ProfileData: Introduce InstrProfWriter using the naive text format

This isn't a format we'll want to write out in practice, but moving it
to the writer library simplifies llvm-profdata and isolates it from
further changes to the format.

This also allows us to update the tests to not rely on the text output
format.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204489 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/ProfileData/InstrProf.h

@@ -31,7 +31,10 @@ struct instrprof_error {
     too_large,
     truncated,
     malformed,
-    unknown_function
+    unknown_function,
+    hash_mismatch,
+    count_mismatch,
+    counter_overflow
   };
   ErrorType V;
 

include/llvm/ProfileData/InstrProfWriter.h

@@ -0,0 +1,49 @@
+//=-- InstrProfWriter.h - Instrumented profiling writer -----------*- C++ -*-=//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains support for writing profiling data for instrumentation
+// based PGO and coverage.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_PROFILEDATA_INSTRPROF_WRITER_H__
+#define LLVM_PROFILEDATA_INSTRPROF_WRITER_H__
+
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/StringMap.h"
+#include "llvm/ProfileData/InstrProf.h"
+#include "llvm/Support/DataTypes.h"
+#include "llvm/Support/raw_ostream.h"
+
+#include <vector>
+
+namespace llvm {
+
+/// Writer for instrumentation based profile data.
+class InstrProfWriter {
+public:
+  struct CounterData {
+    uint64_t Hash;
+    std::vector<uint64_t> Counts;
+  };
+private:
+  StringMap<CounterData> FunctionData;
+public:
+  /// Add function counts for the given function. If there are already counts
+  /// for this function and the hash and number of counts match, each counter is
+  /// summed.
+  error_code addFunctionCounts(StringRef FunctionName, uint64_t FunctionHash,
+                               ArrayRef<uint64_t> Counters);
+  /// Ensure that all data is written to disk.
+  void write(raw_ostream &OS);
+};
+
+} // end namespace llvm
+
+#endif // LLVM_PROFILE_INSTRPROF_WRITER_H__