[WebAssembly] Error out when block/loop markers mismatch
Summary:
Currently InstPrinter ignores if there are mismatches between block/loop
and end markers by skipping the case if ControlFlowStack is empty. I
guess it is better to explicitly error out in this case, because this
signals invalid input.
Reviewers: aardappel
Subscribers: dschuff, sbc100, jgravelle-google, sunfish, llvm-commits
Differential Revision: https://reviews.llvm.org/D53620
llvm-svn: 345333
diff --git a/llvm/lib/Target/WebAssembly/InstPrinter/WebAssemblyInstPrinter.cpp b/llvm/lib/Target/WebAssembly/InstPrinter/WebAssemblyInstPrinter.cpp
index 08c1155..e26cf1d 100644
--- a/llvm/lib/Target/WebAssembly/InstPrinter/WebAssemblyInstPrinter.cpp
+++ b/llvm/lib/Target/WebAssembly/InstPrinter/WebAssemblyInstPrinter.cpp
@@ -85,16 +85,16 @@
break;
case WebAssembly::END_LOOP:
case WebAssembly::END_LOOP_S:
- // Have to guard against an empty stack, in case of mismatched pairs
- // in assembly parsing.
- if (!ControlFlowStack.empty())
- ControlFlowStack.pop_back();
+ if (ControlFlowStack.empty())
+ report_fatal_error("End marker mismatch!");
+ ControlFlowStack.pop_back();
break;
case WebAssembly::END_BLOCK:
case WebAssembly::END_BLOCK_S:
- if (!ControlFlowStack.empty())
- printAnnotation(
- OS, "label" + utostr(ControlFlowStack.pop_back_val().first) + ':');
+ if (ControlFlowStack.empty())
+ report_fatal_error("END marker mismatch!");
+ printAnnotation(
+ OS, "label" + utostr(ControlFlowStack.pop_back_val().first) + ':');
break;
}