2014-01-16 Nick Clifton PR middle-end/28865 * varasm.c (output_constant): Return the number of bytes actually emitted. (output_constructor_array_range): Update the field size with the number of bytes emitted by output_constant. (output_constructor_regular_field): Likewise. Also do not complain if the total number of bytes emitted is now greater than the expected fieldpos. * output.h (output_constant): Update prototype and descriptive comment. * gcc.c-torture/compile/pr28865.c: New. * gcc.c-torture/execute/pr28865.c: New. --- gcc/varasm.c (revision 206660) +++ gcc/varasm.c (revision 206661) @@ -4474,8 +4474,10 @@ static unsigned HOST_WIDE_INT This includes the pseudo-op such as ".int" or ".byte", and a newline. Assumes output_addressed_constants has been done on EXP already. - Generate exactly SIZE bytes of assembler data, padding at the end - with zeros if necessary. SIZE must always be specified. + Generate at least SIZE bytes of assembler data, padding at the end + with zeros if necessary. SIZE must always be specified. The returned + value is the actual number of bytes of assembler data generated, which + may be bigger than SIZE if the object contains a variable length field. SIZE is important for structure constructors, since trailing members may have been omitted from the constructor. @@ -4490,14 +4492,14 @@ static unsigned HOST_WIDE_INT ALIGN is the alignment of the data in bits. */ -void +unsigned HOST_WIDE_INT output_constant (tree exp, unsigned HOST_WIDE_INT size, unsigned int align) { enum tree_code code; unsigned HOST_WIDE_INT thissize; if (size == 0 || flag_syntax_only) - return; + return size; /* See if we're trying to initialize a pointer in a non-default mode to the address of some declaration somewhere. If the target says @@ -4562,7 +4564,7 @@ output_constant (tree exp, unsigned HOST && vec_safe_is_empty (CONSTRUCTOR_ELTS (exp))) { assemble_zeros (size); - return; + return size; } if (TREE_CODE (exp) == FDESC_EXPR) @@ -4574,7 +4576,7 @@ output_constant (tree exp, unsigned HOST #else gcc_unreachable (); #endif - return; + return size; } /* Now output the underlying data. If we've handling the padding, return. @@ -4612,8 +4614,7 @@ output_constant (tree exp, unsigned HOST switch (TREE_CODE (exp)) { case CONSTRUCTOR: - output_constructor (exp, size, align, NULL); - return; + return output_constructor (exp, size, align, NULL); case STRING_CST: thissize = MIN ((unsigned HOST_WIDE_INT)TREE_STRING_LENGTH (exp), size); @@ -4648,11 +4649,10 @@ output_constant (tree exp, unsigned HOST case RECORD_TYPE: case UNION_TYPE: gcc_assert (TREE_CODE (exp) == CONSTRUCTOR); - output_constructor (exp, size, align, NULL); - return; + return output_constructor (exp, size, align, NULL); case ERROR_MARK: - return; + return 0; default: gcc_unreachable (); @@ -4660,6 +4660,8 @@ output_constant (tree exp, unsigned HOST if (size > thissize) assemble_zeros (size - thissize); + + return size; } @@ -4759,7 +4761,7 @@ output_constructor_array_range (oc_local if (local->val == NULL_TREE) assemble_zeros (fieldsize); else - output_constant (local->val, fieldsize, align2); + fieldsize = output_constant (local->val, fieldsize, align2); /* Count its size. */ local->total_bytes += fieldsize; @@ -4808,9 +4810,8 @@ output_constructor_regular_field (oc_loc Note no alignment needed in an array, since that is guaranteed if each element has the proper size. */ if ((local->field != NULL_TREE || local->index != NULL_TREE) - && fieldpos != local->total_bytes) + && fieldpos > local->total_bytes) { - gcc_assert (fieldpos >= local->total_bytes); assemble_zeros (fieldpos - local->total_bytes); local->total_bytes = fieldpos; } @@ -4847,7 +4848,7 @@ output_constructor_regular_field (oc_loc if (local->val == NULL_TREE) assemble_zeros (fieldsize); else - output_constant (local->val, fieldsize, align2); + fieldsize = output_constant (local->val, fieldsize, align2); /* Count its size. */ local->total_bytes += fieldsize; --- gcc/output.h (revision 206660) +++ gcc/output.h (revision 206661) @@ -294,11 +294,13 @@ extern void output_quoted_string (FILE * This includes the pseudo-op such as ".int" or ".byte", and a newline. Assumes output_addressed_constants has been done on EXP already. - Generate exactly SIZE bytes of assembler data, padding at the end - with zeros if necessary. SIZE must always be specified. + Generate at least SIZE bytes of assembler data, padding at the end + with zeros if necessary. SIZE must always be specified. The returned + value is the actual number of bytes of assembler data generated, which + may be bigger than SIZE if the object contains a variable length field. ALIGN is the alignment in bits that may be assumed for the data. */ -extern void output_constant (tree, unsigned HOST_WIDE_INT, unsigned int); +extern unsigned HOST_WIDE_INT output_constant (tree, unsigned HOST_WIDE_INT, unsigned int); /* When outputting delayed branch sequences, this rtx holds the sequence being output. It is null when no delayed branch --- gcc/testsuite/gcc.c-torture/execute/pr28865.c (revision 0) +++ gcc/testsuite/gcc.c-torture/execute/pr28865.c (revision 206661) @@ -0,0 +1,21 @@ +struct A { int a; char b[]; }; +union B { struct A a; char b[sizeof (struct A) + 31]; }; +union B b = { { 1, "123456789012345678901234567890" } }; +union B c = { { 2, "123456789012345678901234567890" } }; + +__attribute__((noinline, noclone)) void +foo (int *x[2]) +{ + x[0] = &b.a.a; + x[1] = &c.a.a; +} + +int +main () +{ + int *x[2]; + foo (x); + if (*x[0] != 1 || *x[1] != 2) + __builtin_abort (); + return 0; +} --- gcc/testsuite/gcc.c-torture/compile/pr28865.c (revision 0) +++ gcc/testsuite/gcc.c-torture/compile/pr28865.c (revision 206661) @@ -0,0 +1,16 @@ +struct var_len +{ + int field1; + const char field2[]; +}; + +/* Note - strictly speaking this array declaration is illegal + since each element has a variable length. GCC allows it + (for the moment) because it is used in existing code, such + as glibc. */ +static const struct var_len var_array[] = +{ + { 1, "Long exposure noise reduction" }, + { 2, "Shutter/AE lock buttons" }, + { 3, "Mirror lockup" } +};