[WebAssembly] Test types only used by call_indirect are GC'd correctly

[ncw]

Summary

I don't think it's covered by any existing tests?

Here we have a type which is called with call_indirect but not used anywhere else in the file.

[sbc100]

I believe this is already tested in lld/test/wasm/call-indirect.ll:

; Indirect function call where no function actually has this type.               
; Ensures that the type entry is still created in this case.                     
define void @call_ptr(i64 (i64)* %arg) {                                         
  %1 = call i64 %arg(i64 1)                                                      
  ret void                                                                       
}

[ncw]

D'oh, missed it... OK, I guess this one is a waste of space.

test/wasm/gc-types.ll

+; RUN: llc -filetype=obj %s -o %t.o
+; RUN: wasm-ld --check-signatures -o %t.wasm %t.o
+; RUN: obj2yaml %t.wasm | FileCheck %s
+
+target triple = "wasm32-unknown-unknown-wasm"
+
+; Check that types are GC'd if they are not used by any functions - but are
+; retained if they are used by any call_indirect instructions, even if no
+; function has that type!
+
+define hidden i64 @use_sig1(i64 %arg) {
+  ret i64 0
+}
+
+define hidden void @call_sig1(i64 (i64)* %fn) {
+  %call = call i64 %fn(i64 1)
+  ret void
+}
+
+define hidden void @call_sig2(i64 (i64, i64)* %fn) {
+  %call = call i64 %fn(i64 1, i64 2)
+  ret void
+}
+
+define hidden i64 @unused_sig3(i64 %arg1, i64 %arg2, i64 %arg3) {
+  ret i64 0
+}
+
+define hidden void @_start() {
+entry:
+  call i64 @use_sig1(i64 0)
+  call void @call_sig1(i64 (i64)* null)
+  call void @call_sig2(i64 (i64, i64)* null)
+  ret void
+}
+
+; CHECK:        - Type:            TYPE
+; CHECK-NEXT:     Signatures:
+; CHECK-NEXT:       - Index:           0
+; CHECK-NEXT:         ReturnType:      I64
+; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:           - I64
+; CHECK-NEXT:       - Index:           1
+; CHECK-NEXT:         ReturnType:      I64
+; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:           - I64
+; CHECK-NEXT:           - I64
+; CHECK-NEXT:       - Index:           2
+; CHECK-NEXT:         ReturnType:      NORESULT
+; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:           - I32
+; CHECK-NEXT:       - Index:           3
+; CHECK-NEXT:         ReturnType:      NORESULT
+; CHECK-NEXT:         ParamTypes:
+; CHECK-NEXT:   - Type:            FUNCTION
+; CHECK-NEXT:     FunctionTypes:   [ 0, 2, 2, 3, 3 ]