Fix gdb C++ compilation on Solaris (PR build/20712)

gdb 7.12 doesn't compile as C++ (tried with g++ 4.9) on Solaris (tried
10 and 12, sparc and x86).  The following patch (relative to the 7.12
release, though I expect most if not all issues to be present on trunk,
too) fixes this.

Only a few of the changes bear explanation:

* Initially, compilation failed whereever defs.h. was included:

In file included from /vol/src/gnu/gdb/gdb-7.12/gdb/gdb.c:19:0:
/vol/src/gnu/gdb/gdb-7.12/gdb/defs.h:630:33: error: 'double atof(const char*)' conflicts with a previous declaration
 extern double atof (const char *); /* X3.159-1989  4.10.1.1 */
                                 ^
In file included from /usr/include/stdlib.h:17:0,
                 from build-gnulib/import/stdlib.h:36,
                 from /vol/src/gnu/gdb/gdb-7.12/gdb/common/common-defs.h:32,
                 from /vol/src/gnu/gdb/gdb-7.12/gdb/defs.h:28,
                 from /vol/src/gnu/gdb/gdb-7.12/gdb/gdb.c:19:
/vol/gcc-4.9/lib/gcc/i386-pc-solaris2.10/4.9.0/include-fixed/iso/stdlib_iso.h:119:15: note: previous declaration 'double std::atof(const char*)'
 extern double atof(const char *);
               ^

  This is due to this gem in gdb/defs.h which seems to have been present
  like forever:

#ifndef atof
extern double atof (const char *);	/* X3.159-1989  4.10.1.1 */
#endif

  In the Solaris headers, the appropriate functions are in namespace std,
  thus the conflict.  I've wrapped the defs.h declaration in !__cplusplus
  to avoid this; perhaps it can go completely instead.

* All the casts are necessary to appease g++ and should be pretty
  obvious.

* The sol-thread.c changes are here to handle

/vol/src/gnu/gdb/gdb-7.12/gdb/sol-thread.c: In function 'void _initialize_sol_thread()':
/vol/src/gnu/gdb/gdb-7.12/gdb/sol-thread.c:1252:36: error: invalid conversion from 'void*' to 'void (*)(int)' [-fpermissive]
   if (!(p_##X = dlsym (dlhandle, #X))) \
                                    ^
/vol/src/gnu/gdb/gdb-7.12/gdb/sol-thread.c:1255:3: note: in expansion of macro 'resolve'
   resolve (td_log);
   ^

  and are modeled after linux-thread-db.c (try_thread_db_load_1).

The patch allowed both 32 and 64-bit C++ builds on sparc-sun-solaris2.10
and i386-pc-solaris2.10 to complete.  The resulting binary hasn't seen
more than a smoke test (invoke it on itself, b main, run) yet.

When investigating the failure to detect -static-libstdc++
support (more below), I found two more issues which only show up with
-Werror:

/vol/src/gnu/gdb/gdb/local/gdb/procfs.c: In function 'ssd* proc_get_LDT_entry(procinfo*, int)':
/vol/src/gnu/gdb/gdb/local/gdb/procfs.c:2487:19: error: variable 'old_chain' set but not used [-Werror=unused-but-set-variable]
   struct cleanup *old_chain = NULL;
                   ^

Unless I'm mistaken, you need to run do_cleanups on every return from
the function.

Afterwards, I ran a 32-bit compilation, which (after adding
--disable-largefile to avoid

In file included from /usr/include/sys/procfs.h:28:0,
                 from /vol/src/gnu/gdb/gdb/local/gdb/i386-sol2-nat.c:23:
/usr/include/sys/old_procfs.h:39:2: error: #error "Cannot use procfs in the large file compilation environment"
 #error "Cannot use procfs in the large file compilation environment"
  ^

and two more instances) revealed

/vol/src/gnu/gdb/gdb/local/gdb/top.c: In function 'void gdb_safe_append_history()':
/vol/src/gnu/gdb/gdb/local/gdb/top.c:1170:59: error: format '%d' expects argument of type 'int', but argument 3 has type 'pid_t {aka long int}' [-Werror=format=]
     = xstrprintf ("%s-gdb%d~", history_filename, getpid ());
                                                           ^

Fixed by casting pid_t to long and printing it as such.

