[gcc(refs/vendors/ARM/heads/arm-9-branch)] backport: re PR c++/90947 (Simple lookup table of array of strings is miscompiled)
Joey Ye
jye2@gcc.gnu.org
Thu Feb 27 10:13:00 GMT 2020
https://gcc.gnu.org/g:8af68eba76106d3a5db4490a2510cadf566a8d41
commit 8af68eba76106d3a5db4490a2510cadf566a8d41
Author: Jakub Jelinek <jakub@redhat.com>
Date: Fri Nov 8 19:56:42 2019 +0100
backport: re PR c++/90947 (Simple lookup table of array of strings is miscompiled)
Backported from mainline
2019-10-31 Jakub Jelinek <jakub@redhat.com>
PR c++/90947
* tree.h (type_initializer_zero_p): Remove.
* tree.c (type_initializer_zero_p): Remove.
* 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: r277985
Diff:
---
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(-)
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d1569d5..96a32d7 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,6 +1,12 @@
2019-11-08 Jakub Jelinek <jakub@redhat.com>
Backported from mainline
+ 2019-10-31 Jakub Jelinek <jakub@redhat.com>
+
+ PR c++/90947
+ * tree.h (type_initializer_zero_p): Remove.
+ * tree.c (type_initializer_zero_p): Remove.
+
2019-10-29 Jakub Jelinek <jakub@redhat.com>
* doc/install.texi (--enable-offload-targets): Fix up a typo in the
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 6d54b57..867b6e5 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,6 +1,15 @@
2019-11-08 Jakub Jelinek <jakub@redhat.com>
Backported from mainline
+ 2019-10-31 Jakub Jelinek <jakub@redhat.com>
+
+ 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.
+
2019-10-22 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/85887
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index e15a073..050e4b0 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -7325,6 +7325,11 @@ 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 4878e81..444332e 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -5850,9 +5850,8 @@ 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 1339e9f..ae9bfd2 100644
--- a/gcc/cp/tree.c
+++ b/gcc/cp/tree.c
@@ -5487,6 +5487,68 @@ 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 0000000..f6be350
--- /dev/null
+++ b/gcc/testsuite/g++.dg/init/array54.C
@@ -0,0 +1,13 @@
+// PR c++/90947
+// { dg-do run { target c++11 } }
+
+#include <atomic>
+
+static std::atomic<int> a[1] { {1} };
+
+int
+main ()
+{
+ if (a[0].load () != 1)
+ __builtin_abort ();
+}
diff --git a/gcc/tree.c b/gcc/tree.c
index b20781c..374131c 100644
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -11364,73 +11364,6 @@ 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 331edfc..d650511 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -4525,12 +4525,6 @@ 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);
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