[clang][CodeGen] Remove CWD fallback in compilation directory #150130

cachemeifyoucan · 2025-07-22T22:27:21Z

CWD is queried in clang driver and passed to clang cc1 via flags when
needed. Respect the cc1 flags and do not repeated checking current
working directory in CodeGen.

Created using spr 1.3.6 [skip ci]

Created using spr 1.3.6

llvmbot · 2025-07-22T22:28:00Z

@llvm/pr-subscribers-debuginfo
@llvm/pr-subscribers-clang

@llvm/pr-subscribers-clang-codegen

Author: Steven Wu (cachemeifyoucan)

Changes

CWD is queried in clang driver and passed to clang cc1 via flags when
needed. Respect the cc1 flags and do not repeated checking current
working directory in CodeGen.

Full diff: https://github.com/llvm/llvm-project/pull/150130.diff

12 Files Affected:

(modified) clang/lib/CodeGen/CGDebugInfo.cpp (+4-10)
(modified) clang/lib/CodeGen/CGDebugInfo.h (-1)
(modified) clang/lib/CodeGen/CoverageMappingGen.cpp (+1-6)
(modified) clang/test/CodeGen/debug-info-abspath.c (+2-11)
(modified) clang/test/CodeGen/debug-info-compilation-dir.c (+7)
(modified) clang/test/CodeGen/debug-prefix-map.c (+4-1)
(modified) clang/test/CodeGenCXX/debug-info-function-context.cpp (+1-1)
(modified) clang/test/CodeGenCXX/difile_entry.cpp (+1-1)
(modified) clang/test/PCH/debug-info-pch-container-path.c (+1)
(modified) clang/test/PCH/debug-info-pch-path.c (+2-1)
(modified) clang/test/Profile/coverage-prefix-map.c (+1-1)
(modified) clang/unittests/Frontend/CodeGenActionTest.cpp (-36)

diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index a371b6755f74d..fcad19218502a 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -643,16 +643,7 @@ unsigned CGDebugInfo::getColumnNumber(SourceLocation Loc, bool Force) {
 }
 
 StringRef CGDebugInfo::getCurrentDirname() {
-  if (!CGM.getCodeGenOpts().DebugCompilationDir.empty())
-    return CGM.getCodeGenOpts().DebugCompilationDir;
-
-  if (!CWDName.empty())
-    return CWDName;
-  llvm::ErrorOr<std::string> CWD =
-      CGM.getFileSystem()->getCurrentWorkingDirectory();
-  if (!CWD)
-    return StringRef();
-  return CWDName = internString(*CWD);
+  return CGM.getCodeGenOpts().DebugCompilationDir;
 }
 
 void CGDebugInfo::CreateCompileUnit() {
@@ -3246,6 +3237,9 @@ llvm::DIModule *CGDebugInfo::getOrCreateModuleRef(ASTSourceDescriptor Mod,
     std::string Remapped = remapDIPath(Path);
     StringRef Relative(Remapped);
     StringRef CompDir = TheCU->getDirectory();
+    if (CompDir.empty())
+      return Remapped;
+
     if (Relative.consume_front(CompDir))
       Relative.consume_front(llvm::sys::path::get_separator());
 
diff --git a/clang/lib/CodeGen/CGDebugInfo.h b/clang/lib/CodeGen/CGDebugInfo.h
index 411b2e718da30..497d3a6ab17b1 100644
--- a/clang/lib/CodeGen/CGDebugInfo.h
+++ b/clang/lib/CodeGen/CGDebugInfo.h
@@ -158,7 +158,6 @@ class CGDebugInfo {
   /// This is a storage for names that are constructed on demand. For
   /// example, C++ destructors, C++ operators etc..
   llvm::BumpPtrAllocator DebugInfoNames;
-  StringRef CWDName;
 
   llvm::DenseMap<const char *, llvm::TrackingMDRef> DIFileCache;
   llvm::DenseMap<const FunctionDecl *, llvm::TrackingMDRef> SPCache;
diff --git a/clang/lib/CodeGen/CoverageMappingGen.cpp b/clang/lib/CodeGen/CoverageMappingGen.cpp
index 4aafac349e3e9..38aaceb6c462d 100644
--- a/clang/lib/CodeGen/CoverageMappingGen.cpp
+++ b/clang/lib/CodeGen/CoverageMappingGen.cpp
@@ -2449,12 +2449,7 @@ CoverageMappingModuleGen::CoverageMappingModuleGen(
     : CGM(CGM), SourceInfo(SourceInfo) {}
 
