[llvm-cov] Add support for loading coverage from multiple objects

[vsk]

Summary

llvm-cov currently requires the user to pass in a single object filename via a positional arg.

To retain backwards compatibility, I've kept the original positional arg but made it optional. I've also added an optional "-object" flag (a cl::list). You can specify the "-object" flag multiple times, or a single time using a comma-separated list.

[arphaman]

It looks like phabricator stripped the first component of the filenames ('tools' and 'test'). Can you please re-upload the diff?

[arphaman]

tools/llvm-cov/multiELFsShare.cpp

53 ↗

(On Diff #73017)

This test file is missing a newline at the end.

[vsk]

I think this patch could be simplified if we taught the llvm::CoverageMapping class how to load coverage data from multiple CoverageMappingReaders / multiple filenames. This would require less work in the long run compared to updating all of the reporting logic.

I have a handful of patches that move us in this direction ready locally. The last patch is still WIP, but I hope to have it uploaded for review soon.

[vsk]

@MaggieYi ping, do you have the bandwidth to update this patch to use the new CoverageMapping::load API? If not, I can take a shot at it.

[MaggieYi]

In D25086#572183, @vsk wrote:

@MaggieYi ping, do you have the bandwidth to update this patch to use the new CoverageMapping::load API? If not, I can take a shot at it.

Hi Vedant,

Since I have been moved to another project for a while, my colleague (Sean Eveson) is looking at this review. Since you are more familiar with the coverage, please go ahead and update the patch if you want to.

Thanks

[vsk]

Ok. I'll upload my patch for review.

[vsk]

• Update the patch to use the new CoverageMapping::load() API.

[arphaman]

LGTM

llvm/trunk/docs/CommandGuide/llvm-cov.rst

 .. _llvm-cov-show:
 
 SHOW COMMAND
 ------------
 
 SYNOPSIS
 ^^^^^^^^
 
-:program:`llvm-cov show` [*options*] -instr-profile *PROFILE* *BIN* [*SOURCES*]
+:program:`llvm-cov show` [*options*] -instr-profile *PROFILE* *BIN* [*-object BIN,...*] [[*-object BIN*]] [*SOURCES*]
 
 DESCRIPTION
 ^^^^^^^^^^^
 
-The :program:`llvm-cov show` command shows line by line coverage of a binary
-*BIN* using the profile data *PROFILE*. It can optionally be filtered to only
-show the coverage for the files listed in *SOURCES*.
+The :program:`llvm-cov show` command shows line by line coverage of the
+binaries *BIN*,...  using the profile data *PROFILE*. It can optionally be
+filtered to only show the coverage for the files listed in *SOURCES*.
 
 To use :program:`llvm-cov show`, you need a program that is compiled with
 instrumentation to emit profile and coverage data. To build such a program with
 ``clang`` use the ``-fprofile-instr-generate`` and ``-fcoverage-mapping``
 flags. If linking with the ``clang`` driver, pass ``-fprofile-instr-generate``
 to the link stage to make sure the necessary runtime libraries are linked in.
 
 The coverage information is stored in the built executable or library itself,
-and this is what you should pass to :program:`llvm-cov show` as the *BIN*
+and this is what you should pass to :program:`llvm-cov show` as a *BIN*
 argument. The profile data is generated by running this instrumented program
 normally. When the program exits it will write out a raw profile file,
 typically called ``default.profraw``, which can be converted to a format that
 is suitable for the *PROFILE* argument using the :program:`llvm-profdata merge`
 tool.
 
 OPTIONS
 ^^^^^^^

 .. _llvm-cov-report:
 
 REPORT COMMAND
 --------------
 
 SYNOPSIS
 ^^^^^^^^
 
-:program:`llvm-cov report` [*options*] -instr-profile *PROFILE* *BIN* [*SOURCES*]
+:program:`llvm-cov report` [*options*] -instr-profile *PROFILE* *BIN* [*-object BIN,...*] [[*-object BIN*]] [*SOURCES*]
 
 DESCRIPTION
 ^^^^^^^^^^^
 
-The :program:`llvm-cov report` command displays a summary of the coverage of a
-binary *BIN* using the profile data *PROFILE*. It can optionally be filtered to
-only show the coverage for the files listed in *SOURCES*.
+The :program:`llvm-cov report` command displays a summary of the coverage of
+the binaries *BIN*,... using the profile data *PROFILE*. It can optionally be
+filtered to only show the coverage for the files listed in *SOURCES*.
 