1 files changed, 77 insertions, 51 deletions

diff --git a/gdb/sol-thread.c b/gdb/sol-thread.c
index 000d223..85bf3ff 100644
--- a/gdb/sol-thread.c
+++ b/gdb/sol-thread.c
@@ -98,56 +98,82 @@ static void init_sol_thread_ops (void);
 /* Default definitions: These must be defined in tm.h if they are to
    be shared with a process module such as procfs.  */
 
+/* Types of the libthread_db functions.  */
+
+typedef void (td_log_ftype)(const int on_off);
+typedef td_err_e (td_ta_new_ftype)(const struct ps_prochandle *ph_p,
+				   td_thragent_t **ta_pp);
+typedef td_err_e (td_ta_delete_ftype)(td_thragent_t *ta_p);
+typedef td_err_e (td_init_ftype)(void);
+typedef td_err_e (td_ta_get_ph_ftype)(const td_thragent_t *ta_p,
+				      struct ps_prochandle **ph_pp);
+typedef td_err_e (td_ta_get_nthreads_ftype)(const td_thragent_t *ta_p,
+					    int *nthread_p);
+typedef td_err_e (td_ta_tsd_iter_ftype)(const td_thragent_t *ta_p,
+					td_key_iter_f *cb, void *cbdata_p);
+typedef td_err_e (td_ta_thr_iter_ftype)(const td_thragent_t *ta_p,
+					td_thr_iter_f *cb, void *cbdata_p,
+					td_thr_state_e state, int ti_pri,
+					sigset_t *ti_sigmask_p,
+					unsigned ti_user_flags);
+typedef td_err_e (td_thr_validate_ftype)(const td_thrhandle_t *th_p);
+typedef td_err_e (td_thr_tsd_ftype)(const td_thrhandle_t * th_p,
+				    const thread_key_t key, void **data_pp);
+typedef td_err_e (td_thr_get_info_ftype)(const td_thrhandle_t *th_p,
+					 td_thrinfo_t *ti_p);
+typedef td_err_e (td_thr_getfpregs_ftype)(const td_thrhandle_t *th_p,
+					  prfpregset_t *fpregset);
+typedef td_err_e (td_thr_getxregsize_ftype)(const td_thrhandle_t *th_p,
+					    int *xregsize);
+typedef td_err_e (td_thr_getxregs_ftype)(const td_thrhandle_t *th_p,
+					 const caddr_t xregset);
+typedef td_err_e (td_thr_sigsetmask_ftype)(const td_thrhandle_t *th_p,
+					   const sigset_t ti_sigmask);
+typedef td_err_e (td_thr_setprio_ftype)(const td_thrhandle_t *th_p,
+					const int ti_pri);
+typedef td_err_e (td_thr_setsigpending_ftype)(const td_thrhandle_t *th_p,
+					      const uchar_t ti_pending_flag,
+					      const sigset_t ti_pending);
+typedef td_err_e (td_thr_setfpregs_ftype)(const td_thrhandle_t *th_p,
+					  const prfpregset_t *fpregset);
+typedef td_err_e (td_thr_setxregs_ftype)(const td_thrhandle_t *th_p,
+					 const caddr_t xregset);
+typedef td_err_e (td_ta_map_id2thr_ftype)(const td_thragent_t *ta_p,
+					  thread_t tid,
+					  td_thrhandle_t *th_p);
+typedef td_err_e (td_ta_map_lwp2thr_ftype)(const td_thragent_t *ta_p,
+					   lwpid_t lwpid,
+					   td_thrhandle_t *th_p);
+typedef td_err_e (td_thr_getgregs_ftype)(const td_thrhandle_t *th_p,
+					 prgregset_t regset);
+typedef td_err_e (td_thr_setgregs_ftype)(const td_thrhandle_t *th_p,
+					 const prgregset_t regset);
+
 /* Pointers to routines from libthread_db resolved by dlopen().  */
 
