While testing a patch on Solaris, which does not support split-stack, I
ran across a bug in the handling of caller-saved registers for the
garbage collector. For non-split-stack systems, runtime_mcall is
responsible for saving all caller-saved registers on the stack so that
the GC stack scan will see them. It does this by calling
__builtin_unwind_init and setting the g's gcnextsp field to point to the
current stack. The garbage collector then scans the stack from gcnextsp
to the top of stack.
Unfortunately, the code was setting gcnextsp to point to runtime_mcall's
argument, which meant that even though runtime_mcall was careful to
store all caller-saved registers on the stack, the GC never saw them.
This is, of course, only a problem if a value lives only in a
caller-saved register, and not anywhere else on the stack or heap. And
it is only a problem if that caller-saved register manages to make it
all the way down to runtime_mcall without being saved by any function on
the way. This is moderately unlikely but it turns out that the recent
changes to keep values on the stack when compiling the runtime package
caused it to happen for the local variable `s` in `notifyListWait` in
runtime/sema.go. That function calls goparkunlock which is simple
enough to not require all registers, and itself calls runtime_mcall. So
it was possible for `s` to be released by the GC before the goroutine
returned from goparkunlock, which eventually caused a dangling pointer
to be passed to releaseSudog.
This is not a problem on split-stack systems, which use
__splitstack_get_context, which saves a stack pointer low enough on the
stack to scan the registers saved by runtime_mcall.
Reviewed-on: https://go-review.googlesource.com/31323
From-SVN: r241304
While we're at it, update the runtime/debug package, and start running
its testsuite by default. I'm not sure why runtime/debug was not
previously updated to 1.7. Doing that led me to fix some minor aspects
of runtime.Stack and the C function runtime/debug.readGCStats.
Reviewed-on: https://go-review.googlesource.com/31251
From-SVN: r241261
Fix handling of function values for -fgo-c-header to generate FuncVal*,
not simply FuncVal.
While we're here change runtime.nanotime to use clock_gettime with
CLOCK_MONOTONIC, rather than gettimeofday. This is what the gc library
does. It provides nanosecond precision and a monotonic clock.
Reviewed-on: https://go-review.googlesource.com/31232
From-SVN: r241197
Also create a gccgo version of some of the traceback code in
traceback_gccgo.go, replacing some code currently in C.
This required modifying the compiler so that when compiling the runtime
package a slice expression does not cause a local array variable to
escape to the heap.
Reviewed-on: https://go-review.googlesource.com/31230
From-SVN: r241189
In order to port stack backtraces to Go, we need the ability to look up
file/line information for PC values without allocating memory. This
patch moves the handling of Func from C code to Go code, and simplifies
the C code to just look up function/file/line/entry information for a PC.
Reviewed-on: https://go-review.googlesource.com/31150
From-SVN: r241172
This replaces runtime/cpuprof.goc with go/runtime/cpuprof.go and adjusts
the supporting code in runtime/proc.c.
This adds another case where the compiler needs to avoid heap allocation
in the runtime package: when evaluating a method expression into a
closure. Implementing this required moving the relevant code from
do_get_backend to do_flatten, so that I could easily add a temporary
variable. Doing that let me get rid of Bound_method_expression::do_lower.
Reviewed-on: https://go-review.googlesource.com/31050
From-SVN: r241163
This replaces mem.go and the C runtime_ReadMemStats function with the Go
1.7 mstats.go.
The GCStats code is commented out for now. The corresponding gccgo code
is in runtime/mgc0.c.
The variables memstats and worldsema are shared between the Go code and
the C code, but are not exported. To make this work, add temporary
accessor functions acquireWorldsema, releaseWorldsema, getMstats (the
latter known as mstats in the C code).
Check the preemptoff field of m when allocating and when considering
whether to start a GC. This works with the new stopTheWorld and
startTheWorld functions in Go, which are essentially the Go 1.7
versions.
Change the compiler to stack allocate closures when compiling the
runtime package. Within the runtime packages closures do not escape.
