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tcc-doc.texi
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\input texinfo @c -*- texinfo -*-
@c %**start of header
@setfilename tcc-doc.info
@settitle Tiny C Compiler Reference Documentation
@dircategory Software development
@direntry
* TCC: (tcc-doc). The Tiny C Compiler.
@end direntry
@c %**end of header
@include config.texi
@iftex
@titlepage
@afourpaper
@sp 7
@center @titlefont{Tiny C Compiler Reference Documentation}
@sp 3
@end titlepage
@headings double
@end iftex
@contents
@node Top, Introduction, (dir), (dir)
@top Tiny C Compiler Reference Documentation
This manual documents version @value{VERSION} of the Tiny C Compiler.
@menu
* Introduction:: Introduction to tcc.
* Invoke:: Invocation of tcc (command line, options).
* Clang:: ANSI C and extensions.
* asm:: Assembler syntax.
* linker:: Output file generation and supported targets.
* Bounds:: Automatic bounds-checking of C code.
* Libtcc:: The libtcc library.
* devel:: Guide for Developers.
@end menu
@node Introduction
@chapter Introduction
TinyCC (aka TCC) is a small but hyper fast C compiler. Unlike other C
compilers, it is meant to be self-relying: you do not need an
external assembler or linker because TCC does that for you.
TCC compiles so @emph{fast} that even for big projects @code{Makefile}s may
not be necessary.
TCC not only supports ANSI C, but also most of the new ISO C99
standard and many GNUC extensions including inline assembly.
TCC can also be used to make @emph{C scripts}, 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.
TCC can also automatically generate memory and bound checks
(@pxref{Bounds}) while allowing all C pointers operations. TCC can do
these checks even if non patched libraries are used.
With @code{libtcc}, you can use TCC as a backend for dynamic code
generation (@pxref{Libtcc}).
TCC mainly supports the i386 target on Linux and Windows. There are alpha
ports for the ARM (@code{arm-tcc}) and the TMS320C67xx targets
(@code{c67-tcc}). More information about the ARM port is available at
@url{http://lists.gnu.org/archive/html/tinycc-devel/2003-10/msg00044.html}.
For usage on Windows, see also @url{tcc-win32.txt}.
@node Invoke
@chapter Command line invocation
@section Quick start
@example
@c man begin SYNOPSIS
usage: tcc [options] [@var{infile1} @var{infile2}@dots{}] [@option{-run} @var{infile} @var{args}@dots{}]
@c man end
@end example
@noindent
@c man begin DESCRIPTION
TCC options are a very much like gcc options. The main difference is that TCC
can also execute directly the resulting program and give it runtime
arguments.
Here are some examples to understand the logic:
@table @code
@item @samp{tcc -run a.c}
Compile @file{a.c} and execute it directly
@item @samp{tcc -run a.c arg1}
Compile a.c and execute it directly. arg1 is given as first argument to
the @code{main()} of a.c.
@item @samp{tcc a.c -run b.c arg1}
Compile @file{a.c} and @file{b.c}, link them together and execute them. arg1 is given
as first argument to the @code{main()} of the resulting program.
@ignore
Because multiple C files are specified, @option{--} are necessary to clearly
separate the program arguments from the TCC options.
@end ignore
@item @samp{tcc -o myprog a.c b.c}
Compile @file{a.c} and @file{b.c}, link them and generate the executable @file{myprog}.
@item @samp{tcc -o myprog a.o b.o}
link @file{a.o} and @file{b.o} together and generate the executable @file{myprog}.
@item @samp{tcc -c a.c}
Compile @file{a.c} and generate object file @file{a.o}.
@item @samp{tcc -c asmfile.S}
Preprocess with C preprocess and assemble @file{asmfile.S} and generate
object file @file{asmfile.o}.
@item @samp{tcc -c asmfile.s}
Assemble (but not preprocess) @file{asmfile.s} and generate object file
@file{asmfile.o}.
@item @samp{tcc -r -o ab.o a.c b.c}
Compile @file{a.c} and @file{b.c}, link them together and generate the object file @file{ab.o}.
