fix 3 bugs, dead const_td_is_array code, braceless switch defer wipe, skip_one_stmt label swallowing

Author: dawnlarsson

.github/test.defer.c

@@ -4892,6 +4892,37 @@ static void test_defer_shadow_stmt_expr_local_false_positive(void) {
 	}
 }
 
+// BUG90: braceless inner switch caused find_switch_scope to leak to outer switch,
+// resetting defer_count and silently wiping registered defers.
+static void test_braceless_switch_defer_wipe(void) {
+	printf("\n--- Braceless Switch Defer Wipe (BUG90) ---\n");
+
+	// Defer in outer switch must survive a braceless inner switch
+	{
+		PrismResult r = prism_transpile_source(
+		    "int result = 0;\n"
+		    "void test(int outer, int inner) {\n"
+		    "    switch (outer) {\n"
+		    "        case 0: {\n"
+		    "            defer { result = 42; }\n"
+		    "            switch (inner)\n"
+		    "                if (inner == 1) {\n"
+		    "                    case 1:\n"
+		    "                        break;\n"
+		    "                }\n"
+		    "        }\n"
+		    "    }\n"
+		    "}\n",
+		    "braceless_sw_defer.c", prism_defaults());
+		CHECK_EQ(r.status, PRISM_OK, "braceless-sw-defer: transpiles OK");
+		CHECK(r.output != NULL, "braceless-sw-defer: output not NULL");
+		// The defer body must appear in the output (not be wiped)
+		CHECK(strstr(r.output, "result = 42") != NULL,
+		      "braceless-sw-defer: defer must not be wiped by braceless inner switch");
+		prism_free(&r);
+	}
+}
+
 void run_defer_tests(void) {
 	printf("\n=== DEFER TESTS ===\n");
         test_defer_in_comma_expr_bug();

.github/test.zeroinit.c

@@ -2842,6 +2842,60 @@ static void test_switch_for_init_not_rejected(void) {
 	}
 }
 
+// BUG91: skip_one_stmt didn't handle user labels (L: stmt), causing it to
+// over-consume tokens past the labeled statement, extending variable scopes
+// and triggering false CFG verifier rejections.
+static void test_skip_one_stmt_label_parsing(void) {
+	printf("\n--- skip_one_stmt Label Parsing (BUG91) ---\n");
+
+	// Label before braceless if body in for loop
+	{
+		PrismResult r = prism_transpile_source(
+		    "void test(void) {\n"
+		    "    goto SAFE_TARGET;\n"
+		    "    for (int secret = 0; secret < 1; secret++)\n"
+		    "        L: if (1) { }\n"
+		    "    SAFE_TARGET: ;\n"
+		    "    int safe_var = 1;\n"
+		    "    (void)safe_var;\n"
+		    "}\n",
+		    "label_skip.c", prism_defaults());
+		CHECK_EQ(r.status, PRISM_OK,
+		      "label-skip: goto past labeled braceless for body must not be rejected");
+		prism_free(&r);
+	}
+
+	// Multiple chained labels
+	{
+		PrismResult r = prism_transpile_source(
+		    "void test(void) {\n"
+		    "    goto END;\n"
+		    "    for (int x = 0; x < 1; x++)\n"
+		    "        A: B: C: if (1) { }\n"
+		    "    END: ;\n"
+		    "}\n",
+		    "chain_label_skip.c", prism_defaults());
+		CHECK_EQ(r.status, PRISM_OK,
+		      "chain-label-skip: chained labels before braceless body must work");
+		prism_free(&r);
+	}
+
+	// Label before braced block in while loop
+	{
+		PrismResult r = prism_transpile_source(
+		    "void test(void) {\n"
+		    "    goto DONE;\n"
+		    "    while (0)\n"
+		    "        BODY: { }\n"
+		    "    DONE: ;\n"
+		    "}\n",
+		    "label_while_skip.c", prism_defaults());
+		CHECK_EQ(r.status, PRISM_OK,
+		      "label-while-skip: label before braced while body must work");
+		prism_free(&r);
+	}
+}
+
 // BUG89: emit_type_range stmt-expr bypass in struct bodies
 static void test_struct_body_stmt_expr_features(void) {
 	printf("\n--- Struct Body Statement Expression Features (BUG89) ---\n");
@@ -3058,4 +3112,7 @@ void run_zeroinit_tests(void) {
 #ifdef __GNUC__
 	test_struct_body_stmt_expr_features();
 #endif
+
+	// BUG91: skip_one_stmt label parsing
+	test_skip_one_stmt_label_parsing();
 }

prism.c

@@ -1097,12 +1097,6 @@ static void defer_add(Token *defer_keyword, Token *start, Token *end) {
 	defer_stack[defer_count++] = (DeferEntry){start, end, defer_keyword};
 }
 