This is similar to what the gc compiler does, except that the gc
compiler, when compiling the runtime package, gives an error if escape
analysis shows that a closure does escape. I added this here because
the Go version of ReadMemStats calls systemstack with a closure, and
having that allocate memory was causing some tests that measure memory
allocations to fail.
Reviewed-on: https://go-review.googlesource.com/30972
From-SVN: r241124
Add compiler support for turning concatenating strings into a call to
a runtime function that takes the appropriate number of arguments.
Rename some local variables in mgc0.c to avoid macros that the new
rune.go causes to appear in runtime.inc.
Reviewed-on: https://go-review.googlesource.com/30827
From-SVN: r241074
This triggered a check in releaseSudog that g.param not nil, because
libgo uses the param field when starting a goroutine. Fixed by clearing
g->param in kickoff in proc.c.
Reviewed-on: https://go-review.googlesource.com/30951
From-SVN: r241067
Since sparc is a valid architecture, the name of
getrandom_linux_sparc.go means that it will be ignored on sparc64,
even though it's whitelisted with a +build line.
On SPARC, clone has a unique return value convention which requires
some inline assembly to convert it to the normal convention.
Reviewed-on: https://go-review.googlesource.com/30873
From-SVN: r241051
Update the compiler to use the new names. Add calls to printlock and
printunlock around print statements. Move expression evaluation before
the call to printlock. Update g's writebuf field to a slice, and adjust
C code accordingly.
Reviewed-on: https://go-review.googlesource.com/30717
From-SVN: r240958
Update the compiler to use the new names. Add calls to printlock and
printunlock around print statements. Move expression evaluation before
the call to printlock. Update g's writebuf field to a slice, and adjust
C code accordingly.
Reviewed-on: https://go-review.googlesource.com/30717
From-SVN: r240956
Change the compiler to use the new routines. Drop the separation of
small and large values when sending on a channel. Allocate the select
struct on the stack. Remove the old C implementation of channels. Adjust
the garbage collector for the new data structure.
Bring in part of the tracing code, enough for the channel code to call.
Bump the permitted number of allocations in one of the tests in
context_test.go. The difference is that now receiving from a channel
allocates a sudog, which the C code used to simply put on the
stack. This will be somewhat better when we port proc.go.
Reviewed-on: https://go-review.googlesource.com/30714
From-SVN: r240941
PR go/77809
libgo: strip most C macros from runtime.inc
The Go runtime package is picking up C macros from runtime_sysinfo.go
and then re-exporting them to runtime.inc. This can cause name
conflicts. Change the Makefile so that we only put the macros we need
into runtime.inc. These are the constants that are actually defined by
Go code, not runtime_sysinfo.go. There are only a few, so we can
pattern match.
This is an additional hack on runtime.inc. The long term goal is to
convert the runtime package to Go and eliminate runtime.inc entirely, so
a few hacks seem acceptable.
Fixes GCC PR 77809.
Reviewed-on: https://go-review.googlesource.com/30167
From-SVN: r240724
Remove the old locking code written in C.
Add a shell script mkrsysinfo.sh to generate the runtime_sysinfo.go
file, so that we can get Go copies of the system time structures and
other types.
Tweak the compiler so that when compiling the runtime package the
address operator does not cause local variables to escape. When the gc
compiler compiles the runtime, an escaping local variable is treated as
an error. We should implement that, instead of this change, when escape
analysis is turned on.
Tweak the compiler so that the generated C header does not include names
that start with an underscore followed by a non-upper-case letter,
except for the special cases of _defer and _panic. Otherwise we
translate C types to Go in runtime_sysinfo.go and then generate those Go
types back as C types in runtime.inc, which is useless and painful for
the C code.
Change entersyscall and friends to take a dummy argument, as the gc
versions do, to simplify calls from the shared code.
