clang shows this warning:
/home/emaisin/src/binutils-gdb/gdb/main.c:227:56: error: adding 'int' to a string does not append to the string [-Werror,-Wstring-plus-int]
char *tmp_sys_gdbinit = xstrdup (SYSTEM_GDBINIT + datadir_len);
~~~~~~~~~~~~~~~^~~~~~~~~~~~~
/home/emaisin/src/binutils-gdb/gdb/main.c:227:56: note: use array indexing to silence this warning
char *tmp_sys_gdbinit = xstrdup (SYSTEM_GDBINIT + datadir_len);
^
& [ ]
It's quite easy to get rid of it by using &foo[len] instead of foo + len.
I think this warning is relevant to keep enabled, because it can be an
easy mistake to do.
This warning is already discussed here in GCC bugzilla:
https://gcc.gnu.org/ml/gcc-patches/2017-06/msg00729.html
and a patch series for it was submitted very recently.
gdb/ChangeLog:
* main.c (get_init_files): Replace "SYSTEM_GDBINIT +
datadir_len" with "&SYSTEM_GDBINIT[datadir_len]".
clang shows this warning.
/home/emaisin/src/binutils-gdb/gdb/dtrace-probe.c:424:52: error: while loop has empty body [-Werror,-Wempty-body]
while (*p++ != '\0' && p - strtab < strtab_size);
^
/home/emaisin/src/binutils-gdb/gdb/dtrace-probe.c:424:52: note: put the semicolon on a separate line to silence this warning
Putting the semicolon on its own line is not a big sacrifice to get rid of this
warning. I think it's also useful to keep this, because it can catch errors
like this:
while (something);
{
...
}
although gcc would warn about it in a different way (misleading indentation).
This warning is already discussed here in the GCC bugzilla:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62184
gdb/ChangeLog:
* dtrace-probe.c (dtrace_process_dof_probe): Put semi-colon on
its own line.
This get around this warning given by clang...
/home/emaisin/src/binutils-gdb/gdb/nat/x86-dregs.c:209:7: error: variable 'i' is incremented both in the loop header and in the loop body [-Werror,-Wfor-loop-analysis]
i++;
^
/home/emaisin/src/binutils-gdb/gdb/nat/x86-dregs.c:199:32: note: incremented here
ALL_DEBUG_ADDRESS_REGISTERS (i)
^
... I decided in the end to simply print the debug registers one per
line. I don't think it particularly helps readability to have them two
per line anyway.
gdb/ChangeLog:
* nat/x86-dregs.c (x86_show_dr): Print registers one per line.
The self tests which compare pre-generated target descriptions and
dynamically created target descriptions fail, and it turns out that two
pre-generated target descriptions are wrong, so regenerate them.
gdb:
2017-06-22 Yao Qi <yao.qi@linaro.org>
* regformats/i386/amd64-avx-mpx-avx512-pku-linux.dat: Regenerated.
* regformats/i386/amd64-avx-mpx-avx512-pku.dat: Regenerated.
clang gives this warning:
..../gdb/unittests/environ-selftests.c:139:7: error: explicitly moving variable of type 'gdb_environ' to itself [-Werror,-Wself-move]
env = std::move (env);
~~~ ^ ~~~
Ignoring the warning locally is the right thing to do, since it warns
about behavior we want to unit test, while an explicit self-move in
real code would likely be a mistake that we'd want to catch.
To avoid cluttering the code with preprocessor conditionals, this
commit adds the file common/diagnostics.h, in which we can put macros
used to control compiler diagnostics.
GCC enhancement request here:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81159
gdb/ChangeLog:
2017-06-22 Pedro Alves <palves@redhat.com>
Simon Marchi <simon.marchi@ericsson.com>
* unittests/environ-selftests.c (run_tests): Ignore -Wself-move
warning.
* common/diagnostics.h: New file.
We have several copies of this common idiom under gdb/ currently.
This commit moves them / factors them out to gdb/common/preprocessor.h.
gdb/ChangeLog:
2017-06-22 Pedro Alves <palves@redhat.com>
* common/agent.h: Include "common/preprocessor.h".
(STRINGIZE_1, STRINGIZE): Delete.
(IPA_SYM): Use STRINGIFY instead.
* common/preprocessor.h (STRINGIFY_1, STRINGIFY): New.
* compile/compile-c-support.c: Include "common/preprocessor.h".
(STR, STRINGIFY): Delete.
* ia64-libunwind-tdep.c: Include "common/preprocessor.h".
(STRINGIFY2, STRINGIFY): Delete.
