[llvm-cov] Add an option for "export" command to emit only file summary data.

[Dor1s]

Summary

That allows to get the same data as produced by "llvm-cov report",
but in JSON format, which is better for further processing by end users.

[Dor1s]

Minor changes for the doc text and code comments

[Dor1s]

Vedant, please take a look at this little change when you'll have a few minutes :) This change would simplify code coverage integration on OSS-Fuzz and Chromium side.

[vsk]

Thanks Max! Lgtm with a basic test, e.g;

diff --git a/test/tools/llvm-cov/showLineExecutionCounts.cpp b/test/tools/llvm-cov/showLineExecutionCounts.cpp
index c4b76824aac..f4b0424cee4 100644
--- a/test/tools/llvm-cov/showLineExecutionCounts.cpp
+++ b/test/tools/llvm-cov/showLineExecutionCounts.cpp
@@ -39,6 +39,9 @@ int main() {                              // TEXT: [[@LINE]]|   161|int main(
 // RUN: FileCheck -input-file %t.export.json %S/Inputs/lineExecutionCounts.json
 // RUN: cat %t.export.json | %python -c "import json, sys; json.loads(sys.stdin.read())"
 //
+// RUN: llvm-cov export %S/Inputs/lineExecutionCounts.covmapping -instr-profile %t.profdata 2>/dev/null -summary-only > %t.export-summary.json
+// RUN: not grep '"name":"main"' %t.export-summary.json
+//
 // Test html output.
 // RUN: llvm-cov show %S/Inputs/lineExecutionCounts.covmapping -format html -o %t.html.dir -instr-profile %t.profdata -path-equivalence=/tmp,%S %s
 // RUN: llvm-cov show %S/Inputs/lineExecutionCounts.covmapping -format html -o %t.html.filtered.dir -instr-profile %t.profdata -path-equivalence=/tmp,%S -name=main %s

[Dor1s]

Adding the test

[Dor1s]

Thanks Vedant for the super fast review and for the tests suggestion!

[vsk]

test/tools/llvm-cov/showLineExecutionCounts.cpp

74 ↗

(On Diff #126459)

This test case was a mess... I've simplified it in r320439, sorry for the trouble.

[Dor1s]

test/tools/llvm-cov/showLineExecutionCounts.cpp

74 ↗

(On Diff #126459)

Cool, thanks Vedant!

docs/CommandGuide/llvm-cov.rst

 ^^^^^^^
 
 .. option:: -arch=<name>
 
  If the covered binary is a universal binary, select the architecture to use.
  It is an error to specify an architecture that is not included in the
  universal binary or to use an architecture that does not match a
  non-universal binary.
+
+.. option:: -summary-only
+
+ Export only summary data for each file in the coverage data. This mode will not
+ export coverage information for smaller units such as individual functions or
+ regions. The result will be the same as produced by :program:`llvm-cov export`
+ command, but presented in JSON format.

tools/llvm-cov/CodeCoverage.cpp

cl::opt<bool> RegionSummary(
       "show-region-summary", cl::Optional,
       cl::desc("Show region statistics in summary table"),
       cl::init(true));
 
   cl::opt<bool> InstantiationSummary(
       "show-instantiation-summary", cl::Optional,
       cl::desc("Show instantiation statistics in summary table"));
 
+  cl::opt<bool> SummaryOnly(
+      "summary-only", cl::Optional,
+      cl::desc("Export only summary information per filename"));
+
   auto commandLineParser = [&, this](int argc, const char **argv) -> int {
     cl::ParseCommandLineOptions(argc, argv, "LLVM code coverage tool\n");
     ViewOpts.Debug = DebugDump;
 
     if (!CovFilename.empty())
       ObjectFilenames.emplace_back(CovFilename);
     for (const std::string &Filename : CovFilenames)
       ObjectFilenames.emplace_back(Filename);
auto commandLineParser = [&, this](int argc, const char **argv) -> int {
     if (DebugDumpCollectedPaths) {
       for (const std::string &SF : SourceFiles)
         outs() << SF << '\n';
       ::exit(0);
     }
 
     ViewOpts.ShowRegionSummary = RegionSummary;
     ViewOpts.ShowInstantiationSummary = InstantiationSummary;
+    ViewOpts.ExportSummaryOnly = SummaryOnly;
 
     return 0;
   };
 
   switch (Cmd) {
   case Show:
     return show(argc, argv, commandLineParser);
   case Report:

tools/llvm-cov/CoverageExporterJson.cpp

void renderRoot() {
     FileCoverageSummary Totals = FileCoverageSummary("Totals");
     std::vector<std::string> SourceFiles;
     for (StringRef SF : Coverage.getUniqueSourceFiles())
       SourceFiles.emplace_back(SF);
     auto FileReports = CoverageReport::prepareFileReports(Coverage, Totals,
                                                           SourceFiles, Options);
     renderFiles(SourceFiles, FileReports);
 
+    if (!Options.ExportSummaryOnly) {
+      // Skip functions-level information for summary-only export mode.
       emitDictKey("functions");
       renderFunctions(Coverage.getCoveredFunctions());
+    }
 
     emitDictKey("totals");
     renderSummary(Totals);
 
     // End Export.
     emitDictEnd();
 
     // End List of Exports.
class CoverageExporterJson {
 
   /// \brief Render a single file.
   void renderFile(const CoverageData &FileCoverage,
                   const FileCoverageSummary &FileReport) {
     // Start File.
     emitDictStart();
 
     emitDictElement("filename", FileCoverage.getFilename());
+
+    if (!Options.ExportSummaryOnly) {
+      // Skip segments and expansions for summary-only export mode.
       emitDictKey("segments");
 
       // Start List of Segments.
       emitArrayStart();
 
       for (const auto &Segment : FileCoverage)
         renderSegment(Segment);
 
       // End List of Segments.
       emitArrayEnd();
 
       emitDictKey("expansions");
 
       // Start List of Expansions.
       emitArrayStart();
 
       for (const auto &Expansion : FileCoverage.getExpansions())
         renderExpansion(Expansion);
 
       // End List of Expansions.
       emitArrayEnd();
+    }
 
     emitDictKey("summary");
     renderSummary(FileReport);
 
     // End File.
     emitDictEnd();
   }
 

tools/llvm-cov/CoverageViewOptions.h

struct CoverageViewOptions {
   bool ShowLineNumbers;
   bool ShowLineStats;
   bool ShowRegionMarkers;
   bool ShowExpandedRegions;
   bool ShowFunctionInstantiations;
   bool ShowFullFilenames;
   bool ShowRegionSummary;
   bool ShowInstantiationSummary;
+  bool ExportSummaryOnly;
   OutputFormat Format;
   std::string ShowOutputDirectory;
   std::vector<std::string> DemanglerOpts;
   uint32_t TabSize;
   std::string ProjectTitle;
   std::string CreatedTimeStr;
 
   /// \brief Change the output's stream color if the colors are enabled.