Reviewed-on: https://go-review.googlesource.com/30079
From-SVN: r240657
Also copy over cputicks.go, env_posix.go, vdso_none.go, stubs2.go, and a
part of os_linux.go. Remove the corresponding functions from the C code
in libgo/go/runtime. Add some transitional support functions to
stubs.go. This converts several minor functions from C to Go.
Reviewed-on: https://go-review.googlesource.com/29962
From-SVN: r240609
Tweak the makefile rules for the runtime/check test to
insure that the runtime package is compiled with
"-fgo-compiling-runtime". This resolves a test failure
(unsat on runtime.getcallerpc) when in a build directory where the
compiler flags have been configured to disable optimization.
Reviewed-on: https://go-review.googlesource.com/30010
From-SVN: r240588
This is a step toward a version of mksysinfo that generates information
for the runtime package. This will be used to generate the
runtime_sysinfo.go file, which is currently directly generated by a
Makefile target.
Reviewed-on: https://go-review.googlesource.com/29683
From-SVN: r240560
This change removes the gccgo-specific hashmap code and replaces it with
the hashmap code from the Go 1.7 runtime. The Go 1.7 hashmap code is
more efficient, does a better job on details like when to update a key,
and provides some support against denial-of-service attacks.
The compiler is changed to call the new hashmap functions instead of the
old ones.
The compiler now tracks which types are reflexive and which require
updating when used as a map key, and records the information in map type
descriptors.
Map_index_expression is simplified. The special case for a map index on
the right hand side of a tuple expression has been unnecessary for some
time, and is removed. The support for specially marking a map index as
an lvalue is removed, in favor of lowering an assignment to a map index
into a function call. The long-obsolete support for a map index of a
pointer to a map is removed.
The __go_new_map_big function (known to the compiler as
Runtime::MAKEMAPBIG) is no longer needed, as the new runtime.makemap
function takes an int64 hint argument.
The old map descriptor type and supporting expression is removed.
The compiler was still supporting the long-obsolete syntax `m[k] = 0,
false` to delete a value from a map. That is now removed, requiring a
change to one of the gccgo-specific tests.
The builtin len function applied to a map or channel p is now compiled
as `p == nil ? 0 : *(*int)(p)`. The __go_chan_len function (known to
the compiler as Runtime::CHAN_LEN) is removed.
Support for a shared zero value for maps to large value types is
introduced, along the lines of the gc compiler. The zero value is
handled as a common variable.
The hash function is changed to take a seed argument, changing the
runtime hash functions and the compiler-generated hash functions.
Unlike the gc compiler, both the hash and equal functions continue to
take the type length.
Types that can not be compared now store nil for the hash and equal
functions, rather than pointing to functions that throw. Interface hash
and comparison functions now check explicitly for nil. This matches the
gc compiler and permits a simple implementation for ismapkey.
The compiler is changed to permit marking struct and array types as
incomparable, meaning that they have no hash or equal function. We use
this for thunk types, removing the existing special code to avoid
generating hash/equal functions for them.
The C runtime code adds memclr, memequal, and memmove functions.
The hashmap code uses go:linkname comments to make the functions
visible, as otherwise the compiler would discard them.
The hashmap code comments out the unused reference to the address of the
first parameter in the race code, as otherwise the compiler thinks that
the parameter escapes and copies it onto the heap. This is probably not
needed when we enable escape analysis.
Several runtime map tests that ere previously skipped for gccgo are now
run.
The Go runtime picks up type kind information and stubs. The type kind
information causes the generated runtime header file to define some
constants, including `empty`, and the C code is adjusted accordingly.
A Go-callable version of runtime.throw, that takes a Go string, is
added to be called from the hashmap code.
Reviewed-on: https://go-review.googlesource.com/29447
* go.go-torture/execute/map-1.go: Replace old map deletion syntax
with call to builtin delete function.
From-SVN: r240334
PR go/77642
runtime: pass correct type to __splitstack_find
The code was passing uintptr* to a function that expected size_t*.
Based on patch by Andreas Krebbel.
Fixes GCC PR 77642.