This is the portion of gdb_test which performs the match against
the RE (regular expression) passed to it:
return [gdb_test_multiple $command $message {
-re "\[\r\n\]*($pattern)\[\r\n\]+$gdb_prompt $" {
if ![string match "" $message] then {
pass "$message"
}
}
In a test that I've been working on recently, I wanted to use
a backreference - that's the \1 in the the RE below:
gdb_test "info threads" \
{.*[\r\n]+\* +([0-9]+) +Thread[^\r\n]* do_something \(n=\1\) at.*}
Put into English, I wanted to make sure that the value of n passed to
do_something() is the same as the thread number shown in the "info
threads" Id column. (I've structured the test case so that this
*should* be the case.)
It didn't work though. It turned out that ($pattern) in the RE
noted above is capturing the attempted backreference. So, in this
case, the backreference does not refer to ([0-9]+) as intended, but
instead refers to ($pattern). This is wrong because it's not what I
intended, but is also wrong because, if allowed, it could only match a
string of infinite length.
This problem can be fixed by using parens for a "noncapturing
subpattern". The way that this is done, syntactically, is to use
(?:$pattern) instead of ($pattern).
My research shows that this feature has been present since tcl8.1 which
was released in 1999.
The current tcl version is 8.6 - at least that's what I have on my
machine. It appears to me that mingw uses some subversion of tcl8.4
which will also have this feature (since 8.4 > 8.1).
So it seems to me that any platform upon which we might wish to test
GDB will have a version of tcl which has this feature. That being the
case, my hope is that there won't be any objections to its use.
When I looked at the implementation of gdb_test, I wondered whether
the parens were needed at all. I've concluded that they are. In the
event that $pattern is an RE which uses alternation at the top level,
e.g. a|b, we need to make $pattern a subpattern (via parens) to limit
the extend of the alternation. I.e, we don't want the alternation to
extend to the other portions of the RE which gdb_test uses to match
potential blank lines at the beginning of the pattern or the gdb
prompt at the end.
gdb/testsuite/ChangeLog:
* gdb.exp (gdb_test): Using noncapturing parens for the $pattern
subpattern.
The commit
d309493 target: consider addressable unit size when reading/writing memory
introduced the possibility of reading memory of targets with
non-8-bit-bytes (e.g. memories that store 16 bits at each address).
The documentation of target_read and target_write was updated
accordingly, but to_xfer_partial, which is very related, wasn't updated.
This commit fixes that.
gdb/ChangeLog:
* target.h (struct target_ops) <to_xfer_partial>: Update doc to
talk about addressable units instead of bytes.
Even though C++11 supports modifying containers using a const_iterator
(e.g., calling the 'erase' method of a std::vector), early versions of
libstdc++ did not implement that. Some of our buildslaves are using
these versions (e.g., the AArch64 buildslave uses gcc 4.8.8), and my
previous commit causes a breakage on them. The solution is simple:
just use a normal iterator, without const.
gdb/ChangeLog:
2017-06-20 Sergio Durigan Junior <sergiodj@redhat.com>
* common/environ.c (gdb_environ::unset): Use '::iterator' instead
of '::const_iterator'.
As part of the preparation necessary for my upcoming task, I'd like to
propose that we turn gdb_environ into a class. The approach taken
here is simple: the class gdb_environ contains everything that is
needed to manipulate the environment variables. These variables are
stored in an std::vector<char *>, which can be converted to a 'char
**' and passed as argument to functions that need it.
The usage has not changed much. As per Pedro's suggestion, this class
uses a static factory method initialization. This means that when an
instance is created, it is initially empty. When needed, it has to be
initialized using the static method 'from_host_environ'.
As mentioned before, this is a preparation for an upcoming work that I
will be posting in the next few weeks or so. For that work, I'll
probably create another data structure that will contain all the
environment variables that were set by the user using the 'set
environment' command, because I'll need access to them. This will be
much easier with the class-ification of gdb_environ.
As noted, this has been regression-tested with the new version of
environ.exp and no regressions were found.
gdb/ChangeLog:
2017-06-20 Sergio Durigan Junior <sergiodj@redhat.com>
* Makefile.in (SUBDIR_UNITTESTS_SRCS): Add
'unittests/environ-selftests.c'.
(SUBDIR_UNITTESTS_OBS): Add 'environ-selftests.o'.
* charset.c (find_charset_names): Declare object 'iconv_env'.
Update code to use 'iconv_env' object. Remove call to
'free_environ'.
* common/environ.c: Include <utility>.
