[llvm-cov] don't include all source files when provided source files are filtered out

[zequanwu]

Summary

When all provided source files are filtered out either due to --ignore-filename-regex or not part of binary, don't generate coverage reults for all source files. Because if users want to generate coverage results for all source files, they don't even need to provid selected source files or --ignore-filename-regex.

[vsk]

Looks reasonable, but please add a test.

[zequanwu]

• Add a test case
• Fix broken test cases caused by -path-equivalence= not working correctly with . and .. in paths.

[vsk]

Thanks, lgtm!

[thakis]

Looks like this breaks tests on windows: http://45.33.8.238/win/25951/step_11.txt

[zequanwu]

Put a fix here: https://reviews.llvm.org/rG19ae9b6e21e2491debeb910e2c541be9796f1b13

[jmorse]

I've reverted this and the follow-up patch in rG0a7f41739fd994a50 as it continued to fail tools/llvm-cov/warnings.h on Windows-based platforms.

[zequanwu]

Fix test cases which failed on Windows.

[Dor1s]

llvm/tools/llvm-cov/CodeCoverage.cpp

412

Why was this line added? Looks like it broke some big deployments: https://github.com/google/oss-fuzz/issues/4608

[zequanwu]

llvm/tools/llvm-cov/CodeCoverage.cpp

412

I put a fix here: https://github.com/llvm/llvm-project/commit/c75a0a1e9dc29be4e00d37d0d00288afc1a6153f

[Dor1s]

llvm/tools/llvm-cov/CodeCoverage.cpp

412

Thank you for the quick response!

llvm/tools/llvm-cov/CodeCoverage.cpp

private:
   int doExport(int argc, const char **argv,
                CommandLineParserType commandLineParser);
 
   std::vector<StringRef> ObjectFilenames;
   CoverageViewOptions ViewOpts;
   CoverageFiltersMatchAll Filters;
   CoverageFilters IgnoreFilenameFilters;
 
+  /// True if InputSourceFiles are provided.
+  bool HasInputSourceFiles;
+
   /// The path to the indexed profile.
   std::string PGOFilename;
 
   /// A list of input source files.
   std::vector<std::string> SourceFiles;
 
   /// In -path-equivalence mode, this maps the absolute paths from the coverage
   /// mapping data to the input source files.
void CodeCoverageTool::remapPathNames(const CoverageMapping &Coverage) {
   };
   std::string RemapFrom = nativeWithTrailing(PathRemapping->first);
   std::string RemapTo = nativeWithTrailing(PathRemapping->second);
 
   // Create a mapping from coverage data file paths to local paths.
   for (StringRef Filename : Coverage.getUniqueSourceFiles()) {
     SmallString<128> NativeFilename;
     sys::path::native(Filename, NativeFilename);
     if (NativeFilename.startswith(RemapFrom)) {
       RemappedFilenames[Filename] =
           RemapTo + NativeFilename.substr(RemapFrom.size()).str();
     }
   }
 
   // Convert input files from local paths to coverage data file paths.
   StringMap<std::string> InvRemappedFilenames;
   for (const auto &RemappedFilename : RemappedFilenames)
if (!Arches.empty()) {
         CoverageArches.emplace_back(Arch);
       }
       if (CoverageArches.size() != ObjectFilenames.size()) {
         error("Number of architectures doesn't match the number of objects");
         return 1;
       }
     }
 
+    HasInputSourceFiles = !InputSourceFiles.empty();
+
     // IgnoreFilenameFilters are applied even when InputSourceFiles specified.
     for (const std::string &File : InputSourceFiles)
       collectPaths(File);
 
     if (DebugDumpCollectedPaths) {
       for (const std::string &SF : SourceFiles)
         outs() << SF << '\n';
       ::exit(0);
ViewOpts.CreatedTimeStr = (found != std::string::npos)
                                 : "Created: " + ModifiedTimeStr;
 
   auto Coverage = load();
   if (!Coverage)
     return 1;
 
   auto Printer = CoveragePrinter::create(ViewOpts);
 
-  if (SourceFiles.empty())
+  if (SourceFiles.empty() && !HasInputSourceFiles)
     // Get the source files from the function coverage mapping.
     for (StringRef Filename : Coverage->getUniqueSourceFiles()) {
       if (!IgnoreFilenameFilters.matchesFilename(Filename))
         SourceFiles.push_back(std::string(Filename));
     }
 
   // Create an index out of the source files.
   if (ViewOpts.hasOutputDirectory()) {