Reviewed-on: https://go-review.googlesource.com/29433
From-SVN: r240275
Copy over the Go 1.7 runtime/internal/sys package, but instead of having
separate files for each GOARCH and GOOS value, set the values in
configure.ac and write them out in Makefile.am. Setting the values in
configure.ac should make it easier to add new processors.
Remove the automake GOARCH conditionals, which are no longer used.
Leave the GOOS conditionals for now, as they are used for the C runtime
package.
Reviewed-on: https://go-review.googlesource.com/29018
From-SVN: r240083
Copy over the Go 1.7 runtime/internal/atomic package, but implement the
functions in C using __atomic functions rather than using the
processor-specific assembler code.
Reviewed-on: https://go-review.googlesource.com/29010
From-SVN: r240070
The definition and most uses of MAKECONTEXT_STACK_TOP were removed in
https://golang.org/cl/88660043, which removed support for Solaris 8/9.
One use of MAKECONTEXT_STACK_TOP was accidentally left in the source
code. Remove it now.
Reviewed-on: https://go-review.googlesource.com/28911
From-SVN: r240045
Some systems, such as ia64 and PPC, require that a ucontext_t pointer
passed to getcontext and friends be aligned to a 16-byte boundary.
Currently the ucontext_t fields in the g structure are defined in Go,
and Go has no way to ensure a 16-byte alignment for a struct field.
The fields are currently represented by an array of unsafe.Pointer.
Enforce the alignment by making the array larger, and picking an offset
into the array that is 16-byte aligned.
Reviewed-on: https://go-review.googlesource.com/28910
From-SVN: r240044
The default stack size for the gsignal goroutine, 32K, is not enough on
ia64. Make sure that the stack size is at least SIGSTKSZ.
Reviewed-on: https://go-review.googlesource.com/28224
From-SVN: r239894
Use the new -fgo-c-header option to build a header file for the Go
runtime code in libgo/go/runtime, and use the new header file in the C
runtime code in libgo/runtime. This will ensure that the Go code and C
code share the same data structures as we convert the runtime from C to
Go.
The new file libgo/go/runtime/runtime2.go is copied from the Go 1.7
release, and then edited to remove unnecessary data structures and
modify others for use with libgo.
The new file libgo/go/runtime/mcache.go is an initial version of the
same files in the Go 1.7 release, and will be replaced by the Go 1.7
file when we convert to the new memory allocator.
The new file libgo/go/runtime/type.go describes the gccgo version of the
reflection data structures, and replaces the Go 1.7 runtime file which
describes the gc version of those structures.
Using the new header file means changing a number of struct fields to
use Go naming conventions (that is, no underscores) and to rename
constants to have a leading underscore so that they are not exported
from the Go package. These names were updated in the C code.
The C code was also changed to drop the thread-local variable m, as was
done some time ago in the gc sources. Now the m field is always
accessed using g->m, where g is the single remaining thread-local
variable. This in turn required some adjustments to set g->m correctly
in all cases.
Also pass the new -fgo-compiling-runtime option when compiling the
runtime package, although that option doesn't do anything yet.
Reviewed-on: https://go-review.googlesource.com/28051
From-SVN: r239872
The go/build package does not know that gccgo's standard packages don't
have source, and will report an error saying that it can not find them.
Work around that in the cmd/go sources, since the go/build sources don't
currently have a list of standard packages.
This should get a real fix in the master sources, somehow.
Fixesgolang/go#16701.
Reviewed-on: https://go-review.googlesource.com/27052
From-SVN: r239486
Reportedly ksh fails to unset a variable that was not previously set.
Change match.sh and gotest to not unset LANG, but instead set LANG=C.
Also don't combine exporting and setting variable in a single statement.
Reviewed-on: https://go-review.googlesource.com/26999
From-SVN: r239443
These files are used to select s390x assembler support in the gc
toolchain. We don't currently have that support, as it is written in
the cmd/asm syntax rather than gas syntax. Mark the files to be ignored
for now, falling back to the default implementations.
