forked from OSchip/llvm-project
25c30324e9
We generate symbols like `profc`/`profd` for each function, and put them into csects. When there are weak functions, we generate weak symbols for the functions as well, with ELF (and some others), linker (binder) will discard and only keep one copy of the weak symbols. However, on AIX, the current binder can NOT discard the weak symbols if we put all of them into the same csect, as binder can NOT discard a subset of a csect. This creates a unique challenge for using those symbols to calculate some relative offsets. This patch changed the linkage of `profc`/`profd` symbols to be private, so that all the profc/profd for each weak symbol will be *local* to objects, and all kept in the csect, so we won't have problem. Although only one of the counters will be used, all the pointer in the profd is correct. The downside is that we won't be able to discard the duplicated counters and profile data, but those can not be discarded even if we keep the weak linkage, due to the binder limitation of not discarding a subsect of the csect either . Reviewed By: Whitney, MaskRay Differential Revision: https://reviews.llvm.org/D110422 |
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| .. | ||
| Inputs | ||
| README | ||
| branch-logical-mixed.cpp | ||
| branch-profdup.cpp | ||
| c-avoid-direct-call.c | ||
| c-captured.c | ||
| c-collision.c | ||
| c-counter-overflows.c | ||
| c-general.c | ||
| c-generate.c | ||
| c-indirect-call.c | ||
| c-linkage-available_externally.c | ||
| c-linkage.c | ||
| c-outdated-data.c | ||
| c-ternary.c | ||
| c-unprofiled-blocks.c | ||
| c-unprofiled.c | ||
| c-unreachable-after-switch.c | ||
| coverage-prefix-map.c | ||
| cxx-abc-deleting-dtor.cpp | ||
| cxx-class.cpp | ||
| cxx-hash-v2.cpp | ||
| cxx-implicit.cpp | ||
| cxx-indirect-call.cpp | ||
| cxx-lambda.cpp | ||
| cxx-linkage.cpp | ||
| cxx-missing-bodies.cpp | ||
| cxx-rangefor.cpp | ||
| cxx-stmt-initializers.cpp | ||
| cxx-structors.cpp | ||
| cxx-templates.cpp | ||
| cxx-throws.cpp | ||
| cxx-virtual-destructor-calls.cpp | ||
| def-assignop.cpp | ||
| def-ctors.cpp | ||
| def-dtors.cpp | ||
| func-entry.c | ||
| gcc-flag-compatibility-aix.c | ||
| gcc-flag-compatibility.c | ||
| objc-general.m | ||
| profile-does-not-exist.c | ||
| profile-summary.c | ||
README
These are tests for instrumentation based profiling. This specifically means the -fprofile-instr-generate and -fprofile-instr-use driver flags. Tests in this directory should usually test both: - the generation of instrumentation (-fprofile-instr-generate), and - the use of profile data from instrumented runs (-fprofile-instr-use). In order to test -fprofile-instr-use without actually running an instrumented program, .profdata files are checked into Inputs/. The input source files must include a main function such that building with -fprofile-instr-generate and running the resulting program generates the same .profdata file that is consumed by the tests for -fprofile-instr-use. Even tests that only check -fprofile-instr-use should include such a main function, so that profile data can be regenerated as the .profdata file format evolves.