diff options
Diffstat (limited to 'gcc/expr.c')
| -rw-r--r-- | gcc/expr.c | 62 |
1 files changed, 37 insertions, 25 deletions
@@ -11294,12 +11294,15 @@ string_constant (tree arg, tree *ptr_offset) tree idx = TREE_OPERAND (arg, 1); if (TREE_CODE (idx) != INTEGER_CST) { - /* Extract the variable index to prevent - get_addr_base_and_unit_offset() from failing due to - it. Use it later to compute the non-constant offset + /* From a pointer (but not array) argument extract the variable + index to prevent get_addr_base_and_unit_offset() from failing + due to it. Use it later to compute the non-constant offset into the string and return it to the caller. */ varidx = idx; ref = TREE_OPERAND (arg, 0); + + if (TREE_CODE (TREE_TYPE (arg)) == ARRAY_TYPE) + return NULL_TREE; } } array = get_addr_base_and_unit_offset (ref, &base_off); @@ -11327,6 +11330,12 @@ string_constant (tree arg, tree *ptr_offset) tree offset; if (tree str = string_constant (arg0, &offset)) { + /* Avoid pointers to arrays (see bug 86622). */ + if (POINTER_TYPE_P (TREE_TYPE (arg)) + && TREE_CODE (TREE_TYPE (TREE_TYPE (arg))) == ARRAY_TYPE + && TREE_CODE (TREE_OPERAND (arg0, 0)) == ARRAY_REF) + return NULL_TREE; + tree type = TREE_TYPE (arg1); *ptr_offset = fold_build2 (PLUS_EXPR, type, offset, arg1); return str; @@ -11343,16 +11352,17 @@ string_constant (tree arg, tree *ptr_offset) { if (TREE_CODE (TREE_TYPE (array)) != ARRAY_TYPE) return NULL_TREE; - if (tree eltsize = TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (array)))) - { - /* Add the scaled variable index to the constant offset. */ - tree eltoff = fold_build2 (MULT_EXPR, TREE_TYPE (offset), - fold_convert (sizetype, varidx), - eltsize); - offset = fold_build2 (PLUS_EXPR, TREE_TYPE (offset), offset, eltoff); - } - else - return NULL_TREE; + + gcc_assert (TREE_CODE (arg) == ARRAY_REF); + tree chartype = TREE_TYPE (TREE_TYPE (TREE_OPERAND (arg, 0))); + if (TREE_CODE (chartype) != INTEGER_TYPE) + return NULL; + + tree charsize = array_ref_element_size (arg); + /* Set the non-constant offset to the non-constant index scaled + by the size of the character type. */ + offset = fold_build2 (MULT_EXPR, TREE_TYPE (offset), + fold_convert (sizetype, varidx), charsize); } if (TREE_CODE (array) == STRING_CST) @@ -11371,11 +11381,6 @@ string_constant (tree arg, tree *ptr_offset) return NULL_TREE; if (TREE_CODE (init) == CONSTRUCTOR) { - if (TREE_CODE (arg) != ARRAY_REF - && TREE_CODE (arg) == COMPONENT_REF - && TREE_CODE (arg) == MEM_REF) - return NULL_TREE; - /* Convert the 64-bit constant offset to a wider type to avoid overflow. */ offset_int wioff; @@ -11391,11 +11396,15 @@ string_constant (tree arg, tree *ptr_offset) init = fold_ctor_reference (NULL_TREE, init, base_off, 0, array, &fieldoff); HOST_WIDE_INT cstoff; - if (init && base_off.is_constant (&cstoff)) - { - cstoff = (cstoff - fieldoff) / BITS_PER_UNIT; - offset = build_int_cst (sizetype, cstoff); - } + if (!base_off.is_constant (&cstoff)) + return NULL_TREE; + + cstoff = (cstoff - fieldoff) / BITS_PER_UNIT; + tree off = build_int_cst (sizetype, cstoff); + if (varidx) + offset = fold_build2 (PLUS_EXPR, TREE_TYPE (offset), offset, off); + else + offset = off; } if (!init || TREE_CODE (init) != STRING_CST) @@ -11413,8 +11422,11 @@ string_constant (tree arg, tree *ptr_offset) const char a[4] = "abc\000\000"; The excess elements contribute to TREE_STRING_LENGTH() but not to strlen(). */ - unsigned HOST_WIDE_INT length - = strnlen (TREE_STRING_POINTER (init), TREE_STRING_LENGTH (init)); + unsigned HOST_WIDE_INT charsize + = tree_to_uhwi (TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (init)))); + unsigned HOST_WIDE_INT length = TREE_STRING_LENGTH (init); + length = string_length (TREE_STRING_POINTER (init), charsize, + length / charsize); if (compare_tree_int (array_size, length + 1) < 0) return NULL_TREE; |