[Darwin] Patch: new flag -mone-byte-bool

[Darwin] Patch: new flag -mone-byte-bool

[Matt Austern]

I can't say I'm thrilled with this feature, but, unfortunately, it's 
necessary.  gcc on Darwin/PowerPC defines sizeof(bool) to be 4.  
Changing this isn't a viable option: ABI stability is too important.  
This flag is for those few developers who absolutely need bool to have 
a particular size and who are sophisticated enough to be able to deal 
with an ABI-changing flag.  Think of it as something like 
-fshort-wchar.

Bootstrapped and tested on Darwin/PowerPC (of course).  Documentation, 
test cases, and ChangeLog entries included.

OK to commit to mainline?

			--Matt


Index: gcc/ChangeLog
===================================================================
RCS file: /cvs/gcc/gcc/gcc/ChangeLog,v
retrieving revision 2.4718
diff -p -r2.4718 ChangeLog
*** gcc/ChangeLog	28 Jul 2004 05:13:05 -0000	2.4718
--- gcc/ChangeLog	28 Jul 2004 05:53:38 -0000
***************
*** 1,3 ****
--- 1,12 ----
+ 2004-07-28  Matt Austern  <austern@apple.com>
+
+ 	* config/darwin.c (darwin_one_byte_bool): New global variable.
+ 	* config/darwin.h (darwin_one_byte_bool): Declare.
+ 	(SUBTARGET_OPTIONS): Define macro.  (for -mone-byte-bool flag.)
+ 	* config/rs6000/darwin.h (BOOL_TYPE_SIZE): Conditionalize on
+ 	value of darwin_one_byte_bool.
+ 	* doc/invoke.texi: Document -mone-byte-bool flag.
+ 	
   2004-07-28  Diego Novillo  <dnovillo@redhat.com>

   	* tree-optimize.c (init_tree_optimization_passes): Schedule
Index: gcc/config/darwin.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/darwin.c,v
retrieving revision 1.72
diff -p -r1.72 darwin.c
*** gcc/config/darwin.c	23 Jul 2004 04:35:14 -0000	1.72
--- gcc/config/darwin.c	28 Jul 2004 05:53:38 -0000
*************** Boston, MA 02111-1307, USA.  */
*** 44,49 ****
--- 44,53 ----
   #include "errors.h"
   #include "hashtab.h"

+ /* Nonzero if the user passes the -mone-byte-bool switch, which forces
+    sizeof(bool) to be 1. */
+ const char *darwin_one_byte_bool = 0;
+
   int
   name_needs_quotes (const char *name)
   {
Index: gcc/config/darwin.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/darwin.h,v
retrieving revision 1.86
diff -p -r1.86 darwin.h
*** gcc/config/darwin.h	23 Jul 2004 04:35:15 -0000	1.86
--- gcc/config/darwin.h	28 Jul 2004 05:53:40 -0000
*************** Boston, MA 02111-1307, USA.  */
*** 130,136 ****
--- 130,147 ----
     { "-single_module", "-Zsingle_module" },  \
     { "-unexported_symbols_list", "-Zunexported_symbols_list" }, \
     SUBTARGET_OPTION_TRANSLATE_TABLE
+
+ /* Nonzero if the user has chosen to force sizeof(bool) to be 1
+    by providing the -mone-byte-bool switch.  It would be better
+    to use SUBTARGET_SWITCHES for this instead of SUBTARGET_OPTIONS,
+    but there are no more bits in rs6000 TARGET_SWITCHES.  Note
+    that this switch has no "no-" variant. */
+ extern const char *darwin_one_byte_bool;

+ #undef SUBTARGET_OPTIONS
+ #define SUBTARGET_OPTIONS \
+   {"one-byte-bool", &darwin_one_byte_bool, N_("Set sizeof(bool) to 
1"), 0 }
+
   /* These compiler options take n arguments.  */