@end table
Scripting:
TCC can be invoked from @emph{scripts}, just as shell scripts. You just
need to add @code{#!/usr/local/bin/tcc -run} at the start of your C source:
@example
#!/usr/local/bin/tcc -run
#include <stdio.h>
int main()
@{
printf("Hello World\n");
return 0;
@}
@end example
TCC can read C source code from @emph{standard input} when @option{-} is used in
place of @option{infile}. Example:
@example
echo 'main()@{puts("hello");@}' | tcc -run -
@end example
@c man end
@section Option summary
General Options:
@c man begin OPTIONS
@table @option
@item -c
Generate an object file.
@item -o outfile
Put object file, executable, or dll into output file @file{outfile}.
@item -run source [args...]
Compile file @var{source} and run it with the command line arguments
@var{args}. In order to be able to give more than one argument to a
script, several TCC options can be given @emph{after} the
@option{-run} option, separated by spaces:
@example
tcc "-run -L/usr/X11R6/lib -lX11" ex4.c
@end example
In a script, it gives the following header:
@example
#!/usr/local/bin/tcc -run -L/usr/X11R6/lib -lX11
@end example
@item -v
Display TCC version.
@item -vv
Show included files. As sole argument, print search dirs. -vvv shows tries too.
@item -bench
Display compilation statistics.
@end table
Preprocessor options:
@table @option
@item -Idir
Specify an additional include path. Include paths are searched in the
order they are specified.
System include paths are always searched after. The default system
include paths are: @file{/usr/local/include}, @file{/usr/include}
and @file{PREFIX/lib/tcc/include}. (@file{PREFIX} is usually
@file{/usr} or @file{/usr/local}).
@item -Dsym[=val]
Define preprocessor symbol @samp{sym} to
val. If val is not present, its value is @samp{1}. Function-like macros can
also be defined: @option{-DF(a)=a+1}
@item -Usym
Undefine preprocessor symbol @samp{sym}.
@item -E
Preprocess only, to stdout or file (with -o).
@end table
Compilation flags:
Note: each of the following options has a negative form beginning with
@option{-fno-}.
@table @option
@item -funsigned-char
Let the @code{char} type be unsigned.
@item -fsigned-char
Let the @code{char} type be signed.
@item -fno-common
Do not generate common symbols for uninitialized data.
@item -fleading-underscore
Add a leading underscore at the beginning of each C symbol.
@item -fms-extensions
Allow a MS C compiler extensions to the language. Currently this
assumes a nested named structure declaration without an identifier
behaves like an unnamed one.
@item -fdollars-in-identifiers
Allow dollar signs in identifiers
@item -ftest-coverage
Create code coverage code. After running the resulting code an executable.tcov
or sofile.tcov file is generated with code coverage.
@end table
Warning options:
@table @option
@item -w
Disable all warnings.
@end table
Note: each of the following warning options has a negative form beginning with
@option{-Wno-}.
@table @option
@item -Wimplicit-function-declaration
Warn about implicit function declaration.
@item -Wunsupported
Warn about unsupported GCC features that are ignored by TCC.
@item -Wwrite-strings
Make string constants be of type @code{const char *} instead of @code{char
*}.
@item -Werror
Abort compilation if a warning is issued. Can be given an option to enable
the specified warning and turn it into an error, for example
@option{-Werror=unsupported}.
@item -Wall
Activate some useful warnings.
@end table
Linker options:
@table @option
@item -Ldir
Specify an additional static library path for the @option{-l} option. The
default library paths are @file{/usr/local/lib}, @file{/usr/lib} and @file{/lib}.
@item -lxxx
Link your program with dynamic library libxxx.so or static library
libxxx.a. The library is searched in the paths specified by the
@option{-L} option and @env{LIBRARY_PATH} variable.
@item -Bdir
Set the path where the tcc internal libraries (and include files) can be
found (default is @file{PREFIX/lib/tcc}).
@item -shared
Generate a shared library instead of an executable.
@item -soname name
set name for shared library to be used at runtime
@item -static
Generate a statically linked executable (default is a shared linked
executable).
@item -rdynamic
Export global symbols to the dynamic linker. It is useful when a library
opened with @code{dlopen()} needs to access executable symbols.
@item -r
Generate an object file combining all input files.
@item -Wl,-rpath=path
Put custom search path for dynamic libraries into executable.
@item -Wl,--enable-new-dtags
When putting a custom search path for dynamic libraries into the executable,
create the new ELF dynamic tag DT_RUNPATH instead of the old legacy DT_RPATH.
