diff options
| -rw-r--r-- | gcc/ChangeLog | 21 | ||||
| -rw-r--r-- | gcc/c-pragma.c | 107 | ||||
| -rw-r--r-- | gcc/common.opt | 4 | ||||
| -rw-r--r-- | gcc/defaults.h | 4 | ||||
| -rw-r--r-- | gcc/doc/extend.texi | 25 | ||||
| -rw-r--r-- | gcc/doc/invoke.texi | 10 | ||||
| -rw-r--r-- | gcc/doc/tm.texi | 15 | ||||
| -rw-r--r-- | gcc/opts.c | 10 | ||||
| -rw-r--r-- | gcc/stor-layout.c | 4 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 8 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/abi/vbase10.C | 4 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/Wpadded.c | 4 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/c99-flex-array-4.c | 4 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/pack-test-2.c | 4 | ||||
| -rw-r--r-- | gcc/tree.h | 4 |
15 files changed, 152 insertions, 76 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 1b36cab..71218fc 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,24 @@ +2004-09-03 Jan Beulich <jbeulich@novell.com> + + 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. + 2004-09-03 Devang Patel <dpatel@apple.com> * dwarf2out.c (gen_field_die). Equate decl number to die. diff --git a/gcc/c-pragma.c b/gcc/c-pragma.c index 0bf2f12..cb518e0 100644 --- a/gcc/c-pragma.c +++ b/gcc/c-pragma.c @@ -42,7 +42,6 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA typedef struct align_stack GTY(()) { int alignment; - unsigned int num_pushes; tree id; struct align_stack * prev; } align_stack; @@ -59,8 +58,9 @@ static void handle_pragma_pack (cpp_reader *); happens, we restore the value to this, not to a value of 0 for maximum_field_alignment. Value is in bits. */ static int default_alignment; -#define SET_GLOBAL_ALIGNMENT(ALIGN) \ - (default_alignment = maximum_field_alignment = (ALIGN)) +#define SET_GLOBAL_ALIGNMENT(ALIGN) (maximum_field_alignment = *(alignment_stack == NULL \ + ? &default_alignment \ + : &alignment_stack->alignment) = (ALIGN)) static void push_alignment (int, tree); static void pop_alignment (tree); @@ -69,31 +69,23 @@ static void pop_alignment (tree); static void push_alignment (int alignment, tree id) { - if (alignment_stack == NULL - || alignment_stack->alignment != alignment - || id != NULL_TREE) - { - align_stack * entry; + align_stack * entry; - entry = ggc_alloc (sizeof (* entry)); + entry = ggc_alloc (sizeof (* entry)); - entry->alignment = alignment; - entry->num_pushes = 1; - entry->id = id; - entry->prev = alignment_stack; - - /* The current value of maximum_field_alignment is not necessarily - 0 since there may be a #pragma pack(<n>) in effect; remember it - so that we can restore it after the final #pragma pop(). */ - if (alignment_stack == NULL) - default_alignment = maximum_field_alignment; - - alignment_stack = entry; + entry->alignment = alignment; + entry->id = id; + entry->prev = alignment_stack; + + /* The current value of maximum_field_alignment is not necessarily + 0 since there may be a #pragma pack(<n>) in effect; remember it + so that we can restore it after the final #pragma pop(). */ + if (alignment_stack == NULL) + default_alignment = maximum_field_alignment; + + alignment_stack = entry; - maximum_field_alignment = alignment; - } - else - alignment_stack->num_pushes ++; + maximum_field_alignment = alignment; } /* Undo a push of an alignment onto the stack. */ @@ -103,12 +95,7 @@ pop_alignment (tree id) align_stack * entry; if (alignment_stack == NULL) - { - warning ("\ -#pragma pack (pop) encountered without matching #pragma pack (push, <n>)" - ); - return; - } + GCC_BAD("#pragma pack (pop) encountered without matching #pragma pack (push)"); /* If we got an identifier, strip away everything above the target entry so that the next step will restore the state just below it. */ @@ -117,27 +104,20 @@ pop_alignment (tree id) for (entry = alignment_stack; entry; entry = entry->prev) if (entry->id == id) { - entry->num_pushes = 1; alignment_stack = entry; break; } if (entry == NULL) warning ("\ -#pragma pack(pop, %s) encountered without matching #pragma pack(push, %s, <n>)" +#pragma pack(pop, %s) encountered without matching #pragma pack(push, %s)" , IDENTIFIER_POINTER (id), IDENTIFIER_POINTER (id)); } - if (-- alignment_stack->num_pushes == 0) - { - entry = alignment_stack->prev; + entry = alignment_stack->prev; - if (entry == NULL) - maximum_field_alignment = default_alignment; - else - maximum_field_alignment = entry->alignment; + maximum_field_alignment = entry ? entry->alignment : default_alignment; - alignment_stack = entry; - } + alignment_stack = entry; } #else /* not HANDLE_PRAGMA_PACK_PUSH_POP */ #define SET_GLOBAL_ALIGNMENT(ALIGN) (maximum_field_alignment = (ALIGN)) @@ -150,7 +130,9 @@ pop_alignment (tree id) /* #pragma pack () #pragma pack (N) + #pragma pack (push) #pragma pack (push, N) + #pragma pack (push, ID) #pragma pack (push, ID, N) #pragma pack (pop) #pragma pack (pop, ID) */ @@ -169,7 +151,7 @@ handle_pragma_pack (cpp_reader * ARG_UNUSED (dummy)) if (token == CPP_CLOSE_PAREN) { action = set; - align = 0; + align = initial_max_fld_align; } else if (token == CPP_NUMBER) { @@ -180,8 +162,8 @@ handle_pragma_pack (cpp_reader * ARG_UNUSED (dummy)) } else if (token == CPP_NAME) { -#define GCC_BAD_ACTION do { if (action == push) \ - GCC_BAD ("malformed '#pragma pack(push[, id], <n>)' - ignored"); \ +#define GCC_BAD_ACTION do { if (action != pop) \ + GCC_BAD ("malformed '#pragma pack(push[, id][, <n>])' - ignored"); \ else \ GCC_BAD ("malformed '#pragma pack(pop[, id])' - ignored"); \ } while (0) @@ -194,31 +176,21 @@ handle_pragma_pack (cpp_reader * ARG_UNUSED (dummy)) else GCC_BAD2 ("unknown action '%s' for '#pragma pack' - ignored", op); - token = c_lex (&x); - if (token != CPP_COMMA && action == push) - GCC_BAD_ACTION; - - if (token == CPP_COMMA) + while ((token = c_lex (&x)) == CPP_COMMA) { token = c_lex (&x); - if (token == CPP_NAME) + if (token == CPP_NAME && id == 0) { id = x; - if (action == push && c_lex (&x) != CPP_COMMA) - GCC_BAD_ACTION; - token = c_lex (&x); } - - if (action == push) + else if (token == CPP_NUMBER && action == push && align == -1) { - if (token == CPP_NUMBER) - { - align = TREE_INT_CST_LOW (x); - token = c_lex (&x); - } - else - GCC_BAD_ACTION; + align = TREE_INT_CST_LOW (x); + if (align == -1) + action = set; } + else + GCC_BAD_ACTION; } if (token != CPP_CLOSE_PAREN) @@ -231,6 +203,9 @@ handle_pragma_pack (cpp_reader * ARG_UNUSED (dummy)) if (c_lex (&x) != CPP_EOF) warning ("junk at end of '#pragma pack'"); + if (flag_pack_struct) + GCC_BAD ("#pragma pack has no effect with -fpack-struct - ignored"); + if (action != pop) switch (align) { @@ -242,6 +217,12 @@ handle_pragma_pack (cpp_reader * ARG_UNUSED (dummy)) case 16: align *= BITS_PER_UNIT; break; + case -1: + if (action == push) + { + align = maximum_field_alignment; + break; + } default: GCC_BAD2 ("alignment must be a small power of two, not %d", align); } diff --git a/gcc/common.opt b/gcc/common.opt index c3baf31..a74921d 100644 --- a/gcc/common.opt +++ b/gcc/common.opt @@ -575,6 +575,10 @@ fpack-struct Common Report Var(flag_pack_struct) Pack structure members together without holes +fpack-struct= +Common RejectNegative Joined UInteger +-fpack-struct=<number> Set initial maximum structure member alignment + fpcc-struct-return Common Report Var(flag_pcc_struct_return,1) VarExists Return small aggregates in memory, not registers diff --git a/gcc/defaults.h b/gcc/defaults.h index d16adf4..dd5c21f 100644 --- a/gcc/defaults.h +++ b/gcc/defaults.h @@ -476,6 +476,10 @@ do { fputs (integer_asm_op (POINTER_SIZE / BITS_PER_UNIT, TRUE), FILE); \ #define PREFERRED_STACK_BOUNDARY STACK_BOUNDARY #endif +#ifndef TARGET_DEFAULT_PACK_STRUCT +#define TARGET_DEFAULT_PACK_STRUCT 0 +#endif + /* By default, the C++ compiler will use function addresses in the vtable entries. Setting this nonzero tells the compiler to use function descriptors instead. The value of this macro says how diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi index 5023f27..fe25cd1 100644 --- a/gcc/doc/extend.texi +++ b/gcc/doc/extend.texi @@ -7672,6 +7672,7 @@ for further explanation. * Darwin Pragmas:: * Solaris Pragmas:: * Symbol-Renaming Pragmas:: +* Structure-Packing Pragmas:: @end menu @node ARM Pragmas @@ -7848,6 +7849,30 @@ labels, but if @code{#pragma extern_prefix} triggers first we have no way of knowing