   #undef  WORD_SWITCH_TAKES_ARG
Index: gcc/config/rs6000/darwin.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/rs6000/darwin.h,v
retrieving revision 1.54
diff -p -r1.54 darwin.h
*** gcc/config/rs6000/darwin.h	1 Jul 2004 04:09:05 -0000	1.54
--- gcc/config/rs6000/darwin.h	28 Jul 2004 05:53:40 -0000
*************** do {									\
*** 321,328 ****
   #define DOUBLE_INT_ASM_OP "\t.quad\t"

   /* For binary compatibility with 2.95; Darwin C APIs use bool from
!    stdbool.h, which was an int-sized enum in 2.95.  */
! #define BOOL_TYPE_SIZE INT_TYPE_SIZE

   #undef REGISTER_TARGET_PRAGMAS
   #define REGISTER_TARGET_PRAGMAS DARWIN_REGISTER_TARGET_PRAGMAS
--- 321,330 ----
   #define DOUBLE_INT_ASM_OP "\t.quad\t"

   /* For binary compatibility with 2.95; Darwin C APIs use bool from
!    stdbool.h, which was an int-sized enum in 2.95.  Users can 
explicitly
!    choose to have sizeof(bool)==1 with the -mone-byte-bool switch. */
! extern const char *darwin_one_byte_bool;
! #define BOOL_TYPE_SIZE (darwin_one_byte_bool ? CHAR_TYPE_SIZE : 
INT_TYPE_SIZE)

   #undef REGISTER_TARGET_PRAGMAS
   #define REGISTER_TARGET_PRAGMAS DARWIN_REGISTER_TARGET_PRAGMAS
Index: gcc/doc/invoke.texi
===================================================================
RCS file: /cvs/gcc/gcc/gcc/doc/invoke.texi,v
retrieving revision 1.492
diff -p -r1.492 invoke.texi
*** gcc/doc/invoke.texi	25 Jul 2004 22:52:18 -0000	1.492
--- gcc/doc/invoke.texi	28 Jul 2004 05:53:44 -0000
*************** in the following sections.
*** 423,429 ****
   -single_module  -static  -sub_library  -sub_umbrella @gol
   -twolevel_namespace  -umbrella  -undefined @gol
   -unexported_symbols_list  -weak_reference_mismatches @gol
! -whatsloaded -F -gused -gfull}

   @emph{DEC Alpha Options}
   @gccoptlist{-mno-fp-regs  -msoft-float  -malpha-as  -mgas @gol
--- 423,429 ----
   -single_module  -static  -sub_library  -sub_umbrella @gol
   -twolevel_namespace  -umbrella  -undefined @gol
   -unexported_symbols_list  -weak_reference_mismatches @gol
! whatsloaded -F -gused -gfull -mone-byte-bool}

   @emph{DEC Alpha Options}
   @gccoptlist{-mno-fp-regs  -msoft-float  -malpha-as  -mgas @gol
*************** This is by default ON.
*** 6930,6935 ****
--- 6930,6948 ----
   @opindex -gfull
   Emit debugging information for all symbols and types.

+ @item -mone-byte-bool
+ @opindex -mone-byte-bool
+ Override the defaults for @samp{bool} so that @samp{sizeof(bool)==1}.
+ By default @samp{sizeof(bool)} is @samp{4} when compiling for
+ Darwin/PowerPC and @samp{1} when compiling for Darwin/x86, so this
+ option has no effect on x86.
+
+ @strong{Warning:} The @option{-mone-byte-bool} switch causes GCC
+ to generate code that is not binary compatible with code generated
+ without that switch.  Using this switch may require recompiling all
+ other modules in a program, including system libraries.  Use this
+ switch to conform to a non-default data model.
+
   @item -all_load
   @opindex all_load
   Loads all members of static archive libraries.
Index: gcc/testsuite/ChangeLog
===================================================================
RCS file: /cvs/gcc/gcc/gcc/testsuite/ChangeLog,v
retrieving revision 1.4061
diff -p -r1.4061 ChangeLog
*** gcc/testsuite/ChangeLog	28 Jul 2004 05:13:09 -0000	1.4061
--- gcc/testsuite/ChangeLog	28 Jul 2004 05:53:48 -0000
***************
*** 1,3 ****
--- 1,8 ----
+ 2004-07-27  Matt Austern <austern@apple.com>
+
+ 	* gcc.dg/darwin-bool-1.c: New test.
+ 	* gcc.dg/darwin-bool-2.c: New test.
+ 	
   2004-07-28  Diego Novillo  <dnovillo@redhat.com>

