[C API] Fix several null pointer dereferences.

llvm-svn: 286704

diff --git a/llvm/lib/IR/Core.cpp b/llvm/lib/IR/Core.cpp
index 1cf17b1..a969e08 100644 (file)
--- a/llvm/lib/IR/Core.cpp
+++ b/llvm/lib/IR/Core.cpp
@@ -1842,12 +1842,16 @@ void LLVMAddAttributeAtIndex(LLVMValueRef F, LLVMAttributeIndex Idx,
 
 unsigned LLVMGetAttributeCountAtIndex(LLVMValueRef F, LLVMAttributeIndex Idx) {
   auto *ASN = AttributeSetNode::get(unwrap<Function>(F)->getAttributes(), Idx);
+  if (!ASN)
+    return 0;
   return ASN->getNumAttributes();
 }
 
 void LLVMGetAttributesAtIndex(LLVMValueRef F, LLVMAttributeIndex Idx,
                               LLVMAttributeRef *Attrs) {
   auto *ASN = AttributeSetNode::get(unwrap<Function>(F)->getAttributes(), Idx);
+  if (!ASN)
+    return;
   for (auto A: make_range(ASN->begin(), ASN->end()))
     *Attrs++ = wrap(A);
 }
@@ -2173,6 +2177,8 @@ unsigned LLVMGetCallSiteAttributeCount(LLVMValueRef C,
                                        LLVMAttributeIndex Idx) {
   auto CS = CallSite(unwrap<Instruction>(C));
   auto *ASN = AttributeSetNode::get(CS.getAttributes(), Idx);
+  if (!ASN)
+    return 0;
   return ASN->getNumAttributes();
 }
 
@@ -2180,6 +2186,8 @@ void LLVMGetCallSiteAttributes(LLVMValueRef C, LLVMAttributeIndex Idx,
                                LLVMAttributeRef *Attrs) {
   auto CS = CallSite(unwrap<Instruction>(C));
   auto *ASN = AttributeSetNode::get(CS.getAttributes(), Idx);
+  if (!ASN)
+    return;
   for (auto A: make_range(ASN->begin(), ASN->end()))
     *Attrs++ = wrap(A);
 }