(make_environ): Delete function.
(free_environ): Delete function.
(gdb_environ::clear): New function.
(gdb_environ::operator=): New function.
(gdb_environ::get): Likewise.
(environ_vector): Delete function.
(set_in_environ): Delete function.
(gdb_environ::set): New function.
(unset_in_environ): Delete function.
(gdb_environ::unset): New function.
(gdb_environ::envp): Likewise.
* common/environ.h: Include <vector>.
(struct gdb_environ): Delete; transform into...
(class gdb_environ): ... this class.
(free_environ): Delete prototype.
(init_environ, get_in_environ, set_in_environ, unset_in_environ,
environ_vector): Likewise.
* infcmd.c (run_command_1): Update code to call
'envp' from 'gdb_environ' class.
(environment_info): Update code to call methods from 'gdb_environ'
class.
(unset_environment_command): Likewise.
(path_info): Likewise.
(path_command): Likewise.
* inferior.c (inferior::~inferior): Delete call to 'free_environ'.
(inferior::inferior): Initialize 'environment' using the host's
information.
* inferior.h: Remove forward declaration of 'struct gdb_environ'.
Include "environ.h".
(class inferior) <environment>: Change type from 'struct
gdb_environ' to 'gdb_environ'.
* mi/mi-cmd-env.c (mi_cmd_env_path): Update code to call
methods from 'gdb_environ' class.
* solib.c (solib_find_1): Likewise
* unittests/environ-selftests.c: New file.
gdb/gdbserver/ChangeLog:
2017-06-20 Sergio Durigan Junior <sergiodj@redhat.com>
* linux-low.c (linux_create_inferior): Adjust code to access the
environment information via 'gdb_environ' class.
* lynx-low.c (lynx_create_inferior): Likewise.
* server.c (our_environ): Make it an instance of 'gdb_environ'.
(get_environ): Return a pointer to 'our_environ'.
(captured_main): Initialize 'our_environ'.
* server.h (get_environ): Adjust prototype.
* spu-low.c (spu_create_inferior): Adjust code to access the
environment information via 'gdb_environ' class.
Exchange the order of 32bit-linux.xml and 32bit-sse.xml in
i386/i386-linux.xml, to align with other i386 linux .xml files.
gdb:
2017-06-20 Yao Qi <yao.qi@linaro.org>
* features/i386/i386-linux.xml: Exchange the order of including
32bit-linux.xml and 32bit-sse.xml.
* features/i386/i386-linux.c: Regenerated.
'info registers' for MIPS throws an error and when it first encounters
an unavailable register. This does not match other architectures
which annotate unavailable registers and continue to print out the
values of subsequent registers. Replace the error by displaying an
aligned "<unavailable>". This string is truncated to "<unavl>" when
displaying a 32-bit register.
gdb/ChangeLog:
* mips-tdep.c (print_gp_register_row): Don't error for unavailable
registers.
When I added the new lnia extended mnemonic for addpcis, I updated the
assembler/disassembler test cases, but overlooked the GDB test cases.
This patch fixes that oversight and associated test case failure.
* gdb.arch/powerpc-power9.exp: Update test case for new lnia
extended mnemonic.
* gdb.arch/powerpc-power9.s: Likewise.
We should close the file before unlinking because on MS-Windows one
cannot delete a file that is still open.
I considered making 'gdb::unlinker::unlinker(const char *)'
'noexcept(true)' and then adding
static_assert (noexcept (gdb::unlinker (filename.c_str ())), "");
but that doesn't really work because gdb::unlinker has a gdb_assert,
which can throw a QUIT if/when the assertion fails. 'noexcept(true)'
would cause GDB to abruptly terminate if/when the assertion fails.
gdb/ChangeLog:
2017-06-19 Pedro Alves <palves@redhat.com>
* dwarf2read.c (write_psymtabs_to_index): Construct file_closer
after gdb::unlinker.
This is a spinoff of
<https://sourceware.org/ml/gdb-patches/2017-06/msg00437.html>.
mi-cmd-env.c is using the whole gdb_environ machinery in order to
access just one variable, which can be easily replaced by a simple
call to getenv. This patch does that, and doesn't cause regressions.
gdb/ChangeLog:
2017-06-18 Sergio Durigan Junior <sergiodj@redhat.com>
* mi/mi-cm-env.c (_initialize_mi_cmd_env): Use getenv instead of
gdb_environ to access an environment variable.
