[PGO] Fix bogus warning for merging empty llvm profile file

Profile runtime can generate an empty raw profile (when there is no function in
the shared library). This empty profile is treated as a text format profile.  A
test format profile without the flag of "#IR" is thought to be a clang
generated profile.  So in llvm profile merging, we will get a bogus warning of
"Merge IR generated profile with Clang generated profile."

The fix here is to skip the empty profile (when the buffer size is 0) for
profile merge.

Reviewers: vsk, davidxl

Differential Revision: http://reviews.llvm.org/D25687

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284659 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/ProfileData/InstrProf.h b/include/llvm/ProfileData/InstrProf.h
index 4b7fb6f940012903f355b7cba034b1de2c794814..4d12df903da1f2d5b6e7c0a8666f46ff21eac90c 100644 (file)
--- a/include/llvm/ProfileData/InstrProf.h
+++ b/include/llvm/ProfileData/InstrProf.h
@@ -292,7 +292,8 @@ enum class instrprof_error {
   counter_overflow,
   value_site_count_mismatch,
   compress_failed,
-  uncompress_failed
+  uncompress_failed,
+  empty_raw_profile
 };
 
 inline std::error_code make_error_code(instrprof_error E) {

diff --git a/lib/ProfileData/InstrProf.cpp b/lib/ProfileData/InstrProf.cpp
index dac919501838ef0900e68c7915f5a52b6da31afa..b512f543e954ca97fad4baee5ebf1379bff51ae0 100644 (file)
--- a/lib/ProfileData/InstrProf.cpp
+++ b/lib/ProfileData/InstrProf.cpp
@@ -70,6 +70,8 @@ std::string getInstrProfErrString(instrprof_error Err) {
     return "Failed to compress data (zlib)";
   case instrprof_error::uncompress_failed:
     return "Failed to uncompress data (zlib)";
+  case instrprof_error::empty_raw_profile:
+    return "Empty raw profile file";
   }
   llvm_unreachable("A value of instrprof_error has no message.");
 }

diff --git a/lib/ProfileData/InstrProfReader.cpp b/lib/ProfileData/InstrProfReader.cpp
index 81c13b35ce30d9ecc957862911b8d53ee64ae7a9..ed927a98604db6281ebd8327b647f5705d7d9bb9 100644 (file)
--- a/lib/ProfileData/InstrProfReader.cpp
+++ b/lib/ProfileData/InstrProfReader.cpp
@@ -46,6 +46,9 @@ InstrProfReader::create(std::unique_ptr<MemoryBuffer> Buffer) {
   if (Buffer->getBufferSize() > std::numeric_limits<unsigned>::max())
     return make_error<InstrProfError>(instrprof_error::too_large);
 
+  if (Buffer->getBufferSize() == 0)
+    return make_error<InstrProfError>(instrprof_error::empty_raw_profile);
+
   std::unique_ptr<InstrProfReader> Result;
   // Create the reader.
   if (IndexedInstrProfReader::hasFormat(*Buffer))

diff --git a/test/tools/llvm-profdata/Inputs/IR_profile.proftext b/test/tools/llvm-profdata/Inputs/IR_profile.proftext
new file mode 100644 (file)
index 0000000..7b7340e
--- /dev/null
+++ b/test/tools/llvm-profdata/Inputs/IR_profile.proftext
@@ -0,0 +1,9 @@
+:ir
+main
+# Func Hash:
+12884901887
+# Num Counters:
+1
+# Counter Values:
+1
+

diff --git a/test/tools/llvm-profdata/Inputs/clang_profile.proftext b/test/tools/llvm-profdata/Inputs/clang_profile.proftext
new file mode 100644 (file)
index 0000000..5419d23
--- /dev/null
+++ b/test/tools/llvm-profdata/Inputs/clang_profile.proftext
@@ -0,0 +1,8 @@
+main
+# Func Hash:
+0
+# Num Counters:
+1
+# Counter Values:
+1
+

diff --git a/test/tools/llvm-profdata/merge_empty_profile.test b/test/tools/llvm-profdata/merge_empty_profile.test
new file mode 100644 (file)
index 0000000..7f9d31b
--- /dev/null
+++ b/test/tools/llvm-profdata/merge_empty_profile.test
@@ -0,0 +1,17 @@
+# Tests for merge of empty profile files.
+
+RUN: touch %t_empty.proftext
+RUN: llvm-profdata merge -text -o %t_clang.proftext %t_empty.proftext %p/Inputs/clang_profile.proftext
+RUN: FileCheck --input-file=%t_clang.proftext %s -check-prefix=CLANG_PROF_TEXT
+CLANG_PROF_TEXT: main
+CLANG_PROF_TEXT: 0
+CLANG_PROF_TEXT: 1
+CLANG_PROF_TEXT: 1
+
+RUN: llvm-profdata merge -text -o %t_ir.proftext %t_empty.proftext %p/Inputs/IR_profile.proftext
+RUN: FileCheck --input-file=%t_ir.proftext %s -check-prefix=IR_PROF_TEXT
+IR_PROF_TEXT: :ir
+IR_PROF_TEXT: main
+IR_PROF_TEXT: 0
+IR_PROF_TEXT: 1
+IR_PROF_TEXT: 1

diff --git a/tools/llvm-profdata/llvm-profdata.cpp b/tools/llvm-profdata/llvm-profdata.cpp
index 08f74d955c636b3c82e103fd289e6acb11cc2147..b9e30255ae399205cb4561d8d4b156e05486b1f5 100644 (file)
--- a/tools/llvm-profdata/llvm-profdata.cpp
+++ b/tools/llvm-profdata/llvm-profdata.cpp
@@ -140,8 +140,13 @@ static void loadInput(const WeightedFile &Input, WriterContext *WC) {
   WC->ErrWhence = Input.Filename;
 
   auto ReaderOrErr = InstrProfReader::create(Input.Filename);
-  if ((WC->Err = ReaderOrErr.takeError()))
+  if (Error E = ReaderOrErr.takeError()) {
+    // Skip the empty profiles by returning sliently.
+    instrprof_error IPE = InstrProfError::take(std::move(E));
+    if (IPE != instrprof_error::empty_raw_profile)
+      WC->Err = make_error<InstrProfError>(IPE);
     return;
+  }
 
   auto Reader = std::move(ReaderOrErr.get());
   bool IsIRProfile = Reader->isIRLevelProfile();