gcov is an "Edge Profiling with Edge Counters" application according to
Optimally Profiling and Tracing Programs (1994).
The minimum number of counters necessary is |E|-(|V|-1). The unmeasured edges
form a spanning tree. Both GCC --coverage and clang -fprofile-generate leverage
this optimization. This patch implements the optimization for clang --coverage.
The produced .gcda files are much smaller now.
As reported in Bug 42535, `clang` doesn't inline atomic ops on 32-bit
Sparc, unlike `gcc` on Solaris. In a 1-stage build with `gcc`, only two
testcases are affected (currently `XFAIL`ed), while in a 2-stage build more
than 100 tests `FAIL` due to this issue.
The reason for this `gcc`/`clang` difference is that `gcc` on 32-bit
Solaris/SPARC defaults to `-mpcu=v9` where atomic ops are supported, unlike
with `clang`'s default of `-mcpu=v8`. This patch changes `clang` to use
`-mcpu=v9` on 32-bit Solaris/SPARC, too.
Doing so uncovered two bugs:
`clang -m32 -mcpu=v9` chokes with any Solaris system headers included:
/usr/include/sys/isa_defs.h:461:2: error: "Both _ILP32 and _LP64 are defined"
#error "Both _ILP32 and _LP64 are defined"
While `clang` currently defines `__sparcv9` in a 32-bit `-mcpu=v9`
compilation, neither `gcc` nor Studio `cc` do. In fact, the Studio 12.6
`cc(1)` man page clearly states:
These predefinitions are valid in all modes:
[...]
__sparcv8 (SPARC)
__sparcv9 (SPARC -m64)
At the same time, the patch defines `__GCC_HAVE_SYNC_COMPARE_AND_SWAP_[1248]`
for a 32-bit Sparc compilation with any V9 cpu. I've also changed
`MaxAtomicInlineWidth` for V9, matching what `gcc` does and the Oracle
Developer Studio 12.6: C User's Guide documents (Ch. 3, Support for Atomic
Types, 3.1 Size and Alignment of Atomic C Types).
The two testcases that had been `XFAIL`ed for Bug 42535 are un-`XFAIL`ed
again.
Tested on `sparcv9-sun-solaris2.11` and `amd64-pc-solaris2.11`.
Differential Revision: https://reviews.llvm.org/D86621
Two tests `FAIL` on 32-bit sparc:
Profile-sparc :: Posix/instrprof-gcov-parallel.test
UBSan-Standalone-sparc :: TestCases/Float/cast-overflow.cpp
The failure mode is similar:
Undefined first referenced
symbol in file
__atomic_store_4 /var/tmp/instrprof-gcov-parallel-6afe8d.o
__atomic_load_4 /var/tmp/instrprof-gcov-parallel-6afe8d.o
Undefined first referenced
symbol in file
__atomic_load_1 /var/tmp/cast-overflow-72a808.o
This is a known bug: `clang` doesn't inline atomics on 32-bit sparc, unlike
`gcc`.
The patch therefore `XFAIL`s the tests.
Tested on `sparcv9-sun-solaris2.11` and `amd64-pc-solaris2.11`.
Differential Revision: https://reviews.llvm.org/D85346
... on systems where wait() isn't one of the declarations transitively included
via unistd.h (i.e. Darwin).
Differential Revision: https://reviews.llvm.org/D84207
GCC r187297 (2012-05) introduced `__gcov_dump` and `__gcov_reset`.
`__gcov_flush = __gcov_dump + __gcov_reset`
The resolution to https://gcc.gnu.org/PR93623 ("No need to dump gcdas when forking" target GCC 11.0) removed the unuseful and undocumented __gcov_flush.
Close PR38064.
Reviewed By: calixte, serge-sans-paille
Differential Revision: https://reviews.llvm.org/D83149
atexit registered functions run earlier so `__attribute__((destructor))`
annotated functions cannot be tracked.
Set a priority of 100 (compatible with GCC 7 onwards) to track
destructors and destructors whose priorities are greater than 100.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=7970
Reviewed By: calixte, marco-c
Differential Revision: https://reviews.llvm.org/D82253
It seems that after dc52ce424b, all big-endian problems have been fixed.
01899bb4e4 seems to have fixed XFAIL: * of
profile/instrprof-gcov-__gcov_flush-terminate.test
This essentially reverts commit 5a9b792d72 and
93d5ae3af1.
