[PATCH] D95753: [CoverageMapping] Don't absolutize source paths

[Petr Hosek via Phabricator via cfe-commits]

phosek created this revision.
phosek added reviewers: vsk, davidxl.
phosek requested review of this revision.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.

We currently always absolutize paths in coverage mapping. This is
problematic for reproducibility and it poses a problem for distributed
compilation where source location might differ across machines. It also
doesn't match path handling elsewhere in the compiler, for example in
debug info or __FILE__ expansion: we use the path as given to the
compiler, that is if Clang is invoked with a relative source path then
we use the relative path, and if invoked with an absolute path, then we
use the absolute path. This patch changes the coverage mapping behavior
to match that. We still cannonicalize the path by removing dots to avoid
duplicates in the coverage report.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D95753

Files:
  clang/lib/CodeGen/CoverageMappingGen.cpp
  clang/test/CoverageMapping/abspath.cpp
  clang/test/Profile/profile-prefix-map.c


Index: clang/test/Profile/profile-prefix-map.c
===================================================================
--- clang/test/Profile/profile-prefix-map.c
+++ clang/test/Profile/profile-prefix-map.c
@@ -5,10 +5,14 @@
 // RUN: echo "void f1() {}" > %t/root/nested/profile-prefix-map.c
 // RUN: cd %t/root
 
-// RUN: %clang_cc1 -fprofile-instrument=clang -fcoverage-mapping -emit-llvm -mllvm -enable-name-compression=false -main-file-name profile-prefix-map.c nested/profile-prefix-map.c -o - | FileCheck --check-prefix=ABSOLUTE %s
+// RUN: %clang_cc1 -fprofile-instrument=clang -fcoverage-mapping -emit-llvm -mllvm -enable-name-compression=false -main-file-name profile-prefix-map.c %t/root/nested/profile-prefix-map.c -o - | FileCheck --check-prefix=ABSOLUTE %s
 //
 // ABSOLUTE: @__llvm_coverage_mapping = {{.*"\\01.*root.*nested.*profile-prefix-map\.c}}
 
-// RUN: %clang_cc1 -fprofile-instrument=clang -fcoverage-mapping -emit-llvm -mllvm -enable-name-compression=false -main-file-name profile-prefix-map.c nested/profile-prefix-map.c -fprofile-prefix-map=%/t/root=. -o - | FileCheck --check-prefix=PROFILE-PREFIX-MAP %s --implicit-check-not=root
+// RUN: %clang_cc1 -fprofile-instrument=clang -fcoverage-mapping -emit-llvm -mllvm -enable-name-compression=false -main-file-name profile-prefix-map.c ../root/nested/profile-prefix-map.c -o - | FileCheck --check-prefix=RELATIVE %s
 //
+// RELATIVE: @__llvm_coverage_mapping = {{.*"\\01[^/]*}}..{{/|\\+}}root{{/|\\+}}nested{{.*profile-prefix-map\.c}}
+
+// RUN: %clang_cc1 -fprofile-instrument=clang -fcoverage-mapping -emit-llvm -mllvm -enable-name-compression=false -main-file-name profile-prefix-map.c %t/root/nested/profile-prefix-map.c -fprofile-prefix-map=%/t/root=. -o - | FileCheck --check-prefix=PROFILE-PREFIX-MAP %s
+// RUN: %clang_cc1 -fprofile-instrument=clang -fcoverage-mapping -emit-llvm -mllvm -enable-name-compression=false -main-file-name profile-prefix-map.c ../root/nested/profile-prefix-map.c -fprofile-prefix-map=../root=. -o - | FileCheck --check-prefix=PROFILE-PREFIX-MAP %s
 // PROFILE-PREFIX-MAP: @__llvm_coverage_mapping = {{.*"\\01[^/]*}}.{{/|\\+}}nested{{.*profile-prefix-map\.c}}
Index: clang/test/CoverageMapping/abspath.cpp
===================================================================
--- clang/test/CoverageMapping/abspath.cpp
+++ clang/test/CoverageMapping/abspath.cpp
@@ -7,9 +7,14 @@
 // RUN: mkdir -p %t/test && cd %t/test
 // RUN: echo "void f1() {}" > f1.c
 // RUN: %clang_cc1 -mllvm -emptyline-comment-coverage=false -fprofile-instrument=clang -fcoverage-mapping -mllvm -enable-name-compression=false -emit-llvm -main-file-name abspath.cpp ../test/f1.c -o - | FileCheck -check-prefix=RELPATH %s
+// RUN: %clang_cc1 -mllvm -emptyline-comment-coverage=false -fprofile-instrument=clang -fcoverage-mapping -mllvm -enable-name-compression=false -emit-llvm -main-file-name abspath.cpp %t/test/f1.c -o - | FileCheck -check-prefix=ABSPATH %s
 
 // RELPATH: @__llvm_coverage_mapping = {{.*}}"\01
-// RELPATH: {{[/\\].*(/|\\\\)test(/|\\\\)f1}}.c
+// RELPATH: {{..(/|\\\\)test(/|\\\\)f1}}.c
 // RELPATH: "
 
+// ABSPATH: @__llvm_coverage_mapping = {{.*}}"\01
+// ABSPATH: {{[/\\].*(/|\\\\)test(/|\\\\)f1}}.c
+// ABSPATH: "
+
 void f1() {}
Index: clang/lib/CodeGen/CoverageMappingGen.cpp
===================================================================
--- clang/lib/CodeGen/CoverageMappingGen.cpp
+++ clang/lib/CodeGen/CoverageMappingGen.cpp
@@ -1593,7 +1593,6 @@
 
 std::string CoverageMappingModuleGen::normalizeFilename(StringRef Filename) {
   llvm::SmallString<256> Path(Filename);
-  llvm::sys::fs::make_absolute(Path);
   llvm::sys::path::remove_dots(Path, /*remove_dot_dot=*/true);
   for (const auto &Entry : ProfilePrefixMap) {
     if (llvm::sys::path::replace_path_prefix(Path, Entry.first, Entry.second))


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