Example 59 Signed bit field of length 1

Cadvise warns cases where signed bit field of length 1 is being used and then assigned with a value, which is excessive of its size.

For example, see the tags in the following code:

$ cat bitfield.c

struct { int bit:1; } s; void test()

{

s.bit = 1;

}

In such cases, cadvise generates the following warnings:

"bitfield.c", line 1: warning #2108-D: signed bit field of length 1 struct { int bit:1; } s;

^

"bitfield.c", line 5: warning #4251-D: the assignment has an excessive size for a bit field

s.bit = 1;

^

8.3 Detecting 32-bit to 64-bit migraton issues

The +w64bit option enables warnings that help detection of potential problems in converting 32-bit applications to 64-bit. The +w64bit option applies only to a 64-bit compile (using +DD64). This option is equivalent to the +M2 option. Following are some of the checks performed by this option:

•64–bit value is implicitly converted to a 32 bit value, for example, long to int.

•Pointer to a 4-byte aligned object is implicitly converted to a pointer to a 8-byte aligned object. For example, see the following code:

Example 60 Detecting 32–bit to 64–bit migraton issues

$ cat convert.c

int *int_to_ptr (int i)

{

return (int *)i;

}

In such cases, cadvise generates the following warning:

"convert.c", line 3: warning #4231-D: 64 bit migration: conversion between types of different sizes has occurred

(from "int" to "int *" ) return (int *)i;

^

8.4 Detecting endianness migration issues

The +wendian option helps you to detect code fragments which are endian dependent. The following example shows the detection of endian dependent code fragments.

8.3 Detecting 32-bit to 64-bit migraton issues 51