 std::string CoverageMappingModuleGen::getCurrentDirname() {
-  if (!CGM.getCodeGenOpts().CoverageCompilationDir.empty())
-    return CGM.getCodeGenOpts().CoverageCompilationDir;
-
-  SmallString<256> CWD;
-  llvm::sys::fs::current_path(CWD);
-  return CWD.str().str();
+  return CGM.getCodeGenOpts().CoverageCompilationDir;
 }
 
 std::string CoverageMappingModuleGen::normalizeFilename(StringRef Filename) {
diff --git a/clang/test/CodeGen/debug-info-abspath.c b/clang/test/CodeGen/debug-info-abspath.c
index b2047a7deb0e0..193a72c0a66fd 100644
--- a/clang/test/CodeGen/debug-info-abspath.c
+++ b/clang/test/CodeGen/debug-info-abspath.c
@@ -2,20 +2,15 @@
 // RUN: cp %s %t/UNIQUEISH_SENTINEL/debug-info-abspath.c
 
 // RUN: %clang_cc1 -debug-info-kind=limited -triple %itanium_abi_triple \
+// RUN:   -fdebug-compilation-dir=%t/UNIQUEISH_SENTINEL/debug-info-abspath.c \
 // RUN:   %t/UNIQUEISH_SENTINEL/debug-info-abspath.c -emit-llvm -o - \
 // RUN:   | FileCheck %s
 
 // RUN: cp %s %t.c
 // RUN: %clang_cc1 -debug-info-kind=limited -triple %itanium_abi_triple \
+// RUN:   -fdebug-compilation-dir=%t \
 // RUN:   %t.c -emit-llvm -o - | FileCheck %s --check-prefix=INTREE
 
-// RUN: cd %t/UNIQUEISH_SENTINEL
-// RUN: %clang_cc1 -debug-info-kind=limited -triple %itanium_abi_triple \
-// RUN:   debug-info-abspath.c -emit-llvm -o - \
-// RUN:   | FileCheck %s --check-prefix=CURDIR
-// RUN: %clang_cc1 -debug-info-kind=limited -triple %itanium_abi_triple \
-// RUN:   %s -emit-llvm -o - | FileCheck %s --check-prefix=CURDIR
-
 void foo(void) {}
 
 // Since %s is an absolute path, directory should be the common
@@ -28,7 +23,3 @@ void foo(void) {}
 
 // INTREE: = distinct !DISubprogram({{.*}}![[SPFILE:[0-9]+]]
 // INTREE: DIFile({{.*}}directory: "{{.+}}CodeGen{{.*}}")
-
-// CURDIR: = distinct !DICompileUnit({{.*}}file: ![[CUFILE:[0-9]+]]
-// CURDIR: ![[CUFILE]] = !DIFile({{.*}}directory: "{{.+}}UNIQUEISH_SENTINEL")
-
diff --git a/clang/test/CodeGen/debug-info-compilation-dir.c b/clang/test/CodeGen/debug-info-compilation-dir.c
index b49a0f5751f8e..5f5542c525495 100644
--- a/clang/test/CodeGen/debug-info-compilation-dir.c
+++ b/clang/test/CodeGen/debug-info-compilation-dir.c
@@ -7,3 +7,10 @@
 // RUN: %clang_cc1 -emit-llvm -debug-info-kind=limited %s -o - | FileCheck -check-prefix=CHECK-DIR %s
 // CHECK-DIR: CodeGen
 
+/// Test path remapping.
+// RUN: %clang_cc1 -fdebug-compilation-dir=%S -main-file-name %s -emit-llvm -debug-info-kind=limited %s -o - | FileCheck -check-prefix=CHECK-ABS %s
+// CHECK-ABS: DIFile(filename: "{{.*}}debug-info-compilation-dir.c", directory: "{{.*}}CodeGen")
+
+// RUN: %clang_cc1 -main-file-name %s -emit-llvm -debug-info-kind=limited %s -o - | FileCheck -check-prefix=CHECK-NOMAP %s
+// CHECK-NOMAP: DIFile(filename: "{{.*}}debug-info-compilation-dir.c", directory: "")
+
diff --git a/clang/test/CodeGen/debug-prefix-map.c b/clang/test/CodeGen/debug-prefix-map.c
index e2421806b055b..e58909f5acaaa 100644
--- a/clang/test/CodeGen/debug-prefix-map.c
+++ b/clang/test/CodeGen/debug-prefix-map.c
@@ -12,6 +12,7 @@
 // RUN: rm -rf %t && mkdir -p %t/a/b && cp %s %t/a/b/c.c
 // RUN: %clang_cc1 -emit-llvm -debug-info-kind=standalone -I%S -fdebug-prefix-map=%t/a/b=y -fdebug-prefix-map=%t/a=x %t/a/b/c.c -o - | FileCheck %s --check-prefix=CHECK-X
 // RUN: %clang_cc1 -emit-llvm -debug-info-kind=standalone -I%S -fdebug-prefix-map=%t/a=x -fdebug-prefix-map=%t/a/b=y %t/a/b/c.c -o - | FileCheck %s --check-prefix=CHECK-Y
+// RUN: %clang_cc1 -emit-llvm -debug-info-kind=standalone -I%S -main-file-name %t/a/b/c.c -fdebug-compilation-dir=%t/a -fdebug-prefix-map=%t/a=x -fdebug-prefix-map=%t/a/b=y %t/a/b/c.c -o - | FileCheck %s --check-prefix=CHECK-REMAP-Y
 