On noMMU platforms, the following code gets compiled:
child_stack = xmalloc (STACK_SIZE * 4);
Where child_stack is a gdb_byte*, and xmalloc() returns a void*. While
the lack of cast is valid in C, it is not in C++, causing the
following build failure:
../nat/linux-ptrace.c: In function 'int linux_fork_to_function(gdb_byte*, int (*)(void*))':
../nat/linux-ptrace.c:273:29: error: invalid conversion from 'void*' to 'gdb_byte* {aka unsigned char*}' [-fpermissive]
child_stack = xmalloc (STACK_SIZE * 4);
Therefore, this commit adds the appropriate cast.
gdb/ChangeLog:
* nat/linux-ptrace.c (linux_fork_to_function): Add cast to
gdb_byte*.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
clang complains that the fmt passed to vwarning in trace_start_error is
not a literal. This looks like a fair warning, which can be removed by
adding ATTRIBUTE_PRINTF to the declaration of trace_start_error.
gdb/ChangeLog:
* nat/fork-inferior.h (trace_start_error): Add ATTRIBUTE_PRINTF.
AFAIK, the register keyword is not relevant today, and clang complains
about it:
/home/emaisin/src/binutils-gdb/gdb/gdbserver/linux-low.c:5873:3: error: 'register' storage class specifier is deprecated and incompatible with C++1z
[-Werror,-Wdeprecated-register]
register PTRACE_XFER_TYPE *buffer;
^~~~~~~~~
I think we can safely remove it.
gdb/gdbserver/ChangeLog:
* linux-low.c (linux_read_memory, linux_write_memory): Remove
usage of "register" keyword.
clang complains that for some types, we use both the class and struct
keywords in different places. It's not really a problem, so I think we
can safely turn this warning off.
gdb/ChangeLog:
* configure: Re-generate.
* warning.m4 (build_warnings): Add -Wno-mismatched-tags.
gdb/gdbserver/ChangeLog:
* configure: Re-generate.
In warning.m4, we pass all the warning flags one by one to the compiler
to test if they are supported by this particular compiler. If the
compiler exits with an error, we conclude that this warning flag is not
supported and exclude it. This allows us to use warning flags without
having to worry about which versions of which compilers support each
flag.
clang, by default, only emits a warning if an unknown flag is passed:
warning: unknown warning option '-Wfoo' [-Wunknown-warning-option]
The result is that we think that all the warning flags we use are
supported by clang (they are not), and the compilation fails later when
building with -Werror, since the aforementioned warning becomes an
error. The fix is to also pass -Werror when probing for supported
flags, then we'll correctly get an error when using an unknown warning,
and we'll exclude it:
error: unknown warning option '-Wfoo' [-Werror,-Wunknown-warning-option]
I am not sure why there is a change in a random comment in
gdbserver/configure, but I suppose it's a leftfover from a previous
patch, so I included it.
gdb/ChangeLog:
* configure: Re-generate.
* warning.m4: Pass -Werror to compiler when checking for
supported warning flags.
gdb/gdbserver/ChangeLog:
* configure: Re-generate.
Because we are compiling .c files containing C++ code, clang++ complains
with:
clang: error: treating 'c' input as 'c++' when in C++ mode, this behavior is deprecated
If renaming all the source files to .cpp is out of the question, an
alternative is to pass "-x c++" to convince the compiler that we are
really compiling C++. It works fine with GCC too.
gdb/ChangeLog:
* Makefile.in (COMPILE.pre): Add "-x c++".
gdb/gdbserver/ChangeLog:
* Makefile.in (COMPILE.pre): Add "-x c++".
This patch converts functions extract_{unsigned,signed}_integer
to a function template extract_integer, which has two instantiations. It
also does the similar changes to store__{unsigned,signed}_integer,
regcache::raw_read_{unsigned,signed}, regcache::raw_write_{unsigned,signed},
regcache::cooked_read_{unsigned,signed},
regcache::cooked_write_{unsigned,signed}.
This patch was posted here
https://sourceware.org/ml/gdb-patches/2017-05/msg00492.html but the
problem was fixed in a different way. However, I think the patch is still
useful to shorten the code.
gdb:
2017-06-16 Alan Hayward <alan.hayward@arm.com>
Pedro Alves <palves@redhat.com>
Yao Qi <yao.qi@linaro.org>
* defs.h (RequireLongest): New.
(extract_integer): Declare function template.
(extract_signed_integer): Remove the declaration, but define it
static inline.
(extract_unsigned_integer): Likewise.
(store_integer): Declare function template.
(store_signed_integer): Remove the declaration, but define it
static inline.
(store_unsigned_integer): Likewise.
