Rollup merge of #91207 - richkadel:rk-bump-coverage-version, r=tmandry

Add support for LLVM coverage mapping format versions 5 and 6

This PR cherry-pick's Swatinem's initial commit in unsubmitted PR #90047.

My additional commit augments Swatinem's great starting point, but adds full support for LLVM
Coverage Mapping Format version 6, conditionally, if compiling with LLVM 13.

Version 6 requires adding the compilation directory when file paths are
relative, and since Rustc coverage maps use relative paths, we should
add the expected compilation directory entry.

Note, however, that with the compilation directory, coverage reports
from `llvm-cov show` can now report file names (when the report includes
more than one file) with the full absolute path to the file.

This would be a problem for test results, but the workaround (for the
rust coverage tests) is to include an additional `llvm-cov show`
parameter: `--compilation-dir=.`

1 files changed, 7 insertions, 2 deletions

diff --git a/compiler/rustc_llvm/llvm-wrapper/CoverageMappingWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/CoverageMappingWrapper.cpp
index 8cd2bd12450..154f554d607 100644
--- a/compiler/rustc_llvm/llvm-wrapper/CoverageMappingWrapper.cpp
+++ b/compiler/rustc_llvm/llvm-wrapper/CoverageMappingWrapper.cpp
@@ -10,6 +10,7 @@ using namespace llvm;
 
 struct LLVMRustCounterMappingRegion {
   coverage::Counter Count;
+  coverage::Counter FalseCount;
   uint32_t FileID;
   uint32_t ExpandedFileID;
   uint32_t LineStart;
@@ -53,7 +54,7 @@ extern "C" void LLVMRustCoverageWriteMappingToBuffer(
   MappingRegions.reserve(NumMappingRegions);
   for (const auto &Region : makeArrayRef(RustMappingRegions, NumMappingRegions)) {
     MappingRegions.emplace_back(
-        Region.Count, Region.FileID, Region.ExpandedFileID,
+        Region.Count, Region.FalseCount, Region.FileID, Region.ExpandedFileID,
         Region.LineStart, Region.ColumnStart, Region.LineEnd, Region.ColumnEnd,
         Region.Kind);
   }
@@ -108,5 +109,9 @@ extern "C" void LLVMRustCoverageWriteMappingVarNameToString(RustStringRef Str) {
 }
 
 extern "C" uint32_t LLVMRustCoverageMappingVersion() {
-  return coverage::CovMapVersion::Version4;
+#if LLVM_VERSION_GE(13, 0)
+  return coverage::CovMapVersion::Version6;
+#else
+  return coverage::CovMapVersion::Version5;
+#endif
 }