MIR Serialization: Report an error when machine functions have the same name.

This commit reports an error when the MIR parser encounters a machine
function with the name that is the same as the name of a different
machine function.

Reviewers: Duncan P. N. Exon Smith

Differential Revision: http://reviews.llvm.org/D10130

llvm-svn: 239774

2 files changed, 13 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/MIRParser/MIRParser.cpp b/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
index 69ecb923ed7..19e845fc01f 100644
--- a/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
+++ b/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
@@ -156,6 +156,9 @@ bool MIRParserImpl::parseMachineFunction(yaml::Input &In) {
   if (In.error())
     return true;
   auto FunctionName = MF->Name;
+  if (Functions.find(FunctionName) != Functions.end())
+    return error(Twine("redefinition of machine function '") + FunctionName +
+                 "'");
   Functions.insert(std::make_pair(FunctionName, std::move(MF)));
   return false;
 }
diff --git a/llvm/test/CodeGen/MIR/machine-function-redefinition-error.mir b/llvm/test/CodeGen/MIR/machine-function-redefinition-error.mir
new file mode 100644
index 00000000000..be84161b563
--- /dev/null
+++ b/llvm/test/CodeGen/MIR/machine-function-redefinition-error.mir
@@ -0,0 +1,10 @@
+# RUN: not llc -start-after branch-folder -stop-after branch-folder -o /dev/null %s 2>&1 | FileCheck %s
+# This test ensures that the machine function errors are reported correctly.
+
+---
+name:            foo
+...
+---
+# CHECK: redefinition of machine function 'foo'
+name:            foo
+...