Name of symbol missing when printing global variable's address

The build_address_symbolic funnction filters out data symbols if
their size is set to zero.  But the problem is that the COFF symbol
table (for instance) does not provide any size information, leaving
the size to its default value of zero, thus always triggering
the filter.

This shows up when trying to print the address of a global variable
when debugging a Windows executable, for instance.

gdb/ChangeLog:

        * symtab.h (struct minimal_symbol) [has_size]: New field.
        (MSYMBOL_SIZE): Adjust to forbid macro from being used as lvalue.
        (SET_MSYMBOL_SIZE, MSYMBOL_HAS_SIZE): New macros.
        * printcmd.c (build_address_symbolic): Only filter out zero-sized
        minimal symbols if the symbol's size is actually known.
        * minsyms.c (prim_record_minimal_symbol_full): Adjust setting
        of msymbol's size field.  Add comment.
        * elfread.c (elf_symtab_read, elf_rel_plt_read): Use
        SET_MSYMBOL_SIZE to set the minimal symbol size.

1 files changed, 3 insertions, 1 deletions

diff --git a/gdb/minsyms.c b/gdb/minsyms.c
index b6df4ea..a3a376c 100644
--- a/gdb/minsyms.c
+++ b/gdb/minsyms.c
@@ -937,7 +937,9 @@ prim_record_minimal_symbol_full (const char *name, int name_len, int copy_name,
   MSYMBOL_TYPE (msymbol) = ms_type;
   MSYMBOL_TARGET_FLAG_1 (msymbol) = 0;
   MSYMBOL_TARGET_FLAG_2 (msymbol) = 0;
-  MSYMBOL_SIZE (msymbol) = 0;
+  /* Do not use the SET_MSYMBOL_SIZE macro to initialize the size,
+     as it would also set the has_size flag.  */
+  msymbol->size = 0;
 
   /* The hash pointers must be cleared! If they're not,
      add_minsym_to_hash_table will NOT add this msymbol to the hash table.  */