compiler: canonicalize method signature identities

The interface lowering pass used a separate formatter for method
signatures. Same-named local aliases could therefore make distinct generic
methods compare equal. Reuse getTypeCodeName so interface checks preserve
type identity.

compiler/interface.go

@@ -980,14 +980,15 @@ func (c *compilerContext) getTypeMethodSet(typ types.Type) llvm.Value {
 // getMethodSignatureName returns a unique name (that can be used as the name of
 // a global) for the given method.
 func (c *compilerContext) getMethodSignatureName(method *types.Func) string {
-	signature := methodSignature(method)
+	name := method.Name()
-	var globalName string
+	var prefix string
 	if token.IsExported(method.Name()) {
-		globalName = "reflect/methods." + signature
+		prefix = "reflect/methods."
 	} else {
-		globalName = method.Type().(*types.Signature).Recv().Pkg().Path() + ".$methods." + signature
+		prefix = method.Type().(*types.Signature).Recv().Pkg().Path() + ".$methods."
 	}
-	return globalName
+	signature, _ := c.getTypeCodeName(method.Type())
+	return prefix + name + ":" + signature
 }
 
 // getMethodSignature returns a global variable which is a reference to an
@@ -1298,108 +1299,3 @@ func (c *compilerContext) getInterfaceInvokeWrapper(fn *ssa.Function, llvmFnType
 
 	return wrapper
 }
-
-// methodSignature creates a readable version of a method signature (including
-// the function name, excluding the receiver name). This string is used
-// internally to match interfaces and to call the correct method on an
-// interface. Examples:
-//
-//	String() string
-//	Read([]byte) (int, error)
-func methodSignature(method *types.Func) string {
-	return method.Name() + signature(method.Type().(*types.Signature))
-}
-
-// Make a readable version of a function (pointer) signature.
-// Examples:
-//
-//	() string
-//	(string, int) (int, error)
-func signature(sig *types.Signature) string {
-	var s strings.Builder
-	if sig.Params().Len() == 0 {
-		s.WriteString("()")
-	} else {
-		s.WriteString("(")
-		i := 0
-		for v := range sig.Params().Variables() {
-			if i > 0 {
-				s.WriteString(", ")
-			}
-			s.WriteString(typestring(v.Type()))
-			i++
-		}
-		s.WriteString(")")
-	}
-	if sig.Results().Len() == 0 {
-		// keep as-is
-	} else if sig.Results().Len() == 1 {
-		s.WriteString(" " + typestring(sig.Results().At(0).Type()))
-	} else {
-		s.WriteString(" (")
-		i := 0
-		for v := range sig.Results().Variables() {
-			if i > 0 {
-				s.WriteString(", ")
-			}
-			s.WriteString(typestring(v.Type()))
-			i++
-		}
-		s.WriteString(")")
-	}
-	return s.String()
-}
-
-// typestring returns a stable (human-readable) type string for the given type
-// that can be used for interface equality checks. It is almost (but not
-// exactly) the same as calling t.String(). The main difference is some
-// normalization around `byte` vs `uint8` for example.
-func typestring(t types.Type) string {
-	// See: https://github.com/golang/go/blob/master/src/go/types/typestring.go
-	switch t := types.Unalias(t).(type) {
-	case *types.Array:
-		return "[" + strconv.FormatInt(t.Len(), 10) + "]" + typestring(t.Elem())
-	case *types.Basic:
-		return basicTypeNames[t.Kind()]
-	case *types.Chan:
-		switch t.Dir() {
-		case types.SendRecv:
-			return "chan (" + typestring(t.Elem()) + ")"
-		case types.SendOnly:
-			return "chan<- (" + typestring(t.Elem()) + ")"
-		case types.RecvOnly:
-			return "<-chan (" + typestring(t.Elem()) + ")"
-		default:
-			panic("unknown channel direction")
-		}
-	case *types.Interface:
-		methods := make([]string, t.NumMethods())
-		for i := range methods {
-			method := t.Method(i)
-			methods[i] = method.Name() + signature(method.Type().(*types.Signature))
-		}
-		return "interface{" + strings.Join(methods, ";") + "}"
-	case *types.Map:
-		return "map[" + typestring(t.Key()) + "]" + typestring(t.Elem())
-	case *types.Named:
-		return t.String()
-	case *types.Pointer:
-		return "*" + typestring(t.Elem())
-	case *types.Signature:
-		return "func" + signature(t)
-	case *types.Slice:
-		return "[]" + typestring(t.Elem())
-	case *types.Struct:
-		fields := make([]string, t.NumFields())
-		for i := range fields {
-			field := t.Field(i)
-			fields[i] = field.Name() + " " + typestring(field.Type())
-			if tag := t.Tag(i); tag != "" {
-				fields[i] += " " + strconv.Quote(tag)
-			}
-		}
-		return "struct{" + strings.Join(fields, ";") + "}"
-	default:
-		panic("unknown type: " + t.String())
-	}
-}

