.
* breakpoint.c (breakpoint_kind): New function.
(insert_bp_location): Set target_info.placed_size and
target_info.placed_address.
(bkpt_insert_location): Likewise.
* cris-tdep.c: Add comments.
* gdbarch.sh (breakpoint_kind_from_pc): New.
(sw_breakpoint_from_kind): New.
* gdbarch.c, gdbarch.h: Regenerated.
* ia64-tdep.c (ia64_memory_insert_breakpoint): Don't set
bp_tgt->placed_size.
(ia64_memory_remove_breakpoint): Don't assert
bp_tgt->placed_size.
(ia64_breakpoint_kind_from_pc): New function.
(ia64_gdbarch_init): Install ia64_breakpoint_kind_from_pc.
* m32r-tdep.c (m32r_memory_insert_breakpoint): Don't set
bp_tgt->placed_size.
* mem-break.c (default_memory_insert_breakpoint): Don't set
bp_tgt->placed_size. Call gdbarch_sw_breakpoint_from_kind.
(default_memory_remove_breakpoint): Call
gdbarch_sw_breakpoint_from_kind.
(memory_validate_breakpoint): Don't check bp_tgt->placed_size.
* mips-tdep.c: Add comments.
* mt-tdep.c: Likewise.
* nios2-tdep.c: Likewise.
* record-full.c (record_full_insert_breakpoint): Don't call
gdbarch_breakpoint_from_pc. Don't set bp_tgt->placed_address
and bp_tgt->placed_size.
* remote.c (remote_insert_breakpoint): Don't call
gdbarch_remote_breakpoint_from_pc. Use bp_tgt->placed_size.
Don't set bp_tgt->placed_address and bp_tgt->placed_size.
(remote_insert_hw_breakpoint): Likewise.
* score-tdep.c: Likewise.
* sh-tdep.c: Likewise.
* tic6x-tdep.c: Likewise.
* v850-tdep.c: Likewise.
* xtensa-tdep.c: Likewise.
At this point, all TYPE_CODE_FLT types carry their floating-point format,
except for those creating from reading DWARF or stabs debug info. Those
will be addressed by this commit.
The main issue here is that we actually have to determine which floating-
point format to use. Currently, we only have the type length as input
to this decision. In the future, we may hopefully get --at least in
DWARF-- additional information to help disambiguate multiple different
formats of the same length. For now, we can still look at the type name
as a hint.
This decision logic is encapsulated in a gdbarch callback to allow
platform-specific overrides. The default implementation use the same
logic (compare type length against the various gdbarch_..._bit sizes)
that is currently implemented in floatformat_from_length.
With this commit, all platforms still use the default logic, so there
should be no actual change in behavior. A follow-on commit will add
support for __float128 on Intel and Power.
Once dwarf2read.c and stabsread.c make use of the new callback to
determine floating-point formats, we're now sure every TYPE_CODE_FLT
type will always carry its format. The commit therefore adds asserts
to verify_floatformat to ensure new code will continue to always
provide formats, and removes the code in floatformat_from_type that
used to handle types with a NULL TYPE_FLOATFORMAT.
gdb/ChangeLog:
* gdbarch.sh (floatformat_for_type): New gdbarch callback.
* gdbarch.h, gdbarch.c: Re-generate.
* arch-utils.h (default_floatformat_for_type): New prototype.
* arch-utils.c (default_floatformat_for_type): New function.
* doublest.c (floatformat_from_length): Remove.
(floatformat_from_type): Assume TYPE_FLOATFORMAT is non-NULL.
* gdbtypes.c (verify_floatformat): Require non-NULL format.
* dwarf2read.c (dwarf2_init_float_type): New function.
(read_base_type): Use it.
* stabsread.c (dbx_init_float_type): New function.
(read_sun_floating_type): Use it.
(read_range_type): Likewise.
Signed-off-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>
Nowadays, GDB can't insert breakpoint on the return address of the
exception handler on ARM M-profile, because the address is a magic
one 0xfffffff9,
(gdb) bt
#0 CT32B1_IRQHandler () at ../src/timer.c:67
#1 <signal handler called>
#2 main () at ../src/timer.c:127
(gdb) info frame
Stack level 0, frame at 0x200ffa8:
pc = 0x4ec in CT32B1_IRQHandler (../src/timer.c:67); saved pc = 0xfffffff9
called by frame at 0x200ffc8
source language c.
Arglist at 0x200ffa0, args:
Locals at 0x200ffa0, Previous frame's sp is 0x200ffa8
Saved registers:
r7 at 0x200ffa0, lr at 0x200ffa4
(gdb) x/x 0xfffffff9
0xfffffff9: Cannot access memory at address 0xfffffff9
(gdb) finish
Run till exit from #0 CT32B1_IRQHandler () at ../src/timer.c:67
Ed:15: Target error from Set break/watch: Et:96: Pseudo-address (0xFFFFFFxx) for EXC_RETURN is invalid (GDB error?)
Warning:
Cannot insert hardware breakpoint 0.
Could not insert hardware breakpoints:
You may have requested too many hardware breakpoints/watchpoints.
Command aborted.
even some debug probe can't set hardware breakpoint on the magic
address too,
(gdb) hbreak *0xfffffff9
Hardware assisted breakpoint 2 at 0xfffffff9
(gdb) c
Continuing.
Ed:15: Target error from Set break/watch: Et:96: Pseudo-address (0xFFFFFFxx) for EXC_RETURN is invalid (GDB error?)
Warning:
Cannot insert hardware breakpoint 2.
Could not insert hardware breakpoints:
You may have requested too many hardware breakpoints/watchpoints.
Command aborted.
The problem described above is quite similar to PR 8841, in which GDB
can't set breakpoint on signal trampoline, which is mapped to a read-only
page by kernel. The rationale of this patch is to skip "unwritable"
frames when looking for caller frames in command "finish", and a new
gdbarch method code_of_frame_writable is added. This patch fixes
the problem on ARM cortex-m target, but it can be used to fix
PR 8841 too.
gdb:
2016-05-10 Yao Qi <yao.qi@arm.com>
* arch-utils.c (default_code_of_frame_writable): New function.
* arch-utils.h (default_code_of_frame_writable): Declare.
* arm-tdep.c (arm_code_of_frame_writable): New function.
(arm_gdbarch_init): Install gdbarch method
code_of_frame_writable if the target is M-profile.
* frame.c (skip_unwritable_frames): New function.
* frame.h (skip_unwritable_frames): Declare.
* gdbarch.sh (code_of_frame_writable): New.
