🚀 go-pugleaf

GDB 4.7 contains several instances of integer overflow in constant expressions.
Here are some generic examples of the kinds of problems involved.

	int x = UINT_MAX;  /* this number is too big for int */
	int x = 0x82007ee0; /* ditto */
	char x = (unsigned char)0x80;  /* the right side evaluates to 128,
				which is too big for signed char */

Strictly speaking, these examples do not conform to the ANSI C standard; some
compilers generate warnings about them.  Here are the warning messages
generated by my compiler (GCC 2.3 hacked pre-release, SunOS 4.1.2, sparc) when
compiling GDB 4.7:

coffcode.h:3333: warning: signed integer overflow in constant expression
coffcode.h:3334: warning: signed integer overflow in constant expression
coffcode.h:3335: warning: signed integer overflow in constant expression
coffcode.h:3336: warning: signed integer overflow in constant expression
coffcode.h:3337: warning: signed integer overflow in constant expression
coffcode.h:3338: warning: signed integer overflow in constant expression
coffcode.h:3339: warning: signed integer overflow in constant expression
coffcode.h:3340: warning: signed integer overflow in constant expression
coffcode.h:3341: warning: signed integer overflow in constant expression
coffcode.h:3342: warning: signed integer overflow in constant expression
coffcode.h:3343: warning: signed integer overflow in constant expression
command.c:1059: warning: signed integer overflow in constant expression
ieee-float.c:86: warning: signed integer overflow in constant expression
main.c:2193: warning: signed integer overflow in constant expression
mmcheck.c:104: warning: signed integer overflow in constant expression
mmcheck.c:133: warning: signed integer overflow in constant expression
mmcheck.c:63: warning: signed integer overflow in constant expression
sparc-tdep.c:233: warning: signed integer overflow in constant expression
sparc-tdep.c:282: warning: signed integer overflow in constant expression
valops.c:697: warning: signed integer overflow in constant expression


Here is a patch.  This patch changes gdb/tm-sparc.h so that REGISTER_TYPE is
an unsigned type (so that large hexadecimal constants can be used with it);
most of the other tm-*.h files probably need to be patched similarly, but I've
omitted those patches here.

===================================================================
RCS file: gdb/command.c,v
retrieving revision 4.7
diff -c -r4.7 gdb/command.c
*** gdb/command.c	1992/10/16 19:16:45	4.7
--- gdb/command.c	1992/10/25 07:02:26
***************
*** 1055,1062 ****
  	  if (arg == NULL)
  	    error_no_arg ("integer to set it to.");
  	  *(int *) c->var = parse_and_eval_address (arg);
! 	  if (*(int *) c->var == 0)
! 	    *(int *) c->var = UINT_MAX;
  	  break;
  	case var_zinteger:
  	  if (arg == NULL)
--- 1055,1062 ----
  	  if (arg == NULL)
  	    error_no_arg ("integer to set it to.");
  	  *(int *) c->var = parse_and_eval_address (arg);
! 	  if (*(unsigned int *) c->var == 0)
! 	    *(unsigned int *) c->var = UINT_MAX;
  	  break;
  	case var_zinteger:
  	  if (arg == NULL)
===================================================================
RCS file: gdb/ieee-float.c,v
retrieving revision 4.7
diff -c -r4.7 gdb/ieee-float.c
*** gdb/ieee-float.c	1992/07/06 17:10:52	4.7
--- gdb/ieee-float.c	1992/10/25 07:02:26
***************
*** 82,89 ****
      return;			/* Result is zero */
    if (dfrom != dfrom) {
      /* From is NaN */
!     to[EXPBYTE_H] = (unsigned char)(EXT_EXP_NAN >> 8);
!     to[EXPBYTE_L] = (unsigned char)EXT_EXP_NAN;
      to[MANBYTE_H] = 1; /* Be sure it's not infinity, but NaN value is irrel */
      return;			/* Result is NaN */
    }
--- 82,89 ----
      return;			/* Result is zero */
    if (dfrom != dfrom) {
      /* From is NaN */
!     ((unsigned char *)to)[EXPBYTE_H] = EXT_EXP_NAN >> 8;
!     ((unsigned char *)to)[EXPBYTE_L] = EXT_EXP_NAN;
      to[MANBYTE_H] = 1; /* Be sure it's not infinity, but NaN value is irrel */
      return;			/* Result is NaN */
    }
===================================================================
RCS file: gdb/main.c,v
retrieving revision 4.7
diff -c -r4.7 gdb/main.c
*** gdb/main.c	1992/10/08 00:30:49	4.7
--- gdb/main.c	1992/10/25 07:02:26
***************
*** 2189,2198 ****
    else if (history_size >= 0)
      stifle_history (history_size);
    else
!     {
!       history_size = UINT_MAX;
!       error ("History size must be non-negative");
!     }
  }
  
  /* ARGSUSED */
--- 2189,2195 ----
    else if (history_size >= 0)
      stifle_history (history_size);
    else
!     error ("History size must be non-negative");
  }
  
