HP aC++/HP C A.06.20 Programmer's Guide

This warning can be suppressed by not using a hex/octal constant:

char a[4] = { 17, 0x22, 0x33, 0x44 }; // OK

+wendian also warns of unions that make assumptions about data layout:

union u1 {

char c[4];

int v; };

union u2 {

long long ll;

short s[4];

char c[8]; };

This warning can be suppressed by adding a dummy member:

union u1 { // OK

char c[4];

int v;

char dummy; };

Another type of warning is on the use of IO functions that read/write persistent data

from files that may be endian-dependent:

read(0, &i, sizeof(i));

fread(&ai[0], sizeof(int), elems_of(ai, int), stdin);

write(1, &i, sizeof(i));

fwrite(&ai[0], sizeof(int), elems_of(ai, int), stdout);

This warning can be suppressed by adding an extra cast:

fread((char*)(void*)ai, sizeof(char), 1, stdin); // OK

Preprocessor Options

The following options are accepted by the preprocessor:

-C

Using the -C option prevents the preprocessor from stripping comments. See the

description of cpp in the cpp(1) manpage for details.

-dM

When -dM is present, instead of normal preprocessor output the compiler lists the

#define directives it encounters as it preprocesses the file, thus providing a list of all

macros that are in effect at the start of the compilation. The -dM option requires that

-P or -E also be specified.

A common use of this option is to determine the compiler's predefined macros. For

example:

Preprocessor Options 95