Hi! The PR119204 r15-7955 fix caused some regressions. The problem is that the fold_builtin* APIs document that expr is either a CALL_EXPR of the call or NULL, so using TREE_TYPE (expr) can crash e.g. during constexpr evaluation etc.
As can be seen in the surrounding patch, for the neighbouring builtins (both modf and strpbrk) fold_builtin_2 passes down type, which is the result type, TREE_TYPE (TREE_TYPE (fndecl)) and those builtins use it to build the return value, while strspn was always building size_type_node and strcspn had this change from that to TREE_TYPE (expr). The patch passes type to these two and uses it there as well. The patch keeps passing expr because it is used in the check_nul_terminated_array calls done for both strspn and strcspn, those calls clearly can deal with NULL expr but prefer if it is non-NULL for some warning. Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? 2025-03-12 Jakub Jelinek <ja...@redhat.com> PR middle-end/119204 PR middle-end/119219 * builtins.cc (fold_builtin_2): Pass type as another argument to fold_builtin_strspn and fold_builtin_strcspn. (fold_builtin_strspn): Add type argument, use it instead of size_type_node. (fold_builtin_strcspn): Add type argument, use it instead of TREE_TYPE (expr). --- gcc/builtins.cc.jj 2025-03-11 12:05:42.561533453 +0100 +++ gcc/builtins.cc 2025-03-11 15:36:47.774314011 +0100 @@ -176,8 +176,8 @@ static tree fold_builtin_iseqsig (locati static tree fold_builtin_varargs (location_t, tree, tree*, int); static tree fold_builtin_strpbrk (location_t, tree, tree, tree, tree); -static tree fold_builtin_strspn (location_t, tree, tree, tree); -static tree fold_builtin_strcspn (location_t, tree, tree, tree); +static tree fold_builtin_strspn (location_t, tree, tree, tree, tree); +static tree fold_builtin_strcspn (location_t, tree, tree, tree, tree); static rtx expand_builtin_object_size (tree); static rtx expand_builtin_memory_chk (tree, rtx, machine_mode, @@ -10800,10 +10800,10 @@ fold_builtin_2 (location_t loc, tree exp return fold_builtin_modf (loc, arg0, arg1, type); case BUILT_IN_STRSPN: - return fold_builtin_strspn (loc, expr, arg0, arg1); + return fold_builtin_strspn (loc, expr, arg0, arg1, type); case BUILT_IN_STRCSPN: - return fold_builtin_strcspn (loc, expr, arg0, arg1); + return fold_builtin_strcspn (loc, expr, arg0, arg1, type); case BUILT_IN_STRPBRK: return fold_builtin_strpbrk (loc, expr, arg0, arg1, type); @@ -11304,7 +11304,7 @@ fold_builtin_strpbrk (location_t loc, tr form of the builtin function call. */ static tree -fold_builtin_strspn (location_t loc, tree expr, tree s1, tree s2) +fold_builtin_strspn (location_t loc, tree expr, tree s1, tree s2, tree type) { if (!validate_arg (s1, POINTER_TYPE) || !validate_arg (s2, POINTER_TYPE)) @@ -11320,8 +11320,7 @@ fold_builtin_strspn (location_t loc, tre if ((p1 && *p1 == '\0') || (p2 && *p2 == '\0')) /* Evaluate and ignore both arguments in case either one has side-effects. */ - return omit_two_operands_loc (loc, size_type_node, size_zero_node, - s1, s2); + return omit_two_operands_loc (loc, type, size_zero_node, s1, s2); return NULL_TREE; } @@ -11344,7 +11343,7 @@ fold_builtin_strspn (location_t loc, tre form of the builtin function call. */ static tree -fold_builtin_strcspn (location_t loc, tree expr, tree s1, tree s2) +fold_builtin_strcspn (location_t loc, tree expr, tree s1, tree s2, tree type) { if (!validate_arg (s1, POINTER_TYPE) || !validate_arg (s2, POINTER_TYPE)) @@ -11360,8 +11359,7 @@ fold_builtin_strcspn (location_t loc, tr { /* Evaluate and ignore argument s2 in case it has side-effects. */ - return omit_one_operand_loc (loc, TREE_TYPE (expr), - size_zero_node, s2); + return omit_one_operand_loc (loc, type, size_zero_node, s2); } /* If the second argument is "", return __builtin_strlen(s1). */ @@ -11375,7 +11373,7 @@ fold_builtin_strcspn (location_t loc, tr if (!fn) return NULL_TREE; - return fold_convert_loc (loc, TREE_TYPE (expr), + return fold_convert_loc (loc, type, build_call_expr_loc (loc, fn, 1, s1)); } return NULL_TREE; Jakub