Commit Graph

7 Commits

Author SHA1 Message Date
Anna Zaks 8ed1d8196b [asan] Skip promotable allocas to improve performance at -O0
Currently, the ASan executables built with -O0 are unnecessarily slow.
The main reason is that ASan instrumentation pass inserts redundant
checks around promotable allocas. These allocas do not get instrumented
under -O1 because they get converted to virtual registered by mem2reg.
With this patch, ASan instrumentation pass will only instrument non
promotable allocas, giving us a speedup of 39% on a collection of
benchmarks with -O0. (There is no measurable speedup at -O1.)

llvm-svn: 230724
2015-02-27 03:12:36 +00:00
Alexey Samsonov e595e1ade0 Remove top-level Clang -fsanitize= flags for optional ASan features.
Init-order and use-after-return modes can currently be enabled
by runtime flags. use-after-scope mode is not really working at the
moment.

The only problem I see is that users won't be able to disable extra
instrumentation for init-order and use-after-scope by a top-level Clang flag.
But this instrumentation was implicitly enabled for quite a while and
we didn't hear from users hurt by it.

llvm-svn: 210924
2014-06-13 17:53:44 +00:00
Alexander Potapenko 7aafd31dad [ASan] Add -asan-module to the ASan .ll tests.
After the -asan pass had been split into -asan (function-level) and -asan-module (module-level) some of the
tests have silently stopped working, because they didn't instrument the globals anymore.
We've decided to have every test using both passes, irrespective of the presence of globals in it.

llvm-svn: 204335
2014-03-20 11:16:34 +00:00
Alexey Samsonov a788b940f7 [ASan] Fix PR17867 - make sure ASan doesn't crash if use-after-scope and use-after-return are combined.
llvm-svn: 195014
2013-11-18 14:53:55 +00:00
Kostya Serebryany cf880b9443 Unify clang/llvm attributes for asan/tsan/msan (LLVM part)
These are two related changes (one in llvm, one in clang).
LLVM: 
- rename address_safety => sanitize_address (the enum value is the same, so we preserve binary compatibility with old bitcode)
- rename thread_safety => sanitize_thread
- rename no_uninitialized_checks -> sanitize_memory

CLANG: 
- add __attribute__((no_sanitize_address)) as a synonym for __attribute__((no_address_safety_analysis))
- add __attribute__((no_sanitize_thread))
- add __attribute__((no_sanitize_memory))

for S in address thread memory
If -fsanitize=S is present and __attribute__((no_sanitize_S)) is not
set llvm attribute sanitize_S

llvm-svn: 176075
2013-02-26 06:58:09 +00:00
Alexey Samsonov 29dd7f2090 [ASan] Fix lifetime intrinsics handling. Now for each intrinsic we check if it describes one of 'interesting' allocas. Assume that allocas can go through casts and phi-nodes before apperaring as llvm.lifetime arguments
llvm-svn: 171153
2012-12-27 08:50:58 +00:00
Alexey Samsonov 261177a1e1 ASan: add initial support for handling llvm.lifetime intrinsics in ASan - emit calls into runtime library that poison memory for local variables when their lifetime is over and unpoison memory when their lifetime begins.
llvm-svn: 169200
2012-12-04 01:34:23 +00:00