Move the whole calculation of binary operations', compare and logical
expressions' constness flags to the evaluation phase such that expressions
like
0 + __builtin_choose_expr(0, 0, 0)
0 < __builtin_choose_expr(0, 0, 0)
0 && __builtin_choose_expr(0, 0, 0)
can now be recognized as qualifying as integer constant expressions.
Signed-off-by: Nicolai Stange <nicstange@xxxxxxxxx>
---
evaluate.c | 28 +++++++++-------------------
expression.c | 5 -----
validation/constexpr-binop.c | 33 +++++++++++++++++++++++++++++++++
3 files changed, 42 insertions(+), 24 deletions(-)
create mode 100644 validation/constexpr-binop.c
diff --git a/evaluate.c b/evaluate.c
index 24a7f2f..32e5930 100644
--- a/evaluate.c
+++ b/evaluate.c
@@ -878,12 +878,9 @@ static struct symbol *evaluate_logical(struct expression *expr)
/* the result is int [6.5.13(3), 6.5.14(3)] */
expr->ctype = &int_ctype;
- if (expr->constexpr_flags) {
- if (!(expr->left->constexpr_flags &
- expr->right->constexpr_flags &
- CONSTEXPR_FLAG_INT_CONST_EXPR))
- expr->constexpr_flags = CONSTEXPR_FLAG_NONE;
- }
+ expr->constexpr_flags = expr->left->constexpr_flags &
+ expr->right->constexpr_flags &
+ ~CONSTEXPR_FLAG_DECAY_CONSTS_MASK;
return &int_ctype;
}
@@ -894,15 +891,12 @@ static struct symbol *evaluate_binop(struct expression *expr)
int rclass = classify_type(expr->right->ctype, &rtype);
int op = expr->op;
- if (expr->constexpr_flags) {
- if (!(expr->left->constexpr_flags &
- expr->right->constexpr_flags &
- CONSTEXPR_FLAG_INT_CONST_EXPR))
- expr->constexpr_flags = CONSTEXPR_FLAG_NONE;
- }
-
/* number op number */
if (lclass & rclass & TYPE_NUM) {
+ expr->constexpr_flags = expr->left->constexpr_flags &
+ expr->right->constexpr_flags &
+ ~CONSTEXPR_FLAG_DECAY_CONSTS_MASK;
+
if ((lclass | rclass) & TYPE_FLOAT) {
switch (op) {
case '+': case '-': case '*': case '/':
@@ -1004,12 +998,8 @@ static struct symbol *evaluate_compare(struct expression *expr)
struct symbol *ctype;
const char *typediff;
- if (expr->constexpr_flags) {
- if (!(expr->left->constexpr_flags &
- expr->right->constexpr_flags &
- CONSTEXPR_FLAG_INT_CONST_EXPR))
- expr->constexpr_flags = CONSTEXPR_FLAG_NONE;
- }
+ expr->constexpr_flags = left->constexpr_flags &
+ right->constexpr_flags & ~CONSTEXPR_FLAG_DECAY_CONSTS_MASK;
/* Type types? */
if (is_type_type(ltype) && is_type_type(rtype))
diff --git a/expression.c b/expression.c
index 759bee8..5970b1b 100644
--- a/expression.c
+++ b/expression.c
@@ -147,7 +147,6 @@ static struct token *builtin_types_compatible_p_expr(struct token *token,
{
struct expression *expr = alloc_expression(
token->pos, EXPR_COMPARE);
- expr->constexpr_flags = CONSTEXPR_FLAG_INT_CONST_EXPR_SET_MASK;
expr->op = SPECIAL_EQUAL;
token = token->next;
if (!match_op(token, '('))
@@ -766,10 +765,6 @@ static struct token *cast_expression(struct token *token, struct expression **tr
sparse_error(next->pos, "No right hand side of '%s'-expression", show_special(op)); \
break; \
} \
- top->constexpr_flags = \
- left->constexpr_flags & \
- right->constexpr_flags & \
- ~CONSTEXPR_FLAG_DECAY_CONSTS_MASK; \
top->op = op; \
top->left = left; \
top->right = right; \
diff --git a/validation/constexpr-binop.c b/validation/constexpr-binop.c
new file mode 100644
index 0000000..85a88e3
--- /dev/null
+++ b/validation/constexpr-binop.c
@@ -0,0 +1,33 @@
+static int a[] = {
+ [0 + 0] = 0, // OK
+ [0 + 0.] = 0, // KO
+ [(void*)0 + 0] = 0, // KO
+ [0 + __builtin_choose_expr(0, 0, 0)] = 0, // OK
+ [0 + __builtin_choose_expr(0, 0., 0)] = 0, // OK
+ [0 + __builtin_choose_expr(0, 0, 0.)] = 0, // KO
+ [0 < 0] = 0, // OK
+ [0 < 0.] = 0, // KO
+ [0 < __builtin_choose_expr(0, 0, 0)] = 0, // OK
+ [0 < __builtin_choose_expr(0, 0., 0)] = 0, // OK
+ [0 < __builtin_choose_expr(0, 0, 0.)] = 0, // KO
+ [0 && 0] = 0, // OK
+ [0 && 0.] = 0, // KO
+ [0 && __builtin_choose_expr(0, 0, 0)] = 0, // OK
+ [0 && __builtin_choose_expr(0, 0., 0)] = 0, // OK
+ [0 && __builtin_choose_expr(0, 0, 0.)] = 0, // KO
+ [0 + __builtin_types_compatible_p(int, float)] = 0, // OK
+};
+
+/*
+ * check-name: Expression constness propagation in binops and alike
+ *
+ * check-error-start
+constexpr-binop.c:3:12: error: bad constant expression
+constexpr-binop.c:4:19: error: bad integer constant expression
+constexpr-binop.c:7:12: error: bad constant expression
+constexpr-binop.c:9:12: error: bad integer constant expression
+constexpr-binop.c:12:12: error: bad integer constant expression
+constexpr-binop.c:14:12: error: bad integer constant expression
+constexpr-binop.c:17:12: error: bad integer constant expression
+ * check-error-end
+ */
--
2.7.0
--
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