* findvar.c (extract_integer): New function template.
(extract_signed_integer): Remove.
(extract_unsigned_integer): Remove.
(extract_integer<LONGEST>, extract_integer<ULONGEST>): Explicit
instantiations.
(store_integer): New function template.
(store_signed_integer): Remove.
(store_unsigned_integer): Remove.
(store_integer): Explicit instantiations.
* regcache.c (regcache_raw_read_signed): Update.
(regcache::raw_read): New function.
(regcache::raw_read_signed): Remove.
(regcache::raw_read_unsigned): Remove.
(regcache_raw_read_unsigned): Update.
(regcache_raw_write_unsigned): Update.
(regcache::raw_write_signed): Remove.
(regcache::raw_write): New function.
(regcache_cooked_read_signed): Update.
(regcache::raw_write_unsigned): Remove.
(regcache::cooked_read_signed): Remove.
(regcache_cooked_read_unsigned): Update.
(regcache::cooked_read_unsigned): Remove.
(regcache_cooked_write_signed): Update.
(regcache_cooked_write_unsigned): Update.
* regcache.h (regcache) <raw_read_signed>: Remove.
<raw_write_signed, raw_read_unsigned, raw_write_unsigned>: Remove.
<raw_read, raw_write>: New.
<cooked_read_signed, cooked_write_signed>: Remove.
<cooked_write_unsigned, cooked_read_unsigned>: Remove.
<cooked_read, cooked_write>: New.
* sh64-tdep.c (sh64_pseudo_register_read): Update.
(sh64_pseudo_register_write): Update.
Enforce CPU model for disassembler via its options, if it was specified in XML
target description, otherwise use default method of determining CPU implemented
in disassembler - scanning ELF private header. The latter requires
disassemble_info->section to be properly initialized. To make sure that
info->section is set in all cases this patch partially reverts [1] for ARC: it
reinstates arc_delayed_print_insn as a "print_insn" function for ARC, but
now this function only sets disassemble_info->section and then calls
default_print_insn to do the rest of the job.
Support for CPU in disassembler options for ARC has been added in [2].
[1] https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=39503f82427e22ed8e04d986ccdc8562091ec62e
[2] https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=10045478d984f9924cb945423388ba25b7dd3ffe
gdb/ChangeLog:
yyyy-mm-dd Anton Kolesov <anton.kolesov@synopsys.com>
* arc-tdep.c (arc_disassembler_options): New variable.
(arc_gdbarch_init): Set and use it. Use arc_delayed_print_insn instead
of default_print_insn.
(arc_delayed_print_insn): Set info->section when needed,
use default_print_insn to retrieve a disassembler.
This simple patch updates the documentation of "help run" in order to
mention that the shell used to start the inferior comes from the
$SHELL environment variable. It also mentions that this behaviour can
be disabled by using the "set startup-with-shell off" command.
gdb/ChangeLog:
2017-06-14 Sergio Durigan Junior <sergiodj@redhat.com>
PR gdb/21574
* infcmd.c (_initialize_infcmd): Expand "help run" documentation
to mention $SHELL and startup-with-shell.
This is a follow-up to
[PATCH 0/6] Unify the disassembler selection in gdb and objdump
https://sourceware.org/ml/binutils/2017-05/msg00192.html
that is, opcodes is able to select the right disassembler, so gdb
doesn't have to select them. Instead, gdb can just use
default_print_insn. As a result, these print_insn_XXX are not used
out of opcodes, so this patch also moves their declarations from
include/dis-asm.h to opcodes/disassemble.h. With this change,
GDB doesn't use any print_insn_XXX directly any more.
gdb:
2017-06-14 Yao Qi <yao.qi@linaro.org>
* aarch64-tdep.c (aarch64_gdb_print_insn): Call
default_print_insn instead of print_insn_aarch64.
* arm-tdep.c (gdb_print_insn_arm): Call
default_print_insn instead of print_insn_big_arm
and print_insn_little_arm.
* i386-tdep.c (i386_print_insn): Call default_print_insn
instead of print_insn_i386.
* ia64-tdep.c (ia64_print_insn): Call
default_print_insn instead of print_insn_ia64.
* mips-tdep.c (gdb_print_insn_mips): Call
default_print_insn instead of print_insn_big_mips
and print_insn_little_mips.
* spu-tdep.c (gdb_print_insn_spu): Call default_print_insn
instead of print_insn_spu.
include:
2017-06-14 Yao Qi <yao.qi@linaro.org>
* dis-asm.h (print_insn_aarch64): Move it to opcodes/disassemble.h.
