[gcov] Sort file info before printing it

[vsk]

Summary

The order in which GCOV file info is printed depends on the string hash
function. This makes some GCOV tests brittle, because the tests must be
updated whenever the hash function changes.

Sort the filenames before printing out the file info to solve the
problem. This should be relatively cheap.

[scott.smith]

lib/IR/GCOV.cpp

592

Personally I wouldn't bother with SmallVector; you'll probably get more mileage just specifying how many entries to expect by calling vector::reserve(LineInfo.size()).

I'm sure it's all noise either way though.

[davide]

LGTM

lib/IR/GCOV.cpp

if (EC) {
     return llvm::make_unique<raw_null_ostream>();
   }
   return std::move(OS);
 }
 
 /// print -  Print source files with collected line count information.
 void FileInfo::print(raw_ostream &InfoOS, StringRef MainFilename,
                      StringRef GCNOFile, StringRef GCDAFile) {
-  for (const auto &LI : LineInfo) {
-    StringRef Filename = LI.first();
+  SmallVector<StringRef, 4> Filenames;
+  for (const auto &LI : LineInfo)
+    Filenames.push_back(LI.first());
+  std::sort(Filenames.begin(), Filenames.end());
+
+  for (StringRef Filename : Filenames) {
     auto AllLines = LineConsumer(Filename);
 
     std::string CoveragePath = getCoveragePath(Filename, MainFilename);
     std::unique_ptr<raw_ostream> CovStream = openCoveragePath(CoveragePath);
     raw_ostream &CovOS = *CovStream;
 
     CovOS << "        -:    0:Source:" << Filename << "\n";
     CovOS << "        -:    0:Graph:" << GCNOFile << "\n";
     CovOS << "        -:    0:Data:" << GCDAFile << "\n";
     CovOS << "        -:    0:Runs:" << RunCount << "\n";
     CovOS << "        -:    0:Programs:" << ProgramCount << "\n";
 
-    const LineData &Line = LI.second;
+    const LineData &Line = LineInfo[Filename];
     GCOVCoverage FileCoverage(Filename);
     for (uint32_t LineIndex = 0; LineIndex < Line.LastLine || !AllLines.empty();
          ++LineIndex) {
       if (Options.BranchInfo) {
         FunctionLines::const_iterator FuncsIt = Line.Functions.find(LineIndex);
         if (FuncsIt != Line.Functions.end())
           printFunctionSummary(CovOS, FuncsIt->second);
       }

test/tools/llvm-cov/Inputs/test_-b.output

+File './test.h'
+Lines executed:100.00% of 1
+No branches
+No calls
+./test.h:creating 'test.h.gcov'
+
 File 'test.cpp'
 Lines executed:84.21% of 38
 Branches executed:100.00% of 15
 Taken at least once:86.67% of 15
 No calls
 test.cpp:creating 'test.cpp.gcov'
 
-File './test.h'
-Lines executed:100.00% of 1
-No branches
-No calls
-./test.h:creating 'test.h.gcov'
-

test/tools/llvm-cov/Inputs/test_-f.output

+Function '_ZN1AC1Ev'
+Lines executed:100.00% of 1
+
+Function '_ZN1AC2Ev'
+Lines executed:100.00% of 1
+
 Function '_ZN1A1BEv'
 Lines executed:100.00% of 1
 
 Function '_Z7uselessv'
 Lines executed:0.00% of 1
 
 Function '_Z12more_uselessv'
 Lines executed:0.00% of 1
 
 Function '_Z3foov'
 Lines executed:100.00% of 2
 
 Function '_Z3barv'
 Lines executed:0.00% of 2
 
 Function '_Z6assignii'
 Lines executed:100.00% of 3
 
 Function '_Z15initialize_gridv'
 Lines executed:100.00% of 4
 
 Function 'main'
 Lines executed:91.67% of 24
 
-Function '_ZN1AC1Ev'
-Lines executed:100.00% of 1
-
-Function '_ZN1AC2Ev'
+File './test.h'
 Lines executed:100.00% of 1
+./test.h:creating 'test.h.gcov'
 
 File 'test.cpp'
 Lines executed:84.21% of 38
 test.cpp:creating 'test.cpp.gcov'
 
