From 2f3b7d8eb5f3f7823556b77cdd48ff2ae51b09c4 Mon Sep 17 00:00:00 2001
From: Jim Kingdon <jkingdon@engr.sgi.com>
Date: Thu, 24 Mar 1994 18:32:31 +0000
Subject: [PATCH] 	* valops.c (value_at, value_at_lazy): Give error if we
 dereference 	a pointer to void. 	* gdbtypes.h: Fix comments regarding
 TYPE_CODE_VOID. 	* stabsread.c: Use 1, not 0, for TYPE_LENGTH of void
 types.

---
 gdb/ChangeLog   |  5 +++++
 gdb/gdbtypes.h  |  6 +++++-
 gdb/stabsread.c | 19 ++++++++++++-------
 3 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index b7572558823..06de4db6041 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,10 @@
 Thu Mar 24 07:12:09 1994  Jim Kingdon  (kingdon@lioth.cygnus.com)
 
+	* valops.c (value_at, value_at_lazy): Give error if we dereference
+	a pointer to void.
+	* gdbtypes.h: Fix comments regarding TYPE_CODE_VOID.
+	* stabsread.c: Use 1, not 0, for TYPE_LENGTH of void types.
+
 	* stabsread.c (patch_block_stabs): Add comment about what happens
 	if the definition is in another compilation unit from the stab.
 
diff --git a/gdb/gdbtypes.h b/gdb/gdbtypes.h
index 90faea2b071..acd21c0dcc7 100644
--- a/gdb/gdbtypes.h
+++ b/gdb/gdbtypes.h
@@ -86,7 +86,11 @@ enum type_code
      of GDB which bogusly assume that TYPE_CODE_FLT can mean complex.  */
   TYPE_CODE_FLT,
 
-  /* Void type (values zero length; the length field is ignored).  */
+  /* Void type.  The length field specifies the length (probably always
+     one) which is used in pointer arithmetic involving pointers to
+     this type, but actually dereferencing such a pointer is invalid;
+     a void type has no length and no actual representation in memory
+     or registers.  A pointer to a void type is a generic pointer.  */
   TYPE_CODE_VOID,
 
   TYPE_CODE_SET,		/* Pascal sets */
diff --git a/gdb/stabsread.c b/gdb/stabsread.c
index af486ff1cbe..6c81c10ae7e 100644
--- a/gdb/stabsread.c
+++ b/gdb/stabsread.c
@@ -1487,7 +1487,7 @@ read_type (pp, objfile)
 
 	if (typenums[0] == xtypenums[0] && typenums[1] == xtypenums[1])
 	  /* It's being defined as itself.  That means it is "void".  */
-	  type = init_type (TYPE_CODE_VOID, 0, 0, NULL, objfile);
+	  type = init_type (TYPE_CODE_VOID, 1, 0, NULL, objfile);
 	else
 	  {
 	    struct type *xtype;
@@ -1783,7 +1783,7 @@ rs6000_builtin_type (typenum)
 			   "unsigned long", NULL);
       break;
     case 11:
-      rettype = init_type (TYPE_CODE_VOID, 0, 0, "void", NULL);
+      rettype = init_type (TYPE_CODE_VOID, 1, 0, "void", NULL);
       break;
     case 12:
       /* IEEE single precision (32 bit).  */
@@ -3150,10 +3150,15 @@ read_sun_builtin_type (pp, typenums, objfile)
   if (**pp == ';')
     ++(*pp);
 
-  return init_type (type_bits == 0 ? TYPE_CODE_VOID : TYPE_CODE_INT,
-		    type_bits / TARGET_CHAR_BIT,
-		    signed_type ? 0 : TYPE_FLAG_UNSIGNED, (char *)NULL,
-		    objfile);
+  if (type_bits == 0)
+    return init_type (TYPE_CODE_VOID, 1,
+		      signed_type ? 0 : TYPE_FLAG_UNSIGNED, (char *)NULL,
+		      objfile);
+  else
+    return init_type (TYPE_CODE_INT,
+		      type_bits / TARGET_CHAR_BIT,
+		      signed_type ? 0 : TYPE_FLAG_UNSIGNED, (char *)NULL,
+		      objfile);
 }
 
 static struct type *
@@ -3371,7 +3376,7 @@ read_range_type (pp, typenums, objfile)
 
   /* A type defined as a subrange of itself, with bounds both 0, is void.  */
   if (self_subrange && n2 == 0 && n3 == 0)
-    return init_type (TYPE_CODE_VOID, 0, 0, NULL, objfile);
+    return init_type (TYPE_CODE_VOID, 1, 0, NULL, objfile);
 
   /* If n3 is zero and n2 is not, we want a floating type,
      and n2 is the width in bytes.