(print_insn_big_arm, print_insn_big_mips): Likewise.
(print_insn_i386, print_insn_ia64): Likewise.
(print_insn_little_arm, print_insn_little_mips): Likewise.
(print_insn_spu): Likewise.
opcodes:
2017-06-14 Yao Qi <yao.qi@linaro.org>
* aarch64-dis.c: Include disassemble.h instead of dis-asm.h.
* arm-dis.c: Likewise.
* ia64-dis.c: Likewise.
* mips-dis.c: Likewise.
* spu-dis.c: Likewise.
* disassemble.h (print_insn_aarch64): New declaration, moved from
include/dis-asm.h.
(print_insn_big_arm, print_insn_big_mips): Likewise.
(print_insn_i386, print_insn_ia64): Likewise.
(print_insn_little_arm, print_insn_little_mips): Likewise.
The new test var-access.exp causes FAILs on i686. This is because the
test chooses the wrong name for DWARF register number 1: It uses
"edx" (which corresponds to DWARF register number 2), but should have used
"ecx" instead.
Also, the current logic in var-access.exp does not correctly distinguish
between a 64-bit and a 32-bit program on an x86-64 target. It uses the
64-bit register names for both.
These problems are fixed. In order to address the latter, the convenience
macros is_*_target are exploited where appropriate.
gdb/testsuite/ChangeLog:
* gdb.dwarf2/var-access.exp: Use register name ecx instead of edx
on 32-bit x86 targets. Exploit is_*_target macros where
appropriate.
In some cases we've been replacing heap-allocated gdb_byte buffers
managed with xmalloc/make_cleanup(xfree) with gdb::vector<gdb_byte>.
That usually pessimizes the code a little bit because std::vector
value-initializes elements (which for gdb_byte means
zero-initialization), while if you're creating a temporary buffer,
you're most certaintly going to fill it in with some data. An
alternative is to use
unique_ptr<gdb_byte[]> buf (new gdb_byte[size]);
but it looks like that's not very popular.
Recently, a use of obstacks in dwarf2read.c was replaced with
std::vector<gdb_byte> and that as well introduced a pessimization for
always memsetting the buffer when it's garanteed that the zeros will
be overwritten immediately. (see dwarf2read.c change in this patch to
find it.)
So here's a different take at addressing this issue "by design":
#1 - Introduce default_init_allocator<T>
I.e., a custom allocator that does default construction using default
initialization, meaning, no more zero initialization. That's the
default_init_allocation<T> class added in this patch.
See "Notes" at
<http://en.cppreference.com/w/cpp/container/vector/resize>.
#2 - Introduce def_vector<T>
I.e., a convenience typedef, because typing the allocator is annoying:
using def_vector<T> = std::vector<T, gdb::default_init_allocator<T>>;
#3 - Introduce byte_vector
Because gdb_byte vectors will be the common thing, add a convenience
"byte_vector" typedef:
using byte_vector = def_vector<gdb_byte>;
which is really the same as:
std::vector<gdb_byte, gdb::default_init_allocator<gdb_byte>>;
The intent then is to make "gdb::byte_vector" be the go-to for dynamic
byte buffers. So the less friction, the better.
#4 - Adjust current code to use it.
To set the example going forward. Replace std::vector uses and also
unique_ptr<byte[]> uses.
One nice thing is that with this allocator, for changes like these:
-std::unique_ptr<byte[]> buf (new gdb_byte[some_size]);
+gdb::byte_vector buf (some_size);
fill_with_data (buf.data (), buf.size ());
the generated code is the same as before. I.e., the compiler
de-structures the vector and gets rid of the unused "reserved vs size"
related fields.
The other nice thing is that it's easier to write
gdb::byte_vector buf (size);
than
std::unique_ptr<gdb_byte[]> buf (new gdb_byte[size]);
or even (C++14):
auto buf = std::make_unique<gdb_byte[]> (size); // zero-initializes...
#5 - Suggest s/std::vector<gdb_byte>/gdb::byte_vector/ going forward.
Note that this commit actually fixes a couple of bugs where the current
code is incorrectly using "std::vector::reserve(new_size)" and then
accessing the vector's internal buffer beyond the vector's size: see
dwarf2loc.c and charset.c. That's undefined behavior and may trigger
debug mode assertion failures. With default_init_allocator,
"resize()" behaves like "reserve()" performance wise, in that it
leaves new elements with unspecified values, but, it does that safely
without triggering undefined behavior when you access those values.
gdb/ChangeLog:
2017-06-14 Pedro Alves <palves@redhat.com>
* ada-lang.c: Include "common/byte-vector.h".
