transform: don't rely on struct name of runtime.typecodeID

Sometimes, LLVM may rename named structs when merging modules.
Therefore, we can't rely on typecodeID structs to retain their struct
names.

This commit changes the interface lowering pass to not rely on these
names. The interp package does however still rely on this name, but I
hope to fix that in the future.

compiler/compiler.go

@@ -23,7 +23,7 @@ import (
 // Version of the compiler pacakge. Must be incremented each time the compiler
 // package changes in a way that affects the generated LLVM module.
 // This version is independent of the TinyGo version number.
-const Version = 6 // last change: fix issue 1304
+const Version = 7 // last change: don't rely on runtime.typecodeID struct type name
 
 func init() {
 	llvm.InitializeAllTargets()

compiler/interface.go

@@ -341,7 +341,7 @@ func (b *builder) createTypeAssert(expr *ssa.TypeAssert) llvm.Value {
 		commaOk = b.createRuntimeCall("interfaceImplements", []llvm.Value{actualTypeNum, methodSet}, "")
 
 	} else {
-		globalName := "reflect/types.type:" + getTypeCodeName(expr.AssertedType) + "$id"
+		globalName := "reflect/types.typeid:" + getTypeCodeName(expr.AssertedType)
 		assertedTypeCodeGlobal := b.mod.NamedGlobal(globalName)
 		if assertedTypeCodeGlobal.IsNil() {
 			// Create a new typecode global.

compiler/testdata/interface.ll

@@ -19,7 +19,7 @@ target triple = "i686--linux"
 @"reflect/types.type:interface:{String:func:{}{basic:string}}" = linkonce_odr constant %runtime.typecodeID { %runtime.typecodeID* bitcast ([1 x i8*]* @"reflect/types.interface:interface{String() string}$interface" to %runtime.typecodeID*), i32 0, %runtime.interfaceMethodInfo* null }
 @"func String() string" = external constant i8
 @"reflect/types.interface:interface{String() string}$interface" = linkonce_odr constant [1 x i8*] [i8* @"func String() string"]
-@"reflect/types.type:basic:int$id" = external constant i8
+@"reflect/types.typeid:basic:int" = external constant i8
 @"error$interface" = linkonce_odr constant [1 x i8*] [i8* @"func Error() string"]
 
 declare noalias nonnull i8* @runtime.alloc(i32, i8*, i8*)
@@ -51,7 +51,7 @@ entry:
 
 define hidden i1 @main.isInt(i32 %itf.typecode, i8* %itf.value, i8* %context, i8* %parentHandle) unnamed_addr {
 entry:
-  %typecode = call i1 @runtime.typeAssert(i32 %itf.typecode, i8* nonnull @"reflect/types.type:basic:int$id", i8* undef, i8* null)
+  %typecode = call i1 @runtime.typeAssert(i32 %itf.typecode, i8* nonnull @"reflect/types.typeid:basic:int", i8* undef, i8* null)
   br i1 %typecode, label %typeassert.ok, label %typeassert.next
 
 typeassert.ok:                                    ; preds = %entry

interp/interpreter.go

@@ -328,7 +328,7 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 					return nil, mem, r.errorAt(inst, err)
 				}
 				actualType := actualTypePtrToInt.Operand(0)
-				if actualType.Name()+"$id" == assertedType.Name() {
+				if strings.TrimPrefix(actualType.Name(), "reflect/types.type:") == strings.TrimPrefix(assertedType.Name(), "reflect/types.typeid:") {
 					locals[inst.localIndex] = literalValue{uint8(1)}
 				} else {
 					locals[inst.localIndex] = literalValue{uint8(0)}

interp/testdata/interface.ll

@@ -6,7 +6,7 @@ target triple = "x86_64--linux"
 
