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RFA: char is unsigned on some architectures
- From: Jim Blandy <jimb at zwingli dot cygnus dot com>
- To: gdb-patches at sources dot redhat dot com
- Date: Wed, 19 Dec 2001 17:45:16 -0500 (EST)
- Subject: RFA: char is unsigned on some architectures
ISO C specifies that `char' acts like either `signed char' or
`unsigned char'. At the moment, GDB assumes that `char' is `signed
char'. This patch allows the architecture to specify the correct
answer, and sets the value correctly for the IBM S/390 architecture.
2001-12-19 Jim Blandy <jimb@redhat.com>
* gdbarch.sh (TARGET_CHAR_SIGNED): New macro.
* gdbarch.c, gdbarch.h: Regenerated.
* gdbtypes.c (build_gdbtypes): If TARGET_CHAR_SIGNED is zero,
set the TYPE_FLAG_UNSIGNED bit on the type.
* s390-tdep.c (s390_gdbarch_init): On the S/390, characters
are unsigned by default.
Index: gdb/gdbarch.sh
===================================================================
RCS file: /cvs/cvsfiles/devo/gdb/gdbarch.sh,v
retrieving revision 2.91
diff -c -r2.91 gdbarch.sh
*** gdb/gdbarch.sh 2001/12/11 00:04:41 2.91
--- gdb/gdbarch.sh 2001/12/19 22:35:08
***************
*** 384,389 ****
--- 384,392 ----
# Number of bits in a BFD_VMA for the target object file format.
v::TARGET_BFD_VMA_BIT:int:bfd_vma_bit::::8 * sizeof (void*):TARGET_ARCHITECTURE->bits_per_address::0
#
+ # One if \`char' acts like \`signed char', zero if \`unsigned char'.
+ v::TARGET_CHAR_SIGNED:int:char_signed::::1:-1:1::%d::
+ #
v::IEEE_FLOAT:int:ieee_float::::0:0::0:::
#
f::TARGET_READ_PC:CORE_ADDR:read_pc:ptid_t ptid:ptid::0:generic_target_read_pc::0
Index: gdb/gdbtypes.c
===================================================================
RCS file: /cvs/cvsfiles/devo/gdb/gdbtypes.c,v
retrieving revision 2.126
diff -c -r2.126 gdbtypes.c
*** gdb/gdbtypes.c 2001/12/11 00:04:41 2.126
--- gdb/gdbtypes.c 2001/12/19 22:35:09
***************
*** 2977,2983 ****
"void", (struct objfile *) NULL);
builtin_type_char =
init_type (TYPE_CODE_INT, TARGET_CHAR_BIT / TARGET_CHAR_BIT,
! TYPE_FLAG_NOSIGN,
"char", (struct objfile *) NULL);
builtin_type_true_char =
init_type (TYPE_CODE_CHAR, TARGET_CHAR_BIT / TARGET_CHAR_BIT,
--- 2977,2984 ----
"void", (struct objfile *) NULL);
builtin_type_char =
init_type (TYPE_CODE_INT, TARGET_CHAR_BIT / TARGET_CHAR_BIT,
! (TYPE_FLAG_NOSIGN
! | (TARGET_CHAR_SIGNED ? 0 : TYPE_FLAG_UNSIGNED)),
"char", (struct objfile *) NULL);
builtin_type_true_char =
init_type (TYPE_CODE_CHAR, TARGET_CHAR_BIT / TARGET_CHAR_BIT,
Index: gdb/s390-tdep.c
===================================================================
RCS file: /cvs/cvsfiles/devo/gdb/s390-tdep.c,v
retrieving revision 2.31
diff -c -r2.31 s390-tdep.c
*** gdb/s390-tdep.c 2001/12/19 22:33:10 2.31
--- gdb/s390-tdep.c 2001/12/19 22:35:10
***************
*** 1760,1765 ****
--- 1760,1766 ----
gdbarch = gdbarch_alloc (&info, NULL);
set_gdbarch_believe_pcc_promotion (gdbarch, 0);
+ set_gdbarch_char_signed (gdbarch, 0);
set_gdbarch_frame_args_skip (gdbarch, 0);
set_gdbarch_frame_args_address (gdbarch, s390_frame_args_address);
Index: gdb/gdbarch.c
===================================================================
RCS file: /cvs/cvsfiles/devo/gdb/gdbarch.c,v
retrieving revision 2.112
diff -c -r2.112 gdbarch.c
*** gdb/gdbarch.c 2001/12/11 00:04:41 2.112
--- gdb/gdbarch.c 2001/12/19 22:35:05