(ada_value_primitive_packed_val): Use gdb::byte_vector.
* charset.c (wchar_iterator::iterate): Resize the vector instead
of reserving it.
* common/byte-vector.h: Include "common/def-vector.h".
(wchar_iterator::m_out): Now a gdb::def_vector<gdb_wchar_t>.
* cli/cli-dump.c: Include "common/byte-vector.h".
(dump_memory_to_file, restore_binary_file): Use gdb::byte_vector.
* common/byte-vector.h: New file.
* common/def-vector.h: New file.
* common/default-init-alloc.h: New file.
* dwarf2loc.c: Include "common/byte-vector.h".
(rw_pieced_value): Use gdb::byte_vector, and resize the vector
instead of reserving it.
* dwarf2read.c: Include "common/byte-vector.h".
(data_buf::m_vec): Now a gdb::byte_vector.
* gdb_regex.c: Include "common/def-vector.h".
(compiled_regex::compiled_regex): Use gdb::def_vector<char>.
* mi/mi-main.c: Include "common/byte-vector.h".
(mi_cmd_data_read_memory): Use gdb::byte_vector.
* printcmd.c: Include "common/byte-vector.h".
(print_scalar_formatted): Use gdb::byte_vector.
* valprint.c: Include "common/byte-vector.h".
(maybe_negate_by_bytes, print_decimal_chars): Use
gdb::byte_vector.
I forgot this one, which is kind of related.
The function trace_start_error_with_name has moved in commit "Share
fork_inferior et al with gdbserver", so this additional include is
needed.
Fixes:
darwin-nat.c:1735:5: error: use of undeclared identifier 'trace_start_error_with_name'
trace_start_error_with_name ("close");
gdb/ChangeLog:
* darwin-nat.c: Include "nat/fork-inferior.h".
I happened to be build-testing on macOS and found this:
Undefined symbols for architecture x86_64:
"fork_inferior(char const*, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, char**, void (*)(), void (*)(int), void (*)(), char const*, void (*)(char const*, char* const*, char* const*))", referenced from:
darwin_create_inferior(target_ops*, char const*, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, char**, int) in darwin-nat.o
"startup_inferior(int, int, target_waitstatus*, ptid_t*)", referenced from:
gdb_startup_inferior(int, int) in fork-child.o
"trace_start_error(char const*, ...)", referenced from:
darwin_ptrace_me() in darwin-nat.o
"trace_start_error_with_name(char const*)", referenced from:
darwin_ptrace_me() in darwin-nat.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Adding fork-inferior.o fixes it. I factored out the Darwin bits that
are no architecture-specific in the section meant for that at the top.
I only built-tested this using Travis-CI, since I don't have access to
this platform.
gdb/ChangeLog:
* configure.nat: Factor out Darwin bits that are not
architecture-specific. Add fork-inferior.o.
Trying to build on AIX gives:
ld: 0711-317 ERROR: Undefined symbol: .trace_start_error_with_name(char const*)
ld: 0711-317 ERROR: Undefined symbol: .fork_inferior(char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, char**, void (*)(), void (*)(int), void (*)(), char const*, void (*)(char const*, char* const*, char* const*))
ld: 0711-317 ERROR: Undefined symbol: .startup_inferior(int, int, target_waitstatus*, ptid_t*)
Including fork-inferior.o in the build should help. I also factored out
the AIX bits that are not architecture-specific to be consistent with the other
OSes.
gdb/ChangeLog:
* configure.nat: Factor out AIX bits that are not
architecture-specific. Add fork-inferior.o.
Since read_pieced_value and write_pieced_value share significant logic,
this patch merges them into a single function rw_pieced_value.
gdb/ChangeLog:
* dwarf2loc.c (rw_pieced_value): New. Merge logic from...
(read_pieced_value, write_pieced_value): ...here. Reduce to
wrappers that just call rw_pieced_value.
So far write_pieced_value uses write_memory when writing memory pieces to
the target. However, this is a case where GDB potentially overwrites a
watchpoint value. In such a case write_memory_with_notification should be
used instead, so that memory_changed observers get notified.
gdb/ChangeLog:
* dwarf2loc.c (write_pieced_value): When writing the data for a
memory piece, use write_memory_with_notification instead of
write_memory.
The function read_value_memory accepts a parameter embedded_offset and
expects it to represent the byte offset into the given value. However,
the only invocation with a possibly non-zero embedded_offset happens in
read_pieced_value, where a bit offset is passed instead.
