Re: [PATCH 02/26] -Wpointer-sign: gdb_byte -> char.

[Pedro Alves <palves@redhat.com>]

On 04/12/2013 03:32 AM, Yao Qi wrote:
> On 04/12/2013 06:59 AM, Pedro Alves wrote:
>> diff --git a/gdb/i386-cygwin-tdep.c b/gdb/i386-cygwin-tdep.c
>> index cee2adf..26ffbaa 100644
>> --- a/gdb/i386-cygwin-tdep.c
>> +++ b/gdb/i386-cygwin-tdep.c
>> @@ -125,11 +125,11 @@ core_process_module_section (bfd *abfd, asection *sect, void *obj)
>>     struct cpms_data *data = obj;
>>     enum bfd_endian byte_order = gdbarch_byte_order (data->gdbarch);
>>
>> -  char *module_name;
>> +  gdb_byte *module_name;
>>     size_t module_name_size;
>>     CORE_ADDR base_addr;
>>
>> -  char *buf = NULL;
>> +  gdb_byte *buf = NULL;
>>
>>     if (strncmp (sect->name, ".module", 7) != 0)
>>       return;
>> @@ -160,7 +160,7 @@ core_process_module_section (bfd *abfd, asection *sect, void *obj)
>>
>>     /* The first module is the .exe itself.  */
>>     if (data->module_count != 0)
>> -    windows_xfer_shared_library (module_name, base_addr,
>> +    windows_xfer_shared_library ((char *) module_name, base_addr,
>>                    data->gdbarch, data->obstack);
>>     data->module_count++;
>>
> 
> It would be nice to keep 'module_name' of type 'char *', because it is a string.

Hmm, in my original attempt, I tried it and ended up with more casts overall.
But I now notice that "module_name - buf" is "12".  I've merged this in
into the patch:

 gdb/i386-cygwin-tdep.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/gdb/i386-cygwin-tdep.c b/gdb/i386-cygwin-tdep.c
index 26ffbaa..dc5d614 100644
--- a/gdb/i386-cygwin-tdep.c
+++ b/gdb/i386-cygwin-tdep.c
@@ -125,7 +125,7 @@ core_process_module_section (bfd *abfd, asection *sect, void *obj)
   struct cpms_data *data = obj;
   enum bfd_endian byte_order = gdbarch_byte_order (data->gdbarch);
 
-  gdb_byte *module_name;
+  char *module_name;
   size_t module_name_size;
   CORE_ADDR base_addr;
 
@@ -154,13 +154,13 @@ core_process_module_section (bfd *abfd, asection *sect, void *obj)
   module_name_size =
     extract_unsigned_integer (buf + 8, 4, byte_order);
 
-  module_name = buf + 12;
-  if (module_name - buf + module_name_size > bfd_get_section_size (sect))
+  if (12 + module_name_size > bfd_get_section_size (sect))
     goto out;
+  module_name = (char *) buf + 12;
 
   /* The first module is the .exe itself.  */
   if (data->module_count != 0)
-    windows_xfer_shared_library ((char *) module_name, base_addr,
+    windows_xfer_shared_library (module_name, base_addr,
 				 data->gdbarch, data->obstack);
   data->module_count++;
 

I moved the "module_name =" line below because it's neater
to check overflow before causing it.  Overall this does look nicer.
Thanks.

> bfd_boolean bfd_get_section_contents
>    (bfd *abfd, asection *section, void *location, file_ptr offset,
>     bfd_size_type count);
> 
> the parameter 'location' 's type is 'void *', do we really need to cast 'buf' to 'bfd_byte *'?

Thanks.  I really can't say why I added it.

> Likewise.

Both bits reverted.

Below's the current version.  I've updated the github branch too.

-------------
-Wpointer-sign: gdb_byte -> char.

This is sort of the opposite of a previous patch.  Places that
manipulate strings or interfaces that return strings are changed to
use char* instead of gdb_byte*.

