[llvm-profdata] Add check for text profile formats and improve error reporting

Summary:
This change addresses two possible instances of user error / confusion when
merging sampled profile data.

Previously any input that didn't match the raw or processed instrumented format
would automatically be interpreted as instrumented profile text format data.
No error would be reported during the merge.

Example:
If foo-sampled.profdata and bar-sampled.profdata are binary sampled profiles:

Old behavior:
$ llvm-profdata merge foo-sampled.profdata bar-sampled.profdata -output foobar-sampled.profdata
$ llvm-profdata show -sample foobar-sampled.profdata
error: foobar-sampled.profdata:1: Expected 'mangled_name:NUM:NUM', found  lprofi

This change adds basic checks for valid input data when assuming text input.
It also makes error messages related to file format validity more specific about
the assumbed profile data type.

New behavior:
$ llvm-profdata merge foo-sampled.profdata bar-sampled.profdata -o foobar-sampled.profdata
error: foo.profdata: Unrecognized instrumentation profile encoding format
Perhaps you forgot to use the -sample option?

Reviewers: bogner, davidxl, dnovillo

Subscribers: davidxl, llvm-commits

Differential Revision: http://reviews.llvm.org/D14558

llvm-svn: 252916

1 files changed, 4 insertions, 4 deletions

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: