From: Peter Schauer <Peter.Schauer@mytum.de>
Date: Fri, 1 Apr 1994 08:50:03 +0000 (+0000)
Subject: 	For SVR4 targets, enable gdb to set breakpoints in shared
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=38b90473602f5c7295242ec0cce8f804d171bcbf;p=binutils-gdb.git

	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 da77cffa480..da0b01051fd 100644
--- 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 89df794af2c..11d4b7e0c02 100644
--- 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 4f0dfd6d939..530e19b054b 100644
--- 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);
+}