tint/intrinsics.def: Change language for enums

Previously enum members were added to the global namespace, so that
overload template parameters could be constrained to a single
enum-entry without the need to declare a matcher. While this was a minor
convenience feature, it means that you cannot declare an enum with
members that share the same name as a type. This will be very common for
extensions, like 'f16' where 'f16' is the name of an extension and a
type name.

Change scoping so that enum members need to be fully qualified. Also
change the intrinsic syntax so that enums always need to use a matcher
for enums.

Change-Id: Ided91130e9df537d38dc8ecb41325c0992dea14b
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/97146
Reviewed-by: Dan Sinclair <dsinclair@chromium.org>
Commit-Queue: Ben Clayton <bclayton@google.com>

tools/src/tint/intrinsic/parser/parser.go

@@ -109,10 +109,19 @@ func (p *parser) matcherDecl() ast.MatcherDecl {
 	name := p.expect(tok.Identifier, "matcher name")
 	m := ast.MatcherDecl{Source: name.Source, Name: string(name.Runes)}
 	p.expect(tok.Colon, "matcher declaration")
-	for p.err == nil {
-		m.Options = append(m.Options, p.templatedName())
-		if p.match(tok.Or) == nil {
-			break
+	if p.peekIs(1, tok.Dot) { // enum list
+		for p.err == nil {
+			m.Options.Enums = append(m.Options.Enums, p.memberName())
+			if p.match(tok.Or) == nil {
+				break
+			}
+		}
+	} else { // type list
+		for p.err == nil {
+			m.Options.Types = append(m.Options.Types, p.templatedName())
+			if p.match(tok.Or) == nil {
+				break
+			}
 		}
 	}
 	return m
@@ -277,6 +286,17 @@ func (p *parser) string() string {
 	return string(s.Runes)
 }
 
+func (p *parser) memberName() ast.MemberName {
+	owner := p.expect(tok.Identifier, "member name")
+	p.expect(tok.Dot, "member name")
+	member := p.expect(tok.Identifier, "member name")
+	return ast.MemberName{
+		Source: member.Source,
+		Owner:  string(owner.Runes),
+		Member: string(member.Runes),
+	}
+}
+
 func (p *parser) templatedName() ast.TemplatedName {
 	name := p.expect(tok.Identifier, "type name")
 	m := ast.TemplatedName{Source: name.Source, Name: string(name.Runes)}

tools/src/tint/intrinsic/parser/parser_test.go

@@ -129,7 +129,9 @@ func TestParser(t *testing.T) {
 				Matchers: []ast.MatcherDecl{{
 					Name: "M",
 					Options: ast.MatcherOptions{
-						ast.TemplatedName{Name: "A"},
+						Types: ast.TemplatedNames{
+							{Name: "A"},
+						},
 					},
 				}},
 			},
@@ -140,8 +142,37 @@ func TestParser(t *testing.T) {
 				Matchers: []ast.MatcherDecl{{
 					Name: "M",
 					Options: ast.MatcherOptions{
-						ast.TemplatedName{Name: "A"},
-						ast.TemplatedName{Name: "B"},
+						Types: ast.TemplatedNames{
+							{Name: "A"},
+							{Name: "B"},
+						},
+					},
+				}},
+			},
+		}, { ///////////////////////////////////////////////////////////////////
+			utils.ThisLine(),
+			"match M : A.B",
+			ast.AST{
+				Matchers: []ast.MatcherDecl{{
+					Name: "M",
+					Options: ast.MatcherOptions{
+						Enums: ast.MemberNames{
+							{Owner: "A", Member: "B"},
+						},
+					},
+				}},
+			},
+		}, { ///////////////////////////////////////////////////////////////////
+			utils.ThisLine(),
+			"match M : A.B | B.C",
+			ast.AST{
+				Matchers: []ast.MatcherDecl{{
+					Name: "M",
+					Options: ast.MatcherOptions{
+						Enums: ast.MemberNames{
+							{Owner: "A", Member: "B"},
+							{Owner: "B", Member: "C"},
+						},
 					},
 				}},
 			},