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| author | Marek Polacek <polacek@redhat.com> | 2020-06-17 09:19:02 -0400 |
|---|---|---|
| committer | Marek Polacek <polacek@redhat.com> | 2020-06-17 09:19:02 -0400 |
| commit | ae2ebf011fec926e003645c33c07a03619ea216a (patch) | |
| tree | 22786700ccebc85f8db4afd3fe82fefb9be4f656 /gcc/cp | |
| parent | 4d2b0866d760f822c137b69f14d1c51fc760ce53 (diff) | |
| download | gcc-ae2ebf011fec926e003645c33c07a03619ea216a.zip gcc-ae2ebf011fec926e003645c33c07a03619ea216a.tar.gz gcc-ae2ebf011fec926e003645c33c07a03619ea216a.tar.bz2 | |
c++: ICE with IMPLICIT_CONV_EXPR in array subscript [PR95508]
Since r10-7096 convert_like, when called in a template, creates an
IMPLICIT_CONV_EXPR when we're converting to/from array type.
In this test, we have e[f], and we're converting f (of type class A) to
int, so convert_like in build_new_op_1 created the IMPLICIT_CONV_EXPR
that got into cp_build_array_ref which calls maybe_constant_value. My
patch above failed to adjust this spot to call fold_non_dependent_expr
instead, which can handle codes like I_C_E in a template. Fixed by
using a new function maybe_fold_non_dependent_expr, which, if the expr
can't be evaluated to a constant, returns the original expression.
gcc/cp/ChangeLog:
PR c++/95508
* constexpr.c (maybe_fold_non_dependent_expr): New.
* cp-tree.h (maybe_fold_non_dependent_expr): Declare.
* typeck.c (cp_build_array_ref): Call maybe_fold_non_dependent_expr
instead of maybe_constant_value.
gcc/testsuite/ChangeLog:
PR c++/95508
* g++.dg/template/conv16.C: New test.
Diffstat (limited to 'gcc/cp')
| -rw-r--r-- | gcc/cp/constexpr.c | 13 | ||||
| -rw-r--r-- | gcc/cp/cp-tree.h | 2 | ||||
| -rw-r--r-- | gcc/cp/typeck.c | 2 |
3 files changed, 16 insertions, 1 deletions
diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c index c01c42b..f766abd 100644 --- a/gcc/cp/constexpr.c +++ b/gcc/cp/constexpr.c @@ -7093,6 +7093,19 @@ fold_non_dependent_expr (tree t, return maybe_constant_value (t, object, manifestly_const_eval); } +/* Like fold_non_dependent_expr, but if EXPR couldn't be folded to a constant, + return the original expression. */ + +tree +maybe_fold_non_dependent_expr (tree expr, + tsubst_flags_t complain/*=tf_warning_or_error*/) +{ + tree t = fold_non_dependent_expr (expr, complain); + if (t && TREE_CONSTANT (t)) + return t; + + return expr; +} /* Like maybe_constant_init but first fully instantiate the argument. */ diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h index 50d83ad..ee27610 100644 --- a/gcc/cp/cp-tree.h +++ b/gcc/cp/cp-tree.h @@ -7933,6 +7933,8 @@ extern tree maybe_constant_init (tree, tree = NULL_TREE, bool = false); extern tree fold_non_dependent_expr (tree, tsubst_flags_t = tf_warning_or_error, bool = false, tree = NULL_TREE); +extern tree maybe_fold_non_dependent_expr (tree, + tsubst_flags_t = tf_warning_or_error); extern tree fold_non_dependent_init (tree, tsubst_flags_t = tf_warning_or_error, bool = false); diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c index f01ae65..7e84f11 100644 --- a/gcc/cp/typeck.c +++ b/gcc/cp/typeck.c @@ -3565,7 +3565,7 @@ cp_build_array_ref (location_t loc, tree array, tree idx, pointer arithmetic.) */ idx = cp_perform_integral_promotions (idx, complain); - idx = maybe_constant_value (idx); + idx = maybe_fold_non_dependent_expr (idx, complain); /* An array that is indexed by a non-constant cannot be stored in a register; we must be able to do |