Backport https://golang.org/cl/163237 from the master library:
Ensure that cmd/go consistently calls base.Exit rather than os.Exit,
so that we don't incorrectly leave the work directory around on exit.
Test this by modifying the testsuite to run all the tests with TMPDIR
set to a temporary directory, and then check that no files are left
behind in that temporary directory. Adjust a couple of tests to make
this approach work.
Updates https://gcc.gnu.org/PR89406
Reviewed-on: https://go-review.googlesource.com/c/163198
From-SVN: r269086
In signal-triggered stack scan, if the signal is delivered at
certain bad time (e.g. in vdso, or in the middle of setcontext?),
the unwinder may not be able to unwind the whole stack, while it
still reports _URC_END_OF_STACK. So we cannot rely on _URC_END_OF_STACK
to tell if it successfully scanned the stack. Instead, we check
the last Go frame to see it actually reached the end of the stack.
For Go-created stack, this is runtime.kickoff. For C-created
stack, we need to record the outermost Go frame when it enters
the Go side.
Also we cannot unwind the stack if the signal is delivered in the
middle of runtime.gogo, halfway through a goroutine switch, where
the g and the stack don't match. Give up in this case as well.
Reviewed-on: https://go-review.googlesource.com/c/159098
From-SVN: r269018
Currently, the compiler lowers runtime.getcallersp to
__builtin_frame_address(1). In the C side of the runtime,
getcallersp is defined as __builtin_frame_address(0). They don't
match. Further, neither of them actually returns the caller's SP.
On AMD64, __builtin_frame_address(0) just returns the frame
pointer. __builtin_frame_address(1) returns the memory content
where the frame pointer points to, which is typically the
caller's frame pointer but can also be garbage if the frame
pointer is not enabled.
This CL changes it to use __builtin_dwarf_cfa(), which returns
the caller's SP at the call site. This matches the SP we get
from unwinding the stack.
Currently getcallersp is not used for anything real. It will be
used for precise stack scan (a new version of CL 159098).
Reviewed-on: https://go-review.googlesource.com/c/162905
* go-gcc.cc (Gcc_backend::Gcc_backend): Define __builtin_dwarf_cfa
instead of __builtin_frame_address.
From-SVN: r268952
Compiling with LTO revealed a number of cases in the runtime and
standard library where C and Go disagreed about the type of an object or
function (or where Go and code generated by the compiler disagreed). In
all cases the underlying representation was the same (e.g., uintptr vs.
void*), so this wasn't causing actual problems, but it did result in a
number of annoying warnings when compiling with LTO.
Reviewed-on: https://go-review.googlesource.com/c/160700
From-SVN: r268923
PR go/89168
libgo: change gotest to run examples with output
Change the gotest script to act like "go test" and run examples that
have "output" comments. This is not done with full generality, but
just enough to run the libgo tests. Other packages should be tested
with "go test" as usual.
While we're here clean up some old bits of gotest, and only run
TestXXX functions that are actually in *_test.go files. The latter
change should fix https://gcc.gnu.org/PR89168.
Reviewed-on: https://go-review.googlesource.com/c/162139
From-SVN: r268922
Also stop converting st_dev on Hurd; it shouldn't appear, but if it
somehow does we don't want to convert it.
Reviewed-on: https://go-review.googlesource.com/c/161961
From-SVN: r268785
PR go/89199
sync/atomic: use strong form of atomic_compare_exchange_n
In the recent change to use atomic_compare_exchange_n I thought we
could use the weak form, which can spuriously fail. But that is not
how it is implemented in the gc library, and it is not what the rest
of the library expects.
Thanks to Lynn Boger for identifying the problem.
Fixes https://gcc.gnu.org/PR89199
Reviewed-on: https://go-review.googlesource.com/c/161359
From-SVN: r268591
GCC has supported the __atomic intrinsics since 4.7. They are better
than the __sync intrinsics in that they specify a memory model and,
more importantly for our purposes, they are reliably implemented
either in the compiler or in libatomic.
