Convert exit/die constants to function call at compile time

php · Apr 30, 2024 · 0549f75 · 0549f75
1 parent d4fa6df
commit 0549f75
Show file tree

Hide file tree

Showing 3 changed files with 31 additions and 10 deletions.
diff --git a/Zend/zend_compile.c b/Zend/zend_compile.c
@@ -7714,7 +7714,7 @@ static zend_string *zend_begin_func_decl(znode *result, zend_op_array *op_array,
 		zend_string *separator = zend_empty_string;
 		zend_string *function = filename;
 		char *parens = "";
-		
+
 		if (CG(active_op_array) && CG(active_op_array)->function_name) {
 			if (CG(active_op_array)->fn_flags & ZEND_ACC_CLOSURE) {
 				/* If the parent function is a closure, don't redundantly
@@ -8714,6 +8714,13 @@ static void zend_compile_const_decl(zend_ast *ast) /* {{{ */
 		value_node.op_type = IS_CONST;
 		zend_const_expr_to_zval(value_zv, value_ast_ptr, /* allow_dynamic */ true);
 
+		if (UNEXPECTED(
+			zend_string_equals_literal_ci(unqualified_name, "exit")
+			|| zend_string_equals_literal_ci(unqualified_name, "die")
+		)) {
+			zend_throw_error(NULL, "Cannot define constant with name %s", ZSTR_VAL(unqualified_name));
+			return;
+		}
 		if (zend_get_special_const(ZSTR_VAL(unqualified_name), ZSTR_LEN(unqualified_name))) {
 			zend_error_noreturn(E_COMPILE_ERROR,
 				"Cannot redeclare constant '%s'", ZSTR_VAL(unqualified_name));
@@ -10009,16 +10016,36 @@ static void zend_compile_const(znode *result, zend_ast *ast) /* {{{ */
 
 	bool is_fully_qualified;
 	zend_string *orig_name = zend_ast_get_str(name_ast);
-	zend_string *resolved_name = zend_resolve_const_name(orig_name, name_ast->attr, &is_fully_qualified);
 
+	/* The fake "constants" exit and die must be converted to a function call for exit() */
 	if (UNEXPECTED(
 		zend_string_equals_literal_ci(orig_name, "exit")
 		|| zend_string_equals_literal_ci(orig_name, "die")
 	)) {
-		zend_throw_error(NULL, "Cannot define constant with name %s", ZSTR_VAL(orig_name));
+		zval *fbc_zv = zend_hash_find(CG(function_table), ZSTR_KNOWN(ZEND_STR_EXIT));
+		ZEND_ASSERT(fbc_zv && "exit() function should always exist");
+		zend_function *fbc = Z_PTR_P(fbc_zv);
+
+		znode name_node;
+		name_node.op_type = IS_CONST;
+		ZVAL_STR(&name_node.u.constant, ZSTR_KNOWN(ZEND_STR_EXIT));
+
+        opline = zend_emit_op(NULL, ZEND_INIT_FCALL, NULL, &name_node);
+        opline->result.num = zend_alloc_cache_slot();
+
+        /* Store offset to function from symbol table in op2.extra. */
+        {
+        	Bucket *fbc_bucket = (Bucket*)((uintptr_t)fbc_zv - XtOffsetOf(Bucket, val));
+        	Z_EXTRA_P(CT_CONSTANT(opline->op2)) = fbc_bucket - CG(function_table)->arData;
+        }
+
+		zend_ast *args_list = zend_ast_create_list_0(ZEND_AST_ARG_LIST);
+		zend_compile_call_common(result, args_list, fbc, ast->lineno);
 		return;
 	}
 
+	zend_string *resolved_name = zend_resolve_const_name(orig_name, name_ast->attr, &is_fully_qualified);
+
 	if (zend_string_equals_literal(resolved_name, "__COMPILER_HALT_OFFSET__") || (name_ast->attr != ZEND_NAME_RELATIVE && zend_string_equals_literal(orig_name, "__COMPILER_HALT_OFFSET__"))) {
 		zend_ast *last = CG(ast);
 

diff --git a/Zend/zend_execute.c b/Zend/zend_execute.c
@@ -5017,13 +5017,6 @@ static zend_always_inline zend_result _zend_quick_get_constant(
 	}
 
 	if (!c) {
-		if (UNEXPECTED(
-			zend_string_equals_literal_ci(Z_STR_P(key), "exit")
-			|| zend_string_equals_literal_ci(Z_STR_P(key), "die")
-		)) {
-			zend_throw_unwind_exit();
-			return FAILURE;
-		}
 		if (!check_defined_only) {
 			zend_throw_error(NULL, "Undefined constant \"%s\"", Z_STRVAL_P(RT_CONSTANT(opline, opline->op2)));
 			ZVAL_UNDEF(EX_VAR(opline->result.var));

diff --git a/Zend/zend_string.h b/Zend/zend_string.h
@@ -572,6 +572,7 @@ EMPTY_SWITCH_DEFAULT_CASE()
 	_(ZEND_STR_ARGS,                   "args") \
 	_(ZEND_STR_UNKNOWN,                "unknown") \
 	_(ZEND_STR_UNKNOWN_CAPITALIZED,    "Unknown") \
+	_(ZEND_STR_EXIT,                   "exit") \
 	_(ZEND_STR_EVAL,                   "eval") \
 	_(ZEND_STR_INCLUDE,                "include") \
 	_(ZEND_STR_REQUIRE,                "require") \