Avoiding Pitfalls in Multi-Language Programming

Debugging Tips

POSIX Environment

This paper will not address the issues of interfacing with the older compatibility mode languages and

data types.

That it is possible at all to intermix routines from multiple languages is due to the HP Precision

Architecture Procedure Calling Convention as described in the

Procedure Calling Conventions

Manual, which is listed in the Bibliography.

To permit this paper to address the diverse

issues and multiple languages herein, it has been

necessary to generalize statements and to omit minor exceptions that might

contradict those

generalities. The references are the most complete description of the topics discussed and should be

used as the authoritative source for actual implementation. We

intend that this paper will be of use as

an overview of the subject.

Data Representation

Pitfalls:

Pascal data types not generally supported by

other languages include enumerated types, sets, and

pointers.

Fortran REAL*16 datatype is not supported by other languages.

Cobol does not support floating-point data types.

Basic DECIMAL format is different from Cobol PACKED-DECIMAL.

RPG only passes character and packed decimal parameters.

TRANSACT supports several extended precision datatype sizes not available elsewhere.

Strings are stored in differing formats by

the various languages. Only the simplest character arrays

are transferable among most languages.

Recommendations:

Use the simple data types (integers, characters, and reals).

Details:

Table 1

Data Representation Equivalences Across Languages

Data Types that are highly compatible across many languages:

Pascal Fortran Cobol C Basic Transact Note ---------------------------------------------

----------------------------------------------------------------------

Char CHARACTER PIC X char x$ X(1)

Integer INTEGER*4 S9(9)COMP int INTEGER I(9)

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Avoiding Pitfalls in Multi

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