InstrProf: Strip filename prefixes from the names we display for coverage

For consumers of coverage data, any filename prefixes we store in the
profile data are just noise. Strip this prefix if it exists.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236558 91177308-0d34-0410-b5e6-96231b3b80d8

lib/ProfileData/CoverageMapping.cpp

@@ -20,6 +20,7 @@
 #include "llvm/ProfileData/InstrProfReader.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/Path.h"
 #include "llvm/Support/raw_ostream.h"
 
 using namespace llvm;
@@ -178,6 +179,18 @@ void FunctionRecordIterator::skipOtherFiles() {
     *this = FunctionRecordIterator();
 }
 
+/// Get the function name from the record, removing the filename prefix if
+/// necessary.
+static StringRef getFuncNameWithoutPrefix(const CoverageMappingRecord &Record) {
+  StringRef FunctionName = Record.FunctionName;
+  if (Record.Filenames.empty())
+    return FunctionName;
+  StringRef Filename = sys::path::filename(Record.Filenames[0]);
+  if (FunctionName.startswith(Filename))
+    FunctionName = FunctionName.drop_front(Filename.size() + 1);
+  return FunctionName;
+}
+
 ErrorOr<std::unique_ptr<CoverageMapping>>
 CoverageMapping::load(CoverageMappingReader &CoverageReader,
                       IndexedInstrProfReader &ProfileReader) {
@@ -199,7 +212,8 @@ CoverageMapping::load(CoverageMappingReader &CoverageReader,
       Ctx.setCounts(Counts);
 
     assert(!Record.MappingRegions.empty() && "Function has no regions");
-    FunctionRecord Function(Record.FunctionName, Record.Filenames);
+
+    FunctionRecord Function(getFuncNameWithoutPrefix(Record), Record.Filenames);
     for (const auto &Region : Record.MappingRegions) {
       ErrorOr<int64_t> ExecutionCount = Ctx.evaluate(Region.Count);
       if (!ExecutionCount)