-File './test.h'
-Lines executed:100.00% of 1
-./test.h:creating 'test.h.gcov'
-

test/tools/llvm-cov/Inputs/test_long_file_names.output

-File 'srcdir/./nested_dir/../test.h'
-Lines executed:100.00% of 1
-srcdir/./nested_dir/../test.h:creating 'test_paths.cpp##test.h.gcov'
-
 File 'srcdir/./nested_dir/../test.cpp'
 Lines executed:84.21% of 38
 srcdir/./nested_dir/../test.cpp:creating 'test_paths.cpp##test.cpp.gcov'
 
+File 'srcdir/./nested_dir/../test.h'
+Lines executed:100.00% of 1
+srcdir/./nested_dir/../test.h:creating 'test_paths.cpp##test.h.gcov'
+

test/tools/llvm-cov/Inputs/test_long_paths.output

-File 'srcdir/./nested_dir/../test.h'
-Lines executed:100.00% of 1
-srcdir/./nested_dir/../test.h:creating 'srcdir#^#test_paths.cpp##srcdir#nested_dir#^#test.h.gcov'
-
 File 'srcdir/./nested_dir/../test.cpp'
 Lines executed:84.21% of 38
 srcdir/./nested_dir/../test.cpp:creating 'srcdir#^#test_paths.cpp##srcdir#nested_dir#^#test.cpp.gcov'
 
+File 'srcdir/./nested_dir/../test.h'
+Lines executed:100.00% of 1
+srcdir/./nested_dir/../test.h:creating 'srcdir#^#test_paths.cpp##srcdir#nested_dir#^#test.h.gcov'
+

test/tools/llvm-cov/Inputs/test_missing.output

-File 'srcdir/./nested_dir/../test.h'
-Lines executed:100.00% of 1
-srcdir/./nested_dir/../test.h:creating 'test.h.gcov'
-
 File 'srcdir/./nested_dir/../test.cpp'
 Lines executed:84.21% of 38
 srcdir/./nested_dir/../test.cpp:creating 'test.cpp.gcov'
 
+File 'srcdir/./nested_dir/../test.h'
+Lines executed:100.00% of 1
+srcdir/./nested_dir/../test.h:creating 'test.h.gcov'
+

test/tools/llvm-cov/Inputs/test_no_gcda.output

-File 'test.cpp'
-Lines executed:0.00% of 38
-test.cpp:creating 'test.cpp.gcov'
-
 File './test.h'
 Lines executed:0.00% of 1
 ./test.h:creating 'test.h.gcov'
 
+File 'test.cpp'
+Lines executed:0.00% of 38
+test.cpp:creating 'test.cpp.gcov'
+

test/tools/llvm-cov/Inputs/test_no_options.output

-File 'test.cpp'
-Lines executed:84.21% of 38
-test.cpp:creating 'test.cpp.gcov'
-
 File './test.h'
 Lines executed:100.00% of 1
 ./test.h:creating 'test.h.gcov'
 
+File 'test.cpp'
+Lines executed:84.21% of 38
+test.cpp:creating 'test.cpp.gcov'
+

test/tools/llvm-cov/Inputs/test_no_output.output

-File 'test.cpp'
-Lines executed:84.21% of 38
-
 File './test.h'
 Lines executed:100.00% of 1
 
+File 'test.cpp'
+Lines executed:84.21% of 38
+

test/tools/llvm-cov/Inputs/test_no_preserve_paths.output

-File 'srcdir/./nested_dir/../test.h'
-Lines executed:100.00% of 1
-srcdir/./nested_dir/../test.h:creating 'test.h.gcov'
-
 File 'srcdir/./nested_dir/../test.cpp'
 Lines executed:84.21% of 38
 srcdir/./nested_dir/../test.cpp:creating 'test.cpp.gcov'
 
+File 'srcdir/./nested_dir/../test.h'
+Lines executed:100.00% of 1
+srcdir/./nested_dir/../test.h:creating 'test.h.gcov'
+

test/tools/llvm-cov/Inputs/test_preserve_paths.output

-File 'srcdir/./nested_dir/../test.h'
-Lines executed:100.00% of 1
-srcdir/./nested_dir/../test.h:creating 'srcdir#nested_dir#^#test.h.gcov'
-
 File 'srcdir/./nested_dir/../test.cpp'
 Lines executed:84.21% of 38
 srcdir/./nested_dir/../test.cpp:creating 'srcdir#nested_dir#^#test.cpp.gcov'
 
+File 'srcdir/./nested_dir/../test.h'
+Lines executed:100.00% of 1
+srcdir/./nested_dir/../test.h:creating 'srcdir#nested_dir#^#test.h.gcov'
+