compiler/testdata/generics.ll

@@ -192,5 +192,5 @@ declare i1 @"interface:{Get:func:{}{named:main.aliasMethodResult[basic:float32]}
 attributes #0 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
 attributes #1 = { nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
 attributes #2 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #3 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-methods"="reflect/methods.Get() main.aliasMethodResult[main.F]" }
+attributes #3 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-methods"="reflect/methods.Get:func:{}{named:main.aliasMethodResult[basic:float32]}" }
 attributes #4 = { nounwind }

compiler/testdata/goroutine-cortex-m-qemu-tasks.ll

@@ -195,6 +195,6 @@ attributes #5 = { nounwind "target-features"="+armv7-m,+hwdiv,+soft-float,+thumb
 attributes #6 = { nounwind "target-features"="+armv7-m,+hwdiv,+soft-float,+thumb-mode,-aes,-bf16,-cdecp0,-cdecp1,-cdecp2,-cdecp3,-cdecp4,-cdecp5,-cdecp6,-cdecp7,-crc,-crypto,-d32,-dotprod,-dsp,-fp-armv8,-fp-armv8d16,-fp-armv8d16sp,-fp-armv8sp,-fp16,-fp16fml,-fp64,-fpregs,-fullfp16,-hwdiv-arm,-i8mm,-lob,-mve,-mve.fp,-neon,-pacbti,-ras,-sb,-sha2,-vfp2,-vfp2sp,-vfp3,-vfp3d16,-vfp3d16sp,-vfp3sp,-vfp4,-vfp4d16,-vfp4d16sp,-vfp4sp" "tinygo-gowrapper" }
 attributes #7 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
 attributes #8 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
-attributes #9 = { "target-features"="+armv7-m,+hwdiv,+soft-float,+thumb-mode,-aes,-bf16,-cdecp0,-cdecp1,-cdecp2,-cdecp3,-cdecp4,-cdecp5,-cdecp6,-cdecp7,-crc,-crypto,-d32,-dotprod,-dsp,-fp-armv8,-fp-armv8d16,-fp-armv8d16sp,-fp-armv8sp,-fp16,-fp16fml,-fp64,-fpregs,-fullfp16,-hwdiv-arm,-i8mm,-lob,-mve,-mve.fp,-neon,-pacbti,-ras,-sb,-sha2,-vfp2,-vfp2sp,-vfp3,-vfp3d16,-vfp3d16sp,-vfp3sp,-vfp4,-vfp4d16,-vfp4d16sp,-vfp4sp" "tinygo-invoke"="reflect/methods.Print(string)" "tinygo-methods"="reflect/methods.Print(string)" }
+attributes #9 = { "target-features"="+armv7-m,+hwdiv,+soft-float,+thumb-mode,-aes,-bf16,-cdecp0,-cdecp1,-cdecp2,-cdecp3,-cdecp4,-cdecp5,-cdecp6,-cdecp7,-crc,-crypto,-d32,-dotprod,-dsp,-fp-armv8,-fp-armv8d16,-fp-armv8d16sp,-fp-armv8sp,-fp16,-fp16fml,-fp64,-fpregs,-fullfp16,-hwdiv-arm,-i8mm,-lob,-mve,-mve.fp,-neon,-pacbti,-ras,-sb,-sha2,-vfp2,-vfp2sp,-vfp3,-vfp3d16,-vfp3d16sp,-vfp3sp,-vfp4,-vfp4d16,-vfp4d16sp,-vfp4sp" "tinygo-invoke"="reflect/methods.Print:func:{basic:string}{}" "tinygo-methods"="reflect/methods.Print:func:{basic:string}{}" }
 attributes #10 = { nounwind "target-features"="+armv7-m,+hwdiv,+soft-float,+thumb-mode,-aes,-bf16,-cdecp0,-cdecp1,-cdecp2,-cdecp3,-cdecp4,-cdecp5,-cdecp6,-cdecp7,-crc,-crypto,-d32,-dotprod,-dsp,-fp-armv8,-fp-armv8d16,-fp-armv8d16sp,-fp-armv8sp,-fp16,-fp16fml,-fp64,-fpregs,-fullfp16,-hwdiv-arm,-i8mm,-lob,-mve,-mve.fp,-neon,-pacbti,-ras,-sb,-sha2,-vfp2,-vfp2sp,-vfp3,-vfp3d16,-vfp3d16sp,-vfp3sp,-vfp4,-vfp4d16,-vfp4d16sp,-vfp4sp" "tinygo-gowrapper"="interface:{Print:func:{basic:string}{}}.Print$invoke" }
 attributes #11 = { nounwind }

