* buildsym.c (scan_file_globals): Beware the null file.

Fix from Jim Williams.

* stack.c (return_command):  Evaluate expression *before* popping
off the stack frames!  Fix inspired by Jim Williams.
(up_silently_command, down_silently_command):  No sel frame is error.

* defs.h (memcpy, memset):  Conditionalize decls on
#ifndef MEM_FNS_DECLARED, since DECstation differs.
(alloca):  Break out the STDC and non-STDC alloca cases, to make
it work on old preprocessors as well as "picky ANSI" ones.
* xm-mips.h (memcpy, memset):  Declare, and set MEM_FNS_DECLARED.

* mips-tdep.c (heuristic_proc_start):  Zero arg produces zero.
* utils.c (fputs_demangled):  Rename SLOP since DECstation system
header files define it!

7 files changed, 102 insertions, 65 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 2fb16a7..251f9b5 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,22 @@
 Mon Jun 29 18:30:57 1992  John Gilmore  (gnu at cygnus.com)
 
+	* buildsym.c (scan_file_globals):  Beware the null file.
+	Fix from Jim Williams.
+
+	* stack.c (return_command):  Evaluate expression *before* popping
+	off the stack frames!  Fix inspired by Jim Williams.
+	(up_silently_command, down_silently_command):  No sel frame is error.
+
+	* defs.h (memcpy, memset):  Conditionalize decls on
+	#ifndef MEM_FNS_DECLARED, since DECstation differs.
+	(alloca):  Break out the STDC and non-STDC alloca cases, to make
+	it work on old preprocessors as well as "picky ANSI" ones.
+	* xm-mips.h (memcpy, memset):  Declare, and set MEM_FNS_DECLARED.
+
+	* mips-tdep.c (heuristic_proc_start):  Zero arg produces zero.
+	* utils.c (fputs_demangled):  Rename SLOP since DECstation system
+	header files define it!
+
 	* tm-29k.h (BREAKPOINT):  Allow it to be overridden with -D.
 
 Mon Jun 29 16:30:25 1992  Fred Fish  (fnf@cygnus.com)
diff --git a/gdb/buildsym.c b/gdb/buildsym.c
index bf8cdda..e9ca175 100644
--- a/gdb/buildsym.c
+++ b/gdb/buildsym.c
@@ -985,6 +985,9 @@ scan_file_globals (objfile)
   struct minimal_symbol *msymbol;
   struct symbol *sym, *prev;
 
+  if (objfile->msymbols == 0)		/* Beware the null file.  */
+    return;
+
   for (msymbol = objfile -> msymbols; msymbol -> name != NULL; msymbol++)
     {
       QUIT;
diff --git a/gdb/defs.h b/gdb/defs.h
index a4b0a23..1190f05 100644
--- a/gdb/defs.h
+++ b/gdb/defs.h
@@ -664,8 +664,10 @@ qsort PARAMS ((void *base, size_t nmemb,		/* 4.10.5.2 */
 	       size_t size,
 	       int (*comp)(const void *, const void *)));
 
+#ifndef	MEM_FNS_DECLARED	/* Some non-ANSI use void *, not char *.  */
 extern PTR
 memcpy PARAMS ((void *, const void *, size_t));		/* 4.11.2.1 */
+#endif
 
 extern int
 memcmp PARAMS ((const void *, const void *, size_t));	/* 4.11.4.1 */
@@ -682,8 +684,10 @@ strstr PARAMS ((const char *, const char *));		/* 4.11.5.7 */
 extern char *
 strtok PARAMS ((char *, const char *));			/* 4.11.5.8 */
 
