The `compile_to_c` Command

The `compile_to_c` command is the SmartEiffel ANSI C code generator. Usually this command is called automatically by the `compile` command but you can use it separately to produce C code. There are two invocation modes: traditional and ACE. In traditional mode, a variety of compiler options can be specified on the command line. In ACE mode, these options are not permitted; it is presumed that the required compiler options are listed in the ACE file.

Usage

Traditional mode
`compile_to_c [options] <RootClass> [<RootProcedure>]
[*.c] [*.o] [-l*] [other options for C compiler/linker]`

ACE mode
`compile_to_c [general_options] <ACEfile.ace>`

In traditional mode, the `compile_to_c` command must be given at least one argument to indicate the starting execution point of the system. Thus your program will start in <RootProcedure> of <RootClass>. The default <RootProcedure> is make.

In ACE mode, the name of the ACE file must end with the `.ace` suffix. For examples of how to use ACE files, have a look in the `SmartEiffel/tutorial/ace` directory.

The `compile_to_c` command produces all the required C files as well as a script file. The name of this script file depends on the operating system used (*.make on Unix or *.BAT on DOS, for example).

Load Path for Eiffel Source Files

`compile_to_c` uses the technique described in the documentation for the `finder` command to locate the Eiffel source files it tries to compile. Note that what actually happens depends on the invocation mode (traditional or ACE).

General Compiler Options

-help:
  Display a brief summary of the command-line syntax and a complete list of compiler options.
-verbose:
  Print system information during the compilation (full path of files loaded, type inference score, removed files, etc.).
-version:
  Display the version number of the SmartEiffel release you're using.
-o <output_name>:
  Name the executable file `output_name`.
  This has the same meaning as the -o option of many C compilers.

Options to Select Eiffel Compilation Modes (traditional mode only)

There are eight compilation modes given by the following option names: -debug_check -all_check -loop_check -invariant_check -ensure_check -require_check -no_check and -boost. These options do change the generated C code (various assertions levels). Only one mode can be selected for the whole system. Mode -all_check is the default.

-boost:
  Compilation mode with the highest level of optimizations.
  There are no target existence tests and no system-level validity checking. Some routines are inlined. No code is generated to get an execution trace in case of failure. No assertions are checked.
-no_check:
  Compilation mode in which no Eiffel assertions are checked.
  Target existence tests are performed. Some code is generated for system-level validity checking, and to produce an execution trace. (An execution stack is managed.)
  There is no inlining and no assertion checking.
-require_check:
  Compilation mode in which Eiffel preconditions are checked.
  The generated code is similar to that of the previous mode, but also includes code to test preconditions (require clauses).
-ensure_check:
  The generated code is similar to that of the previous mode, but also includes code to test postconditions (ensure clauses).
-invariant_check:
  The generated code is similar to that of the previous mode, but also includes code to test class invariants.
-loop_check:
  The generated code is similar to that of the previous mode, but also includes code to test loop variants and loop invariants.
-all_check:
  The default mode. The generated code is similar to that of the previous mode, but also includes code to execute the instructions given in "check" blocks.
-debug_check:
  The generated code is similar to that of the previous mode, but also includes code to execute the instructions given in "debug" blocks. All debugs are checked regardless of the optional string key.

Warnings Levels

These options affect the compilation process, but do not change the generated C code.

-no_style_warning:
  Suppress output for warning messages related to the non-respecting of standard Eiffel style guidelines (for example, `ItEm` will not trigger a warning).
-case_insensitive:
  Switch case-insensitive mode on.
  For example, when this mode is selected, the Eiffel parser considers that the following identifiers refer to the same feature: `item`, `ITEM`, `ItEm`, ...
-no_warning:
  Suppress output for all warning messages. (Error messages are still printed.)

Advanced Compiler Options (traditional mode only)

These options affect the compilation process, but do not change the generated C code.

-cc <c_compiler>:
  Call <c_compiler> instead of the default C compiler. Check the `READ_ME` file in the `SmartEiffel/sys` directory to see how to set the default C compiler, as well as the default linker.
-no_split:
  Produce only one C file for the whole Eiffel system.
  This may enable the C compiler to inline more function calls. This option is useful only to finalize an application (the incremental C compiling mode is switched off with -no_split).
-no_strip:
  Do not remove symbol information from the generated executable file.
  This option is useful mainly when you need to debug at C code level.
-high_memory_compiler:
  Allow the compiler to use more memory at compile time (caching, bigger buffers, etc.). Compilation is likely to be quicker, if you have enough memory (RAM, not disk!)...

Advanced Options Affecting the Generated C Code (traditional mode only)

-no_gc:
  No Garbage Collector.
  When this option is selected, no GC is produced and (at least) one actual malloc is performed for each object creation. This option is useful when one prefers to use another GC provided by an external library (such as the Boehm-Demers-Weiser conservative GC), or when no GC is needed. Whithout the -no_gc flag, SmartEiffel computes a customized GC for each system.
  It is important to rememeber that some architecture-dependent code may be required for the proper operation of the GC (see the file `SmartEiffel/sys/gc` for details).
-gc_info:
  Garbage Collector status information.
  When this option is selected, the GC produced also contains code to display some status information.
-cecil <cecil_file>:
  Allow some Eiffel features to be called from C (see the `cecil` file for details). To call C functions/macros from Eiffel see the `external` file.
-no_main:
  Don't generate a C `main()` function: thus, the root procedure is not started. This is useful when one prefers to start execution from outside before calling Eiffel routines via the cecil interface. Before calling the first Eiffel routine one has to call once a predefined C function in order to initialize internal runtime information for the Eiffel world (see the example in the directory `SmartEiffel/tutorial/cecil/example7` for details).
-sedb:
  This option adds the SmartEiffel DeBugger into your executable system. (The debugger is embedded.) Thus, to debug your Eiffel system, just recompile your system with the -sedb flag and run the executable as usual. The very first screen gives you access to the on-line documentation and the debugger is waiting for your first command.
  The `sedb` debugger features step by step execution, navigation into the run-time stack, multi-conditions breakpoints, garbage collector invocation and profiling support.
  When profiling support is activated (see command `T` of `sedb`), a "trace.se" file is generated at execution time. When one interactively chooses the generation of this trace file, a (usually huge) "trace.se" file is created in the launch directory which shows the code the program is executing: which line, which column, in which Eiffel source file. Because all classes are traced, "trace.se" is a huge file even for a small program.
  Feature GENERAL.trace_switch allows trace generation to be turned on/off dynamically. At run time, if the argument of trace_switch is true, trace printing is switched on. (Conversely, false means switch off trace printing.)
  The -sedb option is not effective in conjunction with -boost. Using -sedb with -boost has the same effect as using -sedb with -no_check.
-manifest_string_trace:
  This option adds some extra code into the executable in order to track non-once manifest string allocations. The default behavior is to print an information message each time a non-once manifest string is allocated at runtime. The message also indicates the position of the corresponding manifest string in the Eiffel source file. This default behavior can be adapted to your needs by modifying the `SmartEiffel/sys/runtime/manifest_string_trace.c` file.
-wedit:
  Add Wedit support.
  When this option is used, the generated C code includes some support for the Wedit debugger.

Options Passed to the C Compiler

Any remaining options, *.c files, *.o files, -l* libraries, C optimizations options... are passed to the C compiler/linker. They do not affect the Eiffel to C compilation process.

Copyright © Dominique COLNET and Suzanne COLLIN - <SmartEiffel@loria.fr>
Last modified: Thu Sep 5 22:55:27 MET DST 2002