Fixes https://gcc.gnu.org/PR52084
Reviewed-on: https://go-review.googlesource.com/c/160820
From-SVN: r268458
If sigtramp and sigtrampgo are both on stack, n -= framesToDiscard
is executed twice, which should actually run only once.
Reviewed-on: https://go-review.googlesource.com/c/159238
From-SVN: r268366
If a panic happens in the runtime we turn that into a fatal error.
We use the caller's PC to determine if the panic call is inside
the runtime. getcallerpc returns the PC immediately after the
call instruction. If the call is the very last instruction of a
function, it may not find this PC belong to a runtime function,
giving false result. We need to back off the PC by 1 to the call
instruction.
The gc runtime doesn't do this because the gc compiler always
emit an instruction following a panic call, presumably an UNDEF
instruction which turns into an architecture-specific illegal
instruction. Our compiler doesn't do this.
Reviewed-on: https://go-review.googlesource.com/c/159437
From-SVN: r268358
Precise stack scan uses SIGURG to trigger a stack scan. We need
to have Go signal handler installed for SIGURG.
Reviewed-on: https://go-review.googlesource.com/c/159097
From-SVN: r268230
For the gofrontend copy, change calls to types.SizesFor to pass
"gccgo" rather than "gc". Leave the asmdecl pass unchanged since that
pass is gc-specific anyhow.
This has been fixed in a better way in the external repo by
https://golang.org/cl/158317 and friends, but that is not in 1.12, so
use this approach for now.
Reviewed-on: https://go-review.googlesource.com/c/158842
From-SVN: r268153
PR go/88927
runtime, internal/cpu: fix build for ARM GNU/Linux
Was failing with
../../../libgo/go/internal/cpu/cpu.go:138:2: error: reference to undefined name 'doinit'
138 | doinit()
| ^
Fix it by adding in Go 1.12 internal/cpu/cpu_arm.go, and the code in
runtime that initializes the values.
Fixes https://gcc.gnu.org/PR88927.
Reviewed-on: https://go-review.googlesource.com/c/158717
From-SVN: r268131
Restore some of the fixes that were applied to golang_org/x/net/lif
but were lost when 1.12 moved the directory to internal/x/net/lif.
Add support for reading /proc to fetch argc/argv/env for c-archive mode.
Reviewed-on: https://go-review.googlesource.com/c/158640
From-SVN: r268130
Reviewed-on: https://go-review.googlesource.com/c/158019
gotools/:
* Makefile.am (go_cmd_vet_files): Update for Go1.12beta2 release.
(GOTOOLS_TEST_TIMEOUT): Increase to 600.
(check-runtime): Export LD_LIBRARY_PATH before computing GOARCH
and GOOS.
(check-vet): Copy golang.org/x/tools into check-vet-dir.
* Makefile.in: Regenerate.
gcc/testsuite/:
* go.go-torture/execute/names-1.go: Stop using debug/xcoff, which
is no longer externally visible.
From-SVN: r268084
Currently, we dropg (which clears gp.m) after we CAS the g status
to _Grunnable or _Gwaiting. Immediately after CASing the g status,
another thread may CAS it to _Gscan status and scan its stack.
With precise stack scan, it accesses gp.m in order to switch to g
and back (in doscanstackswitch). This races with dropg. If
doscanstackswitch reads gp.m, then dropg runs, when we restore
the m at the end of the scan it will set to a stale value. Worse,
if dropg runs after doscanstackswitch sets the new m, gp will be
running with a nil m.
To fix this, we do dropg before CAS g status to _Grunnable or
_Gwaiting. We can do this safely if we are CASing from _Grunning,
as we own the g when it is in _Grunning. There is one case where
we CAS from _Gsyscall to _Grunnable. It is not safe to dropg when
it is in _Gsyscall, as precise stack scan needs to read gp.m in
order to signal the m. So we need to introduce a transient state,
_Gexitingsyscall, between _Gsyscall and _Grunnable, where the GC
should not scan its stack.
In is a little unfortunate that we have to add another g status.
We could reuse an existing one (e.g. _Gcopystack), but it is
clearer and safer to just use a new one, as Austin suggested.
