Integrate GNU poke in GDBusers/jemarch/poke-gdb

This patch integrates GNU poke (http://jemarch.net/poke) in GDB by
mean of libpoke.  It allows the GDB user to execute Poke code from
within the debugger with access to the target memory, types and
values.

How this stuff works:

- GDB links with libpoke.so and uses the interface in libpoke.h.
  This is also how the GNU poke application (the command-line
  editor) is implemented.

- There are three commands:

  poke STR
  poke-add-type EXPR
  poke-add-types REGEXP
  poke-dump-types

  All three commands make sure to start the poke incremental
  compiler if it isn't running already.

- Access to the target's memory is provided by GDB by installing
  a Foreign IO device in the incremental compiler.  This is
  `iod_if' in poke.c.

- Access to the terminal is provided by GDB by providing a
  pk_term_if implementation to the incremental compiler.  This is
  `poke_term_if' in poke.c.

- Access to GDB values is provided by GDB by installing an alien
  token handler in the incremental compiler.  This is
  `poke_alien_token_handler' in poke.c.

gdb/ChangeLog:

2021-05-10  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* configure.ac: Support --enable-poke.
	* configure: Regenerate.
	* Makefile.in (POKE_OBS): Define based on @POKE_OBS@.
	(DEPFILES): Add POKE_OBS.
	* poke.c: New file.

gdb/doc/ChangeLog:

2021-05-10  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* Makefile.in (GDB_DOC_FILES): Add poke.texi.
	* poke.texi: New file.
	* gdb.texinfo (Data): Add meny entry for Poke and @include poke.texi.

1 files changed, 92 insertions, 8 deletions

diff --git a/gdb/configure b/gdb/configure
index 5bb2a0795e5..003197303af 100755
--- a/gdb/configure
+++ b/gdb/configure
@@ -757,6 +757,7 @@ ZSTD_LIBS
 ZSTD_CFLAGS
 zlibinc
 zlibdir
+POKE_OBS
 MIG
 WINDRES
 DLLTOOL
@@ -874,6 +875,7 @@ infodir
 docdir
 oldincludedir
 includedir
+runstatedir
 localstatedir
 sharedstatedir
 sysconfdir
@@ -922,6 +924,7 @@ enable_profiling
 enable_codesign
 with_pkgversion
 with_bugurl
+with_poke
 with_system_zlib
 with_zstd
 enable_rpath
@@ -1033,6 +1036,7 @@ datadir='${datarootdir}'
 sysconfdir='${prefix}/etc'
 sharedstatedir='${prefix}/com'
 localstatedir='${prefix}/var'
+runstatedir='${localstatedir}/run'
 includedir='${prefix}/include'
 oldincludedir='/usr/include'
 docdir='${datarootdir}/doc/${PACKAGE}'
@@ -1285,6 +1289,15 @@ do
   | -silent | --silent | --silen | --sile | --sil)
     silent=yes ;;
 
