Re: [all pushed] Re: [PATCH 00/36] Support building GDB as a C++ program

[asmwarrior <asmwarrior at gmail dot com>]

Hi, Pedro, I just found another build issue when building gdb under g++.

Building mingw GDB with --enable-build-with-cxx shows:

../../binutils-gdb/gdb/python/py-unwind.c:500:45: error: cannot convert 'cached_frame_info::reg_info*' to 'pyuw_prev_register(frame_info*, void**, int)::reg_info*' in initialization
   struct reg_info *reg_info = cached_frame->reg;
                                             ^
../../binutils-gdb/gdb/python/py-unwind.c:501:60: error: invalid use of incomplete type 'struct pyuw_prev_register(frame_info*, void**, int)::reg_info'
   struct reg_info *reg_info_end = reg_info + cached_frame->reg_count;
                                                            ^
../../binutils-gdb/gdb/python/py-unwind.c:500:10: error: forward declaration of 'struct pyuw_prev_register(frame_info*, void**, int)::reg_info'
   struct reg_info *reg_info = cached_frame->reg;
          ^
../../binutils-gdb/gdb/python/py-unwind.c:505:37: error: cannot increment a pointer to incomplete type 'pyuw_prev_register(frame_info*, void**, int)::reg_info'
   for (; reg_info < reg_info_end; ++reg_info)
                                     ^
../../binutils-gdb/gdb/python/py-unwind.c:507:29: error: invalid use of incomplete type 'struct pyuw_prev_register(frame_info*, void**, int)::reg_info'
       if (regnum == reg_info->number)
                             ^
../../binutils-gdb/gdb/python/py-unwind.c:500:10: error: forward declaration of 'struct pyuw_prev_register(frame_info*, void**, int)::reg_info'
   struct reg_info *reg_info = cached_frame->reg;
          ^
../../binutils-gdb/gdb/python/py-unwind.c:508:68: error: invalid use of incomplete type 'struct pyuw_prev_register(frame_info*, void**, int)::reg_info'
         return frame_unwind_got_bytes (this_frame, regnum, reg_info->data);
                                                                    ^
../../binutils-gdb/gdb/python/py-unwind.c:500:10: error: forward declaration of 'struct pyuw_prev_register(frame_info*, void**, int)::reg_info'
   struct reg_info *reg_info = cached_frame->reg;
          ^
../../binutils-gdb/gdb/python/py-unwind.c: In function 'int pyuw_sniffer(const frame_unwind*, frame_info*, void**)':
../../binutils-gdb/gdb/python/py-unwind.c:574:70: warning: invalid conversion from 'void*' to 'cached_frame_info*' [-fpermissive]
                             reg_count * sizeof (cached_frame->reg[0]));
                                                                      ^
../../binutils-gdb/gdb/python/py-unwind.c: In function 'void pyuw_on_new_gdbarch(gdbarch*)':
../../binutils-gdb/gdb/python/py-unwind.c:636:47: warning: invalid conversion from 'void*' to 'pyuw_gdbarch_data_type*' [-fpermissive]
       gdbarch_data (newarch, pyuw_gdbarch_data);
                                               ^
../../binutils-gdb/gdb/python/py-unwind.c:647:29: warning: invalid conversion from 'void*' to 'const frame_data*' [-fpermissive]
       unwinder->unwind_data = (void *) newarch;
                             ^
../../binutils-gdb/gdb/python/py-unwind.c: At global scope:
../../binutils-gdb/gdb/python/py-unwind.c:699:21: error: redefinition of 'PyTypeObject pending_frame_object_type'
 static PyTypeObject pending_frame_object_type =
                     ^
../../binutils-gdb/gdb/python/py-unwind.c:96:21: error: 'PyTypeObject pending_frame_object_type' previously declared here
 static PyTypeObject pending_frame_object_type
                     ^
../../binutils-gdb/gdb/python/py-unwind.c:749:21: error: redefinition of 'PyTypeObject unwind_info_object_type'
 static PyTypeObject unwind_info_object_type =
                     ^
../../binutils-gdb/gdb/python/py-unwind.c:99:21: error: 'PyTypeObject unwind_info_object_type' previously declared here
 static PyTypeObject unwind_info_object_type
                     ^


The first kind of error is caused by embedded struct definition, so I moved it out of the parent struct.
The second kind of error is caused by using static keyword on a CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF decoreated variable, I see that all other files use extern, so I changed to extern.


Here is the patch:

43f2422c2dea00287eff57bd2b3aaa478e6de88d
 gdb/python/py-unwind.c | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/gdb/python/py-unwind.c b/gdb/python/py-unwind.c
index bcfea4b..10b5731 100644
--- a/gdb/python/py-unwind.c
+++ b/gdb/python/py-unwind.c
@@ -72,6 +72,15 @@ typedef struct
 /* The data we keep for a frame we can unwind: frame ID and an array of
    (register_number, register_value) pairs.  */
 
+struct reg_info
+{
+  /* Register number.  */
+  int number;
+
+  /* Register data bytes pointer.  */
+  gdb_byte data[MAX_REGISTER_SIZE];
+};
+
 typedef struct
 {
   /* Frame ID.  */
@@ -83,20 +92,13 @@ typedef struct
   /* Length of the `reg' array below.  */
   int reg_count;
 
-  struct reg_info
-  {
-    /* Register number.  */
-    int number;
-
-    /* Register data bytes pointer.  */
-    gdb_byte data[MAX_REGISTER_SIZE];
-  } reg[];
+  struct reg_info reg[];
 } cached_frame_info;
 
-static PyTypeObject pending_frame_object_type
+extern PyTypeObject pending_frame_object_type
     CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("pending_frame_object");
 
-static PyTypeObject unwind_info_object_type
+extern PyTypeObject unwind_info_object_type
     CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("unwind_info_object");
 
 static unsigned int pyuw_debug = 0;