Preprocessor Directives

H2cpy handles both #include and #define directives.

Translating #include Directives

H2cpy handles #include directives of the form:

#include <name> where name can be a simple filename with extension, or a filename that includes a relative path
#include "name" where name can be a simple filename with extension, a filename that includes a relative path or a filename that includes an absolute path
#include macro where macro expands to give one of the other two forms

H2cpy looks for the named file, and reads the C source from that. When it reaches the end of the file, it resumes reading the original file.

You do not need to enter the absolute path for a file when you use the #include directive. If you enter a non-absolute filename in quotation marks (" "), H2cpy searches for the file in the current directory first, followed by each directory in the include search path list.

If you enter the filename within angle brackets (<>), the filename is assumed to be a system header file and only the include search path list is searched. The current directory is not searched.

The search path list contains from zero to fourteen absolute directory names. The file is searched for in each of the directories in turn until it is found or the search list is exhausted. If H2cpy still cannot find the file, you receive an error message.

You can add additional directories to the front of the search path list using the -I option described in the section Command-line Options.

The include search path list initially has the one entry /usr/include. H2cpy assumes that the character that delimits directory-names in a path is the backslash (\). Any forward slashes (/) in the filename are converted to backslashes before the file is searched for.

For example, if you set the INCLUDE environment variable as follows:


the directive:

#include <Xm/Xm.h>

causes H2cpy to look for d:\include\Xm\Xm.h. It then searches for e:\sys\include\Xm\Xm.h.

Using the default path of /usr/include, the directive:

#include <Xm/Xm.h>

causes H2cpy to search for /usr/include/Xm/Xm.h only.

Translating #define Directives

H2cpy handles macros with parameters as well as those without parameters. It stores them and expands them if the macro-name is encountered in the C source. A macro can contain any number of C tokens and in general will not be directly translatable to COBOL.

H2cpy translates the following macro definitions to COBOL level-78 items:

  • A single C string literal, character, integer or floating constant
  • A numeric constant expression that can be evaluated to a single integer constant.

If H2cpy encounters a macro that has been defined before in both cases with identical C tokens, H2cpy ignores it. If the definitions are different, you receive an error message.

The #undef directive can be used to undefine a macro-name that may previously have been defined.