Reviewed-on: https://go-review.googlesource.com/c/158157
From-SVN: r268001
Many C syscall functions take pointer arguments. The pointers
don't escape in the C functions. Mark the C functions noescape so
calling them doesn't need allocation.
Reviewed-on: https://go-review.googlesource.com/c/158158
From-SVN: r267989
CL 157557 changes the compiler to add one byte padding to
non-empty struct ending with a zero-sized field. Add the same
padding to the FFI type, so reflect.Call works.
This fixes test/fixedbugs/issue26335.go in the main repo.
Reviewed-on: https://go-review.googlesource.com/c/158018
From-SVN: r267956
This ports https://golang.org/cl/155918 from the master repo.
runtime: panic on uncomparable map key, even if map is empty
Reorg map flags a bit so we don't need any extra space for the extra flag.
This is a pre-req for updating libgo to the Go 1.12beta2 release.
Reviewed-on: https://go-review.googlesource.com/c/157858
From-SVN: r267950
This is following CL 156038. doscanstackswitch uses the same
mechanism of switching goroutines as getTraceback, and so has
the same problem as described in issue golang/go#29448. This CL
applies the same fix.
Reviewed-on: https://go-review.googlesource.com/c/156697
From-SVN: r267661
This is the gccgo version of https://golang.org/cl/141822:
Only return a pointer p to the new slices backing array from makeslice.
Makeslice callers then construct sliceheader{p, len, cap} explictly
instead of makeslice returning the slice.
This change caused the GCC backend to break the runtime/pprof test by
merging together the identical functions allocateReflectTransient and
allocateTransient2M. This caused the traceback to be other than
expected. Fix that by making the functions not identical.
This is a step toward updating libgo to the Go1.12beta1 release.
Reviewed-on: https://go-review.googlesource.com/c/155937
From-SVN: r267660
Currently, when collecting a traceback for another goroutine,
getTraceback calls gogo(gp) switching to gp, which will resume in
mcall, which will call gtraceback, which will set up gp->m. There
is a gap between setting the current running g to gp and setting
gp->m. If a profiling signal arrives in between, sigtramp will
see a non-nil gp with a nil m, and will seg fault. Fix this by
setting up gp->m first.
Fixesgolang/go#29448.
Reviewed-on: https://go-review.googlesource.com/c/156038
From-SVN: r267658
Traceback routines, e.g. callers and funcentry, may call
__go_get_backtrace_state. If a profiling signal arrives while we
are in the critical section of __go_get_backtrace_state, it tries
to do a traceback, which also calls __go_get_backtrace_state,
which tries to enter the same critical section and will deadlock.
Prevent this deadlock by setting up runtime_in_callers before
calling __go_get_backtrace_state.
Found while investigating golang/go#29448. Will add a test in the
next CL.
Updates golang/go#29448.
Reviewed-on: https://go-review.googlesource.com/c/156037
From-SVN: r267590
Precise stack scan needs to unwind the stack. When it is
unwinding the stack, if a profiling signal arrives, which also
does a traceback, it may deadlock in dl_iterate_phdr. Prevent
this deadlock by setting up runtime_in_callers before traceback.
Reviewed-on: https://go-review.googlesource.com/c/155766
From-SVN: r267457
On ARM32 EABI, unlike other platforms, the personality function is
called during _Unwind_Backtrace (libgcc/unwind-arm-common.inc:581).
In this case, simply unwind the frame without returning any
handlers. Otherwise traceback will loop if there is a frame with
a defer on stack.
Reviewed-on: https://go-review.googlesource.com/c/155759
From-SVN: r267434
On ARM32 EABI, when the "compact" unwinding model is used, it
does not have standard LSDA and _Unwind_GetLanguageSpecificData
will not return data that is parseable by us. Check this
conditon before calling _Unwind_GetLanguageSpecificData.
Fix ARM32 build.
Reviewed-on: https://go-review.googlesource.com/c/155758
From-SVN: r267428
The type table encoding can be DW_EH_PE_absptr, but this case
was missing, which was causing abort on ARM32 EABI. Add the
missing case.
Reviewed-on: https://go-review.googlesource.com/c/153857
From-SVN: r267070