@item -Wl,--oformat=fmt
Use @var{fmt} as output format. The supported output formats are:
@table @code
@item elf32-i386
ELF output format (default)
@item binary
Binary image (only for executable output)
@item coff
COFF output format (only for executable output for TMS320C67xx target)
@end table
@item -Wl,--export-all-symbols
@item -Wl,--export-dynamic
Export global symbols to the dynamic linker. It is useful when a library
opened with @code{dlopen()} needs to access executable symbols.
@item -Wl,-subsystem=console/gui/wince/...
Set type for PE (Windows) executables.
@item -Wl,-[Ttext=# | section-alignment=# | file-alignment=# | image-base=# | stack=#]
Modify executable layout.
@item -Wl,-Bsymbolic
Set DT_SYMBOLIC tag.
@item -Wl,-(no-)whole-archive
Turn on/off linking of all objects in archives.
@end table
Debugger options:
@table @option
@item -g
Generate run time stab debug information so that you get clear run time
error messages: @code{ test.c:68: in function 'test5()': dereferencing
invalid pointer} instead of the laconic @code{Segmentation
fault}.
@item -gdwarf[-x]
Generate run time dwarf debug information instead of stab debug information.
@item -b
Generate additional support code to check memory allocations and array/pointer
bounds (@pxref{Bounds}). @option{-g} is implied.
@item -bt[N]
Display N callers in stack traces. This is useful with @option{-g} or @option{-b}.
With executables, additional support for stack traces is included.
A function @code{ int tcc_backtrace(const char *fmt, ...); } is provided
to trigger a stack trace with a message on demand.
@end table
Misc options:
@table @option
@item -M
Just output makefile fragment with dependencies
@item -MM
Like -M except mention only user header files, not system header files.
@item -MD
Generate makefile fragment with dependencies.
@item -MMD
Like -MD except mention only user header files, not system header files.
@item -MF depfile
Use @file{depfile} as output for -MD.
@item -print-search-dirs
Print the configured installation directory and a list of library
and include directories tcc will search.
@item -dumpversion
Print version.
@end table
Target specific options:
@table @option
@item -mms-bitfields
Use an algorithm for bitfield alignment consistent with MSVC. Default is
gcc's algorithm.
@item -mfloat-abi (ARM only)
Select the float ABI. Possible values: @code{softfp} and @code{hard}
@item -mno-sse
Do not use sse registers on x86_64
@item -m32, -m64
Pass command line to the i386/x86_64 cross compiler.
@end table
Note: GCC options @option{-Ox}, @option{-fx} and @option{-mx} are
ignored.
@c man end
@c man begin ENVIRONMENT
Environment variables that affect how tcc operates.
@table @option
@item CPATH
@item C_INCLUDE_PATH
A colon-separated list of directories searched for include files,
directories given with @option{-I} are searched first.
@item LIBRARY_PATH
A colon-separated list of directories searched for libraries for the
@option{-l} option, directories given with @option{-L} are searched first.
@end table
@c man end
@ignore
@setfilename tcc
@settitle Tiny C Compiler
@c man begin SEEALSO
cpp(1),
gcc(1)
@c man end
@c man begin AUTHOR
Fabrice Bellard
@c man end
@end ignore
@node Clang
@chapter C language support
@section ANSI C
TCC implements all the ANSI C standard, including structure bit fields
and floating point numbers (@code{long double}, @code{double}, and
@code{float} fully supported).
@section ISOC99 extensions
TCC implements many features of the new C standard: ISO C99. Currently
missing items are: complex and imaginary numbers.
Currently implemented ISOC99 features:
@itemize
@item variable length arrays.
@item 64 bit @code{long long} types are fully supported.
@item The boolean type @code{_Bool} is supported.
@item @code{__func__} is a string variable containing the current
function name.
@item Variadic macros: @code{__VA_ARGS__} can be used for
function-like macros:
@example
#define dprintf(level, __VA_ARGS__) printf(__VA_ARGS__)
@end example
@noindent
@code{dprintf} can then be used with a variable number of parameters.
@item Declarations can appear anywhere in a block (as in C++).
@item Array and struct/union elements can be initialized in any order by
using designators:
@example
struct @{ int x, y; @} st[10] = @{ [0].x = 1, [0].y = 2 @};
int tab[10] = @{ 1, 2, [5] = 5, [9] = 9@};
@end example
@item Compound initializers are supported:
@example
int *p = (int [])@{ 1, 2, 3 @};
@end example
to initialize a pointer pointing to an initialized array. The same
works for structures and strings.
