re PR c/7054 (#pragma pack handled incorrectly)

        PR c/7054
        * defaults.h (TARGET_DEFAULT_PACK_STRUCT): Provide default.
        * tree.h (initial_max_fld_align): Declare
        * stor-layout.c (initial_max_fld_align): Define and initialize.
        (maximum_field_alignment): Initialize to the same value.
        * common.opt: Add -fpack-struct= variant of switch.
        * opts.c: Handle -fpack-struct= variant of switch.
        * c-pragma.c: Change #pragma pack() handling so that it becomes
        compatible to other compilers: accept individual 'push' argument,
        make final pop restore (command line) default, correct interaction
        of push/pop and sole specification of a new alignment (so that the
        sequence #pragma pack(push) - #pragma pack(<n>) becomes identical
        to #pragma pack(push, <n>).
        * doc/extend.texi: New node "Structure-Packing Pragmas" under
        "Pragmas", describing #pragma pack.
        * doc/invoke.texi: Document -fpack-struct=<n> variant of switch.
        * doc/tm.texi: Adjust description for HANDLE_PRAGMA_PACK_PUSH_POP.
        Document new TARGET_DEFAULT_PACK_STRUCT.
testsuite:
        * gcc.dg/pack-test-2.c: Adjust to permit and check #pragma pack(push).
        * gcc.dg/c99-flex-array-4.c: Add -fpack-struct=8 to provide a
        deterministic starting point for the alignment of structure fields.
        * gcc.dg/Wpadded.c: Dito.
        * g++.dg/abi/vbase10.C: Dito.

From-SVN: r87037

1 files changed, 3 insertions, 1 deletions

diff --git a/gcc/tree.h b/gcc/tree.h
index 9c0fc85..0f619b0 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -3102,8 +3102,10 @@ extern void put_pending_sizes (tree);
    + (BITS_PER_UNIT > 8) + (BITS_PER_UNIT > 16) + (BITS_PER_UNIT > 32) \
    + (BITS_PER_UNIT > 64) + (BITS_PER_UNIT > 128) + (BITS_PER_UNIT > 256))
 
-/* If nonzero, an upper limit on alignment of structure fields, in bits.  */
+/* If nonzero, an upper limit on alignment of structure fields, in bits,  */
 extern unsigned int maximum_field_alignment;
+/* and its original value in bytes, specified via -fpack-struct=<value>. */
+extern unsigned int initial_max_fld_align;
 
 /* If nonzero, the alignment of a bitstring or (power-)set value, in bits.  */
 extern unsigned int set_alignment;