Fixes PR45673
The commit 9180c14fe4 (D76206) resolved only a part of the problem
of concurrent .gcda file creation. It ensured that only one process
creates the file but did not ensure that the process locks the
file first. If not, the process which created the file may clobber
the contents written by a process which locked the file first.
This is the cause of PR45673.
This commit prevents the clobbering by revising the assumption
that a process which creates the file locks the file first.
Regardless of file creation, a process which locked the file first
uses fwrite (new_file==1) and other processes use mmap (new_file==0).
I also tried to keep the creation/first-lock process same by using
mkstemp/link/unlink but the code gets long. This commit is more
simple.
Note: You may be confused with other changes which try to resolve
concurrent file access. My understanding is (may not be correct):
D76206: Resolve race of .gcda file creation (but not lock)
This one: Resolve race of .gcda file creation and lock
D54599: Same as D76206 but abandoned?
D70910: Resolve race of multi-threaded counter flushing
D74953: Resolve counter sharing between parent/children processes
D78477: Revision of D74953
Differential Revision: https://reviews.llvm.org/D79556
The intent of the `llvm_gcda_start_file` function is that only
one process create the .gcda file and initialize it to be updated
by other processes later.
Before this change, if multiple processes are started simultaneously,
some of them may initialize the file because both the first and
second `open` calls may succeed in a race condition and `new_file`
becomes 1 in those processes. This leads incorrect coverage counter
values. This often happens in MPI (Message Passing Interface) programs.
The test program added in this change is a simple reproducer.
This change ensures only one process creates/initializes the file by
using the `O_EXCL` flag.
Differential Revision: https://reviews.llvm.org/D76206
When the %m filename pattern is used, the filename is unique to each
image, so the cached value is wrong.
It struck me that the full filename isn't something that's recomputed
often, so perhaps it doesn't need to be cached at all. David Li pointed
out we can go further and just hide lprofCurFilename. This may regress
workflows that depend on using the set-filename API to change filenames
across all loaded DSOs, but this is expected to be very rare.
rdar://55137071
Differential Revision: https://reviews.llvm.org/D69137
llvm-svn: 375301
This test remains flaky everywhere, I think. We should consider deleting
it and accompanying support code in GCOVProfiling: I've stopped short of
doing that now as the gcov exec* tests appear to be stable.
See the thread re: r347779.
llvm-svn: 373121
These lit configuration files are really Python source code. Using the
.py file extension helps editors and tools use the correct language
mode. LLVM and Clang already use this convention for lit configuration,
this change simply applies it to all of compiler-rt.
Reviewers: vitalybuka, dberris
Differential Revision: https://reviews.llvm.org/D63658
llvm-svn: 364591
Summary:
Before this change, check-profile would run, but all tests would be
marked unsupported on Windows. This is the new status of 'check-profile'
after this change:
Testing Time: 6.66s
Expected Passes : 29
Expected Failures : 5
Unsupported Tests : 39
I moved many tests that exercise posix-y features like dlopen and DSOs
into the Posix subdirectory, and ran the tests on Linux to validate my
changes.
These are the remaining tests that I handled on a case by case basis:
- instrprof-path.c
Passes, Fixed some path portability issues
- instrprof-gcov-exceptions.test
Passes, the FileCheck actually succeeds on Windows, so I RUNX'd it
- instrprof-icall-promo.test
XFAILed, probably due to C++ ABI differences in vtables
- instrprof-merge-match.test
- instrprof-merge.c
- instrprof-merging.cpp
XFAILed, These seem like real bugs that need fixing
- instrprof-version-mismatch.c
XFAILed, Overriding the weak version symbol doesn't work
- instrprof-without-libc.c
UNSUPPORTED, test needs an executable symbol table, Windows has none
Reviewers: davidxl, wmi, void
Subscribers: fedor.sergeev, #sanitizers, llvm-commits
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D57853
llvm-svn: 353435
Summary: Remove the XFAIL for arm since it seems to be ok
Reviewers: marco-c
Reviewed By: marco-c
Subscribers: javed.absar, kristof.beyls, delcypher, chrib, llvm-commits, #sanitizers, sylvestre.ledru
Differential Revision: https://reviews.llvm.org/D54263
llvm-svn: 346409
Summary: instrprof-gcov-fork.test is failing with arm so mark it as XFAIL
Reviewers: marco-c
Reviewed By: marco-c
Subscribers: javed.absar, kristof.beyls, delcypher, chrib, llvm-commits, sylvestre.ledru, #sanitizers
Differential Revision: https://reviews.llvm.org/D54209
llvm-svn: 346329
Fangrui Song