[CoverageMapping] Remove dots from paths inside the profile

[phosek]

Summary

We already remove dots from collected paths and path mappings. This
makes it difficult to match paths inside the profile which contain
dots. For example, we would never match /path/to/../file.c because
the collected path is always be normalized to /path/file.c. This
change enables dot removal for paths inside the profile to address
the issue.

[davidxl]

Is it possible to generate the covmapping file instead of checking a binary blob?

[phosek]

In D123164#3449606, @davidxl wrote:

Is it possible to generate the covmapping file instead of checking a binary blob?

Done

[davidxl]

lgtm

llvm/lib/ProfileData/Coverage/CoverageMappingReader.cpp

for (size_t I = 1; I < NumFilenames; ++I) {
         Filenames.push_back(Filename.str());
       } else {
         SmallString<256> P;
         if (!CompilationDir.empty())
           P.assign(CompilationDir);
         else
           P.assign(CWD);
         llvm::sys::path::append(P, Filename);
-        Filenames.push_back(static_cast<std::string>(P));
+        sys::path::remove_dots(P, /*remove_dot_dot=*/true);
+        Filenames.push_back(static_cast<std::string>(P.str()));
       }
     }
   }
   return Error::success();
 }
 
 Error RawCoverageMappingReader::decodeCounter(unsigned Value, Counter &C) {
   auto Tag = Value & Counter::EncodingTagMask;

llvm/test/tools/llvm-cov/Inputs/relative_dir/header.h

+int f() { return 0; }

llvm/test/tools/llvm-cov/Inputs/relative_dir/main.c

+#include "header.h"
+
+int main() {
+  return f();
+}

llvm/test/tools/llvm-cov/Inputs/relative_dir/main.proftext

+f
+# Func Hash:
+24
+# Num Counters:
+1
+# Counter Values:
+1
+
+main
+# Func Hash:
+24
+# Num Counters:
+1
+# Counter Values:
+1
+

llvm/test/tools/llvm-cov/coverage-prefix-map.test

 # RUN: llvm-cov report -path-equivalence=.,%S/Inputs/coverage_prefix_map \
 # RUN:   -instr-profile %S/Inputs/coverage_prefix_map/main.profdata \
 # RUN:   %S/Inputs/coverage_prefix_map/main.covmapping \
 # RUN:   %S/Inputs/coverage_prefix_map/bar.h \
 # RUN:   | FileCheck --check-prefix=REPORT --implicit-check-not=main.c %s
 
 # RUN: llvm-cov export -format lcov -path-equivalence=.,%S/Inputs/coverage_prefix_map \
 # RUN:   -instr-profile %S/Inputs/coverage_prefix_map/main.profdata \
 # RUN:   %S/Inputs/coverage_prefix_map/main.covmapping \
 # RUN:   %S/Inputs/coverage_prefix_map/bar.h \
 # RUN:   | FileCheck --check-prefix=LCOV --implicit-check-not=main.c %s
 
 # REPORT: {{^}}bar.h{{.*}}
 # REPORT: {{^}}TOTAL{{.*}}100.00%
 
-# LCOV: SF:.{{/|\\+}}bar.h
+# LCOV: SF:bar.h
 # LCOV-NOT: SF
 
 Instructions for regenerating the test:
 # cd %S/Inputs/coverage_prefix_map
 cp -r . /tmp/coverage_prefix_map
 
 clang -fprofile-instr-generate -mllvm -enable-name-compression=false -fcoverage-mapping -fcoverage-prefix-map=$PWD=. main.cc -o main
 LLVM_PROFILE_FILE="main.raw" ./main
 llvm-profdata merge main.raw -o main.profdata
 llvm-cov convert-for-testing ./main -o ./main.covmapping
 rm main main.raw

llvm/test/tools/llvm-cov/relative-dir.test

+# RUN: llvm-profdata merge %S/Inputs/relative_dir/main.proftext \
+# RUN:   -o %t.profdata
+# RUN: llvm-cov report %S/Inputs/relative_dir/main.covmapping \
+# RUN:   -instr-profile %t.profdata \
+# RUN:   -compilation-dir=%S/Inputs/relative_dir/out/default \
+# RUN:   %S/Inputs/relative_dir/header.h \
+# RUN:   | FileCheck -DDIR=%S %s
+
+# CHECK: {{^}}[[DIR]]{{/|\\}}Inputs{{/|\\}}relative_dir{{/|\\}}header.h{{.*}}
+# CHECK: {{^}}TOTAL{{.*}}100.00%

llvm/unittests/ProfileData/CoverageMappingTest.cpp

for (bool Compress : {false, true}) {
     std::vector<std::string> ReadFilenames;
     RawCoverageFilenamesReader Reader(EncodedFilenames, ReadFilenames);
     EXPECT_THAT_ERROR(Reader.read(CovMapVersion::CurrentVersion), Succeeded());
 
     ASSERT_EQ(ReadFilenames.size(), Paths.size());
     for (unsigned I = 1; I < Paths.size(); ++I) {
       SmallString<256> P(Paths[0]);
       llvm::sys::path::append(P, Paths[I]);
-      ASSERT_TRUE(ReadFilenames[I] == P);
+      ASSERT_EQ(ReadFilenames[I], P);
     }
   }
 }
 
 TEST(CoverageMappingTest, filename_compilation_dir) {
   std::vector<std::string> Paths({"dir", "a", "b", "c", "d", "e"});
 
   for (bool Compress : {false, true}) {
for (bool Compress : {false, true}) {
     RawCoverageFilenamesReader Reader(EncodedFilenames, ReadFilenames,
                                       CompilationDir);
     EXPECT_THAT_ERROR(Reader.read(CovMapVersion::CurrentVersion), Succeeded());
 
     ASSERT_EQ(ReadFilenames.size(), Paths.size());
     for (unsigned I = 1; I < Paths.size(); ++I) {
       SmallString<256> P(CompilationDir);
       llvm::sys::path::append(P, Paths[I]);
-      ASSERT_TRUE(ReadFilenames[I] == P);
+      ASSERT_EQ(ReadFilenames[I], P);
     }
   }
 }
 
 } // end anonymous namespace