   	* gcc.dg/tree-ssa/20030714-2.c: Adjust number of expected
Index: gcc/testsuite/gcc.dg/darwin-bool-1.c
===================================================================
RCS file: gcc/testsuite/gcc.dg/darwin-bool-1.c
diff -N gcc/testsuite/gcc.dg/darwin-bool-1.c
*** /dev/null	1 Jan 1970 00:00:00 -0000
--- gcc/testsuite/gcc.dg/darwin-bool-1.c	28 Jul 2004 05:53:52 -0000
***************
*** 0 ****
--- 1,11 ----
+ /* Check that sizeof(bool) is 4 if we don't use special options. */
+ /* Matt Austern  <austern@apple.com> */
+ /* { dg-do run { target powerpc*-*-darwin* } } */
+
+ int dummy1[sizeof(_Bool) - 3];
+ int dummy2[5 - sizeof(_Bool)];
+
+ int main()
+ {
+   return sizeof(_Bool) == 4 ? 0 : 1;
+ }
Index: gcc/testsuite/gcc.dg/darwin-bool-2.c
===================================================================
RCS file: gcc/testsuite/gcc.dg/darwin-bool-2.c
diff -N gcc/testsuite/gcc.dg/darwin-bool-2.c
*** /dev/null	1 Jan 1970 00:00:00 -0000
--- gcc/testsuite/gcc.dg/darwin-bool-2.c	28 Jul 2004 05:53:52 -0000
***************
*** 0 ****
--- 1,12 ----
+ /* Check that sizeof(bool) is 1 if we use the -mone-byte-bool option. 
*/
+ /* Matt Austern  <austern@apple.com> */
+ /* { dg-do run { target powerpc*-*-darwin* } } */
+ /* { dg-options "-mone-byte-bool" } */
+
+ int dummy1[sizeof(_Bool)];
+ int dummy2[2 - sizeof(_Bool)];
+
+ int main()
+ {
+   return sizeof(_Bool) == 1 ? 0 : 1;
+ }

Re: [Darwin] Patch: new flag -mone-byte-bool

[Andreas Schwab]

Matt Austern <austern@apple.com> writes:

> *** 423,429 ****
>    -single_module  -static  -sub_library  -sub_umbrella @gol
>    -twolevel_namespace  -umbrella  -undefined @gol
>    -unexported_symbols_list  -weak_reference_mismatches @gol
> ! -whatsloaded -F -gused -gfull}
>
>    @emph{DEC Alpha Options}
>    @gccoptlist{-mno-fp-regs  -msoft-float  -malpha-as  -mgas @gol
> --- 423,429 ----
>    -single_module  -static  -sub_library  -sub_umbrella @gol
>    -twolevel_namespace  -umbrella  -undefined @gol
>    -unexported_symbols_list  -weak_reference_mismatches @gol
> ! whatsloaded -F -gused -gfull -mone-byte-bool}
   ^^^
Typo.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux AG, Maxfeldstraße 5, 90409 Nürnberg, Germany
Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

Re: [Darwin] Patch: new flag -mone-byte-bool

[Matt Austern]

[-- Attachment #1: Type: text/plain, Size: 837 bytes --]

On Jul 28, 2004, at 1:03 AM, Andreas Schwab wrote:

> Matt Austern <austern@apple.com> writes:
>
>> *** 423,429 ****
>>    -single_module  -static  -sub_library  -sub_umbrella @gol
>>    -twolevel_namespace  -umbrella  -undefined @gol
>>    -unexported_symbols_list  -weak_reference_mismatches @gol
>> ! -whatsloaded -F -gused -gfull}
>>
>>    @emph{DEC Alpha Options}
>>    @gccoptlist{-mno-fp-regs  -msoft-float  -malpha-as  -mgas @gol
>> --- 423,429 ----
>>    -single_module  -static  -sub_library  -sub_umbrella @gol
>>    -twolevel_namespace  -umbrella  -undefined @gol
>>    -unexported_symbols_list  -weak_reference_mismatches @gol
>> ! whatsloaded -F -gused -gfull -mone-byte-bool}
>    ^^^
> Typo.