that that happened.) @end enumerate +@node Structure-Packing Pragmas +@subsection Structure-Packing Pragmas + +For compatibility with Win32, GCC supports as set of @code{#pragma} +directives which change the maximum alignment of members of structures, +unions, and classes subsequently defined. The @var{n} value below always +is required to be a small power of two and specifies the new alignment +in bytes. + +@enumerate +@item @code{#pragma pack(@var{n})} simply sets the new alignment. +@item @code{#pragma pack()} sets the alignment to the one that was in +effect when compilation started (see also command line option +@option{-fpack-struct[=<n>]} @pxref{Code Gen Options}). +@item @code{#pragma pack(push[,@var{n}])} pushes the current alignment +setting on an internal stack and then optionally sets the new alignment. +@item @code{#pragma pack(pop)} restores the alignment setting to the one +saved at the top of the internal stack (and removes that stack entry). +Note that @code{#pragma pack([@var{n}])} does not influence this internal +stack; thus it is possible to have @code{#pragma pack(push)} followed by +multiple @code{#pragma pack(@var{n})} instances and finalized by a single +@code{#pragma pack(pop)}. +@end enumerate + @node Unnamed Fields @section Unnamed struct/union fields within structs/unions. @cindex struct diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 6772ba0..5c0030e 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -699,7 +699,7 @@ See S/390 and zSeries Options. -fpcc-struct-return -fpic -fPIC -fpie -fPIE @gol -freg-struct-return -fshared-data -fshort-enums @gol -fshort-double -fshort-wchar @gol --fverbose-asm -fpack-struct -fstack-check @gol +-fverbose-asm -fpack-struct[=@var{n}] -fstack-check @gol -fstack-limit-register=@var{reg} -fstack-limit-symbol=@var{sym} @gol -fargument-alias -fargument-noalias @gol -fargument-noalias-global -fleading-underscore @gol @@ -11789,9 +11789,13 @@ a register in which function values may be returned. This flag does not have a negative form, because it specifies a three-way choice. -@item -fpack-struct +@item -fpack-struct[=@var{n}] @opindex fpack-struct -Pack all structure members together without holes. +Without a value specified, pack all structure members together without +holes. When a value is specified (which must be a small power of two), pack +structure members according to this value, representing the maximum +alignment (that is, objects with default alignment requirements larger than +this will be output potentially unaligned at the next fitting location. @strong{Warning:} the @option{-fpack-struct} switch causes GCC to generate code that is not binary compatible with code generated without that switch. diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi index bba444c..2672485 100644 --- a/gcc/doc/tm.texi +++ b/gcc/doc/tm.texi @@ -9017,16 +9017,23 @@ of specifically named weak labels, optionally with a value. @findex pragma @defmac HANDLE_PRAGMA_PACK_PUSH_POP Define this macro (to a value of 1) if you want to support the Win32 -style pragmas @samp{#pragma pack(push,@var{n})} and @samp{#pragma -pack(pop)}. The @samp{pack(push,@var{n})} pragma specifies the maximum alignment -(in bytes) of fields within a structure, in much the same way as the -@samp{__aligned__} and @samp{__packed__} @code{__attribute__}s do. A +style pragmas @samp{#pragma pack(push[,@var{n}])} and @samp{#pragma +pack(pop)}. The @samp{pack(push,[@var{n}])} pragma specifies the maximum +alignment (in bytes) of fields within a structure, in much the same way as +the @samp{__aligned__} and @samp{__packed__} @code{__attribute__}s do. A pack value of zero resets the behavior to the default. Successive invocations of this pragma cause the previous values to be stacked, so that invocations of @samp{#pragma pack(pop)} will return to the previous value. @end defmac +@defmac TARGET_DEFAULT_PACK_STRUCT +If your target requires a structure packing default other than 0 (meaning +the machine default), define this macro the the necessary value (in bytes). +This must be a value that would also valid to be used with +@samp{#pragma pack()} (that is, a small power of two). +@end defmac + @defmac DOLLARS_IN_IDENTIFIERS Define this macro to control use of the character @samp{$} in identifier names for the C family of languages. 