+  -runstatedir | --runstatedir | --runstatedi | --runstated \
+  | --runstate | --runstat | --runsta | --runst | --runs \
+  | --run | --ru | --r)
+    ac_prev=runstatedir ;;
+  -runstatedir=* | --runstatedir=* | --runstatedi=* | --runstated=* \
+  | --runstate=* | --runstat=* | --runsta=* | --runst=* | --runs=* \
+  | --run=* | --ru=* | --r=*)
+    runstatedir=$ac_optarg ;;
+
   -sbindir | --sbindir | --sbindi | --sbind | --sbin | --sbi | --sb)
     ac_prev=sbindir ;;
   -sbindir=* | --sbindir=* | --sbindi=* | --sbind=* | --sbin=* \
@@ -1422,7 +1435,7 @@ fi
 for ac_var in	exec_prefix prefix bindir sbindir libexecdir datarootdir \
 		datadir sysconfdir sharedstatedir localstatedir includedir \
 		oldincludedir docdir infodir htmldir dvidir pdfdir psdir \
-		libdir localedir mandir
+		libdir localedir mandir runstatedir
 do
   eval ac_val=\$$ac_var
   # Remove trailing slashes.
@@ -1575,6 +1588,7 @@ Fine tuning of the installation directories:
   --sysconfdir=DIR        read-only single-machine data [PREFIX/etc]
   --sharedstatedir=DIR    modifiable architecture-independent data [PREFIX/com]
   --localstatedir=DIR     modifiable single-machine data [PREFIX/var]
+  --runstatedir=DIR       modifiable per-process data [LOCALSTATEDIR/run]
   --libdir=DIR            object code libraries [EPREFIX/lib]
   --includedir=DIR        C header files [PREFIX/include]
   --oldincludedir=DIR     C header files for non-gcc [/usr/include]
@@ -1680,6 +1694,7 @@ Optional Packages:
                           library
   --with-pkgversion=PKG   Use PKG in the version string in place of "GDB"
   --with-bugurl=URL       Direct users to URL to report a bug
+  --with-poke             Build GDB with poke support (default is NO)
   --with-system-zlib      use installed libz
   --with-zstd             support zstd compressed debug sections
                           (default=auto)
@@ -4944,7 +4959,7 @@ else
     We can't simply define LARGE_OFF_T to be 9223372036854775807,
     since some C++ compilers masquerading as C compilers
     incorrectly reject 9223372036854775807.  */
-#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
+#define LARGE_OFF_T ((((off_t) 1 << 31) << 31) - 1 + (((off_t) 1 << 31) << 31))
   int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
 		       && LARGE_OFF_T % 2147483647 == 1)
 		      ? 1 : -1];
@@ -4990,7 +5005,7 @@ else
     We can't simply define LARGE_OFF_T to be 9223372036854775807,
     since some C++ compilers masquerading as C compilers
     incorrectly reject 9223372036854775807.  */
-#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
+#define LARGE_OFF_T ((((off_t) 1 << 31) << 31) - 1 + (((off_t) 1 << 31) << 31))
   int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
 		       && LARGE_OFF_T % 2147483647 == 1)
 		      ? 1 : -1];
@@ -5014,7 +5029,7 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
     We can't simply define LARGE_OFF_T to be 9223372036854775807,
     since some C++ compilers masquerading as C compilers
     incorrectly reject 9223372036854775807.  */
-#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
+#define LARGE_OFF_T ((((off_t) 1 << 31) << 31) - 1 + (((off_t) 1 << 31) << 31))
   int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
 		       && LARGE_OFF_T % 2147483647 == 1)
 		      ? 1 : -1];
@@ -5059,7 +5074,7 @@ else
     We can't simply define LARGE_OFF_T to be 9223372036854775807,
     since some C++ compilers masquerading as C compilers
     incorrectly reject 9223372036854775807.  */
-#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
+#define LARGE_OFF_T ((((off_t) 1 << 31) << 31) - 1 + (((off_t) 1 << 31) << 31))
   int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
 		       && LARGE_OFF_T % 2147483647 == 1)
 		      ? 1 : -1];
@@ -5083,7 +5098,7 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
     We can't simply define LARGE_OFF_T to be 9223372036854775807,
     since some C++ compilers masquerading as C compilers
     incorrectly reject 9223372036854775807.  */
-#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
+#define LARGE_OFF_T ((((off_t) 1 << 31) << 31) - 1 + (((off_t) 1 << 31) << 31))
   int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
 		       && LARGE_OFF_T % 2147483647 == 1)
 		      ? 1 : -1];
@@ -11448,7 +11463,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11451 "configure"
+#line 11466 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -11554,7 +11569,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11557 "configure"
+#line 11572 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -19585,6 +19600,73 @@ if test "$ac_res" != no; then :
 fi
 
 
+# Integration with GNU poke is done through the libpoke library.
+
+# Check whether --with-poke was given.
+if test "${with_poke+set}" = set; then :
+  withval=$with_poke; with_poke=$withval
+else
+  with_poke=no
+fi
+
+if test "x$with_poke" = "xyes"; then
+  # Note that we need a libpoke with support for registering foreign
+  # IO devices, hence the symbol pk_register_iod.
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for pk_register_iod in -lpoke" >&5
+$as_echo_n "checking for pk_register_iod in -lpoke... " >&6; }
+if ${ac_cv_lib_poke_pk_register_iod+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-lpoke  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char pk_register_iod ();
+int
+main ()
+{
+return pk_register_iod ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_lib_poke_pk_register_iod=yes
+else
+  ac_cv_lib_poke_pk_register_iod=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_poke_pk_register_iod" >&5
+$as_echo "$ac_cv_lib_poke_pk_register_iod" >&6; }
+if test "x$ac_cv_lib_poke_pk_register_iod" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_LIBPOKE 1
+_ACEOF
+
+  LIBS="-lpoke $LIBS"
+
+fi
+
+  POKE_OBS="poke.o"
+
+$as_echo "#define HAVE_POKE 1" >>confdefs.h
+
+  CONFIG_INSTALL="$CONFIG_INSTALL install-poke"
+else
+  POKE_OBS=
+fi
+
+
 # Link in zlib/zstd if we can.  This allows us to read compressed debug
 # sections.
 
@@ -24063,6 +24145,8 @@ main ()
     if (*(data + i) != *(data3 + i))
       return 14;
   close (fd);
+  free (data);
+  free (data3);
   return 0;
 }
 _ACEOF