Compiler Documentation
Building Documentation
Testsuite Documentation
Virtual Machine Documentation

Compiler Documentation

Defaults Flag

The -show-defaults flag instructs the compiler to print out the defaults used related to the standard, optimization, and code generation. When this flag is specified, the compiler will just print the defaults and quit. No compilation is performed.

$ gmqcc -show-defaults

Compiling for an alternitive standard

To compile with a different dialect of the QuakeC programming language the -std flag can be instructed to select one of the following options:

gmqcc	default standard
fteqcc	fteqcc standard
qcc	vanila QuakeC standard

Common compiler options

Options	What it does
-l<path>	Adds <path> to the directories searched by the preprocessor for include file resolution.
-o <file>	Generates the named executable (progs.src) file (when not specified default is progs.src).
-O<level>	Specfies the optimization level: highest being 3, lowest being 0 (no optimization).
-g	Enables generation of debug info for engine backtraces (turns on -flno)
-E	Instructs the compiler to only preprocess the input, writing the preprocessed output to stdout
-D	"define" a macro. Optionally you may supply a value to the macro with "=". Implicitally turns on -fftepp
-Wall	Enables all compiled warnings for the selcted standard
-Werror	Instruct the compiler to treat all warnings as errors
-std=<standard>	Selects the standard dialect

Predefined Macros

Macro	What it represents
__STD_GMQCC__	Specifies the current selected standard is gmqcc.
__STD_FTEQCC__	Specifies the current selected standard is fteqcc.
__STD_QCC__	Specifies the current selected standard is qcc.
GMQCC	Defined always regardless of the selected standard
__STD_VERSION_MINOR__	Specifies the current selected stanadards minor version number.
__STD_VERSION_MAJOR__	Specifies the current selected stanadards major version number.

Unsupported compatability options

GMQCC strives hard for compatability with standard dialects, but not all features of those standards might be implemented. The unsupported features are presented below:

Feature	Standard
Inline Assembly	FTEQCC
Macro expansion in strings	FTEQCC

Less common compiler options

Code generation options

Option	What it does
-foverlap-locals	Reduces codesize by overlapping locals where possible
-fdarkplaces-string-table-bug	Works around a bug in older Darkplaces engine builds where the stringtable size is computed wrong
-fadjust-vector-fields	corrects assignment of vector field pointers (STORE_V instead of STORE_FLD)
-fftepp	Enables FTEQ preprocessor
-frelaxted-switch	Relaxes switch statement semantics
-fshort-logic	Enables short circut evaluation/logic
-fperl-logic	Enables perl evalutaion/logic
-ftranslatable-strings	Enables translatable strings via .po file
-finitialized-nonconstants	Prevents initializations from becoming constant unless 'const' is specified as a qualifer
-fassign-function-types	Allows function types to be assignable even if their signature is invariant
-flno	Enables generation of progs.lno for engine VM backtraces (enabled with -g as well)

Warning options

Option	What it does
-Wunused-uninitialized	Enables warnings about unused or uninitialized variables
-Wunknwon-control-sequence	Enables warnings about unknown control sequences
-Wextension	Enables warnings about the use of (an) extension(s)
-Wfield-redeclared	Enables warnings about redeclared fields
-Wmissing-return-values	Enables warnings about missing return values
-Wtoo-few-paramaters	Enables warnings about missing paramaters for function calls
-Wlocal-shadows	Enables warnings about locals shadowing paramaters or other locals
-Wlocal-constants	Enables warnings about constants specified as locals
-Wvoid-variables	Enables warnings about variables declared as type void
-Wimplicit-function-pointer	Enables warnings about implicitly declared function pointers
-Wvariadic-function	Enables warnings for use of varadics for non-builtin functions
-Wframe-macros	Enables warnings about duplicated frame macros
-Weffectless-statement	Enables warnings about effectiveless statements
-Wend-sys-field	Enables warnings of end_sys_fields being declared a field
-Wassign-function-types	Enables warnings for incompatible function pointer signatures used in assignment
-Wpreprocessor	Enables warnings about redefined macros
-Wmultifile-if	Enables warnings about multifile if statements
-Wdouble-declaration	Enables warnings about double declarations
-Wconst-var	Enables warnings about 'const var' and 'var const'
-Wmultibyte-character	Enables warnings about use of multibyte characters
-Wternary-precedence	Enables warnings about ternary expressions whos precedence may be not what expected

Options	What it does
-Otail-recursion	Enables tail recursion optimization

Individual warnings may be disabled with -Wno-<warning>

$ gmqcc -Wno-frame-macros # disables frame duplication warning

Miscellaneous options

Option	What it does
-force-crc=<num>	Forces a specific checsum into the header
-debug	Turns on compiler debug messages
-memchk	Turns on compiler memory leak checker
-Whelp or -W?	Lists all warning options
-fhelp or -f?	Lists all code generation options
-redirout=<file>	Redirect stdout to any file.
-redirerr=<file>	Redirect stderr to any file.
-nocolor	Turn off colored stdout/stderr.
-config=<file>	Supply a configuration file to set options. Note: If a file named gmqcc.ini or gmqcc.cfg is found it will be loaded implicitally.