* gdbarch.c, gdbarch.h: Re-generated.
* infcmd.c (finish_command): Call skip_unwritable_frames.
When we're looking at a tracefile trace frame where registers are not
available, and the tracepoint has only one location, we supply
the location's address as the PC register. However, this only works
if PC is not a pseudo register, and individual architectures may want
to guess more registers. Add a gdbarch hook that will handle that.
gdb/ChangeLog:
* arch-utils.c (default_guess_tracepoint_registers): New function.
* arch-utils.h (default_guess_tracepoint_registers): New prototype.
* gdbarch.c: Regenerate.
* gdbarch.h: Regenerate.
* gdbarch.sh: Add guess_tracepoint_registers hook.
* tracefile.c (tracefile_fetch_registers): Use the new gdbarch hook.
This patch removes the isize output argument from the
fast_tracepoint_valid_at gdbarch hook. It was used to return the size
of the instruction that needs to be replaced when installing a fast
tracepoint. Instead of getting this value from the
fast_tracepoint_valid_at hook, we can call the gdb_insn_length function.
If we do not do this, then architectures which do not have a restriction
on where to install the fast tracepoint will send uninitialized memory
off to GDBserver. See remote_download_tracepoint:
~~~
int isize;
if (gdbarch_fast_tracepoint_valid_at (target_gdbarch (),
tpaddr, &isize, NULL))
xsnprintf (buf + strlen (buf), BUF_SIZE - strlen (buf), ":F%x",
isize);
~~~
The default implementation of fast_tracepoint_valid_at will not set
isize resulting in uninitialized memory being sent. Later on, GDBserver
could use this information to compute a jump offset.
gdb/ChangeLog:
* arch-utils.c (default_fast_tracepoint_valid_at): Remove unused
isize argument.
* arch-utils.h (default_fast_tracepoint_valid_at): Likewise.
* breakpoint.c (check_fast_tracepoint_sals): Adjust call to
gdbarch_fast_tracepoint_valid_at.
* gdbarch.sh (fast_tracepoint_valid_at): Remove isize argument.
* gdbarch.h: Regenerate.
* gdbarch.c: Regenerate.
* i386-tdep.c (i386_fast_tracepoint_valid_at): Remove isize
argument. Do not set it.
* remote.c (remote_download_tracepoint): Adjust call to
gdbarch_fast_tracepoint_valid_at. Call gdb_insn_length to get
the instruction length.
Add a new gdbarch method to get the length of an addressable memory unit
for a given architecture. The default implementation returns 1.
gdb/ChangeLog:
* arch-utils.h (default_addressable_memory_unit_size): New.
* arch-utils.c (default_addressable_memory_unit_size): New.
* gdbarch.sh (addressable_memory_unit_size): New.
* gdbarch.h: Re-generate.
* gdbarch.c: Re-generate.
Currently inferior memory is allocated by inferior mmap() but it is never
deallocated; despite the injected objfile incl. its symbols is freed. This was
intentional so that one can do for example:
inferior:
char *str = "foo";
GDB:
(gdb) compile code str = "bar";
I believe later patches will be needed to introduce full control over keeping
vs. discarding the injected module as being discussed in:
compile: objfiles lifetime UI
https://sourceware.org/ml/gdb/2015-04/msg00051.html
Message-ID: <20150429135735.GA16974@host1.jankratochvil.net>
https://sourceware.org/ml/gdb/2015-05/msg00007.html
As decided by Phil it is better not to leak inferior pages as users can
workaround the issue above for example by:
(gdb) compile code str = strdup ("bar");
I have checked that in fact gdb/doc/ (written by Phil) already expects the
injected code will be unmapped so that does not need to be changed:
compile code int ff = 5; p = &ff;
In this example, @code{p} would point to @code{ff} when the
@code{compile} command is executing the source code provided to it.
However, as variables in the (example) program persist with their
assigned values, the variable @code{p} would point to an invalid
location when the command exists.
gdb/ChangeLog
2015-04-28 Jan Kratochvil <jan.kratochvil@redhat.com>
* arch-utils.c (default_infcall_munmap): New.
* arch-utils.h (default_infcall_munmap): New declaration.
* compile/compile-object-load.c (struct munmap_list, munmap_list_add)
(munmap_list_free, munmap_listp_free_cleanup): New.
(struct setup_sections_data): Add field munmap_list_headp.
(setup_sections): Call munmap_list_add.
(compile_object_load): New variable munmap_list_head, initialize
setup_sections_data.munmap_list_headp, return munmap_list_head.
* compile/compile-object-load.h (struct munmap_list): New declaration.
(struct compile_module): Add field munmap_list_head.
(munmap_list_free): New declaration.
* compile/compile-object-run.c (struct do_module_cleanup): Add field
munmap_list_head.
(do_module_cleanup): Call munmap_list_free.
(compile_object_run): Pass munmap_list_head to do_module_cleanup.
* gdbarch.c: Regenerate.
* gdbarch.h: Regenerate.
* gdbarch.sh (infcall_munmap): New.
* linux-tdep.c (linux_infcall_munmap): New.
(linux_init_abi): Install it.
gdb/testsuite/ChangeLog
2015-04-28 Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.compile/compile.exp (keep jit in memory): Rename to ...
(do not keep jit in memory): ... this.
(expect 5): Change it to ...
(expect no 5): ... this.
We concluded that gdbarch_in_function_epilogue_p is misnamed, since it
returns true if the given PC is one instruction after the one that
destroyed the stack (which isn't necessarily inside an epilogue),
therefore it should be renamed to stack_frame_destroyed_p.
I also took the liberty of renaming the arch-specific implementations to
*_stack_frame_destroyed_p as well for consistency.
gdb:
2015-05-26 Martin Galvan <martin.galvan@tallertechnologies.com>
* amd64-tdep.c: Replace in_function_epilogue_p with
stack_frame_destroyed_p throughout.
* arch-utils.c: Ditto.
* arch-utils.h: Ditto.
* arm-tdep.c: Ditto.
* breakpoint.c: Ditto.
* gdbarch.sh: Ditto.
* hppa-tdep.c: Ditto.
* i386-tdep.c: Ditto.
* mips-tdep.c: Ditto.
* nios2-tdep.c: Ditto.
* rs6000-tdep.c: Ditto.
* s390-linux-tdep.c: Ditto.
* score-tdep.c: Ditto.
* sh-tdep.c: Ditto.
* sparc-tdep.c: Ditto.
* sparc-tdep.h: Ditto.
* sparc64-tdep.c: Ditto.
* spu-tdep.c: Ditto.