Whoops!  Fixed.  Here's my updated patch (which differs by one
character from the earlier version).

OK to commit to mainline?


[-- Attachment #2: bool.txt --]
[-- Type: text/plain, Size: 7533 bytes --]

? gcc/.gdb_history
Index: gcc/ChangeLog
===================================================================
RCS file: /cvs/gcc/gcc/gcc/ChangeLog,v
retrieving revision 2.4721
diff -p -r2.4721 ChangeLog
*** gcc/ChangeLog	28 Jul 2004 12:12:54 -0000	2.4721
--- gcc/ChangeLog	28 Jul 2004 14:32:44 -0000
***************
*** 1,3 ****
--- 1,12 ----
+ 2004-07-28  Matt Austern  <austern@apple.com>
+ 
+ 	* config/darwin.c (darwin_one_byte_bool): New global variable.
+ 	* config/darwin.h (darwin_one_byte_bool): Declare.
+ 	(SUBTARGET_OPTIONS): Define macro.  (for -mone-byte-bool flag.)
+ 	* config/rs6000/darwin.h (BOOL_TYPE_SIZE): Conditionalize on
+ 	value of darwin_one_byte_bool.
+ 	* doc/invoke.texi: Document -mone-byte-bool flag.
+ 	
  2004-07-28  Aldy Hernandez  <aldyh@redhat.com>
  
  	* config/rs6000/rs6000.md ("move_from_CR_gt_bit"): Rename to
Index: gcc/config/darwin.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/darwin.c,v
retrieving revision 1.72
diff -p -r1.72 darwin.c
*** gcc/config/darwin.c	23 Jul 2004 04:35:14 -0000	1.72
--- gcc/config/darwin.c	28 Jul 2004 14:32:46 -0000
*************** Boston, MA 02111-1307, USA.  */
*** 44,49 ****
--- 44,53 ----
  #include "errors.h"
  #include "hashtab.h"
  
+ /* Nonzero if the user passes the -mone-byte-bool switch, which forces
+    sizeof(bool) to be 1. */
+ const char *darwin_one_byte_bool = 0;
+ 
  int
  name_needs_quotes (const char *name)
  {
Index: gcc/config/darwin.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/darwin.h,v
retrieving revision 1.86
diff -p -r1.86 darwin.h
*** gcc/config/darwin.h	23 Jul 2004 04:35:15 -0000	1.86
--- gcc/config/darwin.h	28 Jul 2004 14:32:46 -0000
*************** Boston, MA 02111-1307, USA.  */
*** 130,136 ****
--- 130,147 ----
    { "-single_module", "-Zsingle_module" },  \
    { "-unexported_symbols_list", "-Zunexported_symbols_list" }, \
    SUBTARGET_OPTION_TRANSLATE_TABLE
+ 
+ /* Nonzero if the user has chosen to force sizeof(bool) to be 1
+    by providing the -mone-byte-bool switch.  It would be better
+    to use SUBTARGET_SWITCHES for this instead of SUBTARGET_OPTIONS,
+    but there are no more bits in rs6000 TARGET_SWITCHES.  Note
+    that this switch has no "no-" variant. */
+ extern const char *darwin_one_byte_bool;
    
+ #undef SUBTARGET_OPTIONS
+ #define SUBTARGET_OPTIONS \
+   {"one-byte-bool", &darwin_one_byte_bool, N_("Set sizeof(bool) to 1"), 0 }
+ 
  /* These compiler options take n arguments.  */
  
