[llvm-cov] Add support for -skip-functions to lcov

[keith]

Summary

This flag was added for the json format to exclude functions from the
output. This mirrors that behavior in lcov (where it was previously
accepted but ignored). This makes the output file smaller which can be
beneficial depending on how you consume it, especially if you don't use
this data anyways.

Patch by Keith Smiley (@keith).

[Dor1s]

LGTM

[keith]

Can someone land this for me? I don't have permissions to do that AFAIK

[Dor1s]

rebase + getting ready to commit

llvm/test/tools/llvm-cov/export_functions-lcov.test

+# Test that llvm-cov export produces function data by default and that it can be
+# turned off with a flag.
+
+RUN: llvm-cov export -format lcov %S/Inputs/report.covmapping -instr-profile %S/Inputs/report.profdata 2>&1 | FileCheck %s
+RUN: llvm-cov export -format lcov %S/Inputs/report.covmapping -instr-profile %S/Inputs/report.profdata -skip-functions 2>&1 | FileCheck -check-prefix=SKIP-FUNCTIONS %s
+
+CHECK: FN:
+SKIP-FUNCTIONS-NOT: FN:

llvm/tools/llvm-cov/CoverageExporterLcov.cpp

 
 void renderLineSummary(raw_ostream &OS, const FileCoverageSummary &Summary) {
   OS << "LF:" << Summary.LineCoverage.getNumLines() << '\n'
      << "LH:" << Summary.LineCoverage.getCovered() << '\n';
 }
 
 void renderFile(raw_ostream &OS, const coverage::CoverageMapping &Coverage,
                 const std::string &Filename,
-                const FileCoverageSummary &FileReport, bool ExportSummaryOnly) {
+                const FileCoverageSummary &FileReport, bool ExportSummaryOnly,
+                bool SkipFunctions) {
   OS << "SF:" << Filename << '\n';
 
-  if (!ExportSummaryOnly) {
+  if (!ExportSummaryOnly && !SkipFunctions) {
     renderFunctions(OS, Coverage.getCoveredFunctions(Filename));
   }
   renderFunctionSummary(OS, FileReport);
 
   if (!ExportSummaryOnly) {
     // Calculate and render detailed coverage information for given file.
     auto FileCoverage = Coverage.getCoverageForFile(Filename);
     renderLineExecutionCounts(OS, FileCoverage);
   }
   renderLineSummary(OS, FileReport);
 
   OS << "end_of_record\n";
 }
 
 void renderFiles(raw_ostream &OS, const coverage::CoverageMapping &Coverage,
                  ArrayRef<std::string> SourceFiles,
                  ArrayRef<FileCoverageSummary> FileReports,
-                 bool ExportSummaryOnly) {
+                 bool ExportSummaryOnly, bool SkipFunctions) {
   for (unsigned I = 0, E = SourceFiles.size(); I < E; ++I)
-    renderFile(OS, Coverage, SourceFiles[I], FileReports[I], ExportSummaryOnly);
+    renderFile(OS, Coverage, SourceFiles[I], FileReports[I], ExportSummaryOnly,
+               SkipFunctions);
 }
 
 } // end anonymous namespace
 
 void CoverageExporterLcov::renderRoot(const CoverageFilters &IgnoreFilters) {
   std::vector<std::string> SourceFiles;
   for (StringRef SF : Coverage.getUniqueSourceFiles()) {
     if (!IgnoreFilters.matchesFilename(SF))
       SourceFiles.emplace_back(SF);
   }
   renderRoot(SourceFiles);
 }
 
 void CoverageExporterLcov::renderRoot(ArrayRef<std::string> SourceFiles) {
   FileCoverageSummary Totals = FileCoverageSummary("Totals");
   auto FileReports = CoverageReport::prepareFileReports(Coverage, Totals,
                                                         SourceFiles, Options);
-  renderFiles(OS, Coverage, SourceFiles, FileReports,
-              Options.ExportSummaryOnly);
+  renderFiles(OS, Coverage, SourceFiles, FileReports, Options.ExportSummaryOnly,
+              Options.SkipFunctions);
 }