---
name: "scc"
section: "1"
platform: "linux"
package: "scheme2c"
version: "2012.10.14-1"
release: "Debian 8 (Jessie)"
platforms: ["linux"]
url: "https://new.carta.tech/s2cc"
---

# scc(1)

Scheme to C compiler

Part of [s2cc(1)](/s2cc/1.md).

## NAME

s2cc - Scheme to C compiler

## SYNTAX

**s2cc** \[ option \] ... file ...

## DESCRIPTION

The  **s2cc** command (previously known as **scc**) invokes a Scheme compiler which accepts the language defined in the essential portions of *Revised4 Report on the Algorithmic Language Scheme,* with minor constraints and some additions.  The compiler produces C source files which are then compiled using the system's C compiler to produce conventional *.o* and *a.out* files.  The C code produced by this compiler may be intermixed with other C code or code written in other languages.

## OPTIONS

These options are accepted by **s2cc**. Other options will be assumed to be options of the system's C compiler and they will be passed to it when it is invoked.

- **-cc** *C compiler*

  Compile the Scheme compiler produced C code with *C compiler*.  If this flag is not supplied, then the C compiler *cc* will be used.

- **-C**

  Compile the Scheme programs found in the files *source*.sc and leave the resulting code in *source*.c files.  No further operations are performed.

- **-I** *directory*

  Specifies a directory to be searched by include for source files.

- **-f** *symbol value*

  Define the compile-time constant *symbol* to *value.* This is equivalent to the construct (define-constant *symbol* *value*) appearing in the Scheme source.

- **-i**

  Combine the source and object files into a Scheme interpreter.  The module name for each Scheme source file is automatically determined.  Module names for previously compiled modules must be specified using the **-m** option.

- **-m** *module-name*

  Specifies the name of a previously compiled module.  Note that the Scheme compiler will downshift the alphabetic characters in the *module-name*. Modules are initialized in the order that the **-m** flags appear.

- **-Ob**

  Optimize code by omitting bounds checks on vectors and strings.

- **-Og**

  Optimize code by omitting stack trace-back code.

- **-On**

  Optimize code by assuming that all numbers are fixed point.

- **-Ot**

  Optimize code by omitting type error checks.

- **-pg**

  Produce profiled code for run-time measurement using *[gprof(1)](/gprof/1.md).* The profiled library is used in lieu of the standard Scheme library.

- **-scgc** *statflag*

  Enables garbage collection statistics.  If set to 1, then garbage collection statistics will be printed.  The default is 0, that will result in no statistics.

- **-sch** *heap*

  Specifies the compiler's initial heap size in megabytes.  The default is system dependent.

- **-scl** *percent*

  Specifies the percent of the heap allocated after a generational garbage collection that will force a full collection.  The default is 40.

- **-scmh** *heap*

  Specifies the compiler's maximum heap size in megabytes.  The default is five times the initial size of the heap.

- **-LIBDIR** *directory*

  Specifies a directory containing the files: predef.sc, objects.h, libs2c.a, and optionally libs2c\_p.a.

- **-log**

  Logs information internal to the compiler to the C source file produced by the compiler.  Each type of information is controlled by a flag: **-source**, **-macro**, **-expand**, **-closed**, **-transform**, **-lambda**, **-tree**, **-lap**, **-peep**.  The flag **-log** is equivalent to specifying the flags: **-source**, **-macro**, **-expand**, **-closed**, **-transform**, **-lambda**, **-tree**.

## ENVIRONMENT VARIABLES

The items controlled by *-sc..* flags can also be controlled by environment variables.  If both the flag and the environment variable are provided, then the flag's value will be used.

- **SCGCINFO**

  Controls the reporting of garbage collection statistics to the standard error file.  If set to 1, then garbage collection statistics will be printed.  The default setting is 0 that will not print the statistics.

- **SCHEAP**

  Specifies the initial size of the heap in megabytes.  The default heap size is system dependent.

- **SCLIMIT**

  Specifies the percent of the heap allocated after a generational garbage collection that will force a full collection.  The default is 40.

- **SCMAXHEAP**

  Specifies the maximum size of the heap in megabytes.

## INPUT FILES

Following the command options come one or more file names.

- *name*.sc

  Scheme source.  Scheme source files will be compiled into C files with the name *name*.c.

- *name*.c

  C source.

- *name*.s

  Assembly language source.

- *name*.o

  Object file which may have been generated by any compiler.

- *name*.a

  Object file archive which may have been generated by any compiler.

## DIAGNOSTICS

The disgnostic messages produced by the compiler are printed on the standard error file.

## FILES

/.../schemetoc/...	source and documentation\
 /.../libs2c.a	library\
 /.../libs2c\_p.a	profiled library (optional)\
 /.../s2cc	shell script\
 /.../s2ccomp	compiler\
 /.../predef.sc	predefined functions\
 /.../objects.h	definitions "#include'd" in the C code\
 SC-TO-C.c	temporary C source file\
 *source*.S2C	temporary C source file\
 SC-TO-C.o	temporary object file\

## LIMITATIONS

When the compiler is able to identify every call to a procedure, it is able to generate it "in-line", and perform tail calls by using "goto".  This analysis covers most loops, conditional expressions, and finite state machines. For non-tail recursive calls, the code generated by the compiler uses the standard C mechanisms for procedure call and return.  This therefore requires that each top-level Scheme procedure, and any Scheme procedure which has more than one call which is not tail-recursive be compiled into its own C procedure. Calls to such procedures will be tail-recursive if and only if the host C compiler optimizes tail-recursion.

## SEE ALSO

Harold Abelson and Gerald Jay Sussman with Julie Sussman, *Structure and Interpretation of Computer Programs,* The MIT Press.

William Clinger and Jonathan Rees (Editors), *Revised4 Report on the Algorithmic Language Scheme,* LISP Pointers, Volume IV, Number 3, July-September 1991.  PostScript for this file is included in the software distribution.

Jerry D. Smith, *An Introduction to Scheme,* Prentice Hall, Inc.  Chapter notes for using this text with Scheme-\>C are included in the software distribution.

R. Kent Dybvig, *The SCHEME Programming Language,* Prentice Hall, Inc.

Daniel P. Friedman and Matthias Felleisen, *The Little LISPer,* MIT Press.

Joel F. Bartlett, *Scheme-\>C  a Portable Scheme-to-C Compiler,* WRL Research Report 89/1.

Additional documentation is included in the software distribution.

[s2ci(1)](/s2ci/1.md)

## QUESTIONS, COMMENTS, AND COMPLAINTS

http://alioth.debian.org/projects/scheme2c/