  #undef  WORD_SWITCH_TAKES_ARG
Index: gcc/config/rs6000/darwin.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/rs6000/darwin.h,v
retrieving revision 1.54
diff -p -r1.54 darwin.h
*** gcc/config/rs6000/darwin.h	1 Jul 2004 04:09:05 -0000	1.54
--- gcc/config/rs6000/darwin.h	28 Jul 2004 14:32:47 -0000
*************** do {									\
*** 321,328 ****
  #define DOUBLE_INT_ASM_OP "\t.quad\t"
  
  /* For binary compatibility with 2.95; Darwin C APIs use bool from
!    stdbool.h, which was an int-sized enum in 2.95.  */
! #define BOOL_TYPE_SIZE INT_TYPE_SIZE
  
  #undef REGISTER_TARGET_PRAGMAS
  #define REGISTER_TARGET_PRAGMAS DARWIN_REGISTER_TARGET_PRAGMAS
--- 321,330 ----
  #define DOUBLE_INT_ASM_OP "\t.quad\t"
  
  /* For binary compatibility with 2.95; Darwin C APIs use bool from
!    stdbool.h, which was an int-sized enum in 2.95.  Users can explicitly
!    choose to have sizeof(bool)==1 with the -mone-byte-bool switch. */
! extern const char *darwin_one_byte_bool;
! #define BOOL_TYPE_SIZE (darwin_one_byte_bool ? CHAR_TYPE_SIZE : INT_TYPE_SIZE)
  
  #undef REGISTER_TARGET_PRAGMAS
  #define REGISTER_TARGET_PRAGMAS DARWIN_REGISTER_TARGET_PRAGMAS
Index: gcc/doc/invoke.texi
===================================================================
RCS file: /cvs/gcc/gcc/gcc/doc/invoke.texi,v
retrieving revision 1.493
diff -p -r1.493 invoke.texi
*** gcc/doc/invoke.texi	28 Jul 2004 09:13:55 -0000	1.493
--- gcc/doc/invoke.texi	28 Jul 2004 14:32:54 -0000
*************** in the following sections.
*** 423,429 ****
  -single_module  -static  -sub_library  -sub_umbrella @gol
  -twolevel_namespace  -umbrella  -undefined @gol
  -unexported_symbols_list  -weak_reference_mismatches @gol
! -whatsloaded -F -gused -gfull}
  
  @emph{DEC Alpha Options}
  @gccoptlist{-mno-fp-regs  -msoft-float  -malpha-as  -mgas @gol
--- 423,429 ----
  -single_module  -static  -sub_library  -sub_umbrella @gol
  -twolevel_namespace  -umbrella  -undefined @gol
  -unexported_symbols_list  -weak_reference_mismatches @gol
! -whatsloaded -F -gused -gfull -mone-byte-bool}
  
  @emph{DEC Alpha Options}
  @gccoptlist{-mno-fp-regs  -msoft-float  -malpha-as  -mgas @gol
*************** This is by default ON.
*** 6931,6936 ****
--- 6931,6949 ----
  @opindex -gfull
  Emit debugging information for all symbols and types.
  
+ @item -mone-byte-bool
+ @opindex -mone-byte-bool
+ Override the defaults for @samp{bool} so that @samp{sizeof(bool)==1}.
+ By default @samp{sizeof(bool)} is @samp{4} when compiling for 
+ Darwin/PowerPC and @samp{1} when compiling for Darwin/x86, so this
+ option has no effect on x86.
+ 
+ @strong{Warning:} The @option{-mone-byte-bool} switch causes GCC
+ to generate code that is not binary compatible with code generated
+ without that switch.  Using this switch may require recompiling all
+ other modules in a program, including system libraries.  Use this 
+ switch to conform to a non-default data model.
+ 
  @item -all_load
  @opindex all_load
  Loads all members of static archive libraries.
Index: gcc/testsuite/ChangeLog
===================================================================
RCS file: /cvs/gcc/gcc/gcc/testsuite/ChangeLog,v
retrieving revision 1.4064
diff -p -r1.4064 ChangeLog
*** gcc/testsuite/ChangeLog	28 Jul 2004 12:38:50 -0000	1.4064
--- gcc/testsuite/ChangeLog	28 Jul 2004 14:32:57 -0000
***************
*** 1,3 ****
--- 1,8 ----
+ 2004-07-27  Matt Austern <austern@apple.com>
+ 
+ 	* gcc.dg/darwin-bool-1.c: New test.
+ 	* gcc.dg/darwin-bool-2.c: New test.
+ 	
  2004-07-28  Diego Novillo  <dnovillo@redhat.com>
  
