[llvm] [WebAssembly] Print instructions with type checking errors (PR #111067)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-webassembly

Author: Heejin Ahn (aheejin)

<details>
<summary>Changes</summary>

When there was a type checking error, we didn't run `InstPrinter`. This can be confusing because when there is an error in, say, block parameter type, `InstPrinter` doesn't run even if it has nothing to do with block parameter types, and all those updates to `ControlFlowStack` or `TryStack` do not happen:
https://github.com/llvm/llvm-project/blob/c20b90ab8557b38efe8e8e993d41d8c08b798267/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyInstPrinter.cpp#L135-L151

For example,
```wast
block (i32) -> () ;; Block input parameter error
end_block         ;; Now this errors out as "End marker mismatch"
```
This is confusing because there is a `block` and the `end_block` is not a mismatch. Only that `block` has a type checking error, but that's not an end marker mismatch.

I think we can just print the instruction whether we had a type checking error or not, and this will be less confusing.

---
Full diff: https://github.com/llvm/llvm-project/pull/111067.diff


2 Files Affected:

- (modified) llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmParser.cpp (+2-2) 
- (added) llvm/test/MC/WebAssembly/annotations-typecheck.s (+11) 


``````````diff
diff --git a/llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmParser.cpp b/llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmParser.cpp
index 5ea6c6bc0758b9..ee8686d1166a5b 100644
--- a/llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmParser.cpp
+++ b/llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmParser.cpp
@@ -1157,8 +1157,8 @@ class WebAssemblyAsmParser final : public MCTargetAsmParser {
           Inst.setOpcode(Opc64);
         }
       }
-      if (!SkipTypeCheck && TC.typeCheck(IDLoc, Inst, Operands))
-        return true;
+      if (!SkipTypeCheck)
+        TC.typeCheck(IDLoc, Inst, Operands);
       Out.emitInstruction(Inst, getSTI());
       if (CurrentState == EndFunction) {
         onEndOfFunction(IDLoc);
diff --git a/llvm/test/MC/WebAssembly/annotations-typecheck.s b/llvm/test/MC/WebAssembly/annotations-typecheck.s
new file mode 100644
index 00000000000000..1fcdb9c0e35878
--- /dev/null
+++ b/llvm/test/MC/WebAssembly/annotations-typecheck.s
@@ -0,0 +1,11 @@
+# RUN: not llvm-mc -triple=wasm32-unknown-unknown < %s | FileCheck %s
+
+# This tests annotations are handled correctly even if there is a type checking
+# error (which are unrelated to the block annotations).
+test_annotation:
+  .functype   test_annotation () -> ()
+  block (i32) -> ()
+    drop
+# CHECK-NOT: # End marker mismatch!
+  end_block
+  end_function

``````````

</details>


https://github.com/llvm/llvm-project/pull/111067