For SVR4 targets, enable gdb to set breakpoints in shared

	library functions before the executable is run.
	* elfread.c (elf_symtab_read):  Handle symbols for shared library
	functions.
	* sparc-tdep.c (in_solib_trampoline):  Renamed to in_plt_section
	and moved to objfiles.c.
	* objfiles.c (in_plt_section):  Moved to here from sparc-tdep.
	* config/tm-sysv4.h (IN_SOLIB_TRAMPOLINE):  Use new in_plt_section.
	* config/sparc/tm-sun4sol2.h (IN_SOLIB_TRAMPOLINE):  Removed,
	the new generic definition from tm-sysv4.h works for Solaris.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index da77cffa480015d62755a70e9cfab70300626382..da0b01051fdd3e2b05316a8b6d5cb429bb15ef36 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,16 @@
+Fri Apr  1 00:44:00 1994  Peter Schauer  (pes@regent.e-technik.tu-muenchen.de)
+
+       For SVR4 targets, enable gdb to set breakpoints in shared
+       library functions before the executable is run.
+       * elfread.c (elf_symtab_read):  Handle symbols for shared library
+       functions.
+       * sparc-tdep.c (in_solib_trampoline):  Renamed to in_plt_section
+       and moved to objfiles.c.
+       * objfiles.c (in_plt_section):  Moved to here from sparc-tdep.
+       * config/tm-sysv4.h (IN_SOLIB_TRAMPOLINE):  Use new in_plt_section.
+       * config/sparc/tm-sun4sol2.h (IN_SOLIB_TRAMPOLINE):  Removed,
+       the new generic definition from tm-sysv4.h works for Solaris.
+
 Wed Mar 30 16:14:27 1994  Ian Lance Taylor  (ian@tweedledumb.cygnus.com)
 
        * elfread.c (elf_symtab_read): Change storage_needed,

diff --git a/gdb/elfread.c b/gdb/elfread.c
index 89df794af2ce81581346b39b1fa1b0e1a1a3e854..11d4b7e0c02d5e6a5058d6d06c2a98d8f7f44d95 100644 (file)
--- a/gdb/elfread.c
+++ b/gdb/elfread.c
@@ -311,7 +311,29 @@ elf_symtab_read (abfd, addr, objfile)
              /* For non-absolute symbols, use the type of the section
                 they are relative to, to intuit text/data.  Bfd provides
                 no way of figuring this out for absolute symbols. */
-             if (sym -> section == &bfd_abs_section)
+             if (sym -> section == &bfd_und_section
+                 && (sym -> flags & BSF_GLOBAL)
+                 && (sym -> flags & BSF_FUNCTION))
+               {
+                 /* Symbol is a reference to a function defined in
+                    a shared library.
+                    If its value is non zero then it is usually the
+                    absolute address of the corresponding entry in
+                    the procedure linkage table.
+                    If its value is zero then the dynamic linker has to
+                    resolve the symbol. We are unable to find any
+                    meaningful address for this symbol in the
+                    executable file, so we skip it.
+                    Irix 5 has a zero value for all shared library functions
+                    in the main symbol table. The dynamic symbol table
+                    would provide the right values, but BFD currently
+                    cannot handle dynamic ELF symbol tables.  */
+                 ms_type = mst_solib_trampoline;
+                 symaddr = sym -> value;
+                 if (symaddr == 0)
+                   continue;
+               }
+             else if (sym -> section == &bfd_abs_section)
                {
                  ms_type = mst_abs;
                }

diff --git a/gdb/objfiles.c b/gdb/objfiles.c
index 4f0dfd6d93922ff1ba9058bdff0e3a3b6b1d0910..530e19b054b58a85a49e81eb25425fbac813221d 100644 (file)
--- a/gdb/objfiles.c
+++ b/gdb/objfiles.c
@@ -825,3 +825,23 @@ find_pc_section(pc)
 
   return(NULL);
 }
+
+/* In SVR4, we recognize a trampoline by it's section name. 
+   That is, if the pc is in a section named ".plt" then we are in
+   a trampoline.  */
+
+int
+in_plt_section(pc, name)
+     CORE_ADDR pc;
+     char *name;
+{
+  struct obj_section *s;
+  int retval = 0;
+  
+  s = find_pc_section(pc);
+  
+  retval = (s != NULL
+           && s->the_bfd_section->name != NULL
+           && STREQ (s->the_bfd_section->name, ".plt"));
+  return(retval);
+}