Fix a crash with assembler source and -g.

llvm-mc or clang with -g normally produces debug info describing the
assembler source itself; however, if that source already contains some
.file/.loc directives, we should instead emit the debug info described
by those directives.  For certain assembler sources seen in the wild
(particularly in the Chrome build) this was causing a crash due to
incorrect assumptions about legal sequences of assembler source text.

Fixes PR38994.

Differential Revision: https://reviews.llvm.org/D63573

llvm-svn: 364039

1 files changed, 2 insertions, 2 deletions

diff --git a/llvm/lib/MC/MCParser/AsmParser.cpp b/llvm/lib/MC/MCParser/AsmParser.cpp
index f0d78a43190..694845e74f5 100644
--- a/llvm/lib/MC/MCParser/AsmParser.cpp
+++ b/llvm/lib/MC/MCParser/AsmParser.cpp
@@ -3395,9 +3395,9 @@ bool AsmParser::parseDirectiveFile(SMLoc DirectiveLoc) {
   } else {
     // In case there is a -g option as well as debug info from directive .file,
     // we turn off the -g option, directly use the existing debug info instead.
-    // Also reset any implicit ".file 0" for the assembler source.
+    // Throw away any implicit file table for the assembler source.
     if (Ctx.getGenDwarfForAssembly()) {
-      Ctx.getMCDwarfLineTable(0).resetRootFile();
+      Ctx.getMCDwarfLineTable(0).resetFileTable();
       Ctx.setGenDwarfForAssembly(false);
     }