* tic6x-tdep.c: Ditto.
* tilegx-tdep.c: Ditto.
* xstormy16-tdep.c: Ditto.
* gdbarch.c, gdbarch.h: Re-generated.
gdb has to inform libcc1.so of the target being used, so that the
correct compiler can be invoked. The compiler is invoked using the
GNU configury triplet prefix, e.g., "x86_64-unknown-linux-gnu-gcc".
In order for this to work we need to map the gdbarch to the GNU
configury triplet arch. In most cases these are identical; however,
the x86 family poses some problems, as the BFD arch names are quite
different from the GNU triplet names. So, we introduce a new gdbarch
method for this. A regular expression is used because there are
various valid values for the arch prefix in the triplet.
This patch also updates the osabi code to associate a regular
expression with the OS ABI. I have only added a concrete value for
Linux. Note that the "-gnu" part is optional, at least on Fedora it
is omitted from the installed GCC executable's name.
gdb/ChangeLog
2014-12-12 Tom Tromey <tromey@redhat.com>
Jan Kratochvil <jan.kratochvil@redhat.com>
* osabi.h (osabi_triplet_regexp): Declare.
* osabi.c (struct osabi_names): New.
(gdb_osabi_names): Change type to struct osabi_names. Update
values.
(gdbarch_osabi_name): Update.
(osabi_triplet_regexp): New function.
(osabi_from_tdesc_string, _initialize_gdb_osabi): Update.
* i386-tdep.c (i386_gnu_triplet_regexp): New method.
(i386_elf_init_abi, i386_go32_init_abi, i386_gdbarch_init): Call
set_gdbarch_gnu_triplet_regexp.
* gdbarch.sh (gnu_triplet_regexp): New method.
* gdbarch.c, gdbarch.h: Rebuild.
* arch-utils.h (default_gnu_triplet_regexp): Declare.
* arch-utils.c (default_gnu_triplet_regexp): New function.
The compiler needed two new gdbarch methods.
The infcall_mmap method allocates memory in the inferior.
This is used when inserting the object code.
The gcc_target_options method computes some arch-specific gcc options
to pass to the compiler. This is used to ensure that gcc generates
object code for the correct architecture.
gdb/ChangeLog
2014-12-12 Jan Kratochvil <jan.kratochvil@redhat.com>
* arch-utils.c (default_infcall_mmap)
(default_gcc_target_options): New functions.
* arch-utils.h (GDB_MMAP_PROT_READ, GDB_MMAP_PROT_WRITE)
(GDB_MMAP_PROT_EXEC): Define.
(default_infcall_mmap, default_gcc_target_options): Declare.
* gdbarch.h: Rebuild.
* gdbarch.c: Rebuild.
* gdbarch.sh (infcall_mmap, gcc_target_options): New methods.
1. Background information
The MIPS architecture, as originally designed and implemented in
mid-1980s has a uniform instruction word size that is 4 bytes, naturally
aligned. As such all MIPS instructions are located at addresses that
have their bits #1 and #0 set to zeroes, and any attempt to execute an
instruction from an address that has any of the two bits set to one
causes an address error exception. This may for example happen when a
jump-register instruction is executed whose register value used as the
jump target has any of these bits set.
Then in mid 1990s LSI sought a way to improve code density for their
TinyRISC family of MIPS cores and invented an alternatively encoded
instruction set in a joint effort with MIPS Technologies (then a
subsidiary of SGI). The new instruction set has been named the MIPS16
ASE (Application-Specific Extension) and uses a variable instruction
word size, which is 2 bytes (as the name of the ASE suggests) for most,
but there are a couple of exceptions that take 4 bytes, and then most of
the 2-byte instructions can be treated with a 2-byte extension prefix to
expand the range of the immediate operands used.
As a result instructions are no longer 4-byte aligned, instead they are
aligned to a multiple of 2. That left the bit #0 still unused for code
references, be it for the standard MIPS (i.e. as originally invented) or
for the MIPS16 instruction set, and based on that observation a clever
trick was invented that on one hand allowed the processor to be
seamlessly switched between the two instruction sets at any time at the
run time while on the other avoided the introduction of any special
control register to do that.
So it is the bit #0 of the instruction address that was chosen as the
selector and named the ISA bit. Any instruction executed at an even
address is interpreted as a standard MIPS instruction (the address still
has to have its bit #1 clear), any instruction executed at an odd
address is interpreted as a MIPS16 instruction.
To switch between modes ordinary jump instructions are used, such as
used for function calls and returns, specifically the bit #0 of the
source register used in jump-register instructions selects the execution
(ISA) mode for the following piece of code to be interpreted in.
Additionally new jump-immediate instructions were added that flipped the
ISA bit to select the opposite mode upon execution. They were
considered necessary to avoid the need to make register jumps in all
cases as the original jump-immediate instructions provided no way to
change the bit #0 at all.
This was all important for cases where standard MIPS and MIPS16 code had
to be mixed, either for compatibility with the existing binary code base
or to access resources not reachable from MIPS16 code (the MIPS16
instruction set only provides access to general-purpose registers, and
not for example floating-point unit registers or privileged coprocessor
0 registers) -- pieces of code in the opposite mode can be executed as
ordinary subroutine calls.
A similar approach has been more recently adopted for the MIPS16
replacement instruction set defined as the so called microMIPS ASE.
This is another instruction set encoding introduced to the MIPS
architecture. Just like the MIPS16 ASE, the microMIPS instruction set
uses a variable-length encoding, where each instruction takes a multiple
of 2 bytes. The ISA bit has been reused and for microMIPS-capable
processors selects between the standard MIPS and the microMIPS mode
instead.
2. Statement of the problem
To put it shortly, MIPS16 and microMIPS code pointers used by GDB are
different to these observed at the run time. This results in the same
expressions being evaluated producing different results in GDB and in
the program being debugged. Obviously it's the results obtained at the
run time that are correct (they define how the program behaves) and
therefore by definition the results obtained in GDB are incorrect.
A bit longer description will record that obviously at the run time the
ISA bit has to be set correctly (refer to background information above
if unsure why so) or the program will not run as expected. This is
recorded in all the executable file structures used at the run time: the
dynamic symbol table (but not always the static one!), the GOT, and
obviously in all the addresses embedded in code or data of the program
itself, calculated by applying the appropriate relocations at the static
link time.