Building Documentation

Building on BSD/NIX

To compile GMQCC on BSD/NIX the following things are required:

GIT
Make
Any C90+ C compiler

Once obtained you may checkout the development repository with the following shell commands

$ git clone git://github.com/graphitemaster/gmqcc.git
$ cd gmqcc

The Makefile contains a few rules, depending on what you want to compile, the following rules are:

Rule	What it does
gmqcc	Builds the gmqcc compiler
qcvm	Builds a standable QuakeC VM
testsuite	Builds the testsuite for GMQCC
all	Builds gmqcc, qcvm, and testsuite
install	Installs gmqcc to /usr/local/
check	Runs the testsuite to verify correctness

Building on Windows

To compile GMQCC on windows the following things are required:

Once obtained you may checkout the development repository with the following msysGit commands from a msysGit shell.

$ git clone git://github.com/graphitemaster/gmqcc.git

Included is a VS project file.

Testsuite Documentation

Running The Testsuite

To run the testsuite you can either use

$ make check

Or if you're on windows or have already compiled the testsuite from source:

$ ./testsuite

Optionally you may provide the testsuite with additional arguments:

Argument	What it does
-redirout=<file>	Redirect stdout to any file.
-redirerr=<file>	Redirect stderr to any file.
-debug	Turn on testsuite debug messages.
-memchk	Turn on testsuite memleak checker.
-nocolor	Turn off colored stdout/stderr.

Writing Tests

GMQCC comes with a complete testsuite for verifying semantics and syntatics. The testsuite executes files from the test/ directory, by reading task template files.

templates are rules for a specific test, used to create a "task" that is executed with those set of rules (arguments, and what not). Tests that don't have a template with them cannot become tasks, since without the information for that test there is no way to properly "test" them. Rules for these templates are described in a template file, using a task template language.

The languge is composed entierly of "tags" which describe a string of text for a task. Think of it much like a configuration file. Except it's been designed to allow flexibility and future support for prodecual semantics.

The following "tags" are suported by the language:

Tag	Description of what the tag does
D:	Used to set a description of the current test, this must be provided, this tag is NOT optional.
F:	Used to set a failure message, this message will be displayed if the test fails, this tag is optional.
S:	Used to set a success message, this message will be displayed if the test succeeds, this tag is optional.
T:	Used to set the procedure for the given task, there are two options for this: -compile This simply performs compilation only -execute This will perform compilation and execution This tag must be provided, this tag is NOT optional.
C:	Used to set the compilation flags for the given task, this must be provided, this tag is NOT optional.
E:	Used to set the execution flags for the given task. This tag must be provided if T == -execute, otherwise it's erroneous as compilation only takes place.
M:	Used to describe a string of text that should be matched from the output of executing the task. If this doesn't match the task fails. This tag must be provided at least once if T == -execute, otherwise it's erroneous as compilation only takes place. Multiple M tags are required for multi-line comparision
I:	Used to specify the INPUT source file to operate on, this must be provided, this tag is NOT optional

Notes

These tags (with exception to M) have one-time use, using them more than once will result in template compilation errors,

Lines beginning with # or // in the template file are comments and are ignored by the template parser. Whitespace is optional, with exception to the colon ':' between the tag and it's assignment value.

The template compiler will detect erronrous tags (optional tags that need not be set), as well as missing tags, and error accordingly which will result in that task failing.

Quake C Virtual Machine Documentation

Included with GMQCC is a minimal implementation of the QCVM used in many game engines. It's primarly used for the testsuite, but you may also use it as a standalone runtime, or even embed it with existing appliciations.

Running The Standalone VM

To run the standalone application you need to have a compiled progs.dat, with an entry function named main The main function can have any amount of arguments as the standalone executor allows main to be invoked with your choice of arguments. An example of invoking the VM:

$ ./qcvm progs.dat -float 200 #execute passing in 200 as a float to main

If main doesn't require arguments:

$ ./qcvm progs.dat #call main with no arguments

The standalone executor supports the following arguments for passing arguments to main

Argument	What it does
-string	Passes in a string to main
-float	Passes in a float to main
-vector	Passes in a vector to main

The order in which the arguments are expected for main, must be preserved, for example if main 's signature is the following:

void main(float a, vector b)

Then to pass the arguments you'd use the same order:

$ ./qcvm -float 200 -vector '1 2 3'

Additional Arguments

The standalone virtual machine has the following optional command line arguments:

Argument	What it does
-trace	Trace the execution call hierarchy.
-profile	Profile the bytecode to find hotspots.
-info	Get info of the running bytecode.
-disasm	Dissasemble the bytecode into assembly.
-printdefs	Prints all definitions for the bytecode running.
-printfields	Prints all fields for the bytecode running.

Builtins

The standalone virtual machine includes the following builtins.

Builtin	Number
print	1
ftos	2
spawn	3
kill	4
vtos	5
error	6
vlen	7
etos	8
stof	9

Support or Contact

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