[compiler-rt] [clang-tools-extra] [clang] [llvm] [IRPGO][ValueProfile] Instrument virtual table address that could be used to do virtual table address comparision for indirect-call-promotion. (PR #66825)

[Mingming Liu via cfe-commits]

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@@ -123,19 +137,29 @@ static int needsCounterPadding(void) {
 COMPILER_RT_VISIBILITY
 void __llvm_profile_get_padding_sizes_for_counters(
     uint64_t DataSize, uint64_t CountersSize, uint64_t NumBitmapBytes,
-    uint64_t NamesSize, uint64_t *PaddingBytesBeforeCounters,
-    uint64_t *PaddingBytesAfterCounters, uint64_t *PaddingBytesAfterBitmapBytes,
-    uint64_t *PaddingBytesAfterNames) {
+    uint64_t NamesSize, uint64_t VTableSize, uint64_t VNameSize,
+    uint64_t *PaddingBytesBeforeCounters, uint64_t *PaddingBytesAfterCounters,
+    uint64_t *PaddingBytesAfterBitmapBytes, uint64_t *PaddingBytesAfterNames,
+    uint64_t *PaddingBytesAfterVTable, uint64_t *PaddingBytesAfterVName) {
+  // Counter padding is needed only if continuous mode is enabled.
   if (!needsCounterPadding()) {
     *PaddingBytesBeforeCounters = 0;
     *PaddingBytesAfterCounters =
         __llvm_profile_get_num_padding_bytes(CountersSize);
     *PaddingBytesAfterBitmapBytes =
         __llvm_profile_get_num_padding_bytes(NumBitmapBytes);
     *PaddingBytesAfterNames = __llvm_profile_get_num_padding_bytes(NamesSize);
+    if (PaddingBytesAfterVTable != NULL)
+      *PaddingBytesAfterVTable =
+          __llvm_profile_get_num_padding_bytes(VTableSize);
+    if (PaddingBytesAfterVName != NULL)
+      *PaddingBytesAfterVName = __llvm_profile_get_num_padding_bytes(VNameSize);
     return;
   }
 
+  // Value profiling not supported in continuous mode at profile-write time.
+  assert(VTableSize == 0 && VNameSize == 0 &&
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minglotus-6 wrote:

As discussed offline, changed this function to return -1 upon errors and return 0 upon success, and updated the caller `lprofWriteDataImpl` to propagated the error (if any) up along the call chain -> currently, the error is handled [at this place](https://github.com/llvm/llvm-project/blob/250d9c86c201799755611c425ce6e02fb5867716/compiler-rt/lib/profile/InstrProfilingFile.c#L1116) to emit " LLVM Profile Error: Failed to write file ..."

https://github.com/llvm/llvm-project/pull/66825