On Mon, Dec 18, 2023 at 5:32 PM Ian Lance Taylor <i...@golang.org> wrote:
>
> This Go frontend patch moves the lowering pass after the type
> determination and the type checking passes. This lets us simplify
> some of the code that determines the type of an expression, which
> previously had to work correctly both before and after type
> determination.
>
> I'm doing this to help with future generic support. For example, with
> generics, we can see code like
>
> func ident[T any](v T) T { return v }
>
> func F() int32 {
> s := int32(1)
> return ident(s)
> }
>
> Before this change, we would type check return statements in the
> lowering pass (see Return_statement::do_lower). With a generic
> example like the above, that means we have to determine the type of s,
> and use that to infer the type arguments passed to ident, and use that
> to determine the result type of ident. That is too much to do at
> lowering time. Of course we can change the way that return statements
> work, but similar issues arise with index expressions, the types of
> closures for function literals, and probably other cases as well.
>
> Rather than try to deal with all those cases, we move the lowering
> pass after type checking. This requires a bunch of changes, notably
> for determining constant types. We have to add type checking for
> various constructs that formerly disappeared in the lowering pass. So
> it's a lot of shuffling. Sorry for the size of the patch.
>
> Bootstrapped and ran Go testsuite on x86_64-pc-linux-gnu. Committed
> to mainline.
Sorry, I forgot to commit the changes to some of the test files. I've
committed this patch to fix them. This fixes PR 113447.
Ian
3d7820c58f9466a80916dfa50dcdfde457b4c597
diff --git a/gcc/testsuite/go.test/test/fixedbugs/issue20185.go
b/gcc/testsuite/go.test/test/fixedbugs/issue20185.go
index 9065868d7f2..24d74f09126 100644
--- a/gcc/testsuite/go.test/test/fixedbugs/issue20185.go
+++ b/gcc/testsuite/go.test/test/fixedbugs/issue20185.go
@@ -10,7 +10,7 @@
package p
func F() {
- switch t := nil.(type) { // ERROR "cannot type switch on non-interface
value"
+ switch t := nil.(type) { // ERROR "cannot type switch on non-interface
value|defined to nil type"
default:
_ = t
}
diff --git a/gcc/testsuite/go.test/test/fixedbugs/issue33386.go
b/gcc/testsuite/go.test/test/fixedbugs/issue33386.go
index 7b2f565285e..c5073910a4c 100644
--- a/gcc/testsuite/go.test/test/fixedbugs/issue33386.go
+++ b/gcc/testsuite/go.test/test/fixedbugs/issue33386.go
@@ -18,7 +18,7 @@ func _() {
func _() {
defer func() { // no error here about deferred function
- 1 + // GCCGO_ERROR "value computed is not used"
+ 1 +
}() // ERROR "expecting expression|expected operand"
}
diff --git a/gcc/testsuite/go.test/test/fixedbugs/issue4085a.go
b/gcc/testsuite/go.test/test/fixedbugs/issue4085a.go
index 200290a081d..f457fcf2b12 100644
--- a/gcc/testsuite/go.test/test/fixedbugs/issue4085a.go
+++ b/gcc/testsuite/go.test/test/fixedbugs/issue4085a.go
@@ -10,9 +10,9 @@ type T []int
func main() {
_ = make(T, -1) // ERROR "negative"
- _ = make(T, 0.5) // ERROR "constant 0.5 truncated to
integer|non-integer len argument"
+ _ = make(T, 0.5) // ERROR "truncated to integer|non-integer len
argument"
_ = make(T, 1.0) // ok
- _ = make(T, 1<<63) // ERROR "len argument too large"
+ _ = make(T, 1<<63) // ERROR "integer constant overflow|len argument too
large"
_ = make(T, 0, -1) // ERROR "negative cap"
_ = make(T, 10, 0) // ERROR "len larger than cap"
}
diff --git a/gcc/testsuite/go.test/test/shift1.go
b/gcc/testsuite/go.test/test/shift1.go
index d6a6c38839f..3b1aa9e6900 100644
--- a/gcc/testsuite/go.test/test/shift1.go
+++ b/gcc/testsuite/go.test/test/shift1.go
@@ -189,12 +189,12 @@ func _() {
var m1 map[int]string
delete(m1, 1<<s)
delete(m1, 1.<<s)
- delete(m1, 1.1<<s) // ERROR "truncated|shift of type float64"
+ delete(m1, 1.1<<s) // ERROR "truncated|shift of type
float64|incompatible|non-integer"
var m2 map[float32]string
- delete(m2, 1<<s) // ERROR "invalid|cannot use 1 << s as type float32"
- delete(m2, 1.<<s) // ERROR "invalid|cannot use 1 << s as type float32"
- delete(m2, 1.1<<s) // ERROR "invalid|cannot use 1.1 << s as type
float32"
+ delete(m2, 1<<s) // ERROR "invalid|cannot use 1 << s as type
float32|incompatible"
+ delete(m2, 1.<<s) // ERROR "invalid|cannot use 1 << s as type
float32|incompatible"
+ delete(m2, 1.1<<s) // ERROR "invalid|cannot use 1.1 << s as type
float32|incompatible"
}
// shifts of shifts
