[PGO] Exposing PGO's Counter Reset and File Dumping APIs (#76471)

This PR exposes four PGO functions 

- `__llvm_profile_set_filename`
- `__llvm_profile_reset_counters`, 
- `__llvm_profile_dump` 
- `__llvm_orderfile_dump` 

to user programs through the new header `instr_prof_interface.h` under
`compiler-rt/include/profile`. This way, the user can include the header
`profile/instr_prof_interface.h` to introduce these four names to their
programs.

Additionally, this PR defines macro `__LLVM_INSTR_PROFILE_GENERATE` when
the program is compiled with profile generation, and defines macro
`__LLVM_INSTR_PROFILE_USE` when the program is compiled with profile
use. `__LLVM_INSTR_PROFILE_GENERATE` together with
`instr_prof_interface.h` define the PGO functions only when the program
is compiled with profile generation. When profile generation is off,
these PGO functions are defined away and leave no trace in the user's
program.

Background:
https://discourse.llvm.org/t/pgo-are-the-llvm-profile-functions-stable-c-apis-across-llvm-releases/75832

1 files changed, 1 insertions, 1 deletions

diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index 56bbef9..ea44a26 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -470,7 +470,7 @@ void CompilerInstance::createPreprocessor(TranslationUnitKind TUKind) {
 
   // Predefine macros and configure the preprocessor.
   InitializePreprocessor(*PP, PPOpts, getPCHContainerReader(),
-                         getFrontendOpts());
+                         getFrontendOpts(), getCodeGenOpts());
 
   // Initialize the header search object.  In CUDA compilations, we use the aux
   // triple (the host triple) to initialize our header search, since we need to