-static void (*p_td_log)(const int on_off);
-static td_err_e (*p_td_ta_new)(const struct ps_prochandle *ph_p,
-			       td_thragent_t **ta_pp);
-static td_err_e (*p_td_ta_delete)(td_thragent_t *ta_p);
-static td_err_e (*p_td_init)(void);
-static td_err_e (*p_td_ta_get_ph)(const td_thragent_t *ta_p,
-				  struct ps_prochandle **ph_pp);
-static td_err_e (*p_td_ta_get_nthreads)(const td_thragent_t *ta_p,
-					int *nthread_p);
-static td_err_e (*p_td_ta_tsd_iter)(const td_thragent_t *ta_p,
-				    td_key_iter_f *cb, void *cbdata_p);
-static td_err_e (*p_td_ta_thr_iter)(const td_thragent_t *ta_p,
-				    td_thr_iter_f *cb, void *cbdata_p,
-				    td_thr_state_e state, int ti_pri,
-				    sigset_t *ti_sigmask_p,
-				    unsigned ti_user_flags);
-static td_err_e (*p_td_thr_validate)(const td_thrhandle_t *th_p);
-static td_err_e (*p_td_thr_tsd)(const td_thrhandle_t * th_p,
-				const thread_key_t key, void **data_pp);
-static td_err_e (*p_td_thr_get_info)(const td_thrhandle_t *th_p,
-				     td_thrinfo_t *ti_p);
-static td_err_e (*p_td_thr_getfpregs)(const td_thrhandle_t *th_p,
-				      prfpregset_t *fpregset);
-static td_err_e (*p_td_thr_getxregsize)(const td_thrhandle_t *th_p,
-					int *xregsize);
-static td_err_e (*p_td_thr_getxregs)(const td_thrhandle_t *th_p,
-				     const caddr_t xregset);
-static td_err_e (*p_td_thr_sigsetmask)(const td_thrhandle_t *th_p,
-				       const sigset_t ti_sigmask);
-static td_err_e (*p_td_thr_setprio)(const td_thrhandle_t *th_p,
-				    const int ti_pri);
-static td_err_e (*p_td_thr_setsigpending)(const td_thrhandle_t *th_p,
-					  const uchar_t ti_pending_flag,
-					  const sigset_t ti_pending);
-static td_err_e (*p_td_thr_setfpregs)(const td_thrhandle_t *th_p,
-				      const prfpregset_t *fpregset);
-static td_err_e (*p_td_thr_setxregs)(const td_thrhandle_t *th_p,
-				     const caddr_t xregset);
-static td_err_e (*p_td_ta_map_id2thr)(const td_thragent_t *ta_p,
-				      thread_t tid,
-				      td_thrhandle_t *th_p);
-static td_err_e (*p_td_ta_map_lwp2thr)(const td_thragent_t *ta_p,
-				       lwpid_t lwpid,
-				       td_thrhandle_t *th_p);
-static td_err_e (*p_td_thr_getgregs)(const td_thrhandle_t *th_p,
-				     prgregset_t regset);
-static td_err_e (*p_td_thr_setgregs)(const td_thrhandle_t *th_p,
-				     const prgregset_t regset);
+static td_log_ftype *p_td_log;
+static td_ta_new_ftype *p_td_ta_new;
+static td_ta_delete_ftype *p_td_ta_delete;
+static td_init_ftype *p_td_init;
+static td_ta_get_ph_ftype *p_td_ta_get_ph;
+static td_ta_get_nthreads_ftype *p_td_ta_get_nthreads;
+static td_ta_tsd_iter_ftype *p_td_ta_tsd_iter;
+static td_ta_thr_iter_ftype *p_td_ta_thr_iter;
+static td_thr_validate_ftype *p_td_thr_validate;
+static td_thr_tsd_ftype *p_td_thr_tsd;
+static td_thr_get_info_ftype *p_td_thr_get_info;
+static td_thr_getfpregs_ftype *p_td_thr_getfpregs;
+static td_thr_getxregsize_ftype *p_td_thr_getxregsize;
+static td_thr_getxregs_ftype *p_td_thr_getxregs;
+static td_thr_sigsetmask_ftype *p_td_thr_sigsetmask;
+static td_thr_setprio_ftype *p_td_thr_setprio;
+static td_thr_setsigpending_ftype *p_td_thr_setsigpending;
+static td_thr_setfpregs_ftype *p_td_thr_setfpregs;
+static td_thr_setxregs_ftype *p_td_thr_setxregs;
+static td_ta_map_id2thr_ftype *p_td_ta_map_id2thr;
+static td_ta_map_lwp2thr_ftype *p_td_ta_map_lwp2thr;
+static td_thr_getgregs_ftype *p_td_thr_getgregs;
+static td_thr_setgregs_ftype *p_td_thr_setgregs;
 
 
 /* Return the libthread_db error string associated with ERRCODE.  If
@@ -818,7 +844,7 @@ ps_err_e
 ps_pdread (gdb_ps_prochandle_t ph, gdb_ps_addr_t addr,
 	   gdb_ps_read_buf_t buf, gdb_ps_size_t size)
 {
-  return rw_common (0, ph, addr, buf, size);
+  return rw_common (0, ph, addr, (gdb_byte *) buf, size);
 }
 
 /* Copies SIZE bytes from debugger memory .data segment to target process.  */
@@ -836,7 +862,7 @@ ps_err_e
 ps_ptread (gdb_ps_prochandle_t ph, gdb_ps_addr_t addr,
 	   gdb_ps_read_buf_t buf, gdb_ps_size_t size)
 {
-  return rw_common (0, ph, addr, buf, size);
+  return rw_common (0, ph, addr, (gdb_byte *) buf, size);
 }
 
 /* Copies SIZE bytes from debugger memory .text segment to target process.  */
@@ -1249,7 +1275,7 @@ _initialize_sol_thread (void)
     goto die;
 
 #define resolve(X) \
-  if (!(p_##X = dlsym (dlhandle, #X))) \
+  if (!(p_##X = (X ## _ftype *) dlsym (dlhandle, #X)))	\
     goto die;
 
   resolve (td_log);