***************
*** 144,149 ****
--- 144,150 ----
int ptr_bit;
int addr_bit;
int bfd_vma_bit;
+ int char_signed;
int ieee_float;
gdbarch_read_pc_ftype *read_pc;
gdbarch_write_pc_ftype *write_pc;
***************
*** 285,290 ****
--- 286,292 ----
8 * sizeof (void*),
8 * sizeof (void*),
8 * sizeof (void*),
+ 1,
0,
0,
0,
***************
*** 446,451 ****
--- 448,454 ----
current_gdbarch->long_double_bit = 2*TARGET_DOUBLE_BIT;
current_gdbarch->ptr_bit = TARGET_INT_BIT;
current_gdbarch->bfd_vma_bit = TARGET_ARCHITECTURE->bits_per_address;
+ current_gdbarch->char_signed = -1;
current_gdbarch->read_pc = generic_target_read_pc;
current_gdbarch->write_pc = generic_target_write_pc;
current_gdbarch->read_fp = generic_target_read_fp;
***************
*** 561,566 ****
--- 564,571 ----
if (gdbarch->addr_bit == 0)
gdbarch->addr_bit = TARGET_PTR_BIT;
/* Skip verify of bfd_vma_bit, invalid_p == 0 */
+ if (gdbarch->char_signed == -1)
+ gdbarch->char_signed = 1;
/* Skip verify of ieee_float, invalid_p == 0 */
/* Skip verify of read_pc, invalid_p == 0 */
/* Skip verify of write_pc, invalid_p == 0 */
***************
*** 1867,1872 ****
--- 1872,1885 ----
"gdbarch_dump: TARGET_BYTE_ORDER = %ld\n",
(long) TARGET_BYTE_ORDER);
#endif
+ #ifdef TARGET_CHAR_SIGNED
+ fprintf_unfiltered (file,
+ "gdbarch_dump: TARGET_CHAR_SIGNED # %s\n",
+ XSTRING (TARGET_CHAR_SIGNED));
+ fprintf_unfiltered (file,
+ "gdbarch_dump: TARGET_CHAR_SIGNED = %d\n",
+ (long) TARGET_CHAR_SIGNED);
+ #endif
#ifdef TARGET_DOUBLE_BIT
fprintf_unfiltered (file,
"gdbarch_dump: TARGET_DOUBLE_BIT # %s\n",
***************
*** 2263,2268 ****
--- 2276,2299 ----
int bfd_vma_bit)
{
gdbarch->bfd_vma_bit = bfd_vma_bit;
+ }
+
+ int
+ gdbarch_char_signed (struct gdbarch *gdbarch)
+ {
+ if (gdbarch->char_signed == -1)
+ internal_error (__FILE__, __LINE__,
+ "gdbarch: gdbarch_char_signed invalid");
+ if (gdbarch_debug >= 2)
+ fprintf_unfiltered (gdb_stdlog, "gdbarch_char_signed called\n");
+ return gdbarch->char_signed;
+ }
+
+ void
+ set_gdbarch_char_signed (struct gdbarch *gdbarch,
+ int char_signed)
+ {
+ gdbarch->char_signed = char_signed;
}
int
Index: gdb/gdbarch.h
===================================================================
RCS file: /cvs/cvsfiles/devo/gdb/gdbarch.h,v
retrieving revision 2.104
diff -c -r2.104 gdbarch.h
*** gdb/gdbarch.h 2001/12/11 00:04:41 2.104
--- gdb/gdbarch.h 2001/12/19 22:35:06
***************
*** 287,292 ****
--- 287,310 ----
#endif
#endif
+ /* One if `char' acts like `signed char', zero if `unsigned char'. */
+
+ /* Default (value) for non- multi-arch platforms. */
+ #if (!GDB_MULTI_ARCH) && !defined (TARGET_CHAR_SIGNED)
+ #define TARGET_CHAR_SIGNED (1)
+ #endif
+
+ extern int gdbarch_char_signed (struct gdbarch *gdbarch);
+ extern void set_gdbarch_char_signed (struct gdbarch *gdbarch, int char_signed);
+ #if (GDB_MULTI_ARCH > GDB_MULTI_ARCH_PARTIAL) && defined (TARGET_CHAR_SIGNED)
+ #error "Non multi-arch definition of TARGET_CHAR_SIGNED"
+ #endif
+ #if GDB_MULTI_ARCH
+ #if (GDB_MULTI_ARCH > GDB_MULTI_ARCH_PARTIAL) || !defined (TARGET_CHAR_SIGNED)
+ #define TARGET_CHAR_SIGNED (gdbarch_char_signed (current_gdbarch))
+ #endif
+ #endif
+
/* Default (value) for non- multi-arch platforms. */
#if (!GDB_MULTI_ARCH) && !defined (IEEE_FLOAT)
#define IEEE_FLOAT (0)