+#ifndef	MEM_FNS_DECLARED	/* Some non-ANSI use void *, not char *.  */
 extern PTR
 memset PARAMS ((void *, int, size_t));			/* 4.11.6.1 */
+#endif
 
 extern char *
 strerror PARAMS ((int));				/* 4.11.6.2 */
@@ -696,7 +700,11 @@ strerror PARAMS ((int));				/* 4.11.6.2 */
 #  ifdef sparc
 #   include <alloca.h>		/* NOTE:  Doesn't declare alloca() */
 #  endif
-   extern PTR alloca PARAMS ((size_t));
+#  ifdef __STDC__
+   extern void *alloca (size_t);
+#  else /* __STDC__ */
+   extern char *alloca ();
+#  endif
 # endif
 #endif
 
diff --git a/gdb/mips-tdep.c b/gdb/mips-tdep.c
index ef22101..c7e6547 100644
--- a/gdb/mips-tdep.c
+++ b/gdb/mips-tdep.c
@@ -61,19 +61,19 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
 #include <sys/stat.h>
 
 
-#define PROC_LOW_ADDR(proc) ((proc)->adr) /* least address */
-#define PROC_HIGH_ADDR(proc) ((proc)->pad2) /* upper address bound */
-#define PROC_FRAME_OFFSET(proc) ((proc)->framesize)
-#define PROC_FRAME_REG(proc) ((proc)->framereg)
-#define PROC_REG_MASK(proc) ((proc)->regmask)
-#define PROC_FREG_MASK(proc) ((proc)->fregmask)
-#define PROC_REG_OFFSET(proc) ((proc)->regoffset)
-#define PROC_FREG_OFFSET(proc) ((proc)->fregoffset)
-#define PROC_PC_REG(proc) ((proc)->pcreg)
-#define PROC_SYMBOL(proc) (*(struct symbol**)&(proc)->isym)
+#define PROC_LOW_ADDR(proc) ((proc)->pdr.adr) /* least address */
+#define PROC_HIGH_ADDR(proc) ((proc)->pdr.iline) /* upper address bound */
+#define PROC_FRAME_OFFSET(proc) ((proc)->pdr.frameoffset)
+#define PROC_FRAME_REG(proc) ((proc)->pdr.framereg)
+#define PROC_REG_MASK(proc) ((proc)->pdr.regmask)
+#define PROC_FREG_MASK(proc) ((proc)->pdr.fregmask)
+#define PROC_REG_OFFSET(proc) ((proc)->pdr.regoffset)
+#define PROC_FREG_OFFSET(proc) ((proc)->pdr.fregoffset)
+#define PROC_PC_REG(proc) ((proc)->pdr.pcreg)
+#define PROC_SYMBOL(proc) (*(struct symbol**)&(proc)->pdr.isym)
 #define _PROC_MAGIC_ 0x0F0F0F0F
-#define PROC_DESC_IS_DUMMY(proc) ((proc)->isym == _PROC_MAGIC_)
-#define SET_PROC_DESC_IS_DUMMY(proc) ((proc)->isym = _PROC_MAGIC_)
+#define PROC_DESC_IS_DUMMY(proc) ((proc)->pdr.isym == _PROC_MAGIC_)
+#define SET_PROC_DESC_IS_DUMMY(proc) ((proc)->pdr.isym = _PROC_MAGIC_)
 
 struct linked_proc_info
 {
@@ -84,7 +84,7 @@ struct linked_proc_info
 
 #define READ_FRAME_REG(fi, regno) read_next_frame_reg((fi)->next, regno)
 
-int
+static int
 read_next_frame_reg(fi, regno)
      FRAME fi;
      int regno;
@@ -113,38 +113,28 @@ int
 mips_frame_saved_pc(frame)
      FRAME frame;
 {
-  mips_extra_func_info_t proc_desc = (mips_extra_func_info_t)frame->proc_desc;
+  mips_extra_func_info_t proc_desc = frame->proc_desc;
   int pcreg = proc_desc ? PROC_PC_REG(proc_desc) : RA_REGNUM;
+
   if (proc_desc && PROC_DESC_IS_DUMMY(proc_desc))
       return read_memory_integer(frame->frame - 4, 4);
-#if 0
-  /* If in the procedure prologue, RA_REGNUM might not have been saved yet.
-   * Assume non-leaf functions start with:
-   *	addiu $sp,$sp,-frame_size
-   *	sw $ra,ra_offset($sp)
-   * This if the pc is pointing at either of these instructions,
-   * then $ra hasn't been trashed.
-   * If the pc has advanced beyond these two instructions,
-   * then $ra has been saved.
-   * critical, and much more complex. Handling $ra is enough to get
-   * a stack trace, but some register values with be wrong.
-   */
-  if (frame->proc_desc && frame->pc < PROC_LOW_ADDR(proc_desc) + 8)
-      return read_register(pcreg);
-#endif
+
   return read_next_frame_reg(frame, pcreg);
 }
 
