diff options
Diffstat (limited to 'gcc/cp/constexpr.c')
| -rw-r--r-- | gcc/cp/constexpr.c | 74 |
1 files changed, 54 insertions, 20 deletions
diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c index fdc296908af..bf8ee003419 100644 --- a/gcc/cp/constexpr.c +++ b/gcc/cp/constexpr.c @@ -628,6 +628,20 @@ build_constexpr_constructor_member_initializers (tree type, tree body) return error_mark_node; } +/* We have an expression tree T that represents a call, either CALL_EXPR + or AGGR_INIT_EXPR. If the call is lexically to a named function, + retrun the _DECL for that function. */ + +static tree +get_function_named_in_call (tree t) +{ + tree fun = cp_get_callee (t); + if (fun && TREE_CODE (fun) == ADDR_EXPR + && TREE_CODE (TREE_OPERAND (fun, 0)) == FUNCTION_DECL) + fun = TREE_OPERAND (fun, 0); + return fun; +} + /* Subroutine of register_constexpr_fundef. BODY is the body of a function declared to be constexpr, or a sub-statement thereof. Returns the return value if suitable, error_mark_node for a statement not allowed in @@ -682,6 +696,15 @@ constexpr_fn_retval (tree body) case USING_STMT: return NULL_TREE; + case CALL_EXPR: + { + tree fun = get_function_named_in_call (body); + if (fun != NULL_TREE + && DECL_FUNCTION_CODE (fun) == BUILT_IN_UNREACHABLE) + return NULL_TREE; + } + /* Fallthru. */ + default: return error_mark_node; } @@ -1098,20 +1121,6 @@ save_fundef_copy (tree fun, tree copy) } /* We have an expression tree T that represents a call, either CALL_EXPR - or AGGR_INIT_EXPR. If the call is lexically to a named function, - retrun the _DECL for that function. */ - -static tree -get_function_named_in_call (tree t) -{ - tree fun = cp_get_callee (t); - if (fun && TREE_CODE (fun) == ADDR_EXPR - && TREE_CODE (TREE_OPERAND (fun, 0)) == FUNCTION_DECL) - fun = TREE_OPERAND (fun, 0); - return fun; -} - -/* We have an expression tree T that represents a call, either CALL_EXPR or AGGR_INIT_EXPR. Return the Nth argument. */ static inline tree @@ -1180,9 +1189,18 @@ cxx_eval_builtin_function_call (const constexpr_ctx *ctx, tree t, tree fun, { if (!*non_constant_p && !ctx->quiet) { - new_call = build_call_array_loc (EXPR_LOCATION (t), TREE_TYPE (t), - CALL_EXPR_FN (t), nargs, args); - error ("%q+E is not a constant expression", new_call); + /* Do not allow__builtin_unreachable in constexpr function. + The __builtin_unreachable call with BUILTINS_LOCATION + comes from cp_maybe_instrument_return. */ + if (DECL_FUNCTION_CODE (fun) == BUILT_IN_UNREACHABLE + && EXPR_LOCATION (t) == BUILTINS_LOCATION) + error ("constexpr call flows off the end of the function"); + else + { + new_call = build_call_array_loc (EXPR_LOCATION (t), TREE_TYPE (t), + CALL_EXPR_FN (t), nargs, args); + error ("%q+E is not a constant expression", new_call); + } } *non_constant_p = true; return t; @@ -1268,8 +1286,6 @@ cxx_bind_parameters_in_call (const constexpr_ctx *ctx, tree t, && is_dummy_object (x)) { x = ctx->object; - /* We don't use cp_build_addr_expr here because we don't want to - capture the object argument during constexpr evaluation. */ x = build_address (x); } bool lval = false; @@ -5271,7 +5287,25 @@ potential_constant_expression_1 (tree t, bool want_rval, bool strict, bool now, case VAR_DECL: if (DECL_HAS_VALUE_EXPR_P (t)) - return RECUR (DECL_VALUE_EXPR (t), rval); + { + if (now && is_normal_capture_proxy (t)) + { + /* -- in a lambda-expression, a reference to this or to a + variable with automatic storage duration defined outside that + lambda-expression, where the reference would be an + odr-use. */ + if (flags & tf_error) + { + tree cap = DECL_CAPTURED_VARIABLE (t); + error ("lambda capture of %qE is not a constant expression", + cap); + if (!want_rval && decl_constant_var_p (cap)) + inform (input_location, "because it is used as a glvalue"); + } + return false; + } + return RECUR (DECL_VALUE_EXPR (t), rval); + } if (want_rval && !var_in_maybe_constexpr_fn (t) && !type_dependent_expression_p (t) |