@item Hexadecimal floating point constants are supported:
@example
double d = 0x1234p10;
@end example
@noindent
is the same as writing
@example
double d = 4771840.0;
@end example
@item @code{inline} keyword is ignored.
@item @code{restrict} keyword is ignored.
@end itemize
@section GNU C extensions
TCC implements some GNU C extensions:
@itemize
@item array designators can be used without '=':
@example
int a[10] = @{ [0] 1, [5] 2, 3, 4 @};
@end example
@item Structure field designators can be a label:
@example
struct @{ int x, y; @} st = @{ x: 1, y: 1@};
@end example
instead of
@example
struct @{ int x, y; @} st = @{ .x = 1, .y = 1@};
@end example
@item @code{\e} is ASCII character 27.
@item case ranges : ranges can be used in @code{case}s:
@example
switch(a) @{
case 1 @dots{} 9:
printf("range 1 to 9\n");
break;
default:
printf("unexpected\n");
break;
@}
@end example
@cindex aligned attribute
@cindex packed attribute
@cindex section attribute
@cindex unused attribute
@cindex cdecl attribute
@cindex stdcall attribute
@cindex regparm attribute
@cindex dllexport attribute
@cindex nodecorate attribute
@item The keyword @code{__attribute__} is handled to specify variable or
function attributes. The following attributes are supported:
@itemize
@item @code{aligned(n)}: align a variable or a structure field to n bytes
(must be a power of two).
@item @code{packed}: force alignment of a variable or a structure field to
1.
@item @code{section(name)}: generate function or data in assembly section
name (name is a string containing the section name) instead of the default
section.
@item @code{unused}: specify that the variable or the function is unused.
@item @code{cdecl}: use standard C calling convention (default).
@item @code{stdcall}: use Pascal-like calling convention.
@item @code{regparm(n)}: use fast i386 calling convention. @var{n} must be
between 1 and 3. The first @var{n} function parameters are respectively put in
registers @code{%eax}, @code{%edx} and @code{%ecx}.
@item @code{dllexport}: export function from dll/executable (win32 only)
@item @code{nodecorate}: do not apply any decorations that would otherwise be applied when exporting function from dll/executable (win32 only)
@end itemize
Here are some examples:
@example
int a __attribute__ ((aligned(8), section(".mysection")));
@end example
@noindent
align variable @code{a} to 8 bytes and put it in section @code{.mysection}.
@example
int my_add(int a, int b) __attribute__ ((section(".mycodesection")))
@{
return a + b;
@}
@end example
@noindent
generate function @code{my_add} in section @code{.mycodesection}.
@item GNU style variadic macros:
@example
#define dprintf(fmt, args@dots{}) printf(fmt, ## args)
dprintf("no arg\n");
dprintf("one arg %d\n", 1);
@end example
@item @code{__FUNCTION__} is interpreted as C99 @code{__func__}
(so it has not exactly the same semantics as string literal GNUC
where it is a string literal).
@item The @code{__alignof__} keyword can be used as @code{sizeof}
to get the alignment of a type or an expression.
@item The @code{typeof(x)} returns the type of @code{x}.
@code{x} is an expression or a type.
@item Computed gotos: @code{&&label} returns a pointer of type
@code{void *} on the goto label @code{label}. @code{goto *expr} can be
used to jump on the pointer resulting from @code{expr}.
@item Inline assembly with asm instruction:
@cindex inline assembly
@cindex assembly, inline
@cindex __asm__
@example
static inline void * my_memcpy(void * to, const void * from, size_t n)
@{
int d0, d1, d2;
__asm__ __volatile__(
"rep ; movsl\n\t"
"testb $2,%b4\n\t"
"je 1f\n\t"
"movsw\n"
"1:\ttestb $1,%b4\n\t"
"je 2f\n\t"
"movsb\n"
"2:"
: "=&c" (d0), "=&D" (d1), "=&S" (d2)
:"0" (n/4), "q" (n),"1" ((long) to),"2" ((long) from)
: "memory");
return (to);
@}
@end example
@noindent
@cindex gas
TCC includes its own x86 inline assembler with a @code{gas}-like (GNU
assembler) syntax. No intermediate files are generated. GCC 3.x named
operands are supported.
@item @code{__builtin_types_compatible_p()} and @code{__builtin_constant_p()}
are supported.
