llvm-cov: add code coverage tool that's based on coverage mapping format and clang's pgo.

This commit expands llvm-cov's functionality by adding support for a new code coverage
tool that uses LLVM's coverage mapping format and clang's instrumentation based profiling.
The gcov compatible tool can be invoked by supplying the 'gcov' command as the first argument,
or by modifying the tool's name to end with 'gcov'.

Differential Revision: http://reviews.llvm.org/D4445

llvm-svn: 216300

1 files changed, 57 insertions, 0 deletions

diff --git a/llvm/tools/llvm-cov/SourceCoverageDataManager.cpp b/llvm/tools/llvm-cov/SourceCoverageDataManager.cpp
new file mode 100644
index 00000000000..03382b266e7
--- /dev/null
+++ b/llvm/tools/llvm-cov/SourceCoverageDataManager.cpp
@@ -0,0 +1,57 @@
+//===- SourceCoverageDataManager.cpp - Manager for source file coverage
+// data-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This class separates and merges mapping regions for a specific source file.
+//
+//===----------------------------------------------------------------------===//
+
+#include "SourceCoverageDataManager.h"
+
+using namespace llvm;
+using namespace coverage;
+
+void SourceCoverageDataManager::insert(const MappingRegion &Region) {
+  SourceRange Range(Region.LineStart, Region.ColumnStart, Region.LineEnd,
+                    Region.ColumnEnd);
+  if (Region.Kind == CounterMappingRegion::SkippedRegion) {
+    SkippedRegions.push_back(Range);
+    return;
+  }
+  Regions.push_back(std::make_pair(Range, Region.ExecutionCount));
+}
+
+ArrayRef<std::pair<SourceCoverageDataManager::SourceRange, uint64_t>>
+SourceCoverageDataManager::getSourceRegions() {
+  if (Uniqued || Regions.size() <= 1)
+    return Regions;
+
+  // Sort.
+  std::sort(Regions.begin(), Regions.end(),
+            [](const std::pair<SourceRange, uint64_t> &LHS,
+               const std::pair<SourceRange, uint64_t> &RHS) {
+    return LHS.first < RHS.first;
+  });
+
+  // Merge duplicate source ranges and sum their execution counts.
+  auto Prev = Regions.begin();
+  for (auto I = Prev + 1, E = Regions.end(); I != E; ++I) {
+    if (I->first == Prev->first) {
+      Prev->second += I->second;
+      continue;
+    }
+    ++Prev;
+    *Prev = *I;
+  }
+  ++Prev;
+  Regions.erase(Prev, Regions.end());
+
+  Uniqued = true;
+  return Regions;
+}