  	PR tree-optimization/16688
Index: gcc/testsuite/gcc.dg/darwin-bool-1.c
===================================================================
RCS file: gcc/testsuite/gcc.dg/darwin-bool-1.c
diff -N gcc/testsuite/gcc.dg/darwin-bool-1.c
*** /dev/null	1 Jan 1970 00:00:00 -0000
--- gcc/testsuite/gcc.dg/darwin-bool-1.c	28 Jul 2004 14:32:59 -0000
***************
*** 0 ****
--- 1,11 ----
+ /* Check that sizeof(bool) is 4 if we don't use special options. */
+ /* Matt Austern  <austern@apple.com> */
+ /* { dg-do run { target powerpc*-*-darwin* } } */
+ 
+ int dummy1[sizeof(_Bool) - 3];
+ int dummy2[5 - sizeof(_Bool)];
+ 
+ int main()
+ {
+   return sizeof(_Bool) == 4 ? 0 : 1;
+ }
Index: gcc/testsuite/gcc.dg/darwin-bool-2.c
===================================================================
RCS file: gcc/testsuite/gcc.dg/darwin-bool-2.c
diff -N gcc/testsuite/gcc.dg/darwin-bool-2.c
*** /dev/null	1 Jan 1970 00:00:00 -0000
--- gcc/testsuite/gcc.dg/darwin-bool-2.c	28 Jul 2004 14:32:59 -0000
***************
*** 0 ****
--- 1,12 ----
+ /* Check that sizeof(bool) is 1 if we use the -mone-byte-bool option. */
+ /* Matt Austern  <austern@apple.com> */
+ /* { dg-do run { target powerpc*-*-darwin* } } */
+ /* { dg-options "-mone-byte-bool" } */
+ 
+ int dummy1[sizeof(_Bool)];
+ int dummy2[2 - sizeof(_Bool)];
+ 
+ int main()
+ {
+   return sizeof(_Bool) == 1 ? 0 : 1;
+ }

[-- Attachment #3: Type: text/plain, Size: 1 bytes --]

Re: [Darwin] Patch: new flag -mone-byte-bool

[Stan Shebs]

Matt Austern wrote:

> On Jul 28, 2004, at 1:03 AM, Andreas Schwab wrote:
>
>> Matt Austern <austern@apple.com> writes:
>>
>>> *** 423,429 ****
>>>    -single_module  -static  -sub_library  -sub_umbrella @gol
>>>    -twolevel_namespace  -umbrella  -undefined @gol
>>>    -unexported_symbols_list  -weak_reference_mismatches @gol
>>> ! -whatsloaded -F -gused -gfull}
>>>
>>>    @emph{DEC Alpha Options}
>>>    @gccoptlist{-mno-fp-regs  -msoft-float  -malpha-as  -mgas @gol
>>> --- 423,429 ----
>>>    -single_module  -static  -sub_library  -sub_umbrella @gol
>>>    -twolevel_namespace  -umbrella  -undefined @gol
>>>    -unexported_symbols_list  -weak_reference_mismatches @gol
>>> ! whatsloaded -F -gused -gfull -mone-byte-bool}
>>
>>    ^^^
>> Typo.
>
>
> Whoops!  Fixed.  Here's my updated patch (which differs by one
> character from the earlier version).
>
> OK to commit to mainline?
>
OK, looks good. I suppose it would be surpassingly annoying to
issue a warning every time the flag is used. :-)

Stan