  /* ARGSUSED */
===================================================================
RCS file: gdb/sparc-tdep.c,v
retrieving revision 4.7
diff -c -r4.7 gdb/sparc-tdep.c
*** gdb/sparc-tdep.c	1992/10/23 03:54:17	4.7
--- gdb/sparc-tdep.c	1992/10/25 07:02:26
***************
*** 228,234 ****
   * original contents of g1.  A * indicates that the actual value of
   * the instruction is modified below.
   */
! static int save_insn_opcodes[] = {
    0x03000000, 0x82007ee0, 0x9de38001, 0x03000000,
    0x82007ee0, 0x91d02001, 0x01000000 };
  
--- 228,234 ----
   * original contents of g1.  A * indicates that the actual value of
   * the instruction is modified below.
   */
! static unsigned int save_insn_opcodes[] = {
    0x03000000, 0x82007ee0, 0x9de38001, 0x03000000,
    0x82007ee0, 0x91d02001, 0x01000000 };
  
***************
*** 279,285 ****
   	t %g0,1
   	sethi %hi(0),%g0	*/
  
! static int restore_insn_opcodes[] = { 0x81e80000, 0x91d02001, 0x01000000 };
  
  static void
  do_restore_insn ()
--- 279,286 ----
   	t %g0,1
   	sethi %hi(0),%g0	*/
  
! static unsigned int restore_insn_opcodes[] = {
!   0x81e80000, 0x91d02001, 0x01000000 };
  
  static void
  do_restore_insn ()
===================================================================
RCS file: gdb/tm-sparc.h,v
retrieving revision 4.7
diff -c -r4.7 gdb/tm-sparc.h
*** gdb/tm-sparc.h	1992/09/25 22:59:23	4.7
--- gdb/tm-sparc.h	1992/10/25 07:02:26
***************
*** 113,119 ****
  
  /* Say how long (ordinary) registers are.  */
  
! #define REGISTER_TYPE long
  
  /* Number of machine registers */
  
--- 113,119 ----
  
  /* Say how long (ordinary) registers are.  */
  
! #define REGISTER_TYPE unsigned long
  
  /* Number of machine registers */
  
===================================================================
RCS file: include/coff/internal.h,v
retrieving revision 4.7
diff -c -r4.7 include/coff/internal.h
*** include/coff/internal.h	1992/09/30 17:57:07	4.7
--- include/coff/internal.h	1992/10/25 07:02:26
***************
*** 121,141 ****
  #define C_EINCL         109     /* Marks ending of include file */
  
  	/* storage classes for stab symbols for RS/6000 */
! #define C_GSYM          ((signed char)0x80)
! #define C_LSYM          ((signed char)0x81)
! #define C_PSYM          ((signed char)0x82)
! #define C_RSYM          ((signed char)0x83)
! #define C_RPSYM         ((signed char)0x84)
! #define C_STSYM         ((signed char)0x85)
! #define C_TCSYM         ((signed char)0x86)
! #define C_BCOMM         ((signed char)0x87)
! #define C_ECOML         ((signed char)0x88)
! #define C_ECOMM         ((signed char)0x89)
! #define C_DECL          ((signed char)0x8c)
! #define C_ENTRY         ((signed char)0x8d)
! #define C_FUN           ((signed char)0x8e)
! #define C_BSTAT         ((signed char)0x8f)
! #define C_ESTAT         ((signed char)0x90)
  
  /********************** SECTION HEADER **********************/
  struct internal_scnhdr {
--- 121,141 ----
  #define C_EINCL         109     /* Marks ending of include file */
  
  	/* storage classes for stab symbols for RS/6000 */
! #define C_GSYM		'\200'
! #define C_LSYM		'\201'
! #define C_PSYM		'\202'
! #define C_RSYM		'\203'
! #define C_RPSYM		'\204'
! #define C_STSYM		'\205'
! #define C_TCSYM		'\206'
! #define C_BCOMM		'\207'
! #define C_ECOML		'\210'
! #define C_ECOMM		'\211'
! #define C_DECL		'\212'
! #define C_ENTRY		'\213'
! #define C_FUN		'\214'
! #define C_BSTAT		'\215'
! #define C_ESTAT		'\220'
  
  /********************** SECTION HEADER **********************/
  struct internal_scnhdr {
===================================================================
RCS file: mmalloc/mmcheck.c,v
retrieving revision 4.7
diff -c -r4.7 mmalloc/mmcheck.c
*** mmalloc/mmcheck.c	1992/04/17 03:01:49	4.7
--- mmalloc/mmcheck.c	1992/10/25 07:02:26
***************
*** 34,40 ****
  
  #define MAGICWORD	(unsigned int) 0xfedabeeb	/* Active chunk */
  #define MAGICWORDFREE	(unsigned int) 0xdeadbeef	/* Inactive chunk */
! #define MAGICBYTE	((char) 0xd7)
  
  /* Each memory allocation is bounded by a header structure and a trailer
     byte.  I.E.
--- 34,40 ----
  
  #define MAGICWORD	(unsigned int) 0xfedabeeb	/* Active chunk */
  #define MAGICWORDFREE	(unsigned int) 0xdeadbeef	/* Inactive chunk */
! #define MAGICBYTE	'\327'
  
  /* Each memory allocation is bounded by a header structure and a trailer
     byte.  I.E.