 #include "Inputs/stdio.h"
 
@@ -26,9 +27,9 @@ void test_rewrite_includes(void) {
   vprintf("string", argp);
 }
 
-// CHECK-NO-MAIN-FILE-NAME: !DIFile(filename: "{{/|.:\\\\}}UNLIKELY_PATH{{/|\\\\}}empty{{/|\\\\}}<stdin>",
 // CHECK-NO-MAIN-FILE-NAME: !DIFile(filename: "{{/|.:\\\\}}UNLIKELY_PATH{{/|\\\\}}empty{{/|\\\\}}{{.*}}",
 // CHECK-NO-MAIN-FILE-NAME-SAME:    directory: "")
+// CHECK-NO-MAIN-FILE-NAME: !DIFile(filename: "{{/|.:\\\\}}UNLIKELY_PATH{{/|\\\\}}empty{{/|\\\\}}<stdin>",
 // CHECK-NO-MAIN-FILE-NAME: !DIFile(filename: "{{/|.:\\\\}}UNLIKELY_PATH{{/|\\\\}}empty{{/|\\\\}}Inputs{{/|\\\\}}stdio.h",
 // CHECK-NO-MAIN-FILE-NAME-SAME:    directory: "")
 // CHECK-NO-MAIN-FILE-NAME-NOT: !DIFile(filename:
@@ -54,3 +55,5 @@ void test_rewrite_includes(void) {
 
 // CHECK-X: !DIFile(filename: "x{{/|\\\\}}b{{/|\\\\}}c.c", directory: "")
 // CHECK-Y: !DIFile(filename: "y{{/|\\\\}}c.c", directory: "")
+
+// CHECK-REMAP-Y: !DIFile(filename: "y{{/|\\\\}}c.c", directory: "x")
diff --git a/clang/test/CodeGenCXX/debug-info-function-context.cpp b/clang/test/CodeGenCXX/debug-info-function-context.cpp
index 63fdf877fdb7d..29c87b6ec0055 100644
--- a/clang/test/CodeGenCXX/debug-info-function-context.cpp
+++ b/clang/test/CodeGenCXX/debug-info-function-context.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -emit-llvm -debug-info-kind=limited -triple x86_64-pc-linux-gnu %s \
+// RUN: %clang_cc1 -emit-llvm -debug-info-kind=limited -triple x86_64-pc-linux-gnu %s -fdebug-compilation-dir=%S \
 // RUN:     -dwarf-version=5 -main-file-name debug-info-function-context.cpp  -o - | FileCheck %s
 
 struct C {
diff --git a/clang/test/CodeGenCXX/difile_entry.cpp b/clang/test/CodeGenCXX/difile_entry.cpp
index 8bf6dc325470b..5fcd56ee3d053 100644
--- a/clang/test/CodeGenCXX/difile_entry.cpp
+++ b/clang/test/CodeGenCXX/difile_entry.cpp
@@ -3,7 +3,7 @@
 /// Test that we canonicalize the DIFile.
 // RUN: rm -rf %t && mkdir %t && cd %t
 // RUN: cp %s .
-// RUN: %clang_cc1 -triple %itanium_abi_triple -main-file-name difile_entry.cpp -debug-info-kind=limited %t/difile_entry.cpp -std=c++11 -emit-llvm -o - | FileCheck %s
+// RUN: %clang_cc1 -triple %itanium_abi_triple -main-file-name difile_entry.cpp -fdebug-compilation-dir=%t -debug-info-kind=limited %t/difile_entry.cpp -std=c++11 -emit-llvm -o - | FileCheck %s
 int x();
 static int i = x();
 