compiler/testdata/goroutine-wasm-asyncify.ll

@@ -206,6 +206,6 @@ attributes #5 = { nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+cal
 attributes #6 = { nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-gowrapper" }
 attributes #7 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
 attributes #8 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
-attributes #9 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-invoke"="reflect/methods.Print(string)" "tinygo-methods"="reflect/methods.Print(string)" }
+attributes #9 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-invoke"="reflect/methods.Print:func:{basic:string}{}" "tinygo-methods"="reflect/methods.Print:func:{basic:string}{}" }
 attributes #10 = { nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-gowrapper"="interface:{Print:func:{basic:string}{}}.Print$invoke" }
 attributes #11 = { nounwind }

compiler/testdata/interface.ll

@@ -131,8 +131,8 @@ declare %runtime._string @"interface:{Error:func:{}{basic:string}}.Error$invoke"
 
 attributes #0 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
 attributes #1 = { nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #2 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-methods"="reflect/methods.Error() string" }
+attributes #2 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-methods"="reflect/methods.Error:func:{}{basic:string}" }
-attributes #3 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-methods"="reflect/methods.String() string" }
+attributes #3 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-methods"="reflect/methods.String:func:{}{basic:string}" }
-attributes #4 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-invoke"="main.$methods.foo(int) uint8" "tinygo-methods"="reflect/methods.String() string; main.$methods.foo(int) uint8" }
+attributes #4 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-invoke"="main.$methods.foo:func:{basic:int}{basic:uint8}" "tinygo-methods"="reflect/methods.String:func:{}{basic:string}; main.$methods.foo:func:{basic:int}{basic:uint8}" }
-attributes #5 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-invoke"="reflect/methods.Error() string" "tinygo-methods"="reflect/methods.Error() string" }
+attributes #5 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-invoke"="reflect/methods.Error:func:{}{basic:string}" "tinygo-methods"="reflect/methods.Error:func:{}{basic:string}" }
 attributes #6 = { nounwind }

testdata/localtypes.txt

@@ -57,5 +57,5 @@ ok: aliasBox[float32] implements Get() float32
 ok: aliasBox[float64] implements Get() float64
 ok: aliasMethod[float32] accepts own
 ok: aliasMethod[float64] accepts own
-BUG: aliasMethod[float32] rejects [float64]
+ok: aliasMethod[float32] rejects [float64]
-BUG: aliasMethod[float64] rejects [float32]
+ok: aliasMethod[float64] rejects [float32]