HP SunSoft Pascal 4.0 Instrukcja Użytkownika Pobierz pdf (Strona 115)

The C–Pascal Interface 91

Precautions with Compatible Types

This section describes the precautions you should take when working with

compatible types.

Theshortreal Type

The Pascal shortreal and C float compatibility works if you pass by

reference. See “Value Parameters” on page 112 for examples that show you

how to pass by value.

Character Strings

C has several assumptions about strings. All C strings are:

• Passed by reference since C strings are arrays

• Terminated by a null byte

• Located in static variable storage

You can satisfy these assumptions as follows:

• Pass by reference by making the strings var, in, out, or in out

parameters.

• Provide the null byte explicitly before passing a string to C. Pascal

guarantees the null byte only if the string is a constant. The null byte is not

required by the ISO Pascal Standard.

array array - Same as element type

variant record struct/union --

ﬁelds in packed

record

bit ﬁeld - -

Table 6-2 C and Pascal Size and Alignment of Compatible Types with –xl

Pascal Type C Type Size (bytes) Alignment (bytes)

real float 44

integer short int 22

Table 6-1 C and Pascal Size and Alignment of Compatible Types (Continued)

Pascal Type C Type Size (bytes) Alignment (bytes)

1 2 ... 110 111 112 113 114 115 116 117 118 119 120 ... 332 333

Brak uwag

HP SunSoft Pascal 4.0 Instrukcja Użytkownika Strona 115