Commit `e3e4af7271`

Koakuma <koachan@protonmail.com>

2021-02-04 14:51:53

stage1: set gen_frame_size alignment to work around requirement mismatch

Explicitly set the alignment requirements to 1 (i.e, mark the load as unaligned) since there are some architectures (e.g SPARCv9) which has different alignment requirements between a function pointer and usize pointer. On those architectures, not explicitly setting it will lead into @frameSize generating usize-aligned load instruction that could crash if the function pointer happens to be not usize-aligned.

master

1 parent 1eb2e48

Changed files (1)

src

stage1

codegen.cpp

@@ -4160,7 +4160,9 @@ static LLVMValueRef gen_frame_size(CodeGen *g, LLVMValueRef fn_val) {
     LLVMValueRef casted_fn_val = LLVMBuildBitCast(g->builder, fn_val, ptr_usize_llvm_type, "");
     LLVMValueRef negative_one = LLVMConstInt(LLVMInt32Type(), -1, true);
     LLVMValueRef prefix_ptr = LLVMBuildInBoundsGEP(g->builder, casted_fn_val, &negative_one, 1, "");
-    return LLVMBuildLoad(g->builder, prefix_ptr, "");
+    LLVMValueRef load_inst = LLVMBuildLoad(g->builder, prefix_ptr, "");
+    LLVMSetAlignment(load_inst, 1);
+    return load_inst;
 }
 
 static void gen_init_stack_trace(CodeGen *g, LLVMValueRef trace_field_ptr, LLVMValueRef addrs_field_ptr) {

Commit e3e4af7271

Commit `e3e4af7271`