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msg_132_ilp32.c revision 1.3 
      1 /*	$NetBSD: msg_132_ilp32.c,v 1.3 2023/03/28 14:44:34 rillig Exp $	*/
      2 # 3 "msg_132_ilp32.c"
      3 
      4 // Test for message: conversion from '%s' to '%s' may lose accuracy [132]
      5 
      6 /*
      7  * On 32-bit platforms, it is possible to add a 64-bit integer to a 32-bit
      8  * pointer.  The 64-bit integer is then converted to the ptrdiff_t of the
      9  * target platform, which results in the non-obvious conversion from
     10  * 'long long' to either 'long' or 'int', depending on the platform's
     11  * ptrdiff_t.
     12  */
     13 
     14 /* lint1-only-if: ilp32 int */
     15 /* lint1-extra-flags: -a -X 351 */
     16 
     17 /*
     18  * Seen in usr.bin/make/var.c, function RegexReplace, in the function call
     19  * SepBuf_AddBytesBetween(buf, wp + m[0].rm_so, wp + m[0].rm_eo).  The
     20  * offsets of regular expression matches have type off_t, which is a 64-bit
     21  * integer.
     22  *
     23  * C11 6.5.6p8 does not explicitly define the meaning of a pointer + an
     24  * overly long integer, it just says "undefined behavior" if the resulting
     25  * pointer would be outside the object.
     26  */
     27 const char *
     28 array_subscript(const char *p, long long idx)
     29 {
     30 	/* expect+1: warning: conversion from 'long long' to 'int' may lose accuracy [132] */
     31 	return p + idx;
     32 }
     33 
     34 /*
     35  * On ILP32 platforms, pointer, long and int have the same size, so there is
     36  * no loss of accuracy.
     37  */
     38 unsigned int
     39 convert_pointer_to_smaller_integer(void *ptr)
     40 {
     41 	return (unsigned long)(ptr) >> 12;
     42 }
     43