diff --git a/clang/test/PCH/debug-info-pch-container-path.c b/clang/test/PCH/debug-info-pch-container-path.c
index 257cbf54e06bc..19b1a28f5bce4 100644
--- a/clang/test/PCH/debug-info-pch-container-path.c
+++ b/clang/test/PCH/debug-info-pch-container-path.c
@@ -9,6 +9,7 @@
 // RUN:     -triple %itanium_abi_triple                         \
 // RUN:     -fdebug-prefix-map=%t=BUILD                         \
 // RUN:     -fdebug-prefix-map=%S=SOURCE                        \
+// RUN:     -fdebug-compilation-dir=%t                          \
 // RUN:     -o %t/prefix.ll %S/debug-info-limited-struct.h      \
 // RUN:   -mllvm -debug-only=pchcontainer &>%t-container.ll
 // RUN: cat %t-container.ll | FileCheck %s
diff --git a/clang/test/PCH/debug-info-pch-path.c b/clang/test/PCH/debug-info-pch-path.c
index f94d2fa8d09e9..22b367f344204 100644
--- a/clang/test/PCH/debug-info-pch-path.c
+++ b/clang/test/PCH/debug-info-pch-path.c
@@ -65,7 +65,8 @@
 // RUN: %clang_cc1 -debug-info-kind=standalone                  \
 // RUN:     -dwarf-ext-refs -fmodule-format=obj                 \
 // RUN:     -triple %itanium_abi_triple                         \
-// RUN:     -include-pch %t/prefix.pch %s -emit-llvm -o %t.abs.ll %s
+// RUN:     -include-pch %t/prefix.pch %s -emit-llvm            \
+// RUN:     -fdebug-compilation-dir=%t -o %t.abs.ll %s
 // RUN: cat %t.abs.ll | FileCheck %s --check-prefix=CHECK-ABS
 
 // CHECK-ABS: !DICompileUnit
diff --git a/clang/test/Profile/coverage-prefix-map.c b/clang/test/Profile/coverage-prefix-map.c
index de9e3773f66d2..1cb095f2bdbf6 100644
--- a/clang/test/Profile/coverage-prefix-map.c
+++ b/clang/test/Profile/coverage-prefix-map.c
@@ -25,7 +25,7 @@
 // COVERAGE-PREFIX-MAP-ORDER: @__llvm_coverage_mapping = {{.*"\\02.*newpath.*root.*nested.*coverage-prefix-map\.c}}
 
 // Test that last -fcoverage-prefix-map option (-fcoverage-prefix-map=%/t/root=.) is applied.
-// RUN: %clang_cc1 -fprofile-instrument=clang -fcoverage-mapping -emit-llvm -mllvm -enable-name-compression=false -main-file-name coverage-prefix-map.c %t/root/nested/coverage-prefix-map.c -fcoverage-prefix-map==newpath -fcoverage-prefix-map=%/t/root=. -o - | FileCheck --check-prefix=COVERAGE-PREFIX-MAP-REORDER %s
+// RUN: %clang_cc1 -fprofile-instrument=clang -fcoverage-mapping -emit-llvm -mllvm -enable-name-compression=false -main-file-name coverage-prefix-map.c %t/root/nested/coverage-prefix-map.c -fcoverage-compilation-dir=%t/root -fcoverage-prefix-map==newpath -fcoverage-prefix-map=%/t/root=. -o - | FileCheck --check-prefix=COVERAGE-PREFIX-MAP-REORDER %s
 // COVERAGE-PREFIX-MAP-REORDER: @__llvm_coverage_mapping =
 // COVERAGE-PREFIX-MAP-REORDER-NOT: newpath
 // COVERAGE-PREFIX-MAP-REORDER-SAME: nested{{.*coverage-prefix-map\.c}}
diff --git a/clang/unittests/Frontend/CodeGenActionTest.cpp b/clang/unittests/Frontend/CodeGenActionTest.cpp
index 90818b72cd6e6..b2792c44ba5fe 100644
--- a/clang/unittests/Frontend/CodeGenActionTest.cpp
+++ b/clang/unittests/Frontend/CodeGenActionTest.cpp
@@ -76,40 +76,4 @@ TEST(CodeGenTest, CodeGenFromIRMemBuffer) {
   bool Success = Compiler.ExecuteAction(Action);
   EXPECT_TRUE(Success);
 }
-
-TEST(CodeGenTest, DebugInfoCWDCodeGen) {
-  // Check that debug info is accessing the current working directory from the
-  // VFS instead of calling \p llvm::sys::fs::current_path() directly.
-
-  auto Sept = llvm::sys::path::get_separator();
-  auto VFS = std::make_unique<llvm::vfs::InMemoryFileSystem>();
-  VFS->setCurrentWorkingDirectory(
-      std::string(llvm::formatv("{0}in-memory-fs-cwd", Sept)));
-  std::string TestPath =
-      std::string(llvm::formatv("{0}in-memory-fs-cwd{0}test.cpp", Sept));
-  VFS->addFile(TestPath, 0, llvm::MemoryBuffer::getMemBuffer("int x;\n"));
-
-  auto Invocation = std::make_shared<CompilerInvocation>();
-  Invocation->getFrontendOpts().Inputs.push_back(
-      FrontendInputFile("test.cpp", Language::CXX));
-  Invocation->getFrontendOpts().ProgramAction = EmitLLVM;
-  Invocation->getTargetOpts().Triple = "x86_64-unknown-linux-gnu";
-  Invocation->getCodeGenOpts().setDebugInfo(codegenoptions::FullDebugInfo);
-  CompilerInstance Compiler(std::move(Invocation));
-
-  SmallString<256> IRBuffer;
-  Compiler.setOutputStream(std::make_unique<raw_svector_ostream>(IRBuffer));
-  Compiler.createDiagnostics(*VFS);
-  Compiler.createFileManager(std::move(VFS));
-
-  EmitLLVMAction Action;
-  bool Success = Compiler.ExecuteAction(Action);
-  EXPECT_TRUE(Success);
-
-  SmallString<128> RealCWD;
-  llvm::sys::fs::current_path(RealCWD);
-  EXPECT_TRUE(!RealCWD.empty());
-  EXPECT_FALSE(IRBuffer.str().contains(RealCWD));
-  EXPECT_TRUE(IRBuffer.str().contains("in-memory-fs-cwd"));
-}
 }