gdb/
2013-04-12  Pedro Alves  <palves@redhat.com>

	* avr-tdep.c (avr_io_reg_read_command): New local 'bufstr'.  Use
	it to get a string view of the byte buffer.
	* i386-cygwin-tdep.c (core_process_module_section): Change local 'buf'
	type to gdb_byte *.  Adjust.
	* linux-tdep.c (linux_info_proc, linux_find_memory_regions_full):
	Change local to char *.
	* solib-darwin.c (find_program_interpreter): Change return type to
	char *.  Adjust.
	(darwin_solib_get_all_image_info_addr_at_init): Adjust.
	* solib-dsbt.c (enable_break2): Change local 'buf' to char *.
	* solib-frv.c (enable_break2): Change local 'buf' to char *.
	* solib-spu.c (spu_current_sos): Add gdb_byte * cast.
	* solib-svr4.c (find_program_interpreter): Change return type to
	char *.  Adjust.
	(enable_break): Change local 'interp_name' to char *.
	* spu-multiarch.c (spu_xfer_partial): Add cast to 'char *'.
	* spu-tdep.c (spu_pseudo_register_read_spu): Add cast to 'char *'.
	(spu_pseudo_register_write_spu): Use char for string buffer.
	Adjust.
	(info_spu_event_command, info_spu_signal_command): Add casts to
	'char *'.
---

 gdb/avr-tdep.c         |    8 +++++---
 gdb/i386-cygwin-tdep.c |    6 +++---
 gdb/linux-tdep.c       |    4 ++--
 gdb/solib-darwin.c     |    6 +++---
 gdb/solib-dsbt.c       |    2 +-
 gdb/solib-frv.c        |    2 +-
 gdb/solib-spu.c        |    2 +-
 gdb/solib-svr4.c       |    6 +++---
 gdb/spu-multiarch.c    |    2 +-
 gdb/spu-tdep.c         |   16 +++++++++-------
 10 files changed, 29 insertions(+), 25 deletions(-)

diff --git a/gdb/avr-tdep.c b/gdb/avr-tdep.c
index b14bf83..0bc08a8 100644
--- a/gdb/avr-tdep.c
+++ b/gdb/avr-tdep.c
@@ -1468,8 +1468,9 @@ avr_io_reg_read_command (char *args, int from_tty)
 {
   LONGEST bufsiz = 0;
   gdb_byte *buf;
+  const char *bufstr;
   char query[400];
-  char *p;
+  const char *p;
   unsigned int nreg = 0;
   unsigned int val;
   int i, j, k, step;
@@ -1477,6 +1478,7 @@ avr_io_reg_read_command (char *args, int from_tty)
   /* Find out how many io registers the target has.  */
   bufsiz = target_read_alloc (&current_target, TARGET_OBJECT_AVR,
 			      "avr.io_reg", &buf);
+  bufstr = (const char *) buf;
 
   if (bufsiz <= 0)
     {
@@ -1486,7 +1488,7 @@ avr_io_reg_read_command (char *args, int from_tty)
       return;
     }
 
-  if (sscanf (buf, "%x", &nreg) != 1)
+  if (sscanf (bufstr, "%x", &nreg) != 1)
     {
       fprintf_unfiltered (gdb_stderr,
 			  _("Error fetching number of io registers\n"));
@@ -1514,7 +1516,7 @@ avr_io_reg_read_command (char *args, int from_tty)
       bufsiz = target_read_alloc (&current_target, TARGET_OBJECT_AVR,
 				  query, &buf);
 
-      p = buf;
+      p = (const char *) buf;
       for (k = i; k < (i + j); k++)
 	{
 	  if (sscanf (p, "%[^,],%x;", query, &val) == 2)
diff --git a/gdb/i386-cygwin-tdep.c b/gdb/i386-cygwin-tdep.c
index cee2adf..dc5d614 100644
--- a/gdb/i386-cygwin-tdep.c
+++ b/gdb/i386-cygwin-tdep.c
@@ -129,7 +129,7 @@ core_process_module_section (bfd *abfd, asection *sect, void *obj)
   size_t module_name_size;
   CORE_ADDR base_addr;
 
-  char *buf = NULL;
+  gdb_byte *buf = NULL;
 
   if (strncmp (sect->name, ".module", 7) != 0)
     return;
@@ -154,9 +154,9 @@ core_process_module_section (bfd *abfd, asection *sect, void *obj)
   module_name_size =
     extract_unsigned_integer (buf + 8, 4, byte_order);
 
-  module_name = buf + 12;
-  if (module_name - buf + module_name_size > bfd_get_section_size (sect))
+  if (12 + module_name_size > bfd_get_section_size (sect))
     goto out;
+  module_name = (char *) buf + 12;
 
