[memprof] Report an error when buildid and profile do not match

[zcfh]

Problem

When the build ids of the profile and binary do not match, the error reported by llvm-profdata is no entries in callstack map after symbolization, but the root cause of this problem is the build id mismatch.

Trigger scenario

For example, when performing memprof optimization on clang, rawprofile is collected through ninja clang. In addition to running clang, some other programs will also be executed, and these programs will also generate rawprofile. When no entries in callstack map after symbolization appears during llvm-profdata merge, users may mistakenly think that the instrumentation failed or other reasons, and will not directly realize that the binary and profile do not match.

Changed

Currently, when the build id does not match, an assert error is triggered only in debug mode. Change it to directly return an error when the build id does not match.

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[llvmbot]

@llvm/pr-subscribers-pgo

Author: None (zcfh)

Changes

Problem

When the build ids of the profile and binary do not match, the error reported by llvm-profdata is no entries in callstack map after symbolization, but the root cause of this problem is the build id mismatch.

Trigger scenario

For example, when performing memprof optimization on clang, rawprofile is collected through ninja clang. In addition to running clang, some other programs will also be executed, and these programs will also generate rawprofile. When no entries in callstack map after symbolization appears during llvm-profdata merge, users may mistakenly think that the instrumentation failed or other reasons, and will not directly realize that the binary and profile do not match.

Changed

Currently, when the build id does not match, an assert error is triggered only in debug mode. Change it to directly return an error when the build id does not match.

---

Full diff: https://github.com/llvm/llvm-project/pull/132504.diff

2 Files Affected:

• (modified) llvm/lib/ProfileData/MemProfReader.cpp (+5-1)
• (modified) llvm/test/tools/llvm-profdata/memprof-buildid.test (+6)

diff --git a/llvm/lib/ProfileData/MemProfReader.cpp b/llvm/lib/ProfileData/MemProfReader.cpp
index 16502a4f1e8af..c57f9b22273d4 100644
--- a/llvm/lib/ProfileData/MemProfReader.cpp
+++ b/llvm/lib/ProfileData/MemProfReader.cpp
@@ -444,7 +444,11 @@ Error RawMemProfReader::setupForSymbolization() {
       ProfiledTextSegmentEnd = Entry.End;
     }
   }
-  assert(NumMatched != 0 && "No matching executable segments in segment info.");
+  if (NumMatched == 0)
+    return make_error<StringError>(
+        Twine("No matching executable segments found in binary ") +
+            Binary.getBinary()->getFileName(),
+        inconvertibleErrorCode());
   assert((PreferredTextSegmentAddress == 0 ||
           (PreferredTextSegmentAddress == ProfiledTextSegmentStart)) &&
          "Expect text segment address to be 0 or equal to profiled text "
diff --git a/llvm/test/tools/llvm-profdata/memprof-buildid.test b/llvm/test/tools/llvm-profdata/memprof-buildid.test
index a5abe6ea7dcb6..d604d18df61ad 100644
--- a/llvm/test/tools/llvm-profdata/memprof-buildid.test
+++ b/llvm/test/tools/llvm-profdata/memprof-buildid.test
@@ -14,3 +14,9 @@ CHECK: Build ID: [[ID:[[:xdigit:]]+]]
 
 COM: Then match it with the profdata output.
 CHECK-COUNT-1: BuildId: {{.*}}[[ID]]
+
+Test that profile build id does not match build id in the binary
+RUN: not llvm-profdata show --memory %p/Inputs/buildid.memprofraw --profiled-binary %p/Inputs/basic.memprofexe -o - 2>&1 | FileCheck %s -check-prefix=BUILDID-NOT-MATCH
+RUN: not llvm-profdata merge %p/Inputs/buildid.memprofraw %p/Inputs/basic.memprofraw  --profiled-binary %p/Inputs/basic.memprofexe -o %t4.prof 2>&1 | FileCheck %s -check-prefix=BUILDID-NOT-MATCH
+
+BUILDID-NOT-MATCH: No matching executable segments found in binary

[teresajohnson]

lgtm - thanks for the fix!