[InstrProf] Emit warnings when correlating lightweight profiles

Emit warnings when `InstrProfCorrelator` finds problems with debug info for lightweight instrumentation profile correlation. To prevent excessive printing, only emit the first 5 warnings.

In addition, remove a diagnostic about missing debug info in `InstrProfiling.cpp`. Some compiler-generated functions, e.g., `__clang_call_terminate`, does not emit debug info and will fail a build if `-Werror` is used. This warning is not actionable by the user and I have not seen non-compiler-generated functions fail this test.

Reviewed By: smeenai

Differential Revision: https://reviews.llvm.org/D156006

1 files changed, 20 insertions, 8 deletions

diff --git a/llvm/tools/llvm-profdata/llvm-profdata.cpp b/llvm/tools/llvm-profdata/llvm-profdata.cpp
index 9da5368..d4266fb 100644
--- a/llvm/tools/llvm-profdata/llvm-profdata.cpp
+++ b/llvm/tools/llvm-profdata/llvm-profdata.cpp
@@ -407,8 +407,8 @@ static void
 mergeInstrProfile(const WeightedFileVector &Inputs, StringRef DebugInfoFilename,
                   SymbolRemapper *Remapper, StringRef OutputFilename,
                   ProfileFormat OutputFormat, uint64_t TraceReservoirSize,
-                  uint64_t MaxTraceLength, bool OutputSparse,
-                  unsigned NumThreads, FailureMode FailMode,
+                  uint64_t MaxTraceLength, int MaxDbgCorrelationWarnings,
+                  bool OutputSparse, unsigned NumThreads, FailureMode FailMode,
                   const StringRef ProfiledBinary) {
   if (OutputFormat == PF_Compact_Binary)
     exitWithError("Compact Binary is deprecated");
@@ -421,7 +421,7 @@ mergeInstrProfile(const WeightedFileVector &Inputs, StringRef DebugInfoFilename,
     if (auto Err =
             InstrProfCorrelator::get(DebugInfoFilename).moveInto(Correlator))
       exitWithError(std::move(Err), DebugInfoFilename);
-    if (auto Err = Correlator->correlateProfileData())
+    if (auto Err = Correlator->correlateProfileData(MaxDbgCorrelationWarnings))
       exitWithError(std::move(Err), DebugInfoFilename);
   }
 
@@ -1270,6 +1270,11 @@ static int merge_main(int argc, const char *argv[]) {
   cl::opt<std::string> DebugInfoFilename(
       "debug-info", cl::init(""),
       cl::desc("Use the provided debug info to correlate the raw profile."));
+  cl::opt<unsigned> MaxDbgCorrelationWarnings(
+      "max-debug-info-correlation-warnings",
+      cl::desc("The maximum number of warnings to emit when correlating "
+               "profile from debug info (0 = no limit)"),
+      cl::init(5));
   cl::opt<std::string> ProfiledBinary(
       "profiled-binary", cl::init(""),
       cl::desc("Path to binary from which the profile was collected."));
@@ -1331,8 +1336,8 @@ static int merge_main(int argc, const char *argv[]) {
     mergeInstrProfile(WeightedInputs, DebugInfoFilename, Remapper.get(),
                       OutputFilename, OutputFormat,
                       TemporalProfTraceReservoirSize,
-                      TemporalProfMaxTraceLength, OutputSparse, NumThreads,
-                      FailureMode, ProfiledBinary);
+                      TemporalProfMaxTraceLength, MaxDbgCorrelationWarnings,
+                      OutputSparse, NumThreads, FailureMode, ProfiledBinary);
   else
     mergeSampleProfile(WeightedInputs, Remapper.get(), OutputFilename,
                        OutputFormat, ProfileSymbolListFile, CompressAllSections,
@@ -2877,6 +2882,7 @@ static int showMemProfProfile(const std::string &Filename,
 static int showDebugInfoCorrelation(const std::string &Filename,
                                     bool ShowDetailedSummary,
                                     bool ShowProfileSymbolList,
+                                    int MaxDbgCorrelationWarnings,
                                     ShowFormat SFormat, raw_fd_ostream &OS) {
   if (SFormat == ShowFormat::Json)
     exitWithError("JSON output is not supported for debug info correlation");
@@ -2884,12 +2890,12 @@ static int showDebugInfoCorrelation(const std::string &Filename,
   if (auto Err = InstrProfCorrelator::get(Filename).moveInto(Correlator))
     exitWithError(std::move(Err), Filename);
   if (SFormat == ShowFormat::Yaml) {
-    if (auto Err = Correlator->dumpYaml(OS))
+    if (auto Err = Correlator->dumpYaml(MaxDbgCorrelationWarnings, OS))
       exitWithError(std::move(Err), Filename);
     return 0;
   }
 
-  if (auto Err = Correlator->correlateProfileData())
+  if (auto Err = Correlator->correlateProfileData(MaxDbgCorrelationWarnings))
     exitWithError(std::move(Err), Filename);
 
   InstrProfSymtab Symtab;
@@ -2989,6 +2995,11 @@ static int show_main(int argc, const char *argv[]) {
       "debug-info", cl::init(""),
       cl::desc("Read and extract profile metadata from debug info and show "
                "the functions it found."));
+  cl::opt<unsigned> MaxDbgCorrelationWarnings(
+      "max-debug-info-correlation-warnings",
+      cl::desc("The maximum number of warnings to emit when correlating "
+               "profile from debug info (0 = no limit)"),
+      cl::init(5));
   cl::opt<bool> ShowCovered(
       "covered", cl::init(false),
       cl::desc("Show only the functions that have been executed."));
@@ -3022,7 +3033,8 @@ static int show_main(int argc, const char *argv[]) {
 
   if (!DebugInfoFilename.empty())
     return showDebugInfoCorrelation(DebugInfoFilename, ShowDetailedSummary,
-                                    ShowProfileSymbolList, SFormat, OS);
+                                    ShowProfileSymbolList,
+                                    MaxDbgCorrelationWarnings, SFormat, OS);
 
   if (ProfileKind == instr)
     return showInstrProfile(