Adjust the implementation of read_value_memory to meet the caller's
expectation. This implicitly fixes the invocation in read_pieced_value.
gdb/ChangeLog:
* valops.c (read_value_memory): Change embedded_offset to
represent a bit offset instead of a byte offset.
* value.h (read_value_memory): Adjust comment.
In read_pieced_value's main loop, the variables `dest_offset_bits' and
`source_offset_bits' are basically just copies of `offset' and
`bits_to_skip', respectively. In write_pieced_value the copies are
reversed. This is not very helpful when trying to keep the logic between
these functions in sync. Since the copies are unnecessary, this patch
just removes them.
gdb/ChangeLog:
* dwarf2loc.c (read_pieced_value): Remove unnecessary variables
dest_offset_bits and source_offset_bits.
(write_pieced_value): Likewise.
So far GDB ignores the piece offset of all kinds of DWARF bit
pieces (DW_OP_bit_piece) and treats such pieces as if the offset was zero.
This is fixed, and an appropriate test is added.
gdb/ChangeLog:
* dwarf2loc.c (read_pieced_value): Respect the piece offset, as
given by DW_OP_bit_piece.
(write_pieced_value): Likewise.
Andreas Arnez <arnez@linux.vnet.ibm.com>
* gdb.dwarf2/var-access.exp: Add test for composite location with
nonzero piece offsets.
So far the main loop in read_pieced_value and write_pieced_value is
structured like this:
(1) Prepare a buffer and some variables we may need;
(2) depending on the DWARF piece type to be handled, use the buffer and
the prepared variables, ignore them, or even recalculate them.
This approach reduces readability and may also lead to unnecessary copying
of data. This patch moves the preparations to the places where sufficient
information is available and removes some of the variables involved.
gdb/ChangeLog:
* dwarf2loc.c (read_pieced_value): Move the buffer allocation and
some other preparations to the places where sufficient information
is available.
(write_pieced_value): Likewise.
For big-endian targets the logic in read/write_pieced_value tries to take
a register piece from the LSB end. This requires offsets and sizes to be
adjusted accordingly, and that's where the current implementation has some
issues:
* The formulas for recalculating the bit- and byte-offsets into the
register are wrong. They just happen to yield correct results if
everything is byte-aligned and the piece's last byte belongs to the
given value.
* After recalculating the bit offset into the register, the number of
bytes to be copied from the register is not recalculated. Of course
this does not matter if everything (particularly the piece size) is
byte-aligned.
These issues are fixed. The size calculation is performed with a new
helper function bits_to_bytes().
gdb/ChangeLog:
* dwarf2loc.c (bits_to_bytes): New function.
(read_pieced_value): Fix offset calculations for register pieces
on big-endian targets.
(write_pieced_value): Likewise.
gdb/testsuite/ChangeLog:
* gdb.dwarf2/var-access.exp: Add test for non-byte-aligned
register pieces.
When the variable 'buffer_size' in read_pieced_value and
write_pieced_value was introduced, it was needed for tracking the buffer's
allocated size. Now that the buffer's data type has been changed to a
std::vector, the variable is no longer necessary; so remove it.
gdb/ChangeLog:
* dwarf2loc.c (read_pieced_value): Remove buffer_size variable.
(write_pieced_value): Likewise.
This verifies some of the previous fixes to the logic in
write_pieced_value when accessing bit-fields.
gdb/testsuite/ChangeLog:
* gdb.dwarf2/var-access.exp: Add tests for accessing bit-fields
located in one or more DWARF pieces.
On big-endian targets, when targeting a bit-field, write_pieced_value
currently transfers the source value's *most* significant bits to the
target value, instead of its least significant bits. This is fixed.
In particular the fix adjusts the initial value of 'offset', which can now
potentially be nonzero. Thus the variable 'type_len' is renamed to
'max_offset', to avoid confusion. And for consistency, the affected logic
that was mirrored in read_pieced_value is changed there in the same way.
gdb/ChangeLog:
* dwarf2loc.c (write_pieced_value): When writing to a bit-field,
transfer the source value's least significant bits, instead of its
lowest-addressed ones. Rename type_len to max_offset.
(read_pieced_value): Mirror above changes to write_pieced_value as
applicable.
Simon Marchi
Alan Hayward
Sergio Durigan Junior
Yao Qi
Pedro Alves
Kevin Buettner
John Baldwin
Peter Bergner
Thomas Petazzoni
Anton Kolesov
Max Filippov
Andreas Arnez