 If no source files are provided, a summary line is printed for each file in the
 coverage data. If any files are provided, summaries are shown for each function
 in the listed files instead.
 
 For information on compiling programs for coverage and generating profile data,
 see :ref:`llvm-cov-show`.
 

 .. _llvm-cov-export:
 
 EXPORT COMMAND
 --------------
 
 SYNOPSIS
 ^^^^^^^^
 
-:program:`llvm-cov export` [*options*] -instr-profile *PROFILE* *BIN*
+:program:`llvm-cov export` [*options*] -instr-profile *PROFILE* *BIN* [*-object BIN,...*] [[*-object BIN*]]
 
 DESCRIPTION
 ^^^^^^^^^^^
 
 The :program:`llvm-cov export` command exports regions, functions, expansions,
-and summaries of the coverage of a binary *BIN* using the profile data
+and summaries of the coverage of the binaries *BIN*,... using the profile data
 *PROFILE* as JSON.
 
 For information on compiling programs for coverage and generating profile data,
 see :ref:`llvm-cov-show`.
 
 OPTIONS
 ^^^^^^^
 
 .. 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.

llvm/trunk/test/tools/llvm-cov/load-multiple-objects.test

+// RUN: llvm-profdata merge %S/Inputs/multiple-files.proftext %S/Inputs/highlightedRanges.profdata -o %t.profdata
+
+// RUN: llvm-cov report -object %S/Inputs/multiple-files.covmapping -instr-profile %t.profdata | FileCheck %s -check-prefix=OBJ1
+
+// RUN: llvm-cov report %S/Inputs/multiple-files.covmapping -object %S/Inputs/highlightedRanges.covmapping -instr-profile %t.profdata | FileCheck %s -check-prefixes=OBJ1,OBJ2
+
+// OBJ2: showHighlightedRanges.cpp
+// OBJ1: f2.c
+// OBJ1: f4.c
+// OBJ1: f3.c
+// OBJ1: f1.c

llvm/trunk/test/tools/llvm-cov/universal-binary.c

 // The coverage reader should be able to handle universal binaries
 
 // CHECK: [[@LINE+1]]| 100|int main
 int main(int argc, const char *argv[]) {}
 
 // RUN: llvm-profdata merge %S/Inputs/universal-binary.proftext -o %t.profdata
 // RUN: llvm-cov show %S/Inputs/universal-binary -instr-profile %t.profdata -filename-equivalence %s -arch x86_64 | FileCheck %s
 // RUN: llvm-cov export %S/Inputs/universal-binary -instr-profile %t.profdata -arch x86_64 2>&1 | FileCheck %S/Inputs/universal-binary.json
 
 
 // RUN: not llvm-cov show %S/Inputs/universal-binary -instr-profile %t.profdata -filename-equivalence %s -arch i386 2>&1 | FileCheck --check-prefix=WRONG-ARCH %s
 // WRONG-ARCH: Failed to load coverage
 
 // RUN: not llvm-cov report -instr-profile %t.profdata 2>&1 | FileCheck --check-prefix=MISSING-BINARY %s
-// MISSING-BINARY: 1 positional argument: See:
+// MISSING-BINARY: No filenames specified!

llvm/trunk/tools/llvm-cov/CodeCoverage.cpp

int show(int argc, const char **argv,
            CommandLineParserType commandLineParser);
 
   int report(int argc, const char **argv,
              CommandLineParserType commandLineParser);
 
   int export_(int argc, const char **argv,
               CommandLineParserType commandLineParser);
 
-  std::string ObjectFilename;
+  std::vector<StringRef> ObjectFilenames;
   CoverageViewOptions ViewOpts;
   CoverageFiltersMatchAll Filters;
 