While a program is being processed by GDB, the ISA bit is stripped off
from any code addresses, presumably to make them the same as the
respective raw memory byte address used by the processor to access the
instruction in the instruction fetch access cycle. This stripping is
actually performed outside GDB proper, in BFD, specifically
_bfd_mips_elf_symbol_processing (elfxx-mips.c, see the piece of code at
the very bottom of that function, starting with an: "If this is an
odd-valued function symbol, assume it's a MIPS16 or microMIPS one."
comment).
This function is also responsible for symbol table dumps made by
`objdump' too, so you'll never see the ISA bit reported there by that
tool, you need to use `readelf'.
This is however unlike what is ever done at the run time, the ISA bit
once present is never stripped off, for example a cast like this:
(short *) main
will not strip the ISA bit off and if the resulting pointer is intended
to be used to access instructions as data, for example for software
instruction decoding (like for fault recovery or emulation in a signal
handler) or for self-modifying code then the bit still has to be
stripped off by an explicit AND operation.
This is probably best illustrated with a simple real program example.
Let's consider the following simple program:
$ cat foobar.c
int __attribute__ ((mips16)) foo (void)
{
return 1;
}
int __attribute__ ((mips16)) bar (void)
{
return 2;
}
int __attribute__ ((nomips16)) foo32 (void)
{
return 3;
}
int (*foo32p) (void) = foo32;
int (*foop) (void) = foo;
int fooi = (int) foo;
int
main (void)
{
return foop ();
}
$
This is plain C with no odd tricks, except from the instruction mode
attributes. They are not necessary to trigger this problem, I just put
them here so that the program can be contained in a single source file
and to make it obvious which function is MIPS16 code and which is not.
Let's try it with Linux, so that everyone can repeat this experiment:
$ mips-linux-gnu-gcc -mips16 -g -O2 -o foobar foobar.c
$
Let's have a look at some interesting symbols:
$ mips-linux-gnu-readelf -s foobar | egrep 'table|foo|bar'
Symbol table '.dynsym' contains 7 entries:
Symbol table '.symtab' contains 95 entries:
55: 00000000 0 FILE LOCAL DEFAULT ABS foobar.c
66: 0040068c 4 FUNC GLOBAL DEFAULT [MIPS16] 12 bar
68: 00410848 4 OBJECT GLOBAL DEFAULT 21 foo32p
70: 00410844 4 OBJECT GLOBAL DEFAULT 21 foop
78: 00400684 8 FUNC GLOBAL DEFAULT 12 foo32
80: 00400680 4 FUNC GLOBAL DEFAULT [MIPS16] 12 foo
88: 00410840 4 OBJECT GLOBAL DEFAULT 21 fooi
$
Hmm, no sight of the ISA bit, but notice how foo and bar (but not
foo32!) have been marked as MIPS16 functions (ELF symbol structure's
`st_other' field is used for that).
So let's try to run and poke at this program with GDB. I'll be using a
native system for simplicity (I'll be using ellipses here and there to
remove unrelated clutter):
$ ./foobar
$ echo $?
1
$
So far, so good.
$ gdb ./foobar
[...]
(gdb) break main
Breakpoint 1 at 0x400490: file foobar.c, line 23.
(gdb) run
Starting program: .../foobar
Breakpoint 1, main () at foobar.c:23
23 return foop ();
(gdb)
Yay, it worked! OK, so let's poke at it:
(gdb) print main
$1 = {int (void)} 0x400490 <main>
(gdb) print foo32
$2 = {int (void)} 0x400684 <foo32>
(gdb) print foo32p
$3 = (int (*)(void)) 0x400684 <foo32>
(gdb) print bar
$4 = {int (void)} 0x40068c <bar>
(gdb) print foo
$5 = {int (void)} 0x400680 <foo>
(gdb) print foop
$6 = (int (*)(void)) 0x400681 <foo>
(gdb)
A-ha! Here's the difference and finally the ISA bit!
(gdb) print /x fooi
$7 = 0x400681
(gdb) p/x $pc
p/x $pc
$8 = 0x400491
(gdb)
And here as well...
(gdb) advance foo
foo () at foobar.c:4
4 }
(gdb) disassemble
Dump of assembler code for function foo:
0x00400680 <+0>: jr ra
0x00400682 <+2>: li v0,1
End of assembler dump.
(gdb) finish
Run till exit from #0 foo () at foobar.c:4
main () at foobar.c:24
24 }
Value returned is $9 = 1
(gdb) continue
Continuing.
[Inferior 1 (process 14103) exited with code 01]
(gdb)
So let's be a bit inquisitive...
(gdb) run
Starting program: .../foobar
Breakpoint 1, main () at foobar.c:23
23 return foop ();
(gdb)
Actually we do not like to run foo here at all. Let's run bar instead!
(gdb) set foop = bar
(gdb) print foop
$10 = (int (*)(void)) 0x40068c <bar>
(gdb)
Hmm, no ISA bit. Is it going to work?
(gdb) advance bar
bar () at foobar.c:9
9 }
(gdb) p/x $pc
$11 = 0x40068c
(gdb) disassemble
Dump of assembler code for function bar:
=> 0x0040068c <+0>: jr ra
0x0040068e <+2>: li v0,2
End of assembler dump.
(gdb) finish
Run till exit from #0 bar () at foobar.c:9
Program received signal SIGILL, Illegal instruction.
bar () at foobar.c:9
9 }
(gdb)
Oops!
(gdb) p/x $pc
$12 = 0x40068c
(gdb)
We're still there!
(gdb) continue
Continuing.
Program terminated with signal SIGILL, Illegal instruction.
The program no longer exists.
(gdb)
So let's try something else:
(gdb) run
Starting program: .../foobar
Breakpoint 1, main () at foobar.c:23
23 return foop ();
(gdb) set foop = foo
(gdb) advance foo
foo () at foobar.c:4
4 }
(gdb) disassemble
Dump of assembler code for function foo:
=> 0x00400680 <+0>: jr ra
0x00400682 <+2>: li v0,1
End of assembler dump.
(gdb) finish
Run till exit from #0 foo () at foobar.c:4
Program received signal SIGILL, Illegal instruction.
foo () at foobar.c:4
4 }
(gdb) continue
Continuing.
Program terminated with signal SIGILL, Illegal instruction.
The program no longer exists.
(gdb)
The same problem!
(gdb) run
Starting program:
/net/build2-lucid-cs/scratch/macro/mips-linux-fsf-gcc/isa-bit/foobar
Breakpoint 1, main () at foobar.c:23
23 return foop ();
(gdb) set foop = foo32
(gdb) advance foo32
foo32 () at foobar.c:14
14 }
(gdb) disassemble
Dump of assembler code for function foo32:
=> 0x00400684 <+0>: jr ra
0x00400688 <+4>: li v0,3
End of assembler dump.
