Syntax: improve invalid semicolon diagnostics

parser/c2_parser.c2

@@ -226,11 +226,6 @@ fn Kind Parser.peekToken2(Parser* p, u32 n, Token* tok) {
 fn void Parser.consumeSemicolon(Parser* p, bool need_semi) {
     if (need_semi) {
         p.expectAndConsume(Semicolon);
-    } else {
-        if (p.tok.kind == Semicolon) {
-            p.diags.error(p.tok.loc, "no semicolon allowed after initializer list");
-            p.consumeToken();
-        }
     }
 }
 
@@ -242,6 +237,14 @@ fn void Parser.expectAndConsume(Parser* p, Kind kind) {
     p.expectError(kind);
 }
 
+fn void Parser.consumeRBrace(Parser* p, const char* context) {
+    p.expectAndConsume(RBrace);
+    if (p.tok.kind == Semicolon) {
+        p.diags.warn(p.tok.loc, "no semicolon allowed after %s", context);
+        p.consumeToken();
+    }
+}
+
 fn void Parser.expect(Parser* p, Kind kind) {
     if (p.tok.kind == kind) return;
 
@@ -377,7 +380,7 @@ fn void Parser.parseImports(Parser* p) {
                     p.consumeToken();
                 }
             }
-            p.expectAndConsume(RBrace);
+            p.consumeRBrace("import list");
         } else {
             p.expectAndConsume(Semicolon);
         }
@@ -1103,7 +1106,7 @@ fn void Parser.parseExternDecl(Parser* p) {
             p.parseTopLevel();
         }
         p.tokenizer.c_mode--; // must set before consuming the token
-        p.consumeToken();
+        p.consumeRBrace("extern \"C\" block");
     } else {
         p.parseTopLevel();
     }

parser/c2_parser_expr.c2

@@ -617,7 +617,7 @@ fn Expr* Parser.parseInitList(Parser* p) {
     if (p.tok.kind == LBrace) p.expect(Comma); // always gives error
 
     SrcLoc endLoc = p.tok.loc;
-    p.expectAndConsume(RBrace);
+    p.consumeRBrace("initializer list");
     Expr* e = (Expr*)p.builder.actOnInitList(loc, endLoc, values.getExprs(), values.size());
     values.free();
     return e;

parser/c2_parser_stmt.c2

@@ -213,7 +213,7 @@ fn CompoundStmt* Parser.parseCompoundStmt(Parser* p) {
     }
 
     SrcLoc endLoc = p.tok.loc + 1;
-    p.expectAndConsume(RBrace);
+    p.consumeRBrace("block");
 
     CompoundStmt* s = p.builder.actOnCompoundStmt(endLoc, stmts.getData(), stmts.size());
     p.putStmtList();

parser/c2_parser_switch.c2

@@ -64,7 +64,7 @@ fn Stmt* Parser.parseSwitchStmt(Parser* p) {
         cases.add(c);
     }
 
-    p.expectAndConsume(RBrace);
+    p.consumeRBrace("switch block");
 
     Stmt* s = p.builder.actOnSwitchStmt(loc, decl, cond, cases.getData(), cases.size(), has_default);
     cases.free();

parser/c2_parser_type.c2

@@ -232,7 +232,7 @@ fn void Parser.parseStructBlock(Parser* p, DeclList* members, bool is_public) {
         p.expectAndConsume(Semicolon);
     }
 
-    p.expectAndConsume(RBrace);
+    p.consumeRBrace("struct definition");
 }
 
 fn void Parser.parseEnumType(Parser* p, u32 name, SrcLoc loc, bool is_public) {
@@ -334,7 +334,7 @@ fn void Parser.parseEnumType(Parser* p, u32 name, SrcLoc loc, bool is_public) {
         }
     }
 
-    p.expectAndConsume(RBrace);
+    p.consumeRBrace("enum definition");
 
     EnumTypeDecl* d = p.builder.actOnEnumType(name,
                                               loc,

test/parser/invalid_initlist.c2

@@ -1,13 +1,13 @@
 // @warnings{no-unused}
 module test;
 
-u32[] a1 = {1, 2, 3};     // @error{no semicolon allowed after initializer list}
+u32[] a1 = {1, 2, 3};     // @warning{no semicolon allowed after initializer list}
 
 u32[+] b;
-a += {1, 2, 3};     // @error{no semicolon allowed after initializer list}
+a += {1, 2, 3};     // @warning{no semicolon allowed after initializer list}
 
 fn void fn1() {
-    u32[] a = {1, 2, 3};     // @error{no semicolon allowed after initializer list}
+    u32[] a = {1, 2, 3};     // @warning{no semicolon allowed after initializer list}
 }
 
 public fn i32 main() {