The assembler can be executed from the command line (shell) prompt of all supported operating systems, as well as from shell scripts, REXX execs, or other command languages. The program name of the assembler is x390. When invoked from the command line, the program name is followed by the options and source file names in any order. The command line arguments are described later in this chapter.
When multiple source file names are specified on the x390 command line, x390 logically concatenates the source files and produces on set of output files. An alternate command-line interface program named txa is also provided. The txa program invokes the x390 program once for each of the source files specified on the command line, creating a set of output files for each source file. The Windows version of txa will expand source file names containing wild card characters.
The third command line interface program is called tas. The tas program provides an interface similar to the GNU assembler. The tas program can be used to assemble the output of the gcc compiler for Linux for S/390 and zSeries. Appendix F contains a further description of the tas program.
In addition to the command-line interface, the Windows version of the assembler includes an Integrated Development Environment. The Tachyon Integrated Development Environment (T.I.D.E.) appears as an item in the Windows Start ... Programs ... menu or the Program Manager.
The Tachyon Integrated Development Environment allows you to set overrides to most of the assembler options. The MSGLEVEL, SYSTERM and TERM options are not available through this interface because they are used by the Tachyon Integrated Development Environment itself. The T.I.D.E. editor cannot edit EBCDIC or Unicode files, but it can read ASCII files containing tabs and lines ending in single X'0C' and X'0D' characters. When files are saved, tab characters are replaced by the correct number of blanks and lines are terminated by the normal X'0C0D' line end characters.
The make utility can be a very effective tool for developing software. Using the specifications in a make control file (usually called Makefile), the make utility will rebuild only the parts of the system that are dependent on changes made to source and copy files. The make utility decides what parts need to be rebuilt and then invokes other utilities, including the assembler, to actually perform the rebuilding. The assemblers MAKEDEPEND and MAKEFILE options can help you build a make control file by producing a dependency file. Because make will normally stop rebuilding the system when an invoked program returns a non-zero exit code, the PROCESS(WARN0) assembler option should be specified if you want to accept warnings from the assembler.
An edit macro is provided with the product to invoke the assembler from within an SPF/SourceEdit, SPF/PC or SPF/Professional edit session. If correctly set up, you can invoke the assembler edit macro by typing TXA on the primary command line of an edit session. It may be used for syntax checking of assembler source without leaving the edit session. It will save any changes, invoke the assembler, and insert any error messages as notes near the statements in error. Normally, no output files are produced.
For SPF/SourceEdit, the TXA.C file should be installed into one of the directories listed in Macro Source in the Options...Paths... screen, or that screen must be updated with the name of the directory conatining the TXA.C file.
For SPF/PC and SPF/Professional, the TXA.SPF file should be installed into one of the directories listed in the Macro and Command Procedure Search Path on the 0.8 screen, or that screen must be updated with the name of the directory conatining the TXA.SPF file.