tcc

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The Tiny C Compiler also known as tcc is famously one of the smallest and fastest C compilers ever written. In addition to being a full-fledged ANSI C and C99 compiler, tcc also supports an interpreted mode. It was originally designed to be deployed on system rescue disks in an era when such media were limited to 5¼″ (1.2MB) or 3½″ (1.44MB) floppy disks. As such, the tcc executable has historically hovered around 100kB in size. Even today on an amd64 system the executable hovers around 300kB in size.

One of the reasons for its speed is the fact that the Tiny C Compiler does not use byte code as intermediate representation during the compilation process. This has two consequences:

  1. It sacrifices advanced compiler optimizations that improve performance or size of the compiled executable. The resulting executable may have been compiled quickly but it's probably larger and less efficient than if it had been compiled with gcc or clang.
  2. The compiler is architecture-bound to the x86 and amd64 processors. The tcc compiler might compile on other architectures but it cannot generate native code for them.

Lesser-known among the features of The Tiny C Compiler is its ability to execute C code directly as if C were a scripting language, similar to Perl or Python.

Though it tends to have a very long development cycle between releases, the Tiny C Compiler remains in active development. It has a dedicated git repository located at https://repo.or.cz/tinycc.git.

Installation

USE flags

USE flags for dev-lang/tcc A very small C compiler for ix86/amd64

test Enable dependencies and/or preparations necessary to run tests (usually controlled by FEATURES=test but can be toggled independently)

Emerge

root #emerge --ask dev-lang/tcc

Environment variables

  • CPATH specifies a list of directories to be searched as if specified.
  • C_INCLUDE_PATH A colon-separated list of directories searched for include files.
  • LIBRARY_PATH A colon-separated list of directories searched for libraries.

Usage

Invocation

user $tcc --help
Tiny C Compiler 0.9.27 - Copyright (C) 2001-2006 Fabrice Bellard
Usage: tcc [options...] [-o outfile] [-c] infile(s)...
       tcc [options...] -run infile [arguments...]
General options:
  -c           compile only - generate an object file
  -o outfile   set output filename
  -run         run compiled source
  -fflag       set or reset (with 'no-' prefix) 'flag' (see tcc -hh)
  -std=c99     Conform to the ISO 1999 C standard (default).
  -std=c11     Conform to the ISO 2011 C standard.
  -Wwarning    set or reset (with 'no-' prefix) 'warning' (see tcc -hh)
  -w           disable all warnings
  -v --version show version
  -vv          show search paths or loaded files
  -h -hh       show this, show more help
  -bench       show compilation statistics
  -            use stdin pipe as infile
  @listfile    read arguments from listfile
Preprocessor options:
  -Idir        add include path 'dir'
  -Dsym[=val]  define 'sym' with value 'val'
  -Usym        undefine 'sym'
  -E           preprocess only
  -C           keep comments (not yet implemented)
Linker options:
  -Ldir        add library path 'dir'
  -llib        link with dynamic or static library 'lib'
  -r           generate (relocatable) object file
  -shared      generate a shared library/dll
  -rdynamic    export all global symbols to dynamic linker
  -soname      set name for shared library to be used at runtime
  -Wl,-opt[=val]  set linker option (see tcc -hh)
Debugger options:
  -g           generate runtime debug info
  -b           compile with built-in memory and bounds checker (implies -g)
  -bt[N]       link with backtrace (stack dump) support [show max N callers]
Misc. options:
  -x[c|a|b|n]  specify type of the next infile (C,ASM,BIN,NONE)
  -nostdinc    do not use standard system include paths
  -nostdlib    do not link with standard crt and libraries
  -Bdir        set tcc's private include/library dir
  -M[M]D       generate make dependency file [ignore system files]
  -M[M]        as above but no other output
  -MF file     specify dependency file name
  -m32/64      defer to i386/x86_64 cross compiler
Tools:
  create library  : tcc -ar [rcsv] lib.a files

Troubleshooting

Inability to run tcc as a script

The Tiny C compiler can be run with a script if the proper shabang is set at the first line of the file. The official upstream documentation provides the shabang as:

#!/usr/local/bin/tcc -run

However, this is inaccurate on a Gentoo system. Presently, the dev-lang/tcc ebuild installs tcc to /usr/bin, thus the shabang should be:

#!/usr/bin/tcc -run

If the script is going to be run on multiple systems where the path to tcc might change, the following shabang is also technically possible:

#!/usr/bin/env -S tcc -run

Note that the -S option is widely available on Linux but it may or may not be present on other operating systems such as macOS or any of the BSD's. Thus, while it is technically valid it should be used with caution in highly homogeneous environments.

Removal

Unmerge

root #emerge --ask --depclean --verbose dev-lang/tcc

See also

  • C — a programming language developed for Bell Labs in the early 1970s
  • clang — a "LLVM native" C/C++/Objective-C compiler using LLVM as a backend and optimizer.