Created using spr 1.3.6 [skip ci]

Created using spr 1.3.6

…e-cwd-fallback-in-compilation-directory

…50130) CWD is queried in clang driver and passed to clang cc1 via flags when needed. Respect the cc1 flags and do not repeated checking current working directory in CodeGen.

Fix a logic mistake in DebugInfo CodeGen that if the compilation directory is empty, the leading separator is dropped with emitting path. This code path is usually not possible in current state unless the compilation is done from a file system that do not have current working directory and compilation caching include tree file system is such a file system. This causes PCMs are encoded with wrong path in the gmodule compilation, causing lost of debug info. Note this is a reduced and safer version from upstream fix: llvm#150130 The test is in swift repo since the only trigger in current branch is to trigger from swift caching builds. rdar://156759645

…50130) CWD is queried in clang driver and passed to clang cc1 via flags when needed. Respect the cc1 flags and do not repeated checking current working directory in CodeGen.

cachemeifyoucan added 2 commits July 22, 2025 15:27

[𝘀𝗽𝗿] changes to main this commit is based on

075ebf7

Created using spr 1.3.6 [skip ci]

[𝘀𝗽𝗿] initial version

75556bb

Created using spr 1.3.6

llvmbot added clang Clang issues not falling into any other category clang:codegen IR generation bugs: mangling, exceptions, etc. debuginfo labels Jul 22, 2025

cachemeifyoucan requested a review from jansvoboda11 July 22, 2025 22:28

cachemeifyoucan mentioned this pull request Jul 22, 2025

[clang] Infer compilation directory in driver #150112

Merged

cachemeifyoucan added 2 commits July 31, 2025 10:43

[𝘀𝗽𝗿] changes introduced through rebase

38f00e3

Created using spr 1.3.6 [skip ci]

rebase to main

a839309

Created using spr 1.3.6

cachemeifyoucan changed the base branch from users/cachemeifyoucan/spr/main.clangcodegen-remove-cwd-fallback-in-compilation-directory to main July 31, 2025 17:45

cachemeifyoucan added 2 commits July 31, 2025 10:46

Rebase to main

aeb20c1

Created using spr 1.3.6

Merge branch 'main' into users/cachemeifyoucan/spr/clangcodegen-remov…

d6025ae

…e-cwd-fallback-in-compilation-directory

cachemeifyoucan merged commit 3c08498 into main Jul 31, 2025
9 checks passed

cachemeifyoucan deleted the users/cachemeifyoucan/spr/clangcodegen-remove-cwd-fallback-in-compilation-directory branch July 31, 2025 23:32

cachemeifyoucan mentioned this pull request Aug 5, 2025

[6.2][clang][DebugInfo] Handle empty comp_dir in CodeGen swiftlang/llvm-project#11125

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[clang][CodeGen] Remove CWD fallback in compilation directory #150130

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