tinycc/tcc-doc.texi
2001-12-16 21:23:42 +00:00

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<title> Tiny C Compiler Reference Documentation </title>
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<h1>
Tiny C Compiler Reference Documentation
</h1>
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<h2>Introduction</h2>
TinyCC (aka TCC) is a small but very fast C compiler. Unlike other C
compilers, it is meant to be self-suffisant: you do not need an
external assembler or linker because TCC does that for you.
<P>
TCC compiles so fast that even for big projects <tt>Makefile</tt>s may
not be necessary.
<P>
TCC can also be used to make <I>C scripts</I>,
i.e. pieces of C source that you run as a Perl or Python
script. Compilation is so fast that your script will be as fast as if
it was an executable.
<h2>Exact differences with ANSI C</h2>
TCC implements almost all the ANSI C standard, except floating point
and long long numbers.
<ul>
<li> The preprocessor tokens are the same as C. It means that in some
rare cases, preprocessed numbers are not handled exactly as in ANSI
C. This approach has the advantage of being simpler and FAST!
<li> Floating point numbers are not fully supported yet (some
implicit casts are missing).
<li> Some typing errors are not signaled.
</ul>
<h2>ISOC99 extensions</h2>
TCC implements many features of the new C standard: ISO C99. Currently
missing items are: complex and imaginary numbers (will come with ANSI
C floating point numbers), <tt>long long</tt>s and variable length
arrays.
Currently implemented ISOC99 features:
<ul>
<li> <tt>'inline'</tt> keyword is ignored.
<li> <tt>'restrict'</tt> keyword is ignored.
<li> <tt>'__func__'</tt> is a string variable containing the current
function name.
<li> Variadic macros: <tt>__VA_ARGS__</tt> can be used for
function-like macros:
<PRE>
#define dprintf(level, __VA_ARGS__) printf(__VA_ARGS__)
</PRE>
<tt>dprintf</tt> can then be used with a variable number of parameters.
<li> Declarations can appear anywhere in a block as in C++.
<li> Array and struct/union elements can be initialized in any order by
using designators:
<PRE>
struct { int x, y; } st[10] = { [0].x = 1, [0].y = 2 };
int tab[10] = { 1, 2, [5] = 5, [9] = 9};
</PRE>
<li> Compound initializers are supported:
<PRE>
int *p = (int []){ 1, 2, 3 };
</PRE>
to initialize a pointer pointing to an initialized array. The same
works for structures and strings.
<li> The boolean type <tt>'_Bool'</tt> is supported.
<li> <tt>'long long'</tt> types not supported yet, except in type
definition or <tt>'sizeof'</tt>.
<li> Hexadecimal floating point constants are supported:
<PRE>
double d = 0x1234p10;
</PRE>
is the same as writing
<PRE>
double d = 4771840.0;
</PRE>
</ul>
<h2>GNU C extensions</h2>
TCC implements some GNU C extensions which are found in many C sources:
<ul>
<li> array designators can be used without '=':
<PRE>
int a[10] = { [0] 1, [5] 2, 3, 4 };
</PRE>
<li> Structure field designators can be a label:
<PRE>
struct { int x, y; } st = { x: 1, y: 1};
</PRE>
instead of
<PRE>
struct { int x, y; } st = { .x = 1, .y = 1};
</PRE>
<li> <tt>'\e'</tt> is ASCII character 27.
</ul>
<h2>TinyCC extensions</h2>
I have added some extensions I find interesting:
<ul>
<li> <tt>__TINYC__</tt> is a predefined macro to <tt>'1'</tt> to
indicate that you use TCC.
<li> <tt>'#!'</tt> at the start of a line is ignored to allow scripting.
<li> Binary digits can be entered (<tt>'0b101'</tt> instead of
<tt>'5'</tt>).
</ul>
<h2> Command line invokation </h2>
<PRE>
usage: tcc [-Idir] [-Dsym] [-llib] [-i infile] infile [infile_args...]
</PRE>
<table>
<tr><td>'-Idir'</td>
<td>specify an additionnal include path. The default ones are:
/usr/include, /usr/lib/tcc, /usr/local/lib/tcc.</td>
<tr><td>'-Dsym'</td>
<td>define preprocessor symbol 'sym' to 1.</td>
<tr><td>'-lxxx'</td>
<td>dynamically link your program with library
libxxx.so. Standard library paths are checked, including those
specificed with LD_LIBRARY_PATH.</td>
<tr><td>'-i file'</td>
<td>compile C source 'file' before main C source. With this
command, multiple C files can be compiled and linked together.</td>
</table>
<hr>
Copyright (c) 2001 Fabrice Bellard <hr>
Fabrice Bellard - <em> fabrice.bellard at free.fr </em> - <A HREF="http://fabrice.bellard.free.fr/"> http://fabrice.bellard.free.fr/ </A> - <A HREF="http://www.tinycc.org/"> http://www.tinycc.org/ </A>
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