Using the Slice Compiler

Common Options

Ice provides a Slice compiler for each language mapping. The compilers share a similar command-line syntax:

slice2<name> [options] file...

Regardless of which compiler you use, a number of command-line options are common to the compilers for any language mapping:

• -h, --help
  Displays a help message.

• -v, --version
  Displays the compiler version.

• -DNAME
  Defines the preprocessor symbol NAME.

• -DNAME=DEF
  Defines the preprocessor symbol NAME with the value DEF.
  Each compiler always predefines the __<compiler name in upper case>__ macro when compiling Slice file. For example, slice2cpp predefines __SLICE2CPP__.

• -UNAME
  Undefines the preprocessor symbol NAME.

• -IDIR
  Add the directory DIR to the search path for #include directives.

• --output-dir DIR
  Place the generated files into directory DIR, which must already exist.

• -d, --debug
  Print debug information showing the operation of the Slice parser.

• --depend
  Print dependency information in Makefile format to standard output by default, or to the file specified by the --depend-file option.

• --depend-xml
  Print dependency information in XML format to standard output by default, or to the file specified by the --depend-file option.

• --depend-file FILE
  Directs dependency information to the specified file. The output format depends on whether --depend,  --depend-xml, or --depend-json is specified.

• --validate
  Checks the provided command-line options for correctness, and does not generate any code.

The Slice compilers permit you to compile more than a single source file, so you can compile several Slice definitions at once, for example:

slice2cpp -I. file1.ice file2.ice file3.ice

The Slice Compiler for PHP

The Slice-to-PHP compiler (slice2php) offers one additional option:

• --all
  Generate code for all Slice definitions, including those from included files.

Compiler Output

For each Slice file X.ice, slice2php generates PHP code into a file named X.php in the output directory. The default output directory is the current working directory, but a different directory can be specified using the --output-dir option.

Include Files

It is important to understand how slice2php handles include files. In the absence of the --all option, the compiler does not generate PHP code for Slice definitions in included files. Rather, the compiler translates Slice #include statements into PHP require statements in the following manner:

1. Determine the full pathname of the included file.

2. Create the shortest possible relative pathname for the included file by iterating over each of the include directories (specified using the -I option) and removing the leading directory from the included file if possible.
   For example, if the full pathname of an included file is /opt/App/slice/OS/Process.ice, and we specified the options -I/opt/App and -I/opt/App/slice, then the shortest relative pathname is OS/Process.ice after removing /opt/App/slice.

3. Replace the .ice extension with .php. Continuing our example from the previous step, the translated require statement becomes

   CODE

   require_once "OS/Process.php";

   As a result, you can use -I options to tailor the require statements generated by the compiler in order to avoid absolute path names and match the organizational structure of your application's source files. 

See Also

• Slice Compilation