(gdb) finish
Run till exit from #0 foo32 () at foobar.c:14
main () at foobar.c:24
24 }
Value returned is $14 = 3
(gdb) continue
Continuing.
[Inferior 1 (process 14113) exited with code 03]
(gdb)
That did work though, so it's the ISA bit only!
(gdb) quit
Enough!
That's the tip of the iceberg only though. So let's rebuild the
executable with some dynamic symbols:
$ mips-linux-gnu-gcc -mips16 -Wl,--export-dynamic -g -O2 -o foobar-dyn foobar.c
$ mips-linux-gnu-readelf -s foobar-dyn | egrep 'table|foo|bar'
Symbol table '.dynsym' contains 32 entries:
6: 004009cd 4 FUNC GLOBAL DEFAULT 12 bar
8: 00410b88 4 OBJECT GLOBAL DEFAULT 21 foo32p
9: 00410b84 4 OBJECT GLOBAL DEFAULT 21 foop
15: 004009c4 8 FUNC GLOBAL DEFAULT 12 foo32
17: 004009c1 4 FUNC GLOBAL DEFAULT 12 foo
25: 00410b80 4 OBJECT GLOBAL DEFAULT 21 fooi
Symbol table '.symtab' contains 95 entries:
55: 00000000 0 FILE LOCAL DEFAULT ABS foobar.c
69: 004009cd 4 FUNC GLOBAL DEFAULT 12 bar
71: 00410b88 4 OBJECT GLOBAL DEFAULT 21 foo32p
72: 00410b84 4 OBJECT GLOBAL DEFAULT 21 foop
79: 004009c4 8 FUNC GLOBAL DEFAULT 12 foo32
81: 004009c1 4 FUNC GLOBAL DEFAULT 12 foo
89: 00410b80 4 OBJECT GLOBAL DEFAULT 21 fooi
$
OK, now the ISA bit is there for a change, but the MIPS16 `st_other'
attribute gone, hmm... What does `objdump' do then:
$ mips-linux-gnu-objdump -Tt foobar-dyn | egrep 'SYMBOL|foo|bar'
foobar-dyn: file format elf32-tradbigmips
SYMBOL TABLE:
00000000 l df *ABS* 00000000 foobar.c
004009cc g F .text 00000004 0xf0 bar
00410b88 g O .data 00000004 foo32p
00410b84 g O .data 00000004 foop
004009c4 g F .text 00000008 foo32
004009c0 g F .text 00000004 0xf0 foo
00410b80 g O .data 00000004 fooi
DYNAMIC SYMBOL TABLE:
004009cc g DF .text 00000004 Base 0xf0 bar
00410b88 g DO .data 00000004 Base foo32p
00410b84 g DO .data 00000004 Base foop
004009c4 g DF .text 00000008 Base foo32
004009c0 g DF .text 00000004 Base 0xf0 foo
00410b80 g DO .data 00000004 Base fooi
$
Hmm, the attribute (0xf0, printed raw) is back, and the ISA bit gone
again.
Let's have a look at some DWARF-2 records GDB uses (I'll be stripping
off a lot here for brevity) -- debug info:
$ mips-linux-gnu-readelf -wi foobar
Contents of the .debug_info section:
[...]
Compilation Unit @ offset 0x88:
Length: 0xbb (32-bit)
Version: 4
Abbrev Offset: 62
Pointer Size: 4
<0><93>: Abbrev Number: 1 (DW_TAG_compile_unit)
<94> DW_AT_producer : (indirect string, offset: 0x19e): GNU C 4.8.0 20120513 (experimental) -meb -mips16 -march=mips32r2 -mhard-float -mllsc -mplt -mno-synci -mno-shared -mabi=32 -g -O2
<98> DW_AT_language : 1 (ANSI C)
<99> DW_AT_name : (indirect string, offset: 0x190): foobar.c
<9d> DW_AT_comp_dir : (indirect string, offset: 0x225): [...]
<a1> DW_AT_ranges : 0x0
<a5> DW_AT_low_pc : 0x0
<a9> DW_AT_stmt_list : 0x27
<1><ad>: Abbrev Number: 2 (DW_TAG_subprogram)
<ae> DW_AT_external : 1
<ae> DW_AT_name : foo
<b2> DW_AT_decl_file : 1
<b3> DW_AT_decl_line : 1
<b4> DW_AT_prototyped : 1
<b4> DW_AT_type : <0xc2>
<b8> DW_AT_low_pc : 0x400680
<bc> DW_AT_high_pc : 0x400684
<c0> DW_AT_frame_base : 1 byte block: 9c (DW_OP_call_frame_cfa)
<c2> DW_AT_GNU_all_call_sites: 1
<1><c2>: Abbrev Number: 3 (DW_TAG_base_type)
<c3> DW_AT_byte_size : 4
<c4> DW_AT_encoding : 5 (signed)
<c5> DW_AT_name : int
<1><c9>: Abbrev Number: 4 (DW_TAG_subprogram)
<ca> DW_AT_external : 1
<ca> DW_AT_name : (indirect string, offset: 0x18a): foo32
<ce> DW_AT_decl_file : 1
<cf> DW_AT_decl_line : 11
<d0> DW_AT_prototyped : 1
<d0> DW_AT_type : <0xc2>
<d4> DW_AT_low_pc : 0x400684
<d8> DW_AT_high_pc : 0x40068c
<dc> DW_AT_frame_base : 1 byte block: 9c (DW_OP_call_frame_cfa)
<de> DW_AT_GNU_all_call_sites: 1
<1><de>: Abbrev Number: 2 (DW_TAG_subprogram)
<df> DW_AT_external : 1
<df> DW_AT_name : bar
<e3> DW_AT_decl_file : 1
<e4> DW_AT_decl_line : 6
<e5> DW_AT_prototyped : 1
<e5> DW_AT_type : <0xc2>
<e9> DW_AT_low_pc : 0x40068c
<ed> DW_AT_high_pc : 0x400690
<f1> DW_AT_frame_base : 1 byte block: 9c (DW_OP_call_frame_cfa)
<f3> DW_AT_GNU_all_call_sites: 1
<1><f3>: Abbrev Number: 5 (DW_TAG_subprogram)
<f4> DW_AT_external : 1
<f4> DW_AT_name : (indirect string, offset: 0x199): main
<f8> DW_AT_decl_file : 1
<f9> DW_AT_decl_line : 21
<fa> DW_AT_prototyped : 1
<fa> DW_AT_type : <0xc2>
<fe> DW_AT_low_pc : 0x400490
<102> DW_AT_high_pc : 0x4004a4
<106> DW_AT_frame_base : 1 byte block: 9c (DW_OP_call_frame_cfa)
<108> DW_AT_GNU_all_tail_call_sites: 1
[...]