 static struct mips_extra_func_info temp_proc_desc;
 static struct frame_saved_regs temp_saved_regs;
 
-CORE_ADDR heuristic_proc_start(pc)
+static CORE_ADDR
+heuristic_proc_start(pc)
     CORE_ADDR pc;
 {
-
     CORE_ADDR start_pc = pc;
     CORE_ADDR fence = start_pc - 200;
+
+    if (start_pc == 0)	return 0;
     if (fence < VM_MIN_ADDRESS) fence = VM_MIN_ADDRESS;
+
     /* search back for previous return */
     for (start_pc -= 4; ; start_pc -= 4)
 	if (start_pc < fence) return 0; 
@@ -160,7 +150,7 @@ CORE_ADDR heuristic_proc_start(pc)
     return start_pc;
 }
 
-mips_extra_func_info_t
+static mips_extra_func_info_t
 heuristic_proc_desc(start_pc, limit_pc, next_frame)
     CORE_ADDR start_pc, limit_pc;
     FRAME next_frame;
@@ -231,18 +221,17 @@ heuristic_proc_desc(start_pc, limit_pc, next_frame)
     return &temp_proc_desc;
 }
 
-mips_extra_func_info_t
+static mips_extra_func_info_t
 find_proc_desc(pc, next_frame)
     CORE_ADDR pc;
     FRAME next_frame;
 {
   mips_extra_func_info_t proc_desc;
-  extern struct block *block_for_pc();
-  struct block   *b = block_for_pc(pc);
-
+  struct block *b = block_for_pc(pc);
   struct symbol *sym =
       b ? lookup_symbol(".gdbinfo.", b, LABEL_NAMESPACE, 0, NULL) : NULL;
-  if (sym != NULL)
+
+  if (sym)
     {
 	/* IF this is the topmost frame AND
 	 * (this proc does not have debugging information OR
@@ -250,11 +239,12 @@ find_proc_desc(pc, next_frame)
 	 * THEN create a "heuristic" proc_desc (by analyzing
 	 * the actual code) to replace the "official" proc_desc.
 	 */
-	proc_desc = (struct mips_extra_func_info *)sym->value.value;
+	proc_desc = (mips_extra_func_info_t)SYMBOL_VALUE(sym);
 	if (next_frame == NULL) {
 	    struct symtab_and_line val;
 	    struct symbol *proc_symbol =
 		PROC_DESC_IS_DUMMY(proc_desc) ? 0 : PROC_SYMBOL(proc_desc);
+
 	    if (proc_symbol) {
 		val = find_pc_line (BLOCK_START
 				    (SYMBOL_BLOCK_VALUE(proc_symbol)),
@@ -271,6 +261,11 @@ find_proc_desc(pc, next_frame)
     }
   else
     {
+      /* Is linked_proc_desc_table really necessary?  It only seems to be used
+	 by procedure call dummys.  However, the procedures being called ought
+	 to have their own proc_descs, and even if they don't,
+	 heuristic_proc_desc knows how to create them! */
+
       register struct linked_proc_info *link;
       for (link = linked_proc_desc_table; link; link = link->next)
 	  if (PROC_LOW_ADDR(&link->info) <= pc
@@ -284,28 +279,23 @@ find_proc_desc(pc, next_frame)
 
 mips_extra_func_info_t cached_proc_desc;
 
