HP C Programmer's Guide (92434-90009)

162 Chapter6

Migrating C Programs to HP-UX

Hexadecimal Escape Sequence

space around the macro invocation.

Hexadecimal Escape Sequence

The HP 9000 Series 700/800 compiler allows character constants containing hexadecimal

escape sequences. For example, can be expressed with the hexadecimal escape sequence .

The HP 9000 Series 200, 300, and 500 do not allow hexadecimal escape sequences.

Check your source ﬁles for any occurrences for \x, and verify that a hexadecimal escape

sequence is intended.

Invalid Structure References

The HP 9000 Series 700/800 compiler does not allow structure members to be referenced

through a pointer to a different type of object. The VAX pcc and HP 9000 Series 200 and

500 compilers allow this. Change any invalid structure references to cast the pointer to the

appropriate type before referencing the member. For example, given the following:

struct x {

int y;

}z;

char *c;

c -> y=5;

c -> y=5; is invalid. Instead, use the following code:

c = (char *) &z;

((struct x *) c)->y = 5;

Leading Underscore

External names on the HP 9000 Series 700/800 do not contain a leading underscore. You

need to change any programs that rely on external names containing leading underscores.

Note that all languages on the HP 9000 Series 700/800 follow the same convention.

Therefore, only assembly language code and names that were aliased in other languages

are affected by this. Because there is no leading underscore, external names contain one

additional signiﬁcant character. Identiﬁers that differ only in the 255th character will

denote different items on the HP 9000 Series 700/800.