$
-- no sign of the ISA bit anywhere -- frame info:
$ mips-linux-gnu-readelf -wf foobar
[...]
Contents of the .debug_frame section:
00000000 0000000c ffffffff CIE
Version: 1
Augmentation: ""
Code alignment factor: 1
Data alignment factor: -4
Return address column: 31
DW_CFA_def_cfa_register: r29
DW_CFA_nop
00000010 0000000c 00000000 FDE cie=00000000 pc=00400680..00400684
00000020 0000000c 00000000 FDE cie=00000000 pc=00400684..0040068c
00000030 0000000c 00000000 FDE cie=00000000 pc=0040068c..00400690
00000040 00000018 00000000 FDE cie=00000000 pc=00400490..004004a4
DW_CFA_advance_loc: 6 to 00400496
DW_CFA_def_cfa_offset: 32
DW_CFA_offset: r31 at cfa-4
DW_CFA_advance_loc: 6 to 0040049c
DW_CFA_restore: r31
DW_CFA_def_cfa_offset: 0
DW_CFA_nop
DW_CFA_nop
DW_CFA_nop
[...]
$
-- no sign of the ISA bit anywhere -- range info (GDB doesn't use arange):
$ mips-linux-gnu-readelf -wR foobar
Contents of the .debug_ranges section:
Offset Begin End
00000000 00400680 00400690
00000000 00400490 004004a4
00000000 <End of list>
$
-- no sign of the ISA bit anywhere -- line info:
$ mips-linux-gnu-readelf -wl foobar
Raw dump of debug contents of section .debug_line:
[...]
Offset: 0x27
Length: 78
DWARF Version: 2
Prologue Length: 31
Minimum Instruction Length: 1
Initial value of 'is_stmt': 1
Line Base: -5
Line Range: 14
Opcode Base: 13
Opcodes:
Opcode 1 has 0 args
Opcode 2 has 1 args
Opcode 3 has 1 args
Opcode 4 has 1 args
Opcode 5 has 1 args
Opcode 6 has 0 args
Opcode 7 has 0 args
Opcode 8 has 0 args
Opcode 9 has 1 args
Opcode 10 has 0 args
Opcode 11 has 0 args
Opcode 12 has 1 args
The Directory Table is empty.
The File Name Table:
Entry Dir Time Size Name
1 0 0 0 foobar.c
Line Number Statements:
Extended opcode 2: set Address to 0x400681
Special opcode 6: advance Address by 0 to 0x400681 and Line by 1 to 2
Special opcode 7: advance Address by 0 to 0x400681 and Line by 2 to 4
Special opcode 55: advance Address by 3 to 0x400684 and Line by 8 to 12
Special opcode 7: advance Address by 0 to 0x400684 and Line by 2 to 14
Advance Line by -7 to 7
Special opcode 131: advance Address by 9 to 0x40068d and Line by 0 to 7
Special opcode 7: advance Address by 0 to 0x40068d and Line by 2 to 9
Advance PC by 3 to 0x400690
Extended opcode 1: End of Sequence
Extended opcode 2: set Address to 0x400491
Advance Line by 21 to 22
Copy
Special opcode 6: advance Address by 0 to 0x400491 and Line by 1 to 23
Special opcode 60: advance Address by 4 to 0x400495 and Line by -1 to 22
Special opcode 34: advance Address by 2 to 0x400497 and Line by 1 to 23
Special opcode 62: advance Address by 4 to 0x40049b and Line by 1 to 24
Special opcode 32: advance Address by 2 to 0x40049d and Line by -1 to 23
Special opcode 6: advance Address by 0 to 0x40049d and Line by 1 to 24
Advance PC by 7 to 0x4004a4
Extended opcode 1: End of Sequence
[...]
-- a-ha, the ISA bit is there! However it's not always right for some
reason, I don't have a small test case to show it, but here's an excerpt
from MIPS16 libc, a prologue of a function:
00019630 <__libc_init_first>:
19630: e8a0 jrc ra
19632: 6500 nop
00019634 <_init>:
19634: f000 6a11 li v0,17
19638: f7d8 0b08 la v1,15e00 <_DYNAMIC+0x15c54>
1963c: f400 3240 sll v0,16
19640: e269 addu v0,v1
19642: 659a move gp,v0
19644: 64f6 save 48,ra,s0-s1
19646: 671c move s0,gp
19648: d204 sw v0,16(sp)
1964a: f352 984c lw v0,-27828(s0)
1964e: 6724 move s1,a0
and the corresponding DWARF-2 line info:
Line Number Statements:
Extended opcode 2: set Address to 0x19631
Advance Line by 44 to 45
Copy
Special opcode 8: advance Address by 0 to 0x19631 and Line by 3 to 48
Special opcode 66: advance Address by 4 to 0x19635 and Line by 5 to 53
Advance PC by constant 17 to 0x19646
Special opcode 25: advance Address by 1 to 0x19647 and Line by 6 to 59
Advance Line by -6 to 53
Special opcode 33: advance Address by 2 to 0x19649 and Line by 0 to 53
Special opcode 39: advance Address by 2 to 0x1964b and Line by 6 to 59
Advance Line by -6 to 53
Special opcode 61: advance Address by 4 to 0x1964f and Line by 0 to 53
-- see that "Advance PC by constant 17" there? It clears the ISA bit,
however code at 0x19646 is not standard MIPS code at all. For some
reason the constant is always 17, I've never seen DW_LNS_const_add_pc
used with any other value -- is that a binutils bug or what?
3. Solution:
I think we should retain the value of the ISA bit in code references,
that is effectively treat them as cookies as they indeed are (although
trivially calculated) rather than raw memory byte addresses.
In a perfect world both the static symbol table and the respective
DWARF-2 records should be fixed to include the ISA bit in all the cases.
I think however that this is infeasible.
All the uses of `_bfd_mips_elf_symbol_processing' can not necessarily be
tracked down. This function is used by `elf_slurp_symbol_table' that in
turn is used by `bfd_canonicalize_symtab' and
`bfd_canonicalize_dynamic_symtab', which are public interfaces.