-static int find_switch_scope(void) {
-	for (int d = ctx->scope_depth - 1; d >= 0; d--)
-		if (scope_stack[d].kind == SCOPE_BLOCK && scope_stack[d].is_switch) return d;
-	return -1;
-}
-
 
 static bool needs_space(Token *prev, Token *tok) {
 	if (!prev || tok_at_bol(tok)) return false;
@@ -3549,10 +3543,8 @@ static Token *handle_const_orelse_fallback(Token *tok,
 		// The old &*(T)0 trick dereferences void* which is a constraint violation
 		// under C99 §6.5.3.2p2 (GCC/Clang tolerate it, but it's non-conforming).
 		bool const_td_is_ptr = false;
-		bool const_td_is_array = false;
 		for (Token *t = type_start; t != type->end; t = tok_next(t)) {
 			if (is_ptr_typedef(t)) { const_td_is_ptr = true; break; }
-			if (is_array_typedef(t)) { const_td_is_array = true; break; }
 		}
 
 		if (pragma_start != type_start)
@@ -3563,12 +3555,6 @@ static Token *handle_const_orelse_fallback(Token *tok,
 			out_char(' '); emit_typeof_keyword(); OUT_LIT("((");
 			emit_type_range(type_start, type->end, strip_type_const, true);
 			OUT_LIT(")0)");
-		} else if (const_td_is_array) {
-			out_char(' '); emit_typeof_keyword(); OUT_LIT("(*(0 ? (");
-			emit_type_range(type_start, type->end, strip_type_const, true);
-			OUT_LIT("*)0 : (");
-			emit_type_range(type_start, type->end, strip_type_const, true);
-			OUT_LIT("*)0))");
 		} else {
 			out_char(' '); emit_typeof_keyword(); OUT_LIT("((");
 			emit_type_range(type_start, type->end, strip_type_const, true);
@@ -5090,30 +5076,7 @@ static Token *handle_goto_keyword(Token *tok) {
 }
 
 static void handle_case_default(Token *tok) {
-	if (!FEAT(F_DEFER)) return;
-	// Braceless switch: ctrl_state.pending is still active, meaning no
-	// SCOPE_BLOCK was pushed for this switch.  find_switch_scope() would
-	// leak through to an enclosing braced switch and corrupt its defer
-	// stack.  Braceless bodies can't contain defers, so just bail out.
-	if (ctrl_state.pending && ctrl_state.parens_just_closed) return;
-	int sd = find_switch_scope();
-	if (sd < 0) return;
-	bool is_case = tok->tag & TT_CASE;
-	bool is_default = (tok->tag & TT_DEFAULT) && !in_generic();
-	if (is_default) {
-		Token *t = skip_noise(tok_next(tok));
-		if (!t || !match_ch(t, ':')) return;
-	}
-	if (!is_case && !is_default) return;
-
-	// Defer-fallthrough and zero-init-bypass errors are now caught by
-	// p1_verify_cfg (Phase 2A) before any code is emitted.  Pass 2 only
-	// needs to reset the defer stack to the switch scope level so that
-	// defers emitted in previous case arms don't bleed into the next one.
-	for (int d = ctx->scope_depth - 1; d >= sd; d--) {
-		if (scope_stack[d].kind != SCOPE_BLOCK) continue;
-		defer_count = scope_stack[d].defer_start_idx;
-	}
+	(void)tok; // defer-fallthrough is caught by p1_verify_cfg (Phase 2A)
 }
 
 static Token *handle_sue_body(Token *tok) {
@@ -6911,6 +6874,14 @@ static Token *skip_one_stmt_impl(Token *tok, uint32_t *cache) {
 		goto unwind_if;
 	}
 
+	// User-defined label: ident ':' (not '::')
+	if (is_identifier_like(tok) && !(tok->tag & (TT_CASE | TT_DEFAULT | TT_TYPE | TT_QUALIFIER | TT_STORAGE))) {
+		Token *colon = skip_noise(tok_next(tok));
+		if (colon && match_ch(colon, ':') && !(tok_next(colon) && match_ch(tok_next(colon), ':'))) {
+			tok = tok_next(colon); goto restart;
+		}
+	}
+
 	// 'case' / 'default' label: skip expr + ':', tail-call on body
 	if ((tok->tag & (TT_CASE | TT_DEFAULT)) && !is_known_typedef(tok)) {
 		int td = 0;