@item @code{#pragma pack} is supported for win32 compatibility.
@end itemize
@section TinyCC extensions
@itemize
@item @code{__TINYC__} is a predefined macro to indicate that you use TCC.
@item @code{#!} at the start of a line is ignored to allow scripting.
@item Binary digits can be entered (@code{0b101} instead of
@code{5}).
@end itemize
@node asm
@chapter TinyCC Assembler
Since version 0.9.16, TinyCC integrates its own assembler. TinyCC
assembler supports a gas-like syntax (GNU assembler). You can
deactivate assembler support if you want a smaller TinyCC executable
(the C compiler does not rely on the assembler).
TinyCC Assembler is used to handle files with @file{.S} (C
preprocessed assembler) and @file{.s} extensions. It is also used to
handle the GNU inline assembler with the @code{asm} keyword.
@section Syntax
TinyCC Assembler supports most of the gas syntax. The tokens are the
same as C.
@itemize
@item C and C++ comments are supported.
@item Identifiers are the same as C, so you cannot use '.' or '$'.
@item Only 32 bit integer numbers are supported.
@end itemize
@section Expressions
@itemize
@item Integers in decimal, octal and hexa are supported.
@item Unary operators: +, -, ~.
@item Binary operators in decreasing priority order:
@enumerate
@item *, /, %
@item &, |, ^
@item +, -
@end enumerate
@item A value is either an absolute number or a label plus an offset.
All operators accept absolute values except '+' and '-'. '+' or '-' can be
used to add an offset to a label. '-' supports two labels only if they
are the same or if they are both defined and in the same section.
@end itemize
@section Labels
@itemize
@item All labels are considered as local, except undefined ones.
@item Numeric labels can be used as local @code{gas}-like labels.
They can be defined several times in the same source. Use 'b'
(backward) or 'f' (forward) as suffix to reference them:
@example
1:
jmp 1b /* jump to '1' label before */
jmp 1f /* jump to '1' label after */
1:
@end example
@end itemize
@section Directives
@cindex assembler directives
@cindex directives, assembler
@cindex align directive
@cindex skip directive
@cindex space directive
@cindex byte directive
@cindex word directive
@cindex short directive
@cindex int directive
@cindex long directive
@cindex quad directive
@cindex globl directive
@cindex global directive
@cindex section directive
@cindex text directive
@cindex data directive
@cindex bss directive
@cindex fill directive
@cindex org directive
@cindex previous directive
@cindex string directive
@cindex asciz directive
@cindex ascii directive
All directives are preceded by a '.'. The following directives are
supported:
@itemize
@item .align n[,value]
@item .skip n[,value]
@item .space n[,value]
@item .byte value1[,...]
@item .word value1[,...]
@item .short value1[,...]
@item .int value1[,...]
@item .long value1[,...]
@item .quad immediate_value1[,...]
@item .globl symbol
@item .global symbol
@item .section section
@item .text
@item .data
@item .bss
@item .fill repeat[,size[,value]]
@item .org n
@item .previous
@item .string string[,...]
@item .asciz string[,...]
@item .ascii string[,...]
@end itemize
@section X86 Assembler
@cindex assembler
All X86 opcodes are supported. Only ATT syntax is supported (source
then destination operand order). If no size suffix is given, TinyCC
tries to guess it from the operand sizes.
Currently, MMX opcodes are supported but not SSE ones.
@node linker
@chapter TinyCC Linker
@cindex linker
@section ELF file generation
@cindex ELF
TCC can directly output relocatable ELF files (object files),
executable ELF files and dynamic ELF libraries without relying on an
external linker.
Dynamic ELF libraries can be output but the C compiler does not generate
position independent code (PIC). It means that the dynamic library
code generated by TCC cannot be factorized among processes yet.
TCC linker eliminates unreferenced object code in libraries. A single pass is
done on the object and library list, so the order in which object files and
libraries are specified is important (same constraint as GNU ld). No grouping
options (@option{--start-group} and @option{--end-group}) are supported.
@section ELF file loader
TCC can load ELF object files, archives (.a files) and dynamic
libraries (.so).
@section PE-i386 file generation
@cindex PE-i386
TCC for Windows supports the native Win32 executable file format (PE-i386). It
generates EXE files (console and gui) and DLL files.
For usage on Windows, see also tcc-win32.txt.