   /* The first module is the .exe itself.  */
   if (data->module_count != 0)
diff --git a/gdb/linux-tdep.c b/gdb/linux-tdep.c
index 9def108..9623d19 100644
--- a/gdb/linux-tdep.c
+++ b/gdb/linux-tdep.c
@@ -261,7 +261,7 @@ linux_info_proc (struct gdbarch *gdbarch, char *args,
   int status_f = (what == IP_STATUS || what == IP_ALL);
   int stat_f = (what == IP_STAT || what == IP_ALL);
   char filename[100];
-  gdb_byte *data;
+  char *data;
   int target_errno;
 
   if (args && isdigit (args[0]))
@@ -676,7 +676,7 @@ linux_find_memory_regions_full (struct gdbarch *gdbarch,
 				void *obfd)
 {
   char mapsfilename[100];
-  gdb_byte *data;
+  char *data;
 
   /* We need to know the real target PID to access /proc.  */
   if (current_inferior ()->fake_pid_p)
diff --git a/gdb/solib-darwin.c b/gdb/solib-darwin.c
index 8c2307e..c4c6308 100644
--- a/gdb/solib-darwin.c
+++ b/gdb/solib-darwin.c
@@ -210,10 +210,10 @@ lookup_symbol_from_bfd (bfd *abfd, char *symname)
 
 /* Return program interpreter string.  */
 
-static gdb_byte *
+static char *
 find_program_interpreter (void)
 {
-  gdb_byte *buf = NULL;
+  char *buf = NULL;
 
   /* If we have an exec_bfd, get the interpreter from the load commands.  */
   if (exec_bfd)
@@ -420,7 +420,7 @@ gdb_bfd_mach_o_fat_extract (bfd *abfd, bfd_format format,
 static void
 darwin_solib_get_all_image_info_addr_at_init (struct darwin_info *info)
 {
-  gdb_byte *interp_name;
+  char *interp_name;
   CORE_ADDR load_addr = 0;
   bfd *dyld_bfd = NULL;
   struct cleanup *cleanup;
diff --git a/gdb/solib-dsbt.c b/gdb/solib-dsbt.c
index e2822c1..90321d9 100644
--- a/gdb/solib-dsbt.c
+++ b/gdb/solib-dsbt.c
@@ -840,7 +840,7 @@ enable_break2 (void)
   if (interp_sect)
     {
       unsigned int interp_sect_size;
-      gdb_byte *buf;
+      char *buf;
       bfd *tmp_bfd = NULL;
       CORE_ADDR addr;
       gdb_byte addr_buf[TIC6X_PTR_SIZE];
diff --git a/gdb/solib-frv.c b/gdb/solib-frv.c
index 52588bc..0f3e5d7 100644
--- a/gdb/solib-frv.c
+++ b/gdb/solib-frv.c
@@ -535,7 +535,7 @@ enable_break2 (void)
   if (interp_sect)
     {
       unsigned int interp_sect_size;
-      gdb_byte *buf;
+      char *buf;
       bfd *tmp_bfd = NULL;
       int status;
       CORE_ADDR addr, interp_loadmap_addr;
diff --git a/gdb/solib-spu.c b/gdb/solib-spu.c
index 7be5232..3acf9c5 100644
--- a/gdb/solib-spu.c
+++ b/gdb/solib-spu.c
@@ -209,7 +209,7 @@ spu_current_sos (void)
 	 yet.  Skip such entries; we'll be back for them later.  */
       xsnprintf (annex, sizeof annex, "%d/object-id", fd);
       len = target_read (&current_target, TARGET_OBJECT_SPU, annex,
-			 id, 0, sizeof id);
+			 (gdb_byte *) id, 0, sizeof id);
       if (len <= 0 || len >= sizeof id)
 	continue;
       id[len] = 0;
diff --git a/gdb/solib-svr4.c b/gdb/solib-svr4.c
index bb2a4e9..f3bff6e 100644
--- a/gdb/solib-svr4.c
+++ b/gdb/solib-svr4.c
@@ -496,7 +496,7 @@ read_program_header (int type, int *p_sect_size, int *p_arch_size)
 
 
 /* Return program interpreter string.  */
-static gdb_byte *
+static char *
 find_program_interpreter (void)
 {
   gdb_byte *buf = NULL;
@@ -521,7 +521,7 @@ find_program_interpreter (void)
   if (!buf)
     buf = read_program_header (PT_INTERP, NULL, NULL);
 