-FRAME_ADDR mips_frame_chain(frame)
+FRAME_ADDR
+mips_frame_chain(frame)
     FRAME frame;
 {
     mips_extra_func_info_t proc_desc;
     CORE_ADDR saved_pc = FRAME_SAVED_PC(frame);
 
-    if (symfile_objfile->ei.entry_file_lowpc)
-      { /* has at least the __start symbol */
-	if (saved_pc == 0 || inside_entry_file (saved_pc)) return 0;
-      }
-    else
-      { /* This hack depends on the internals of __start. */
-	/* We also assume the breakpoints are *not* inserted */
-        if (saved_pc == 0
-	    || read_memory_integer (saved_pc + 8, 4) & 0xFC00003F == 0xD)
-	    return 0;  /* break */
-      }
+    if (saved_pc == 0 || inside_entry_file (saved_pc))
+      return 0;
+
     proc_desc = find_proc_desc(saved_pc, frame);
-    if (!proc_desc) return 0;
+    if (!proc_desc)
+      return 0;
+
     cached_proc_desc = proc_desc;
     return read_next_frame_reg(frame, PROC_FRAME_REG(proc_desc))
-	+ PROC_FRAME_OFFSET(proc_desc);
+      + PROC_FRAME_OFFSET(proc_desc);
 }
 
 void
@@ -316,11 +306,12 @@ init_extra_frame_info(fci)
   /* Use proc_desc calculated in frame_chain */
   mips_extra_func_info_t proc_desc = fci->next ? cached_proc_desc :
       find_proc_desc(fci->pc, fci->next);
+
   fci->saved_regs = (struct frame_saved_regs*)
     obstack_alloc (&frame_cache_obstack, sizeof(struct frame_saved_regs));
   bzero(fci->saved_regs, sizeof(struct frame_saved_regs));
   fci->proc_desc =
-      proc_desc == &temp_proc_desc ? (char*)NULL : (char*)proc_desc;
+      proc_desc == &temp_proc_desc ? 0 : proc_desc;
   if (proc_desc)
     {
       int ireg;
@@ -373,12 +364,11 @@ init_extra_frame_info(fci)
 
       fci->saved_regs->regs[PC_REGNUM] = fci->saved_regs->regs[RA_REGNUM];
     }
-  if (fci->next == 0)
-      supply_register(FP_REGNUM, &fci->frame);
 }
 
 
-CORE_ADDR mips_push_arguments(nargs, args, sp, struct_return, struct_addr)
+CORE_ADDR
+mips_push_arguments(nargs, args, sp, struct_return, struct_addr)
   int nargs;
   value *args;
   CORE_ADDR sp;
@@ -538,7 +528,7 @@ mips_pop_frame()
   set_current_frame (create_new_frame (new_sp, read_pc ()));
 }
 
-static
+static void
 mips_print_register(regnum, all)
      int regnum, all;
 {
@@ -592,6 +582,7 @@ mips_print_register(regnum, all)
 }
 
 /* Replacement for generic do_registers_info.  */
+void
 mips_do_registers_info (regnum, fpregs)
      int regnum;
      int fpregs;
@@ -618,6 +609,7 @@ mips_do_registers_info (regnum, fpregs)
 /* Return number of args passed to a frame. described by FIP.
    Can return -1, meaning no way to tell.  */
 
+int
 mips_frame_num_args(fip)
 	FRAME fip;
 {
@@ -805,7 +797,7 @@ mips_skip_prologue(pc)
 
        Actually, it would not hurt to skip the storing
        of arguments on the stack as well. */
-    if (((struct mips_extra_func_info *)f->value.value)->framesize)
+    if (((mips_extra_func_info_t)SYMBOL_VALUE(f))->pdr.frameoffset)
 	return pc + 4;
 
     return pc;
diff --git a/gdb/stack.c b/gdb/stack.c
index 7857347..4aeb7c4 100644
--- a/gdb/stack.c
+++ b/gdb/stack.c
@@ -1066,7 +1066,7 @@ up_silently_command (count_exp, from_tty)
     count = parse_and_eval_address (count_exp);
   count1 = count;
   
