[MC] - Don't crash on unclosed frame.

llvm-mc can crash when
there is cfi_startproc without cfi_end_proc:

.text
.globl foo
foo:
 .cfi_startproc

Testcase shows the issue, patch fixes it.

Differential revision: https://reviews.llvm.org/D43456

llvm-svn: 325564

diff --git a/llvm/lib/MC/MCStreamer.cpp b/llvm/lib/MC/MCStreamer.cpp
index bc9c93f..a2c58e6 100644 (file)
--- a/llvm/lib/MC/MCStreamer.cpp
+++ b/llvm/lib/MC/MCStreamer.cpp
@@ -816,10 +816,11 @@ void MCStreamer::EmitWindowsUnwindTables() {
 }
 
 void MCStreamer::Finish() {
-  if (!DwarfFrameInfos.empty() && !DwarfFrameInfos.back().End)
-    getContext().reportError(SMLoc(), "Unfinished frame!");
-  if (!WinFrameInfos.empty() && !WinFrameInfos.back()->End)
+  if ((!DwarfFrameInfos.empty() && !DwarfFrameInfos.back().End) ||
+      (!WinFrameInfos.empty() && !WinFrameInfos.back()->End)) {
     getContext().reportError(SMLoc(), "Unfinished frame!");
+    return;
+  }
 
   MCTargetStreamer *TS = getTargetStreamer();
   if (TS)

diff --git a/llvm/test/MC/X86/cfi-scope-unclosed.s b/llvm/test/MC/X86/cfi-scope-unclosed.s
new file mode 100644 (file)
index 0000000..0574a97
--- /dev/null
+++ b/llvm/test/MC/X86/cfi-scope-unclosed.s
@@ -0,0 +1,10 @@
+# RUN: not llvm-mc %s -filetype=obj -triple=x86_64-unknown-linux \
+# RUN:   -o /dev/null 2>&1 | FileCheck %s
+
+## Check we don't crash on unclosed frame scope.
+# CHECK: error: Unfinished frame!
+
+.text
+.globl foo
+foo:
+ .cfi_startproc