 @main.v1 = global i1 0
 @"reflect/types.type:named:main.foo" = private constant %runtime.typecodeID { %runtime.typecodeID* @"reflect/types.type:basic:int", i64 0, %runtime.interfaceMethodInfo* null }
-@"reflect/types.type:named:main.foo$id" = external constant i8
+@"reflect/types.typeid:named:main.foo" = external constant i8
 @"reflect/types.type:basic:int" = external constant %runtime.typecodeID
 
 
@@ -21,7 +21,7 @@ entry:
 define internal void @main.init() unnamed_addr {
 entry:
   ; Test type asserts.
-  %typecode = call i1 @runtime.typeAssert(i64 ptrtoint (%runtime.typecodeID* @"reflect/types.type:named:main.foo" to i64), i8* @"reflect/types.type:named:main.foo$id", i8* undef, i8* null)
+  %typecode = call i1 @runtime.typeAssert(i64 ptrtoint (%runtime.typecodeID* @"reflect/types.type:named:main.foo" to i64), i8* @"reflect/types.typeid:named:main.foo", i8* undef, i8* null)
   store i1 %typecode, i1* @main.v1
   ret void
 }

transform/interface-lowering.go

@@ -163,16 +163,13 @@ func LowerInterfaces(mod llvm.Module, sizeLevel int) error {
 // run runs the pass itself.
 func (p *lowerInterfacesPass) run() error {
 	// Collect all type codes.
-	typecodeID := p.mod.GetTypeByName("runtime.typecodeID")
-	typecodeIDPtr := llvm.PointerType(typecodeID, 0)
 	var typecodeIDs []llvm.Value
 	for global := p.mod.FirstGlobal(); !global.IsNil(); global = llvm.NextGlobal(global) {
-		switch global.Type() {
+		if strings.HasPrefix(global.Name(), "reflect/types.type:") {
-		case typecodeIDPtr:
 			// Retrieve Go type information based on an opaque global variable.
 			// Only the name of the global is relevant, the object itself is
 			// discarded afterwards.
-			name := global.Name()
+			name := strings.TrimPrefix(global.Name(), "reflect/types.type:")
 			if _, ok := p.types[name]; !ok {
 				typecodeIDs = append(typecodeIDs, global)
 				t := &typeInfo{
@@ -196,8 +193,7 @@ func (p *lowerInterfacesPass) run() error {
 	typeAssertUses := getUses(typeAssert)
 	for _, use := range typeAssertUses {
 		typecode := use.Operand(1)
-		name := typecode.Name()            // name with $id suffix
+		name := strings.TrimPrefix(typecode.Name(), "reflect/types.typeid:")
-		name = name[:len(name)-len("$id")] // remove $id suffix
 		if t, ok := p.types[name]; ok {
 			t.countTypeAsserts++
 		}
@@ -360,7 +356,7 @@ func (p *lowerInterfacesPass) run() error {
 			if use.IsAConstantExpr().IsNil() {
 				continue
 			}
-			t := p.types[global.Name()]
+			t := p.types[strings.TrimPrefix(global.Name(), "reflect/types.type:")]
 			typecode := llvm.ConstInt(p.uintptrType, t.num, false)
 			switch use.Opcode() {
 			case llvm.PtrToInt:
@@ -381,8 +377,7 @@ func (p *lowerInterfacesPass) run() error {
 	llvmFalse := llvm.ConstInt(p.ctx.Int1Type(), 0, false)
 	for _, use := range typeAssertUses {
 		actualType := use.Operand(0)
-		name := use.Operand(1).Name()      // name with $id suffix
+		name := strings.TrimPrefix(use.Operand(1).Name(), "reflect/types.typeid:")
-		name = name[:len(name)-len("$id")] // remove $id suffix
 		if t, ok := p.types[name]; ok {
 			// The type exists in the program, so lower to a regular integer
 			// comparison.
@@ -423,13 +418,12 @@ func (p *lowerInterfacesPass) run() error {
 
