compiler: interface typecodes are not passed through defer frames #1033
Description
I encountered a really weird compilation error, I tried to simplify the code to find the root cause and this is the best I could do:
package main
func main() {
foo(nil)
}
type Bar struct {
empty bool
}
func (b *Bar) Close() error {
return nil
}
type Closer interface {
Close() error
}
func foo(bar *Bar) error {
var a int
// replacing this condition with something simpler (i.e. nb > 10)
// works fine
if !bar.empty {
a = 10
// this inner branching is important
if a != 5 {
return nil
}
}
var c Closer = bar
// calling defer on an interface method + the branching above causes the bug
// Replacing this line by func() { b.Close() }() works though
defer c.Close()
return nil
}This causes the following compilation error:
Instruction does not dominate all uses!
%3 = insertvalue %runtime._interface { i32 ptrtoint (%runtime.typeInInterface* @"typeInInterface:reflect/types.type:pointer:named:exp.Bar" to i32), i8* undef }, i8* %pack.ptr, 1
%invoke.typecode16 = extractvalue %runtime._interface %3, 0
Instruction does not dominate all uses!
%3 = insertvalue %runtime._interface { i32 ptrtoint (%runtime.typeInInterface* @"typeInInterface:reflect/types.type:pointer:named:exp.Bar" to i32), i8* undef }, i8* %pack.ptr, 1
%invoke.func.receiver19 = extractvalue %runtime._interface %3, 1
error: verification error after IR construction
I compiled to wasm using the 0.12.0 docker image with the following params:
docker run ... \
tinygo/tinygo:0.12.0 tinygo build -o /dist/exp.wasm -target wasm --no-debug exp