   /// The path to the indexed profile.
   std::string PGOFilename;
 
   /// A list of input source files.
   std::vector<std::string> SourceFiles;
static bool modifiedTimeGT(StringRef LHS, StringRef RHS) {
   auto LHSTime = Status.getLastModificationTime();
   if (sys::fs::status(RHS, Status))
     return false;
   auto RHSTime = Status.getLastModificationTime();
   return LHSTime > RHSTime;
 }
 
 std::unique_ptr<CoverageMapping> CodeCoverageTool::load() {
+  for (StringRef ObjectFilename : ObjectFilenames)
     if (modifiedTimeGT(ObjectFilename, PGOFilename))
       warning("profile data may be out of date - object is newer",
               ObjectFilename);
   auto CoverageOrErr =
-      CoverageMapping::load(ObjectFilename, PGOFilename, CoverageArch);
+      CoverageMapping::load(ObjectFilenames, PGOFilename, CoverageArch);
   if (Error E = CoverageOrErr.takeError()) {
-    error("Failed to load coverage: " + toString(std::move(E)), ObjectFilename);
+    error("Failed to load coverage: " + toString(std::move(E)),
+          join(ObjectFilenames.begin(), ObjectFilenames.end(), ", "));
     return nullptr;
   }
   auto Coverage = std::move(CoverageOrErr.get());
   unsigned Mismatched = Coverage->getMismatchedCount();
   if (Mismatched)
     warning(utostr(Mismatched) + " functions have mismatched data");
 
   if (!SourceFiles.empty())
void CodeCoverageTool::writeSourceFileView(StringRef SourceFile,
   auto OS = std::move(OSOrErr.get());
 
   View->print(*OS.get(), /*Wholefile=*/true,
               /*ShowSourceName=*/ShowFilenames);
   Printer->closeViewFile(std::move(OS));
 }
 
 int CodeCoverageTool::run(Command Cmd, int argc, const char **argv) {
-  cl::opt<std::string, true> ObjectFilename(
-      cl::Positional, cl::Required, cl::location(this->ObjectFilename),
-      cl::desc("Covered executable or object file."));
+  cl::opt<std::string> CovFilename(
+      cl::Positional, cl::desc("Covered executable or object file."));
+
+  cl::list<std::string> CovFilenames(
+      "object", cl::desc("Coverage executable or object file"), cl::ZeroOrMore,
+      cl::CommaSeparated);
 
   cl::list<std::string> InputSourceFiles(
       cl::Positional, cl::desc("<Source files>"), cl::ZeroOrMore);
 
   cl::opt<bool> DebugDumpCollectedPaths(
       "dump-collected-paths", cl::Optional, cl::Hidden,
       cl::desc("Show the collected paths to source files"));
 
int CodeCoverageTool::run(Command Cmd, int argc, const char **argv) {
   cl::list<std::string> DemanglerOpts(
       "Xdemangler", cl::desc("<demangler-path>|<demangler-option>"));
 
   auto commandLineParser = [&, this](int argc, const char **argv) -> int {
     cl::ParseCommandLineOptions(argc, argv, "LLVM code coverage tool\n");
     ViewOpts.Debug = DebugDump;
     CompareFilenamesOnly = FilenameEquivalence;
 
+    if (!CovFilename.empty())
+      ObjectFilenames.emplace_back(CovFilename);
+    for (const std::string &Filename : CovFilenames)
+      ObjectFilenames.emplace_back(Filename);
+    if (ObjectFilenames.empty()) {
+      error("No filenames specified!");
+      ::exit(1);
+    }
+
     ViewOpts.Format = Format;
     switch (ViewOpts.Format) {
     case CoverageViewOptions::OutputFormat::Text:
       ViewOpts.Colors = UseColor == cl::BOU_UNSET
                             ? sys::Process::StandardOutHasColors()
                             : UseColor == cl::BOU_TRUE;
       break;
     case CoverageViewOptions::OutputFormat::HTML: