Reinstate DW_AT_comp_dir support after D55519.

The DIFile used by the CU is special and distinct from the main source
file. Its directory part specifies what becomes the DW_AT_comp_dir
(the compilation directory), even if the source file was specified
with an absolute path.

To support the .dwo workflow, a valid DW_AT_comp_dir is necessary even
if source files were specified with an absolute path.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@349065 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 30 insertions, 9 deletions

diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index e45b38c10e..f3a07a30eb 100644
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -416,7 +416,6 @@ llvm::DIFile *CGDebugInfo::getOrCreateFile(SourceLocation Loc) {
 
   // Cache the results.
   auto It = DIFileCache.find(FileName.data());
-
   if (It != DIFileCache.end()) {
     // Verify that the information still exists.
     if (llvm::Metadata *V = It->second)
@@ -595,22 +594,27 @@ void CGDebugInfo::CreateCompileUnit() {
     break;
   }
 
+  uint64_t DwoId = 0;
+  auto &CGOpts = CGM.getCodeGenOpts();
+  // The DIFile used by the CU is distinct from the main source
+  // file. Its directory part specifies what becomes the
+  // DW_AT_comp_dir (the compilation directory), even if the source
+  // file was specified with an absolute path.
   if (CSKind)
     CSInfo.emplace(*CSKind, Checksum);
+  llvm::DIFile *CUFile = DBuilder.createFile(
+      remapDIPath(MainFileName), remapDIPath(getCurrentDirname()), CSInfo,
+      getSource(SM, SM.getMainFileID()));
 
   // Create new compile unit.
-  // FIXME - Eliminate TheCU.
-  auto &CGOpts = CGM.getCodeGenOpts();
   TheCU = DBuilder.createCompileUnit(
-      LangTag,
-      createFile(MainFileName, CSInfo, getSource(SM, SM.getMainFileID())),
-      CGOpts.EmitVersionIdentMetadata ? Producer : "",
+      LangTag, CUFile, CGOpts.EmitVersionIdentMetadata ? Producer : "",
       LO.Optimize || CGOpts.PrepareForLTO || CGOpts.PrepareForThinLTO,
       CGOpts.DwarfDebugFlags, RuntimeVers,
       (CGOpts.getSplitDwarfMode() != CodeGenOptions::NoFission)
           ? ""
           : CGOpts.SplitDwarfFile,
-      EmissionKind, 0 /* DWOid */, CGOpts.SplitDwarfInlining,
+      EmissionKind, DwoId, CGOpts.SplitDwarfInlining,
       CGOpts.DebugInfoForProfiling,
       CGM.getTarget().getTriple().isNVPTX()
           ? llvm::DICompileUnit::DebugNameTableKind::None
diff --git a/test/CodeGen/debug-info-abspath.c b/test/CodeGen/debug-info-abspath.c
index 1273235793..d360216da2 100644
--- a/test/CodeGen/debug-info-abspath.c
+++ b/test/CodeGen/debug-info-abspath.c
@@ -8,12 +8,29 @@
 // RUN: cp %s %t.c
 // RUN: %clang_cc1 -debug-info-kind=limited -triple %itanium_abi_triple \
 // 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-obj -o /tmp/t.o
+// 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() {}
 
 // Since %s is an absolute path, directory should be the common
 // prefix, but the directory part should be part of the filename.
 
-// CHECK: DIFile(filename: "{{.*}}UNIQUEISH_SENTINEL{{.*}}debug-info-abspath.c"
-// CHECK-NOT:    directory: "{{.*}}UNIQUEISH_SENTINEL
+// CHECK: = distinct !DISubprogram({{.*}}file: ![[SPFILE:[0-9]+]]
+// CHECK: ![[SPFILE]] = !DIFile(filename: "{{.*}}UNIQUEISH_SENTINEL
+// CHECK-SAME:                  debug-info-abspath.c"
+// CHECK-NOT:                   directory: "{{.*}}UNIQUEISH_SENTINEL
 
+// INTREE: = distinct !DISubprogram({{.*}}![[SPFILE:[0-9]+]]
 // INTREE: DIFile({{.*}}directory: "{{.+}}CodeGen{{.*}}")
+
+// CURDIR: = distinct !DICompileUnit({{.*}}file: ![[CUFILE:[0-9]+]]
+// CURDIR: ![[CUFILE]] = !DIFile({{.*}}directory: "{{.+}}UNIQUEISH_SENTINEL")
+