Patch by Andreas Krebbel.
Reviewed-on: https://go-review.googlesource.com/26994
From-SVN: r239442
We want to build dir_regfile.go if not GNU/linux, and not solaris/386,
and not solaris/sparc. The latter two conditions were incorrect. To
write ! solaris/386 we have to write !solaris !386. I forgot De
Morgan's Law.
Reviewed-on: https://go-review.googlesource.com/26870
From-SVN: r239393
CLONE_NEWNET is needed to compile the syscall tests on GNU/Linux.
The symbol is not defined in the CentOS 5.11 header files.
Patch from Uros Bizjak.
Reviewed-on: https://go-review.googlesource.com/26630
From-SVN: r239296
We already lowered the limit of recursive template invocations from
100,000 to 10,000, but the tests still fail occasionally on
x86_64-pc-linux-gnu when using GNU ld (so that split stacks are not
fully functional). Reduce the limit further, to 1000, enough so that
the test passes consistently.
Permitting 1000 recursive template invocations still seems capacious
enough for real world use.
Reviewed-on: https://go-review.googlesource.com/25590
From-SVN: r239261
Having each .lo depend on the corresponding .lo.dep caused too many
rebuilds, because the .lo.dep files are rebuilt when Makefile changes.
Instead, if the .lo.dep file changes, remove the .lo file.
Reviewed-on: https://go-review.googlesource.com/25588
From-SVN: r239258
The recent changes to Makefile.am mean that if you configure with an
absolute path as srcdir then gotest will be invoked with absolute paths
for the files. That case never worked. This patch fixes it.
Reviewed-on: https://go-review.googlesource.com/25587
From-SVN: r239256
PR go/72814
runtime: treat zero-sized result value as void
Change the FFI interface to treat a call to a function that returns a
zero-sized result as a call to a function that returns void.
This is part of the fix for https://gcc.gnu.org/PR72814. On 32-bit
SPARC systems, a call to a function that returns a non-zero-sized struct
is followed by an unimp instruction that describes the size of the
struct. The function returns to the address after the unimp
instruction. The libffi library can not represent a zero-sized struct,
so we wind up treating it as a 1-byte struct. Thus in that case libffi
calls the function with an unimp instruction, but the function does not
adjust the return address. The result is that the program attempts to
execute the unimp instruction, causing a crash.
This is part of a change that fixes the crash by treating all functions
that return zero bytes as functions that return void.
Reviewed-on: https://go-review.googlesource.com/25585
* go-gcc.cc (Gcc_backend::function_type): If the return type is
zero bytes, treat the function as returning void.
(return_statement): If the return type is zero bytes, don't
actually return any values.
From-SVN: r239252
Also change the configure script to set GOARCH correctly for ia64, and
add ia64 as a processor to match.sh and gotest.
Reviewed-on: https://go-review.googlesource.com/25549
From-SVN: r239225
Previously the libgo Makefile explicitly listed the set of files to
compile for each package. For packages that use build tags, this
required a lot of awkward automake conditionals in the Makefile.
This CL changes the build to look at the build tags in the files.
The new shell script libgo/match.sh does the matching. This required
adjusting a lot of build tags, and removing some files that are never
used. I verified that the exact same sets of files are compiled on
amd64 GNU/Linux. I also tested the build on i386 Solaris.
Writing match.sh revealed some bugs in the build tag handling that
already exists, in a slightly different form, in the gotest shell
script. This CL fixes those problems as well.
The old code used automake conditionals to handle systems that were
missing strerror_r and wait4. Rather than deal with those in Go, those
functions are now implemented in runtime/go-nosys.c when necessary, so
the Go code can simply assume that they exist.
The os testsuite looked for dir_unix.go, which was never built for gccgo
and has now been removed. I changed the testsuite to look for dir.go
instead.
Reviewed-on: https://go-review.googlesource.com/25546
From-SVN: r239189
Ian Lance Taylor
Ian Lance Taylor
Ian Lance Taylor