-  if (!target_has_stack)
+  if (target_has_stack == 0 || selected_frame == 0)
     error ("No stack.");
 
   frame = find_relative_frame (selected_frame, &count1);
@@ -1099,7 +1099,7 @@ down_silently_command (count_exp, from_tty)
     count = - parse_and_eval_address (count_exp);
   count1 = count;
   
-  if (!target_has_stack)
+  if (target_has_stack == 0 || selected_frame == 0)
     error ("No stack.");
 
   frame = find_relative_frame (selected_frame, &count1);
@@ -1129,6 +1129,7 @@ return_command (retval_exp, from_tty)
   FRAME frame;
   char *funcname;
   struct cleanup *back_to;
+  value return_value;
 
   if (selected_frame == NULL)
     error ("No selected frame.");
@@ -1136,6 +1137,16 @@ return_command (retval_exp, from_tty)
   selected_frame_addr = FRAME_FP (selected_frame);
   selected_frame_pc = (get_frame_info (selected_frame))->pc;
 
+  /* Compute the return value (if any -- possibly getting errors here).
+     Call VALUE_CONTENTS to make sure we have fully evaluated it, since
+     it might live in the stack frame we're about to pop.  */
+
+  if (retval_exp)
+    {
+      return_value = parse_and_eval (retval_exp);
+      (void) (VALUE_CONTENTS (return_value));
+    }
+
   /* If interactive, require confirmation.  */
 
   if (from_tty)
@@ -1173,7 +1184,7 @@ return_command (retval_exp, from_tty)
      for return values.  */
 
   if (retval_exp)
-    set_return_value (parse_and_eval (retval_exp));
+    set_return_value (return_value);
 
   /* If interactive, print the frame that is now current.  */
 
diff --git a/gdb/utils.c b/gdb/utils.c
index 15efc73..a1c33ed 100644
--- a/gdb/utils.c
+++ b/gdb/utils.c
@@ -1098,7 +1098,7 @@ fputs_demangled (linebuffer, stream, arg_mode)
   && (isalnum(c) || (c) == '_' || (c) == CPLUS_MARKER))
 
   char buf[SYMBOL_MAX+1];
-# define SLOP 5		/* How much room to leave in buf */
+# define DMSLOP 5		/* How much room to leave in buf */
   char *p;
 
   if (linebuffer == NULL)
@@ -1116,7 +1116,7 @@ fputs_demangled (linebuffer, stream, arg_mode)
     int i = 0;
 
     /* collect non-interesting characters into buf */
-    while ( *p != (char) 0 && !SYMBOL_CHAR(*p) && i < (int)sizeof(buf)-SLOP ) {
+    while (*p != (char) 0 && !SYMBOL_CHAR(*p) && i < (int)sizeof(buf)-DMSLOP ) {
       buf[i++] = *p;
       p++;
     }
@@ -1131,7 +1131,7 @@ fputs_demangled (linebuffer, stream, arg_mode)
     while (i < SYMBOL_MAX
      && *p != (char) 0
      && SYMBOL_CHAR(*p)
-     && i < (int)sizeof(buf) - SLOP) {
+     && i < (int)sizeof(buf) - DMSLOP) {
       buf[i++] = *p;
       p++;
     }
diff --git a/gdb/xm-mips.h b/gdb/xm-mips.h
index 42ea055..1318bba 100644
--- a/gdb/xm-mips.h
+++ b/gdb/xm-mips.h
@@ -33,6 +33,12 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
 extern char *strdup();
 #endif
 
+/* DECstation memcpy and memset return void *, not char *.  */
+
+extern void *memcpy();
+extern void *memset();
+#define	MEM_FNS_DECLARED
+
 /* Only used for core files on DECstations. */
 
 #define REGISTER_U_ADDR(addr, blockend, regno) 		\