@section GNU Linker Scripts
@cindex scripts, linker
@cindex linker scripts
@cindex GROUP, linker command
@cindex FILE, linker command
@cindex OUTPUT_FORMAT, linker command
@cindex TARGET, linker command
Because on many Linux systems some dynamic libraries (such as
@file{/usr/lib/libc.so}) are in fact GNU ld link scripts (horrible!),
the TCC linker also supports a subset of GNU ld scripts.
The @code{GROUP} and @code{FILE} commands are supported. @code{OUTPUT_FORMAT}
and @code{TARGET} are ignored.
Example from @file{/usr/lib/libc.so}:
@example
/* GNU ld script
Use the shared library, but some functions are only in
the static library, so try that secondarily. */
GROUP ( /lib/libc.so.6 /usr/lib/libc_nonshared.a )
@end example
@node Bounds
@chapter TinyCC Memory and Bound checks
@cindex bound checks
@cindex memory checks
This feature is activated with the @option{-b} option (@pxref{Invoke}).
Here are some examples of caught errors:
@table @asis
@item Invalid range with standard string function:
@example
@{
char tab[10];
memset(tab, 0, 11);
@}
@end example
@item Out of bounds-error in global or local arrays:
@example
@{
int tab[10];
for(i=0;i<11;i++) @{
sum += tab[i];
@}
@}
@end example
@item Out of bounds-error in malloc'ed data:
@example
@{
int *tab;
tab = malloc(20 * sizeof(int));
for(i=0;i<21;i++) @{
sum += tab[i];
@}
free(tab);
@}
@end example
@item Access of freed memory:
@example
@{
int *tab;
tab = malloc(20 * sizeof(int));
free(tab);
for(i=0;i<20;i++) @{
sum += tab[i];
@}
@}
@end example
@item Double free:
@example
@{
int *tab;
tab = malloc(20 * sizeof(int));
free(tab);
free(tab);
@}
@end example
@end table
TCC defines @code{__BOUNDS_CHECKING_ON} if activated.
There are five environment variables that can be used to control the behavior:
@itemize
@item TCC_BOUNDS_WARN_POINTER_ADD
- Print warning when pointer add creates an illegal pointer.
@item TCC_BOUNDS_PRINT_CALLS
- Print bound checking calls. Can be used for debugging.
@item TCC_BOUNDS_PRINT_HEAP
- Print heap objects that are not freed at exit of program.
@item TCC_BOUNDS_PRINT_STATISTIC
- Print statistic information at exit of program.
@item TCC_BOUNDS_NEVER_FATAL
- Try to continue in case of a bound checking error.
@end itemize
Also, a function @code{__bounds_checking(x)} can be used to turn off/on bounds
checking from usercode (see below).
Notes:
@itemize
@item Only available on i386 (linux and windows), x86_64 (linux and windows),
arm, arm64 and riscv64 for the moment.
@item The generated code is slower and bigger.
@item The bound checking code is not included in shared libraries. The main
executable should always be compiled with the @option{-b}.
@item Pointer size is @emph{unchanged} and code generated with bound checks is
@emph{fully compatible} with unchecked code. When a pointer comes from
unchecked code, it is assumed to be valid. Even very obscure C code with
casts should work correctly.
@item Signal handlers are not compatible with bounds checking. The
bounds checking code disables checking in signal/sigaction handlers.
The fork() function call in a multi threaded application is also a problem.
The bound checking code fixes this for the child process.
@item The reason that signals and fork have problems is that we use locking
inside the bounds checking code.
Inside a signal handler we can not use locks. Also in a multi threaded
application after a fork the child process can have the lock set
by another thread.
@item The BOUNDS_CHECKING_OFF and BOUNDS_CHECKING_ON can also be used to
disable bounds checking for some code.
@item The __bounds_checking call adds a value to a thread local value.
The value starts at 0. If the value is not 0 the code is not checked
for bounds checking errors.
@end itemize
@example
#if defined(__TINYC__) && __BOUNDS_CHECKING_ON
extern void __bounds_checking (int x);
# define BOUNDS_CHECKING_OFF __bounds_checking(1)
# define BOUNDS_CHECKING_ON __bounds_checking(-1)
#else
# define BOUNDS_CHECKING_OFF
# define BOUNDS_CHECKING_ON
#endif
@end example
For more information about the ideas behind this method, see
@url{http://www.doc.ic.ac.uk/~phjk/BoundsChecking.html}.
@node Libtcc