 	// Remove most objects created for interface and reflect lowering.
 	// Unnecessary, but cleans up the IR for inspection and testing.
-	zeroTypeCode := llvm.ConstNull(typecodeID)
 	for _, typ := range p.types {
 		// Only some typecodes have an initializer.
 		initializer := typ.typecode.Initializer()
 		if !initializer.IsNil() {
 			references := llvm.ConstExtractValue(initializer, []uint32{0})
-			typ.typecode.SetInitializer(zeroTypeCode)
+			typ.typecode.SetInitializer(llvm.ConstNull(initializer.Type()))
 			if strings.HasPrefix(typ.name, "reflect/types.type:struct:") {
 				// Structs have a 'references' field that is not a typecode but
 				// a pointer to a runtime.structField array and therefore a

transform/testdata/interface.ll

@@ -5,8 +5,8 @@ target triple = "armv7m-none-eabi"
 %runtime.interfaceMethodInfo = type { i8*, i32 }
 
 @"reflect/types.type:basic:uint8" = external constant %runtime.typecodeID
-@"reflect/types.type:basic:uint8$id" = external constant i8
+@"reflect/types.typeid:basic:uint8" = external constant i8
-@"reflect/types.type:basic:int16$id" = external constant i8
+@"reflect/types.typeid:basic:int16" = external constant i8
 @"reflect/types.type:basic:int" = external constant %runtime.typecodeID
 @"func NeverImplementedMethod()" = external constant i8
 @"Unmatched$interface" = private constant [1 x i8*] [i8* @"func NeverImplementedMethod()"]
@@ -55,7 +55,7 @@ typeswitch.Doubler:
   ret void
 
 typeswitch.notDoubler:
-  %isByte = call i1 @runtime.typeAssert(i32 %typecode, i8* nonnull @"reflect/types.type:basic:uint8$id")
+  %isByte = call i1 @runtime.typeAssert(i32 %typecode, i8* nonnull @"reflect/types.typeid:basic:uint8")
   br i1 %isByte, label %typeswitch.byte, label %typeswitch.notByte
 
 typeswitch.byte:
@@ -66,7 +66,7 @@ typeswitch.byte:
 
 typeswitch.notByte:
   ; this is a type assert that always fails
-  %isInt16 = call i1 @runtime.typeAssert(i32 %typecode, i8* nonnull @"reflect/types.type:basic:int16$id")
+  %isInt16 = call i1 @runtime.typeAssert(i32 %typecode, i8* nonnull @"reflect/types.typeid:basic:int16")
   br i1 %isInt16, label %typeswitch.int16, label %typeswitch.notInt16
 
 typeswitch.int16:

transform/testdata/interface.out.ll

@@ -5,8 +5,8 @@ target triple = "armv7m-none-eabi"
 %runtime.interfaceMethodInfo = type { i8*, i32 }
 
 @"reflect/types.type:basic:uint8" = external constant %runtime.typecodeID
-@"reflect/types.type:basic:uint8$id" = external constant i8
+@"reflect/types.typeid:basic:uint8" = external constant i8
-@"reflect/types.type:basic:int16$id" = external constant i8
+@"reflect/types.typeid:basic:int16" = external constant i8
 @"reflect/types.type:basic:int" = external constant %runtime.typecodeID
 @"func NeverImplementedMethod()" = external constant i8
 @"func Double() int" = external constant i8
@@ -93,14 +93,14 @@ define i32 @"(Number).Double$invoke"(i8* %receiverPtr, i8* %parentHandle) {
 define internal i32 @"(Doubler).Double"(i8* %0, i8* %1, i32 %actualType, i8* %parentHandle) unnamed_addr {
 entry:
   switch i32 %actualType, label %default [
-    i32 68, label %"reflect/types.type:named:Number"
+    i32 68, label %"named:Number"
   ]
 
 default:                                          ; preds = %entry
   call void @runtime.nilPanic(i8* undef, i8* undef)
   unreachable
 
-"reflect/types.type:named:Number":                ; preds = %entry
+"named:Number":                                   ; preds = %entry
   %2 = call i32 @"(Number).Double$invoke"(i8* %0, i8* %1)
   ret i32 %2
 }