From fbdbe8b06a1c5626ad6360a4af33cb638c14cda1 Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Thu, 31 Oct 2019 08:10:57 +0100 Subject: [PATCH] re PR c++/90947 (Simple lookup table of array of strings is miscompiled) PR c++/90947 * tree.h (type_initializer_zero_p): Remove. * tree.c (type_initializer_zero_p): Remove. cp/ * cp-tree.h (type_initializer_zero_p): Declare. * decl.c (reshape_init_array_1): Formatting fix. * tree.c (type_initializer_zero_p): New function. Moved from ../tree.c, use next_initializable_field, formatting fix. Return false for TYPE_NON_AGGREGATE_CLASS types. From-SVN: r277656 --- gcc/ChangeLog | 6 +++ gcc/cp/ChangeLog | 9 ++++ gcc/cp/cp-tree.h | 5 +++ gcc/cp/decl.c | 5 +-- gcc/cp/tree.c | 62 ++++++++++++++++++++++++++ gcc/testsuite/g++.dg/init/array54.C | 13 ++++++ gcc/tree.c | 67 ----------------------------- gcc/tree.h | 6 --- 8 files changed, 97 insertions(+), 76 deletions(-) create mode 100644 gcc/testsuite/g++.dg/init/array54.C diff --git a/gcc/ChangeLog b/gcc/ChangeLog index d1a83f50d12..9f454193905 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2019-10-31 Jakub Jelinek + + PR c++/90947 + * tree.h (type_initializer_zero_p): Remove. + * tree.c (type_initializer_zero_p): Remove. + 2019-10-30 Bernd Edlinger * doc/invoke.texi (-Wshadow, -Wshadow=global diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index 585420a62c3..31f251c1b7e 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,12 @@ +2019-10-31 Jakub Jelinek + + PR c++/90947 + * cp-tree.h (type_initializer_zero_p): Declare. + * decl.c (reshape_init_array_1): Formatting fix. + * tree.c (type_initializer_zero_p): New function. Moved from + ../tree.c, use next_initializable_field, formatting fix. Return + false for TYPE_NON_AGGREGATE_CLASS types. + 2019-10-30 Jason Merrill PR c++/92268 - hard error satisfying return-type-requirement diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h index 42e03a31e20..42d5111ac0f 100644 --- a/gcc/cp/cp-tree.h +++ b/gcc/cp/cp-tree.h @@ -7382,6 +7382,11 @@ extern tree cxx_copy_lang_qualifiers (const_tree, const_tree); extern void cxx_print_statistics (void); extern bool maybe_warn_zero_as_null_pointer_constant (tree, location_t); +/* Analogous to initializer_zerop but also examines the type for + which the initializer is being used. Unlike initializer_zerop, + considers empty strings to be zero initializers for arrays and + non-zero for pointers. */ +extern bool type_initializer_zero_p (tree, tree); /* in ptree.c */ extern void cxx_print_xnode (FILE *, tree, int); diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c index 8320597c108..72acc8f0224 100644 --- a/gcc/cp/decl.c +++ b/gcc/cp/decl.c @@ -5973,9 +5973,8 @@ reshape_init_array_1 (tree elt_type, tree max_index, reshape_iter *d, /* Pointers initialized to strings must be treated as non-zero even if the string is empty. */ tree init_type = TREE_TYPE (elt_init); - if ((POINTER_TYPE_P (elt_type) != POINTER_TYPE_P (init_type))) - last_nonzero = index; - else if (!type_initializer_zero_p (elt_type, elt_init)) + if (POINTER_TYPE_P (elt_type) != POINTER_TYPE_P (init_type) + || !type_initializer_zero_p (elt_type, elt_init)) last_nonzero = index; /* This can happen with an invalid initializer (c++/54501). */ diff --git a/gcc/cp/tree.c b/gcc/cp/tree.c index ca4d3e2a48b..a4b8b00c922 100644 --- a/gcc/cp/tree.c +++ b/gcc/cp/tree.c @@ -5540,6 +5540,68 @@ maybe_warn_zero_as_null_pointer_constant (tree expr, location_t loc) return false; } +/* Given an initializer INIT for a TYPE, return true if INIT is zero + so that it can be replaced by value initialization. This function + distinguishes betwen empty strings as initializers for arrays and + for pointers (which make it return false). */ + +bool +type_initializer_zero_p (tree type, tree init) +{ + if (type == error_mark_node || init == error_mark_node) + return false; + + STRIP_NOPS (init); + + if (POINTER_TYPE_P (type)) + return TREE_CODE (init) != STRING_CST && initializer_zerop (init); + + if (TREE_CODE (init) != CONSTRUCTOR) + return initializer_zerop (init); + + if (TREE_CODE (type) == ARRAY_TYPE) + { + tree elt_type = TREE_TYPE (type); + elt_type = TYPE_MAIN_VARIANT (elt_type); + if (elt_type == char_type_node) + return initializer_zerop (init); + + tree elt_init; + unsigned HOST_WIDE_INT i; + FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (init), i, elt_init) + if (!type_initializer_zero_p (elt_type, elt_init)) + return false; + return true; + } + + if (TREE_CODE (type) != RECORD_TYPE) + return initializer_zerop (init); + + if (TYPE_NON_AGGREGATE_CLASS (type)) + return false; + + tree fld = TYPE_FIELDS (type); + + tree fld_init; + unsigned HOST_WIDE_INT i; + FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (init), i, fld_init) + { + fld = next_initializable_field (fld); + if (!fld) + return true; + + tree fldtype = TREE_TYPE (fld); + if (!type_initializer_zero_p (fldtype, fld_init)) + return false; + + fld = DECL_CHAIN (fld); + if (!fld) + break; + } + + return true; +} + #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007) /* Complain that some language-specific thing hanging off a tree node has been accessed improperly. */ diff --git a/gcc/testsuite/g++.dg/init/array54.C b/gcc/testsuite/g++.dg/init/array54.C new file mode 100644 index 00000000000..f6be350ba72 --- /dev/null +++ b/gcc/testsuite/g++.dg/init/array54.C @@ -0,0 +1,13 @@ +// PR c++/90947 +// { dg-do run { target c++11 } } + +#include + +static std::atomic a[1] { {1} }; + +int +main () +{ + if (a[0].load () != 1) + __builtin_abort (); +} diff --git a/gcc/tree.c b/gcc/tree.c index ad477d3feb2..3866804b99d 100644 --- a/gcc/tree.c +++ b/gcc/tree.c @@ -11123,73 +11123,6 @@ initializer_each_zero_or_onep (const_tree expr) } } -/* Given an initializer INIT for a TYPE, return true if INIT is zero - so that it can be replaced by value initialization. This function - distinguishes betwen empty strings as initializers for arrays and - for pointers (which make it return false). */ - -bool -type_initializer_zero_p (tree type, tree init) -{ - if (type == error_mark_node || init == error_mark_node) - return false; - - STRIP_NOPS (init); - - if (POINTER_TYPE_P (type)) - return TREE_CODE (init) != STRING_CST && initializer_zerop (init); - - if (TREE_CODE (init) != CONSTRUCTOR) - return initializer_zerop (init); - - if (TREE_CODE (type) == ARRAY_TYPE) - { - tree elt_type = TREE_TYPE (type); - elt_type = TYPE_MAIN_VARIANT (elt_type); - if (elt_type == char_type_node) - return initializer_zerop (init); - - tree elt_init; - unsigned HOST_WIDE_INT i; - FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (init), i, elt_init) - if (!type_initializer_zero_p (elt_type, elt_init)) - return false; - return true; - } - - if (TREE_CODE (type) != RECORD_TYPE) - return initializer_zerop (init); - - tree fld = TYPE_FIELDS (type); - - tree fld_init; - unsigned HOST_WIDE_INT i; - FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (init), i, fld_init) - { - /* Advance to the next member, skipping over everything that - canot be initialized (including unnamed bit-fields). */ - while (TREE_CODE (fld) != FIELD_DECL - || DECL_ARTIFICIAL (fld) - || (DECL_BIT_FIELD (fld) && !DECL_NAME (fld))) - { - fld = DECL_CHAIN (fld); - if (!fld) - return true; - continue; - } - - tree fldtype = TREE_TYPE (fld); - if (!type_initializer_zero_p (fldtype, fld_init)) - return false; - - fld = DECL_CHAIN (fld); - if (!fld) - break; - } - - return true; -} - /* Check if vector VEC consists of all the equal elements and that the number of elements corresponds to the type of VEC. The function returns first element of the vector diff --git a/gcc/tree.h b/gcc/tree.h index c825109b5f7..18d6c0e0c21 100644 --- a/gcc/tree.h +++ b/gcc/tree.h @@ -4690,12 +4690,6 @@ extern tree first_field (const_tree); extern bool initializer_zerop (const_tree, bool * = NULL); extern bool initializer_each_zero_or_onep (const_tree); -/* Analogous to initializer_zerop but also examines the type for - which the initializer is being used. Unlike initializer_zerop, - considers empty strings to be zero initializers for arrays and - non-zero for pointers. */ -extern bool type_initializer_zero_p (tree, tree); - extern wide_int vector_cst_int_elt (const_tree, unsigned int); extern tree vector_cst_elt (const_tree, unsigned int); -- 2.30.2