-  return buf;
+  return (char *) buf;
 }
 
 
@@ -1446,7 +1446,7 @@ enable_break (struct svr4_info *info, int from_tty)
   struct minimal_symbol *msymbol;
   const char * const *bkpt_namep;
   asection *interp_sect;
-  gdb_byte *interp_name;
+  char *interp_name;
   CORE_ADDR sym_addr;
 
   info->interp_text_sect_low = info->interp_text_sect_high = 0;
diff --git a/gdb/spu-multiarch.c b/gdb/spu-multiarch.c
index 0922d04..a74bd30 100644
--- a/gdb/spu-multiarch.c
+++ b/gdb/spu-multiarch.c
@@ -285,7 +285,7 @@ spu_xfer_partial (struct target_ops *ops, enum target_object object,
 					    0, sizeof buf) <= 0)
 	    return ret;
 
-	  lslr = strtoulst (buf, NULL, 16);
+	  lslr = strtoulst ((char *) buf, NULL, 16);
 	  return ops_beneath->to_xfer_partial (ops_beneath, TARGET_OBJECT_SPU,
 					       mem_annex, readbuf, writebuf,
 					       addr & lslr, len);
diff --git a/gdb/spu-tdep.c b/gdb/spu-tdep.c
index 32c8f1e..9ea9c73 100644
--- a/gdb/spu-tdep.c
+++ b/gdb/spu-tdep.c
@@ -192,6 +192,7 @@ spu_pseudo_register_read_spu (struct regcache *regcache, const char *regname,
   gdb_byte reg[32];
   char annex[32];
   ULONGEST id;
+  ULONGEST ul;
 
   status = regcache_raw_read_unsigned (regcache, SPU_ID_REGNUM, &id);
   if (status != REG_VALID)
@@ -201,7 +202,8 @@ spu_pseudo_register_read_spu (struct regcache *regcache, const char *regname,
   target_read (&current_target, TARGET_OBJECT_SPU, annex,
 	       reg, 0, sizeof reg);
 
-  store_unsigned_integer (buf, 4, byte_order, strtoulst (reg, NULL, 16));
+  ul = strtoulst ((char *) reg, NULL, 16);
+  store_unsigned_integer (buf, 4, byte_order, ul);
   return REG_VALID;
 }
 
@@ -254,7 +256,7 @@ spu_pseudo_register_write_spu (struct regcache *regcache, const char *regname,
 {
   struct gdbarch *gdbarch = get_regcache_arch (regcache);
   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
-  gdb_byte reg[32];
+  char reg[32];
   char annex[32];
   ULONGEST id;
 
@@ -263,7 +265,7 @@ spu_pseudo_register_write_spu (struct regcache *regcache, const char *regname,
   xsnprintf (reg, sizeof reg, "0x%s",
 	     phex_nz (extract_unsigned_integer (buf, 4, byte_order), 4));
   target_write (&current_target, TARGET_OBJECT_SPU, annex,
-		reg, 0, strlen (reg));
+		(gdb_byte *) reg, 0, strlen (reg));
 }
 
 static void
@@ -2044,7 +2046,7 @@ info_spu_event_command (char *args, int from_tty)
   if (len <= 0)
     error (_("Could not read event_status."));
   buf[len] = '\0';
-  event_status = strtoulst (buf, NULL, 16);
+  event_status = strtoulst ((char *) buf, NULL, 16);
  
   xsnprintf (annex, sizeof annex, "%d/event_mask", id);
   len = target_read (&current_target, TARGET_OBJECT_SPU, annex,
@@ -2052,7 +2054,7 @@ info_spu_event_command (char *args, int from_tty)
   if (len <= 0)
     error (_("Could not read event_mask."));
   buf[len] = '\0';
-  event_mask = strtoulst (buf, NULL, 16);
+  event_mask = strtoulst ((char *) buf, NULL, 16);
  
   chain = make_cleanup_ui_out_tuple_begin_end (current_uiout, "SPUInfoEvent");
 
@@ -2111,7 +2113,7 @@ info_spu_signal_command (char *args, int from_tty)
   if (len <= 0)
     error (_("Could not read signal1_type."));
   buf[len] = '\0';
-  signal1_type = strtoulst (buf, NULL, 16);
+  signal1_type = strtoulst ((char *) buf, NULL, 16);
 
   xsnprintf (annex, sizeof annex, "%d/signal2", id);
   len = target_read (&current_target, TARGET_OBJECT_SPU, annex, buf, 0, 4);
@@ -2129,7 +2131,7 @@ info_spu_signal_command (char *args, int from_tty)
   if (len <= 0)
     error (_("Could not read signal2_type."));
   buf[len] = '\0';
-  signal2_type = strtoulst (buf, NULL, 16);
+  signal2_type = strtoulst ((char *) buf, NULL, 16);
 
   chain = make_cleanup_ui_out_tuple_begin_end (current_uiout, "SPUInfoSignal");