Similarly DWARF-2 records are used outside GDB, one notable if a bit
questionable is the exception unwinder (libgcc/unwind-dw2.c) -- I have
identified at least bits in `execute_cfa_program' and
`uw_frame_state_for', both around the calls to `_Unwind_IsSignalFrame',
that would need an update as they effectively flip the ISA bit freely;
see also the comment about MASK_RETURN_ADDR in gcc/config/mips/mips.h.
But there may be more places. Any change in how DWARF-2 records are
produced would require an update there and would cause compatibility
problems with libgcc.a binaries already distributed; given that this is
a static library a complex change involving function renames would
likely be required.
I propose therefore to accept the existing inconsistencies and deal with
them entirely within GDB. I have figured out that the ISA bit lost in
various places can still be recovered as long as we have symbol
information -- that'll have the `st_other' attribute correctly set to
one of standard MIPS/MIPS16/microMIPS encoding.
Here's the resulting change. It adds a couple of new `gdbarch' hooks,
one to update symbol information with the ISA bit lost in
`_bfd_mips_elf_symbol_processing', and two other ones to adjust DWARF-2
records as they're processed. The ISA bit is set in each address
handled according to information retrieved from the symbol table for the
symbol spanning the address if any; limits are adjusted based on the
address they point to related to the respective base address.
Additionally minimal symbol information has to be adjusted accordingly
in its gdbarch hook.
With these changes in place some complications with ISA bit juggling in
the PC that never fully worked can be removed from the MIPS backend.
Conversely, the generic dynamic linker event special breakpoint symbol
handler has to be updated to call the minimal symbol gdbarch hook to
record that the symbol is a MIPS16 or microMIPS address if applicable or
the breakpoint will be set at the wrong address and either fail to work
or cause SIGTRAPs (this is because the symbol is handled early on and
bypasses regular symbol processing).
4. Results obtained
The change fixes the example above -- to repeat only the crucial steps:
(gdb) break main
Breakpoint 1 at 0x400491: file foobar.c, line 23.
(gdb) run
Starting program: .../foobar
Breakpoint 1, main () at foobar.c:23
23 return foop ();
(gdb) print foo
$1 = {int (void)} 0x400681 <foo>
(gdb) set foop = bar
(gdb) advance bar
bar () at foobar.c:9
9 }
(gdb) disassemble
Dump of assembler code for function bar:
=> 0x0040068d <+0>: jr ra
0x0040068f <+2>: li v0,2
End of assembler dump.
(gdb) finish
Run till exit from #0 bar () at foobar.c:9
main () at foobar.c:24
24 }
Value returned is $2 = 2
(gdb) continue
Continuing.
[Inferior 1 (process 14128) exited with code 02]
(gdb)
-- excellent!
The change removes about 90 failures per MIPS16 multilib in mips-sde-elf
testing too, results for MIPS16 are now similar to that for standard
MIPS; microMIPS results are a bit worse because of host-I/O problems in
QEMU used instead of MIPSsim for microMIPS testing only:
=== gdb Summary ===
# of expected passes 14299
# of unexpected failures 187
# of expected failures 56
# of known failures 58
# of unresolved testcases 11
# of untested testcases 52
# of unsupported tests 174
MIPS16:
=== gdb Summary ===
# of expected passes 14298
# of unexpected failures 187
# of unexpected successes 2
# of expected failures 54
# of known failures 58
# of unresolved testcases 12
# of untested testcases 52
# of unsupported tests 174
microMIPS:
=== gdb Summary ===
# of expected passes 14149
# of unexpected failures 201
# of unexpected successes 2
# of expected failures 54
# of known failures 58
# of unresolved testcases 7
# of untested testcases 53
# of unsupported tests 175
2014-12-12 Maciej W. Rozycki <macro@codesourcery.com>
Maciej W. Rozycki <macro@mips.com>
Pedro Alves <pedro@codesourcery.com>
gdb/
* gdbarch.sh (elf_make_msymbol_special): Change type to `F',
remove `predefault' and `invalid_p' initializers.
(make_symbol_special): New architecture method.
(adjust_dwarf2_addr, adjust_dwarf2_line): Likewise.
(objfile, symbol): New declarations.
* arch-utils.h (default_elf_make_msymbol_special): Remove
prototype.
(default_make_symbol_special): New prototype.
(default_adjust_dwarf2_addr): Likewise.
(default_adjust_dwarf2_line): Likewise.
* mips-tdep.h (mips_unmake_compact_addr): New prototype.
* arch-utils.c (default_elf_make_msymbol_special): Remove
function.
(default_make_symbol_special): New function.
(default_adjust_dwarf2_addr): Likewise.
(default_adjust_dwarf2_line): Likewise.
* dwarf2-frame.c (decode_frame_entry_1): Call
`gdbarch_adjust_dwarf2_addr'.
* dwarf2loc.c (dwarf2_find_location_expression): Likewise.
* dwarf2read.c (create_addrmap_from_index): Likewise.
(process_psymtab_comp_unit_reader): Likewise.
(add_partial_symbol): Likewise.
(add_partial_subprogram): Likewise.
(process_full_comp_unit): Likewise.
(read_file_scope): Likewise.
(read_func_scope): Likewise. Call `gdbarch_make_symbol_special'.
(read_lexical_block_scope): Call `gdbarch_adjust_dwarf2_addr'.
(read_call_site_scope): Likewise.
(dwarf2_ranges_read): Likewise.
(dwarf2_record_block_ranges): Likewise.
(read_attribute_value): Likewise.
(dwarf_decode_lines_1): Call `gdbarch_adjust_dwarf2_line'.
(new_symbol_full): Call `gdbarch_adjust_dwarf2_addr'.
* elfread.c (elf_symtab_read): Don't call
`gdbarch_elf_make_msymbol_special' if unset.
* mips-linux-tdep.c (micromips_linux_sigframe_validate): Strip
the ISA bit from the PC.
* mips-tdep.c (mips_unmake_compact_addr): New function.
(mips_elf_make_msymbol_special): Set the ISA bit in the symbol's
address appropriately.
(mips_make_symbol_special): New function.
(mips_pc_is_mips): Set the ISA bit before symbol lookup.
(mips_pc_is_mips16): Likewise.
(mips_pc_is_micromips): Likewise.
(mips_pc_isa): Likewise.
(mips_adjust_dwarf2_addr): New function.
(mips_adjust_dwarf2_line): Likewise.
(mips_read_pc, mips_unwind_pc): Keep the ISA bit.
(mips_addr_bits_remove): Likewise.
(mips_skip_trampoline_code): Likewise.
(mips_write_pc): Don't set the ISA bit.
(mips_eabi_push_dummy_call): Likewise.
