From 4a305fa2fd4c9d553b26efa00f868aa1e4416a9f Mon Sep 17 00:00:00 2001 From: Marek Polacek Date: Mon, 24 Feb 2020 14:43:48 -0500 Subject: [PATCH] c++: Fix ICE with static_cast when converting from int[] [PR93862] This ICEs since my patch for P0388, which allowed conversions to arrays of unknown bound, but not the reverse, so these two static_casts are ill-formed. [expr.static.cast]/3 says that "cv1 T1" and "cv2 T2" have to be reference-compatible and the comment in build_static_cast_1 says it too but then we actually use reference_related_p... Fixed thus. 2020-02-26 Marek Polacek PR c++/93862 - ICE with static_cast when converting from int[]. * call.c (reference_compatible_p): No longer static. * cp-tree.h (reference_compatible_p): Declare. * typeck.c (build_static_cast_1): Use reference_compatible_p instead of reference_related_p. * g++.dg/cpp0x/rv-cast7.C: New test. --- gcc/cp/ChangeLog | 8 ++++++++ gcc/cp/call.c | 3 +-- gcc/cp/cp-tree.h | 1 + gcc/cp/typeck.c | 2 +- gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/g++.dg/cpp0x/rv-cast7.C | 6 ++++++ 6 files changed, 22 insertions(+), 3 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp0x/rv-cast7.C diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index 1489453..5ba298f 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,5 +1,13 @@ 2020-02-26 Marek Polacek + PR c++/93862 - ICE with static_cast when converting from int[]. + * call.c (reference_compatible_p): No longer static. + * cp-tree.h (reference_compatible_p): Declare. + * typeck.c (build_static_cast_1): Use reference_compatible_p instead + of reference_related_p. + +2020-02-26 Marek Polacek + PR c++/93803 - ICE with constexpr init and [[no_unique_address]]. * constexpr.c (reduced_constant_expression_p): Don't crash on a null field. diff --git a/gcc/cp/call.c b/gcc/cp/call.c index 7a7f07c..e07ee85 100644 --- a/gcc/cp/call.c +++ b/gcc/cp/call.c @@ -204,7 +204,6 @@ static struct z_candidate *add_candidate conversion **, tree, tree, int, struct rejection_reason *, int); static tree source_type (conversion *); static void add_warning (struct z_candidate *, struct z_candidate *); -static bool reference_compatible_p (tree, tree); static conversion *direct_reference_binding (tree, conversion *); static bool promoted_arithmetic_type_p (tree); static conversion *conditional_conversion (tree, tree, tsubst_flags_t); @@ -1554,7 +1553,7 @@ reference_related_p (tree t1, tree t2) /* Returns nonzero if T1 is reference-compatible with T2. */ -static bool +bool reference_compatible_p (tree t1, tree t2) { /* [dcl.init.ref] diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h index c1aafa1..140d5d8 100644 --- a/gcc/cp/cp-tree.h +++ b/gcc/cp/cp-tree.h @@ -6357,6 +6357,7 @@ extern tree make_temporary_var_for_ref_to_temp (tree, tree); extern bool type_has_extended_temps (tree); extern tree strip_top_quals (tree); extern bool reference_related_p (tree, tree); +extern bool reference_compatible_p (tree, tree); extern int remaining_arguments (tree); extern tree perform_implicit_conversion (tree, tree, tsubst_flags_t); extern tree perform_implicit_conversion_flags (tree, tree, tsubst_flags_t, int); diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c index c0c98da..103a1a4 100644 --- a/gcc/cp/typeck.c +++ b/gcc/cp/typeck.c @@ -7383,7 +7383,7 @@ build_static_cast_1 (location_t loc, tree type, tree expr, bool c_cast_p, if (TYPE_REF_P (type) && TYPE_REF_IS_RVALUE (type) && (clk = real_lvalue_p (expr)) - && reference_related_p (TREE_TYPE (type), intype) + && reference_compatible_p (TREE_TYPE (type), intype) && (c_cast_p || at_least_as_qualified_p (TREE_TYPE (type), intype))) { if (processing_template_decl) diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index a18b1f2..08146db 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,5 +1,10 @@ 2020-02-26 Marek Polacek + PR c++/93862 - ICE with static_cast when converting from int[]. + * g++.dg/cpp0x/rv-cast7.C: New test. + +2020-02-26 Marek Polacek + DR 1423, Convertibility of nullptr to bool. * g++.dg/DRs/dr1423.C: New test. diff --git a/gcc/testsuite/g++.dg/cpp0x/rv-cast7.C b/gcc/testsuite/g++.dg/cpp0x/rv-cast7.C new file mode 100644 index 0000000..0eea24f --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/rv-cast7.C @@ -0,0 +1,6 @@ +// PR c++/93862 - ICE with static_cast when converting from int[]. +// { dg-do compile { target c++11 } } + +int(&&intu_rvref)[]{1,2,3,4}; +int(&int4_lvref)[4] = static_cast(intu_rvref); // { dg-error "invalid .static_cast." } +int(&&int4_rvref)[4] = static_cast(intu_rvref); // { dg-error "invalid .static_cast." } -- 2.7.4