Fix SEGV in InlineAsm::ConstraintInfo::Parse.

Fixes bug 24646. Previous code was not checking if an index into a vector
was valid, resulting in a SEGV. Fixed by assuming the construct can't
be parsed when given this input.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246773 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/IR/InlineAsm.cpp b/lib/IR/InlineAsm.cpp
index a181c5e834da9b62ef03145c293cbb7b4ccf201c..b7309b4f67b8b407345171e3220b234950563a4e 100644 (file)
--- a/lib/IR/InlineAsm.cpp
+++ b/lib/IR/InlineAsm.cpp
@@ -159,6 +159,8 @@ bool InlineAsm::ConstraintInfo::Parse(StringRef Str,
       // If Operand N already has a matching input, reject this.  An output
       // can't be constrained to the same value as multiple inputs.
       if (isMultipleAlternative) {
+        if (multipleAlternativeIndex >= ConstraintsSoFar[N].multipleAlternatives.size())
+          return true;
         InlineAsm::SubConstraintInfo &scInfo =
           ConstraintsSoFar[N].multipleAlternatives[multipleAlternativeIndex];
         if (scInfo.MatchingInput != -1)
@@ -290,4 +292,3 @@ bool InlineAsm::Verify(FunctionType *Ty, StringRef ConstStr) {
   if (Ty->getNumParams() != NumInputs) return false;
   return true;
 }
-