(mips_o64_push_dummy_call): Likewise.
(mips_gdbarch_init): Install `mips_make_symbol_special',
`mips_adjust_dwarf2_addr' and `mips_adjust_dwarf2_line' gdbarch
handlers.
* solib.c (gdb_bfd_lookup_symbol_from_symtab): Get
target-specific symbol address adjustments.
* gdbarch.h: Regenerate.
* gdbarch.c: Regenerate.
2014-12-12 Maciej W. Rozycki <macro@codesourcery.com>
gdb/testsuite/
* gdb.base/func-ptrs.c: New file.
* gdb.base/func-ptrs.exp: New file.
breakpoint.c uses gdbarch_breakpoint_from_pc to determine whether a
breakpoint location points at a permanent breakpoint:
static int
bp_loc_is_permanent (struct bp_location *loc)
{
...
addr = loc->address;
bpoint = gdbarch_breakpoint_from_pc (loc->gdbarch, &addr, &len);
...
if (target_read_memory (loc->address, target_mem, len) == 0
&& memcmp (target_mem, bpoint, len) == 0)
retval = 1;
...
So I think we should default the gdbarch_skip_permanent_breakpoint
hook to advancing the PC by the length of the breakpoint instruction,
as determined by gdbarch_breakpoint_from_pc. I believe that simple
implementation does the right thing for most architectures. If
there's an oddball architecture where that doesn't work, then it
should override the hook, just like it should be overriding the hook
if there was no default anyway.
The only two implementation of skip_permanent_breakpoint are
i386_skip_permanent_breakpoint, for x86, and
hppa_skip_permanent_breakpoint, for PA-RISC/HP-UX
The x86 implementation is trivial, and can clearly be replaced by the
new default.
I don't know about the HP-UX one though, I know almost nothing about
PA. It may well be advancing the PC ends up being equivalent.
Otherwise, it must be that "jump $pc_after_bp" doesn't work either...
Tested on x86_64 Fedora 20 native and gdbserver.
gdb/
2014-11-12 Pedro Alves <palves@redhat.com>
* arch-utils.c (default_skip_permanent_breakpoint): New function.
* arch-utils.h (default_skip_permanent_breakpoint): New
declaration.
* gdbarch.sh (skip_permanent_breakpoint): Now an 'f' function.
Install default_skip_permanent_breakpoint as default method.
* i386-tdep.c (i386_skip_permanent_breakpoint): Delete function.
(i386_gdbarch_init): Don't install it.
* infrun.c (resume): Assume there's always a
gdbarch_skip_permanent_breakpoint implementation.
* gdbarch.h, gdbarch.c: Regenerate.
We have a case in solib-svr4.c where we could reuse symfile-mem.c's
vDSO range lookup. Since symfile-mem.c is not present in all
configurations solib-svr4.c is, move that lookup to a gdbarch hook.
This has the minor (good) side effect that we stop even trying the
target_auxv_search lookup against targets that don't have a concept of
a vDSO, in case symfile-mem.c happens to be linked in the build
(--enable-targets=all).
Tested on x86_64 Fedora 20.
gdb/
2014-10-10 Pedro Alves <palves@redhat.com>
* arch-utils.c (default_vsyscall_range): New function.
* arch-utils.h (default_vsyscall_range): New declaration.
* gdbarch.sh (vsyscall_range): New hook.
* gdbarch.h, gdbarch.c: Regenerate.
* linux-tdep.c (linux_vsyscall_range): New function.
(linux_init_abi): Install linux_vsyscall_range as
vsyscall_range gdbarch hook.
* memrange.c (address_in_mem_range): New function.
* memrange.h (address_in_mem_range): New declaration.
* symfile-mem.c (find_vdso_size): Delete function.
(add_vsyscall_page): Use gdbarch_vsyscall_range.
Add new methods to gdbarch for analyzing the instruction at a given address.
Implement those methods for i386 and amd64 architectures.
This is needed by "record btrace" to detect function calls in the
execution trace.
2014-01-16 Markus Metzger <markus.t.metzger@intel.com>
* amd64-tdep.c (amd64_classify_insn_at, amd64_insn_is_call)
(amd64_insn_is_ret, amd64_insn_is_jump, amd64_jmp_p): New.
(amd64_init_abi): Add insn_is_call, insn_is_ret, and insn_is_jump
to gdbarch.
* i386-tdep.c (i386_insn_is_call, i386_insn_is_ret)
(i386_insn_is_jump, i386_jmp_p): New.
(i386_gdbarch_init): Add insn_is_call, insn_is_ret, and
insn_is_jump to gdbarch.
* gdbarch.sh (insn_is_call, insn_is_ret, insn_is_jump): New.
* gdbarch.h: Regenerated.
* gdbarch.c: Regenerated.
* arch-utils.h (default_insn_is_call, default_insn_is_ret)
(default_insn_is_jump): New.
* arch-utils.c (default_insn_is_call, default_insn_is_ret)
(default_insn_is_jump): New.
Two modifications:
1. The addition of 2013 to the copyright year range for every file;
2. The use of a single year range, instead of potentially multiple
year ranges, as approved by the FSF.
* tracepoint.c (encode_actions_1): Add case for $_ret.
(validate_actionline): Check for $_ret.
(trace_dump_actions): Ditto.
* ax-gdb.h (gen_trace_for_return_address): Declare.
* ax-gdb.c: Include arch-utils.h.
(gen_trace_for_return_address): New function.
(agent_command): Add return address special case.
* amd64-tdep.c: Include ax.h and ax-gdb.h.
(amd64_gen_return_address): New function.
(amd64_init_abi): Call it.
* i386-tdep.c: Include ax.h and ax-gdb.h.
(i386_gen_return_address): New function.
(i386_init_abi): Call it.
* arch-utils.h (default_gen_return_address): Declare.
* arch-utils.c (default_gen_return_address): New function.
* gdbarch.sh (gen_return_address): New method.
* gdbarch.h, gdbarch.c: Regenerate.
* gdb.texinfo (Tracepoint Action Lists): Document $_ret.
* gdb.trace/collection.exp: Test collection of $_ret.
Tom Tromey
Joel Brobecker
Markus Metzger
Simon Marchi
Yao Qi
Simon Marchi
Jiong Wang
Ulrich Weigand
Yao Qi
Marcin Kościelnicki
Pierre Langlois
Jan Kratochvil
Martin Galvan
Tom Tromey
Maciej W. Rozycki
Pedro Alves
Joel Brobecker
Yao Qi
Doug Evans
Stan Shebs
Michael Snyder