update

README

@@ -1,23 +1,5 @@
-Tiny C Compiler - Make the best x86 Linux C compiler in less than 8192 bytes.
------------------------------------------------------------------------------
-
-Differences with ANSI C:
------------------------
-
-- Preprocessor: only '#define xx yy' is supported. Recursive defined
-  supported. All other directives are not supported.
-
-- Types: int, char, void, pointers and functions are
-  supported. Function pointers are also supported. struct, union and
-  typedef not supported.
-
-- Operations: 'x=' not supported.
-
-- Keywords: the following keywords are supported: int void char if
-  else while break return for.
-
-- Symbol scope: local variables supported, but they cannot have the
-  same name as global variables.
+Tiny C Compiler - C Scripting Everywhere - The Smallest ANSI C compiler
+-----------------------------------------------------------------------
 
 Features:
 --------
@@ -25,25 +7,123 @@ Features:
 - SMALL! You can compile and execute C code everywhere, for example on
   rescue disks.
 
-- FAST! tcc generate x86 code. No byte code overhead.
+- FAST! tcc generates optimized x86 code. No byte code overhead.
 
-- Compile and execute C source directly. No linking necessary.
+- UNLIMITED! Any C dynamic library can be used directly. TCC is
+  heading torwards full ANSI C compliance. TCC can of course compile
+  itself.
 
-- C script supported : just add '#!/usr/bin/tcc' at the first line of
-  your C source, and execute it directly from the command line !
+- Compile and execute C source directly. No linking or assembly
+  necessary. Full C preprocessor included.
 
-- All C library functions can be used via dynamic linking.
+- C script supported : just add '#!/usr/local/bin/tcc' at the first
+  line of your C source, and execute it directly from the command line !
 
--------------------------------------------------------------------------
-An even smaller compiler can be build from tcc by activating the
-define 'TINY'. The following changes from tcc:
+- For adventurers, tcc is conceived to be able to generate code for
+  other targets.
 
-- Comments are not supported.
+Documentation:
+-------------
 
-- Parsing: No char constants. No '\r' and '\t' in strings. Only base
-  10 numbers are supported.
+1) Installation
 
-- no 'for' loops.
+***TCC currently only work on Linux x86***.
 
-- Operations: '?:', ',', 'x=', shifts, '&&', '||', '!', '~' not supported.
+Type 'make install' to compile and install tcc in /usr/local and
+/usr/local/lib/tcc.
 
+2) Introduction
+
+We assume here that you know ANSI C. Look at the example ex1.c to know
+what the programs look like.
+
+The main limitations of tcc are that you cannot use floats. 
+
+The include file <tcclib.h> can be used if you want a small basic libc
+include support (especially useful for floppy disks). Of course, you
+can also use standard headers, although they are slower to compile.
+
+You can begin your C script with '#!/usr/local/bin/tcc' on the first
+line and set its execute bits (chmod a+x your_script). Then, you can
+launch the C code as a shell or perl script :-) The command line
+arguments are put in 'argc' and 'argv' of the main functions, as in
+ANSI C.
+
+3) Invokation
+
+'-Idir' : specify an additionnal include path. The
+default ones are: /usr/include, /usr/lib/tcc, /usr/local/lib/tcc.
+
+'-Dsym' : define preprocessor symbol 'sym' to 1.
+
+'-lxxx' : dynamically link your program with library
+libxxx.so. Standard library paths are checked, including those
+specificed with LD_LIBRARY_PATH.
+
+Only one source code can be compiled. If you have multiple source
+files, add one which includes all your sources.
+
+4) Examples
+
+ex1.c: simplest example (hello world). Can also be launched directly
+as a script: ./ex2.c.
+
+ex2.c: more complicated example: find a number with the four
+operations given a list of numbers (benchmark).
+
+ex3.c: compute fibonacci numbers (benchmark).
+
+ex4.c: more complicated: X11 program. Very complicated test in fact
+because standard headers are being used ! Currently slow because
+parsing does not use hash tables.
+
+ex5.c: 'hello world' with standard glibc headers.
+
+tcc.c: TCC can compile itself. Used to check the code generator.
+
+prog.c: auto test for TCC which tests many subtle possible bugs. Used
+when doing 'make test'.
+
+Exact differences with ANSI C:
+-----------------------------
+
+1) Preprocessor
+
+ - 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!
+
+ - __LINE__, __FILE__, __DATE__, __TIME__ are currently not handled.
+
+ - #line not handled
+
+2) C language
+
+- Parsing: variables cannot be initialized ('int a = 1' or 'int tab[2] =
+  {1, 2}' not supported).
+
+- Cannot pass struct/union as value. Cannot assign struct/union (use
+  memcpy instead).
+
+- Types: floating point numbers are not supported.
+
+- (BUG) 'char' and 'short' casts do not truncate correctly.
+
+- 'sizeof' may not work if too complex expression is given.
+
+Supported C extensions:
+----------------------
+
+- 'inline' keyword is ignored.
+
+
+License:
+-------
+
+TCC is distributed under the GNU Generic Public License (see COPYING
+file). 
+
+I accept only patches where you give your copyright explictely to me
+to simplify licensing issues.
+
+Fabrice Bellard - Nov 11, 2001.