0 means @samp{$} is @@ -810,6 +810,16 @@ common_handle_option (size_t scode, const char *arg, int value) pp_set_line_maximum_length (global_dc->printer, value); break; + case OPT_fpack_struct_: + if (value <= 0 || (value & (value - 1)) || value > 16) + error("structure alignment must be a small power of two, not %d", value); + else + { + initial_max_fld_align = value; + maximum_field_alignment = value * BITS_PER_UNIT; + } + break; + case OPT_fpeel_loops: flag_peel_loops_set = true; break; diff --git a/gcc/stor-layout.c b/gcc/stor-layout.c index 395a5f9..75ff523 100644 --- a/gcc/stor-layout.c +++ b/gcc/stor-layout.c @@ -43,7 +43,9 @@ tree sizetype_tab[(int) TYPE_KIND_LAST]; /* If nonzero, this is an upper limit on alignment of structure fields. The value is measured in bits. */ -unsigned int maximum_field_alignment; +unsigned int maximum_field_alignment = TARGET_DEFAULT_PACK_STRUCT * BITS_PER_UNIT; +/* ... and its original value in bytes, specified via -fpack-struct=<value>. */ +unsigned int initial_max_fld_align = TARGET_DEFAULT_PACK_STRUCT; /* If nonzero, the alignment of a bitstring or (power-)set value, in bits. May be overridden by front-ends. */ diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 6e8ef6c..c4a0385 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,11 @@ +2004-09-03 Jan Beulich <jbeulich@novell.com> + + * 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. + 2004-09-03 Devang Patel <dpatel@apple.com> * g++.dg/debug/pr15736.cc: New test. diff --git a/gcc/testsuite/g++.dg/abi/vbase10.C b/gcc/testsuite/g++.dg/abi/vbase10.C index a0d113a..b6e7f88 100644 --- a/gcc/testsuite/g++.dg/abi/vbase10.C +++ b/gcc/testsuite/g++.dg/abi/vbase10.C @@ -1,5 +1,7 @@ // { dg-do compile } -// { dg-options "-Wabi -fabi-version=1" } +// -fpack-struct is necessary because the code below assumes the initial +// packing is larger than 1, which cannot ge guaranteed for all targets. +// { dg-options "-Wabi -fabi-version=1 -fpack-struct=8" } // On ARM processors, the alignment of B will be 4 even though it // contains only a single "char". That would avoids the situation // that the warning below is designed to catch. We therefore diff --git a/gcc/testsuite/gcc.dg/Wpadded.c b/gcc/testsuite/gcc.dg/Wpadded.c index 74376e5..e55fd11 100644 --- a/gcc/testsuite/gcc.dg/Wpadded.c +++ b/gcc/testsuite/gcc.dg/Wpadded.c @@ -1,7 +1,9 @@ /* Source: EMC. */ /* { dg-do compile } */ -/* { dg-options "-Wpadded" } */ +/* -fpack-struct is necessary because the warning expected requires the initial + packing to be larger than 1, which cannot ge guaranteed for all targets. */ +/* { dg-options "-Wpadded -fpack-struct=8" } */ struct foo { char bar; diff --git a/gcc/testsuite/gcc.dg/c99-flex-array-4.c b/gcc/testsuite/gcc.dg/c99-flex-array-4.c index ab20cf0..c4a0564 100644 --- a/gcc/testsuite/gcc.dg/c99-flex-array-4.c +++ b/gcc/testsuite/gcc.dg/c99-flex-array-4.c @@ -5,7 +5,9 @@ from Tony Finch <dot@dotat.at>, adapted to a testcase by Joseph Myers <jsm28@cam.ac.uk>. See also WG14 reflector messages 9571-3. */ /* { dg-do compile } */ -/* { dg-options "-std=iso9899:1999 -pedantic-errors" } */ +/* -fpack-struct is necessary because the code below assumes the initial + packing is larger than 1, which cannot ge guaranteed for all targets. */ +/* { dg-options "-std=iso9899:1999 -fpack-struct=8 -pedantic-errors" } */ #include <stddef.h> diff --git a/gcc/testsuite/gcc.dg/pack-test-2.c b/gcc/testsuite/gcc.dg/pack-test-2.c index f15ac84..974d982 100644 --- a/gcc/testsuite/gcc.dg/pack-test-2.c +++ b/gcc/testsuite/gcc.dg/pack-test-2.c @@ -3,9 +3,11 @@ /* { dg-do compile { target *-*-linux* *-*-cygwin* powerpc*-*-eabi* } } */ -#pragma pack(push) /* { dg-error "malformed" } */ #pragma pack(pop) /* { dg-error "without matching" } */ +#pragma pack(push) +#pragma pack(pop) /* reset */ + #pragma pack(push, foo, 1) #pragma pack(pop, foo, 1) /* { dg-error "malformed" } (/ #pragma pack(pop) /* reset */ @@ -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; |