3 files changed, 33 insertions, 23 deletions

diff --git a/llvm/lib/MC/MCContext.cpp b/llvm/lib/MC/MCContext.cpp
index 322ed8e23eb6..062246f9c7ee 100644
--- a/llvm/lib/MC/MCContext.cpp
+++ b/llvm/lib/MC/MCContext.cpp
@@ -855,30 +855,35 @@ void MCContext::addDebugPrefixMapEntry(const std::string &From,
   DebugPrefixMap.insert(std::make_pair(From, To));
 }
 
+void MCContext::remapDebugPath(SmallVectorImpl<char> &Path) {
+  for (const auto &V : DebugPrefixMap)
+    if (llvm::sys::path::replace_path_prefix(Path, V.first, V.second))
+      break;
+}
+
 void MCContext::RemapDebugPaths() {
   const auto &DebugPrefixMap = this->DebugPrefixMap;
   if (DebugPrefixMap.empty())
     return;
 
-  const auto RemapDebugPath = [&DebugPrefixMap](std::string &Path) {
-    SmallString<256> P(Path);
-    for (const auto &Entry : DebugPrefixMap) {
-      if (llvm::sys::path::replace_path_prefix(P, Entry.first, Entry.second)) {
-        Path = P.str().str();
-        break;
-      }
+  // Remap compilation directory.
+  remapDebugPath(CompilationDir);
+
+  // Remap MCDwarfDirs and RootFile.Name in all compilation units.
+  SmallString<256> P;
+  for (auto &CUIDTablePair : MCDwarfLineTablesCUMap) {
+    for (auto &Dir : CUIDTablePair.second.getMCDwarfDirs()) {
+      P = Dir;
+      remapDebugPath(P);
+      Dir = std::string(P);
     }
-  };
 
-  // Remap compilation directory.
-  std::string CompDir = std::string(CompilationDir.str());
-  RemapDebugPath(CompDir);
-  CompilationDir = CompDir;
-
-  // Remap MCDwarfDirs in all compilation units.
-  for (auto &CUIDTablePair : MCDwarfLineTablesCUMap)
-    for (auto &Dir : CUIDTablePair.second.getMCDwarfDirs())
-      RemapDebugPath(Dir);
+    // Used by DW_TAG_compile_unit's DT_AT_name and DW_TAG_label's
+    // DW_AT_decl_file for DWARF v5 generated for assembly source.
+    P = CUIDTablePair.second.getRootFile().Name;
+    remapDebugPath(P);
+    CUIDTablePair.second.getRootFile().Name = std::string(P);
+  }
 }
 
 //===----------------------------------------------------------------------===//
diff --git a/llvm/lib/MC/MCDwarf.cpp b/llvm/lib/MC/MCDwarf.cpp
index 4cbb9981fde2..cc1a662da87e 100644
--- a/llvm/lib/MC/MCDwarf.cpp
+++ b/llvm/lib/MC/MCDwarf.cpp
@@ -266,7 +266,7 @@ void MCDwarfLineTable::emit(MCStreamer *MCOS, MCDwarfLineTableParams Params) {
   // In a v5 non-split line table, put the strings in a separate section.
   Optional<MCDwarfLineStr> LineStr;
   if (context.getDwarfVersion() >= 5)
-    LineStr = MCDwarfLineStr(context);
+    LineStr.emplace(context);
 
   // Switch to the section where the table will be emitted into.
   MCOS->switchSection(context.getObjectFileInfo()->getDwarfLineSection());
@@ -416,9 +416,15 @@ void MCDwarfLineTableHeader::emitV5FileDirTables(
                                     : dwarf::DW_FORM_string);
   MCOS->emitULEB128IntValue(MCDwarfDirs.size() + 1);
   // Try not to emit an empty compilation directory.
-  const StringRef CompDir = CompilationDir.empty()
-                                ? MCOS->getContext().getCompilationDir()
-                                : StringRef(CompilationDir);
+  SmallString<256> Dir;
+  StringRef CompDir = MCOS->getContext().getCompilationDir();
+  if (!CompilationDir.empty()) {
+    Dir = CompilationDir;
+    MCOS->getContext().remapDebugPath(Dir);
+    CompDir = Dir.str();
+    if (LineStr)
+      CompDir = LineStr->getSaver().save(CompDir);
+  }
   if (LineStr) {
     // Record path strings, emit references here.
     LineStr->emitRef(MCOS, CompDir);
diff --git a/llvm/lib/MC/MCParser/ELFAsmParser.cpp b/llvm/lib/MC/MCParser/ELFAsmParser.cpp
index 563d3487ef50..38977b7641a0 100644
--- a/llvm/lib/MC/MCParser/ELFAsmParser.cpp
+++ b/llvm/lib/MC/MCParser/ELFAsmParser.cpp
@@ -566,8 +566,7 @@ bool ELFAsmParser::ParseSectionArguments(bool IsPush, SMLoc loc) {
     }
 
     if (getLexer().isNot(AsmToken::String)) {
-      if (!getContext().getAsmInfo()->usesSunStyleELFSectionSwitchSyntax()
-          || getLexer().isNot(AsmToken::Hash))
+      if (getLexer().isNot(AsmToken::Hash))
         return TokError("expected string in directive");
       extraFlags = parseSunStyleSectionFlags();
     } else {