[PGO] Add runtime hook so that IR instrumentation can override version

IR level instrumentation needs to override version with variant bits.
No change for FE instrumentation is needed. Test case is added to
detect version mismatch.



git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@257230 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 23 insertions, 2 deletions

diff --git a/lib/profile/InstrProfiling.c b/lib/profile/InstrProfiling.c
index 58778aeec..711f2b608 100644
--- a/lib/profile/InstrProfiling.c
+++ b/lib/profile/InstrProfiling.c
@@ -18,6 +18,8 @@
 
 char *(*GetEnvHook)(const char *) = 0;
 
+COMPILER_RT_WEAK uint64_t __llvm_profile_raw_version = INSTR_PROF_RAW_VERSION;
+
 COMPILER_RT_VISIBILITY uint64_t __llvm_profile_get_magic(void) {
   return sizeof(void *) == sizeof(uint64_t) ? (INSTR_PROF_RAW_MAGIC_64)
                                             : (INSTR_PROF_RAW_MAGIC_32);
@@ -32,7 +34,7 @@ __llvm_profile_get_num_padding_bytes(uint64_t SizeInBytes) {
 }
 
 COMPILER_RT_VISIBILITY uint64_t __llvm_profile_get_version(void) {
-  return INSTR_PROF_RAW_VERSION;
+  return __llvm_profile_raw_version;
 }
 
 COMPILER_RT_VISIBILITY void __llvm_profile_reset_counters(void) {
@@ -65,4 +67,3 @@ COMPILER_RT_VISIBILITY void __llvm_profile_reset_counters(void) {
     }
   }
 }
-
diff --git a/lib/profile/InstrProfilingFile.c b/lib/profile/InstrProfilingFile.c
index bf50c0276..98d85d9c1 100644
--- a/lib/profile/InstrProfilingFile.c
+++ b/lib/profile/InstrProfilingFile.c
@@ -214,6 +214,15 @@ int __llvm_profile_write_file(void) {
     return -1;
   }
 
+  /* Check if there is llvm/runtime versino mismatch.  */
+  if (GET_VERSION(__llvm_profile_get_version()) != INSTR_PROF_RAW_VERSION) {
+    PROF_ERR("LLVM Profile: runtime and instrumentation version mismatch : "
+             "expected %d, but get %d\n",
+             INSTR_PROF_RAW_VERSION,
+             (int)GET_VERSION(__llvm_profile_get_version()));
+    return -1;
+  }
+
   /* Write the file. */
   rc = writeFileWithName(__llvm_profile_CurrentFilename);
   if (rc)
diff --git a/test/profile/instrprof-version-mismatch.c b/test/profile/instrprof-version-mismatch.c
new file mode 100644
index 000000000..49ce41177
--- /dev/null
+++ b/test/profile/instrprof-version-mismatch.c
@@ -0,0 +1,11 @@
+// RUN: %clang_profgen -o %t -O3 %s
+// RUN: LLVM_PROFILE_VERBOSE_ERRORS=1 %run %t 1 2>&1 | FileCheck %s
+
+// override the version variable with a bogus version:
+unsigned long long __llvm_profile_raw_version = 10000;
+int main(int argc, const char *argv[]) {
+  if (argc < 2)
+    return 1;
+  return 0;
+}
+// CHECK: LLVM Profile: runtime and instrumentation version mismatch