4 files changed, 42 insertions, 11 deletions
diff --git a/llvm/lib/ProfileData/InstrProf.cpp b/llvm/lib/ProfileData/InstrProf.cpp
index 92a3c251f6e..762f00b48b6 100644
--- a/llvm/lib/ProfileData/InstrProf.cpp
+++ b/llvm/lib/ProfileData/InstrProf.cpp
@@ -32,20 +32,22 @@ class InstrProfErrorCategoryType : public std::error_category {
       return "Success";
     case instrprof_error::eof:
       return "End of File";
+    case instrprof_error::unrecognized_format:
+      return "Unrecognized instrumentation profile encoding format";
     case instrprof_error::bad_magic:
-      return "Invalid profile data (bad magic)";
+      return "Invalid instrumentation profile data (bad magic)";
     case instrprof_error::bad_header:
-      return "Invalid profile data (file header is corrupt)";
+      return "Invalid instrumentation profile data (file header is corrupt)";
     case instrprof_error::unsupported_version:
-      return "Unsupported profiling format version";
+      return "Unsupported instrumentation profile format version";
     case instrprof_error::unsupported_hash_type:
-      return "Unsupported profiling hash";
+      return "Unsupported instrumentation profile hash type";
     case instrprof_error::too_large:
       return "Too much profile data";
     case instrprof_error::truncated:
       return "Truncated profile data";
     case instrprof_error::malformed:
-      return "Malformed profile data";
+      return "Malformed instrumentation profile data";
     case instrprof_error::unknown_function:
       return "No profile data available for function";
     case instrprof_error::hash_mismatch:
diff --git a/llvm/lib/ProfileData/InstrProfReader.cpp b/llvm/lib/ProfileData/InstrProfReader.cpp
index bf10b448e4c..6f201243736 100644
--- a/llvm/lib/ProfileData/InstrProfReader.cpp
+++ b/llvm/lib/ProfileData/InstrProfReader.cpp
@@ -54,8 +54,10 @@ InstrProfReader::create(std::unique_ptr<MemoryBuffer> Buffer) {
     Result.reset(new RawInstrProfReader64(std::move(Buffer)));
   else if (RawInstrProfReader32::hasFormat(*Buffer))
     Result.reset(new RawInstrProfReader32(std::move(Buffer)));
-  else
+  else if (TextInstrProfReader::hasFormat(*Buffer))
     Result.reset(new TextInstrProfReader(std::move(Buffer)));
+  else
+    return instrprof_error::unrecognized_format;
 
   // Initialize the reader and return the result.
   if (std::error_code EC = initializeReader(*Result))
@@ -97,6 +99,15 @@ void InstrProfIterator::Increment() {
     *this = InstrProfIterator();
 }
 
+bool TextInstrProfReader::hasFormat(const MemoryBuffer &Buffer) {
+  // Verify that this really looks like plain ASCII text by checking a
+  // 'reasonable' number of characters (up to profile magic size).
+  size_t count = std::min(Buffer.getBufferSize(), sizeof(uint64_t));
+  StringRef buffer = Buffer.getBufferStart();
+  return count == 0 || std::all_of(buffer.begin(), buffer.begin() + count,
+    [](char c) { return ::isprint(c) || ::isspace(c); });
+}
+
 std::error_code TextInstrProfReader::readNextRecord(InstrProfRecord &Record) {
   // Skip empty lines and comments.
   while (!Line.is_at_end() && (Line->empty() || Line->startswith("#")))
diff --git a/llvm/lib/ProfileData/SampleProf.cpp b/llvm/lib/ProfileData/SampleProf.cpp
index b5d3b2d2e55..856923e164b 100644
--- a/llvm/lib/ProfileData/SampleProf.cpp
+++ b/llvm/lib/ProfileData/SampleProf.cpp
@@ -28,17 +28,17 @@ class SampleProfErrorCategoryType : public std::error_category {
     case sampleprof_error::success:
       return "Success";
     case sampleprof_error::bad_magic:
-      return "Invalid file format (bad magic)";
+      return "Invalid sample profile data (bad magic)";
     case sampleprof_error::unsupported_version:
-      return "Unsupported format version";
+      return "Unsupported sample profile format version";
     case sampleprof_error::too_large:
       return "Too much profile data";
     case sampleprof_error::truncated:
       return "Truncated profile data";
     case sampleprof_error::malformed:
-      return "Malformed profile data";
+      return "Malformed sample profile data";
     case sampleprof_error::unrecognized_format:
-      return "Unrecognized profile encoding format";
+      return "Unrecognized sample profile encoding format";
     case sampleprof_error::unsupported_writing_format:
       return "Profile encoding format unsupported for writing operations";
     case sampleprof_error::truncated_name_table:
diff --git a/llvm/lib/ProfileData/SampleProfReader.cpp b/llvm/lib/ProfileData/SampleProfReader.cpp
index a5d00083b53..0bed4f09f1f 100644
--- a/llvm/lib/ProfileData/SampleProfReader.cpp
+++ b/llvm/lib/ProfileData/SampleProfReader.cpp
@@ -222,6 +222,22 @@ std::error_code SampleProfileReaderText::read() {
   return sampleprof_error::success;
 }
 
+bool SampleProfileReaderText::hasFormat(const MemoryBuffer &Buffer) {
+  bool result = false;
+
+  // Check that the first non-comment line is a valid function header.
+  line_iterator LineIt(Buffer, /*SkipBlanks=*/true, '#');
+  if (!LineIt.is_at_eof()) {
+    if ((*LineIt)[0] != ' ') {
+      uint64_t NumSamples, NumHeadSamples;
+      StringRef FName;
+      result = ParseHead(*LineIt, FName, NumSamples, NumHeadSamples);
+    }
+  }
+
+  return result;
+}
+
 template <typename T> ErrorOr<T> SampleProfileReaderBinary::readNumber() {
   unsigned NumBytesRead = 0;
   std::error_code EC;
@@ -685,8 +701,10 @@ SampleProfileReader::create(StringRef Filename, LLVMContext &C) {
     Reader.reset(new SampleProfileReaderBinary(std::move(Buffer), C));
   else if (SampleProfileReaderGCC::hasFormat(*Buffer))
     Reader.reset(new SampleProfileReaderGCC(std::move(Buffer), C));
-  else
+  else if (SampleProfileReaderText::hasFormat(*Buffer))
     Reader.reset(new SampleProfileReaderText(std::move(Buffer), C));
+  else
+    return sampleprof_error::unrecognized_format;
 
   if (std::error_code EC = Reader->readHeader())
     return EC;