[DirectX] Fix crash in DXILFlattenArrays for function declarations (#116690)

bogner · web-flow · commit e0b522dd94e4 · 2024-11-18T13:56:33.000-08:00
We were skipping intrinsics here, but really we need to skip all
function declarations - if the function doesn't have a body there's
nothing to walk.
diff --git a/llvm/lib/Target/DirectX/DXILFlattenArrays.cpp b/llvm/lib/Target/DirectX/DXILFlattenArrays.cpp
@@ -402,7 +402,7 @@ static bool flattenArrays(Module &M) {
   DenseMap<GlobalVariable *, GlobalVariable *> GlobalMap;
   flattenGlobalArrays(M, GlobalMap);
   for (auto &F : make_early_inc_range(M.functions())) {
-    if (F.isIntrinsic())
+    if (F.isDeclaration())
       continue;
     MadeChange |= Impl.visit(F);
   }
diff --git a/llvm/test/CodeGen/DirectX/flatten-array.ll b/llvm/test/CodeGen/DirectX/flatten-array.ll
@@ -186,3 +186,6 @@ define void @global_gep_store() {
   store i32 1, i32* %3, align 4
   ret void
 }
+
+; Make sure we don't try to walk the body of a function declaration.
+declare void @opaque_function()

Original file line number	Diff line number	Diff line change
`@@ -402,7 +402,7 @@ static bool flattenArrays(Module &M) {`
`402`	`402`	`DenseMap<GlobalVariable , GlobalVariable > GlobalMap;`
`403`	`403`	`flattenGlobalArrays(M, GlobalMap);`
`404`	`404`	`for (auto &F : make_early_inc_range(M.functions())) {`
`405`		`- if (F.isIntrinsic())`
	`405`	`+ if (F.isDeclaration())`
`406`	`406`	`continue;`
`407`	`407`	`MadeChange \|= Impl.visit(F);`
`408`	`408`	`}`
Original file line number	Diff line number	Diff line change
`@@ -186,3 +186,6 @@ define void @global_gep_store() {`
`186`	`186`	`store i32 1, i32* %3, align 4`
`187`	`187`	`ret void`
`188`	`188`	`}`
	`189`	`+`
	`190`	`+; Make sure we don't try to walk the body of a function declaration.`
	`191`	`+declare void @opaque_function()`