diff options
Diffstat (limited to 'gcc/cp/constexpr.c')
| -rw-r--r-- | gcc/cp/constexpr.c | 70 |
1 files changed, 63 insertions, 7 deletions
diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c index 4baaac0..84ed7ac 100644 --- a/gcc/cp/constexpr.c +++ b/gcc/cp/constexpr.c @@ -5739,6 +5739,16 @@ find_heap_var_refs (tree *tp, int *walk_subtrees, void */*data*/) return NULL_TREE; } +/* Find immediate function decls in *TP if any. */ + +static tree +find_immediate_fndecl (tree *tp, int */*walk_subtrees*/, void */*data*/) +{ + if (TREE_CODE (*tp) == FUNCTION_DECL && DECL_IMMEDIATE_FUNCTION_P (*tp)) + return *tp; + return NULL_TREE; +} + /* ALLOW_NON_CONSTANT is false if T is required to be a constant expression. STRICT has the same sense as for constant_value_1: true if we only allow conforming C++ constant expressions, or false if we want a constant value @@ -5767,13 +5777,38 @@ cxx_eval_outermost_constant_expr (tree t, bool allow_non_constant, tree type = initialized_type (t); tree r = t; + bool is_consteval = false; if (VOID_TYPE_P (type)) { if (constexpr_dtor) /* Used for destructors of array elements. */ type = TREE_TYPE (object); else - return t; + { + if (cxx_dialect < cxx2a) + return t; + if (TREE_CODE (t) != CALL_EXPR && TREE_CODE (t) != AGGR_INIT_EXPR) + return t; + /* Calls to immediate functions returning void need to be + evaluated. */ + tree fndecl = cp_get_callee_fndecl_nofold (t); + if (fndecl == NULL_TREE || !DECL_IMMEDIATE_FUNCTION_P (fndecl)) + return t; + else + is_consteval = true; + } + } + else if (cxx_dialect >= cxx2a + && (TREE_CODE (t) == CALL_EXPR + || TREE_CODE (t) == AGGR_INIT_EXPR + || TREE_CODE (t) == TARGET_EXPR)) + { + tree x = t; + if (TREE_CODE (x) == TARGET_EXPR) + x = TARGET_EXPR_INITIAL (x); + tree fndecl = cp_get_callee_fndecl_nofold (x); + if (fndecl && DECL_IMMEDIATE_FUNCTION_P (fndecl)) + is_consteval = true; } if (AGGREGATE_TYPE_P (type) || VECTOR_TYPE_P (type)) { @@ -5874,6 +5909,25 @@ cxx_eval_outermost_constant_expr (tree t, bool allow_non_constant, } } + /* Check that immediate invocation does not return an expression referencing + any immediate function decls. They need to be allowed while parsing + immediate functions, but can't leak outside of them. */ + if (is_consteval + && t != r + && (current_function_decl == NULL_TREE + || !DECL_IMMEDIATE_FUNCTION_P (current_function_decl))) + if (tree immediate_fndecl + = cp_walk_tree_without_duplicates (&r, find_immediate_fndecl, + NULL)) + { + if (!allow_non_constant && !non_constant_p) + error_at (cp_expr_loc_or_input_loc (t), + "immediate evaluation returns address of immediate " + "function %qD", immediate_fndecl); + r = t; + non_constant_p = true; + } + /* Technically we should check this for all subexpressions, but that runs into problems with our internal representation of pointer subtraction and the 5.19 rules are still in flux. */ @@ -6114,7 +6168,8 @@ clear_cv_and_fold_caches (bool sat /*= true*/) static tree fold_non_dependent_expr_template (tree t, tsubst_flags_t complain, - bool manifestly_const_eval) + bool manifestly_const_eval, + tree object) { gcc_assert (processing_template_decl); @@ -6135,7 +6190,7 @@ fold_non_dependent_expr_template (tree t, tsubst_flags_t complain, tree r = cxx_eval_outermost_constant_expr (t, true, true, manifestly_const_eval, - false, NULL_TREE); + false, object); /* cp_tree_equal looks through NOPs, so allow them. */ gcc_checking_assert (r == t || CONVERT_EXPR_P (t) @@ -6171,16 +6226,17 @@ fold_non_dependent_expr_template (tree t, tsubst_flags_t complain, tree fold_non_dependent_expr (tree t, tsubst_flags_t complain /* = tf_warning_or_error */, - bool manifestly_const_eval /* = false */) + bool manifestly_const_eval /* = false */, + tree object /* = NULL_TREE */) { if (t == NULL_TREE) return NULL_TREE; if (processing_template_decl) return fold_non_dependent_expr_template (t, complain, - manifestly_const_eval); + manifestly_const_eval, object); - return maybe_constant_value (t, NULL_TREE, manifestly_const_eval); + return maybe_constant_value (t, object, manifestly_const_eval); } @@ -6197,7 +6253,7 @@ fold_non_dependent_init (tree t, if (processing_template_decl) { t = fold_non_dependent_expr_template (t, complain, - manifestly_const_eval); + manifestly_const_eval, NULL_TREE); /* maybe_constant_init does this stripping, so do it here too. */ if (TREE_CODE (t) == TARGET_EXPR) { |