.\" Process with groff -man -Tascii file.3 .TH GMQCC 1 2012-07-12 "" "gmqcc Manual" .SH NAME gmqcc \- A Quake C compiler built from the NIH realm of sarcastic wit .SH SYNOPSIS .B gmqcc [\fIOPTIONS\fR] [\fIfiles...\fR] .SH DESCRIPTION Traditionally, a QC compiler reads the file \fIprogs.src\fR which in its first line contains the output filename, and the rest is a list of QC source files that are to be compiled in order. \fBgmqcc\fR optionally takes options to specify the output and input files on the commandline, and also accepts assembly files. .SH OPTIONS \fBgmqcc\fR mostly tries to mimick gcc's commandline handling, though there are also traditional long-options available. .TP .B "-h, --help" Show a usage message and exit. .TP .B "-debug" Turn on some compiler debugging mechanisms. .TP .B "-memchk" Turn on compiler mem-check. (Shows allocations and checks for leaks.) .TP .BI "-o, --output=" filename Specify the output filename. Defaults to progs.dat. This will overwrite the output file listed in a \fIprogs.src\fR file in case such a file is used. .TP .BI "-O" number Specify the optimization level .RS .IP 3 Highest optimization level .IP 2 Default optimization level .IP 1 Minimal optimization level .IP 0 Disable optimization entirely .RE .TP .BI "-O" name "\fR, " "" -Ono- name Enable or disable a specific optimization. Note that these options must be used after setting the optimization level, otherwise they'll be overwritten. .TP .B -Ohelp List all possible optimizations and the optimization level they're activated at. .TP .BI -W warning "\fR, " "" -Wno- warning Enable or disable a warning. .TP .B -Wall Enable all warnings. Overrides preceding -W parameters. .TP .BR -Werror ", " -Wno-error Controls whether or not all warnings should be treated as errors. .TP .BI -Werror- warning "\fR, " "" -Wno-error- warning Controls whether a specific warning should be an error. .TP .B -Whelp List all possible warn flags. .TP .BI -f flag "\fR, " "" -fno- flag Enable or disable a specific compile flag. See the list of flags below. .TP .B -fhelp List all possible compile flags. .TP .B -nocolor Disables colored output .TP .BI -config= file Use an ini file to read all the -O, -W and -f flag from. See the CONFIG section about the file format. .TP .BI "-redirout=" file Redirects standard output to a \fIfile\fR .TP .BI "-redirerr=" file Redirects standard error to a \fIfile\fR .TP .BI "-std=" standard Use the specified standard for parsing QC code. The following standards are available: .IR gmqcc , qcc , fteqcc Selecting a standard also implies some -f options and behaves as if those options have been written right after the -std option, meaning if you changed them before the -std option, you're now overwriting them. .sp .BR -std=gmqcc " includes:" .in +4 -fadjust-vector-fields .in .BR -std=qcc " includes:" .in +4 .nf -fassign-function-types -f\fIno-\fRadjust-vector-fields .fi .in .BR -std=fteqcc " includes:" .in +4 .nf -fftepp -ftranslatable-strings -fassign-function-types -Wternary-precedence -f\fIno-\fRadjust-vector-fields -f\fIno-\fRcorrect-ternary .fi .in .SH Warnings .TP .B -Wunused-variable Generate a warning about variables which are declared but never used. This can be avoided by adding the \fInoref\fR keyword in front of the variable declaration. Additionally a complete section of unreferenced variables can be opened using \fI#pragma noref 1\fR, and closed via \fI#pragma noref 0\fR. .TP .B -Wused-uninitialized Generate a warning if it is possible that a variable can be used without prior initialization. Note that this warning is not necessarily reliable if the initialization happens only under certain conditions. The other way is \fInot\fR possible: that the warning is \fInot\fR generated when uninitialized use \fIis possible\fR. .TP .B -Wunknown-control-sequence Generate an error when an unrecognized control sequence in a string is used. Meaning: when there's a character after a backslash in a string which has no known meaning. .TP .B -Wextensions Warn when using special extensions which are not part of the selected standard. .TP .B -Wfield-redeclared Generally QC compilers ignore redeclaration of fields. Here you can optionally enable a warning. .TP .B -Wmissing-return-values Functions which aren't of type \fIvoid\fR will warn if it possible to reach the end without returning an actual value. .TP .B -Wtoo-few-parameters Warn about a function call with fewer parameters than the function expects. .TP .B -Wlocal-shadows Warn when a locally declared variable shadows variable. .TP .B -Wlocal-constants Warn when the initialization of a local variable turns the variable into a constant. This is default behaviour unless \fI-finitialized-nonconstants\fR is used. .TP .B -Wvoid-variables There are only 2 known global variables of type void: end_sys_globals and end_sys_fields. Any other void-variable will warn. .TP .B -Wimplicit-function-pointer A global function which is not declared with the \fIvar\fR keyword is expected to have an implementing body, or be a builtin. If neither is the case, it implicitly becomes a function pointer, and a warning is generated. .TP .B -Wvariadic-function Currently there's no way for an in QC implemented function to access variadic parameters. If a function with variadic parameters has an implementing body, a warning will be generated. .TP .B -Wframe-macros Generate warnings about \fI$frame\fR commands, for instance about duplicate frame definitions. .TP .B -Weffectless-statement Warn about statements which have no effect. Any expression which does not call a function or assigns a variable. .TP .B -Wend-sys-fields The \fIend_sys_fields\fR variable is supposed to be a global variable of type \fIvoid\fR. It is also recognized as a \fIfield\fR but this will generate a warning. .TP .B -Wassign-function-types Warn when assigning to a function pointer with an unmatching signature. This usually happens in cases like assigning the null function to an entity's .think function pointer. .TP .B -Wpreprocessor Enable warnings coming from the preprocessor. Like duplicate macro declarations. This warning triggers when there's a problem with the way the preprocessor has been used, it will \fBnot\fR affect warnings generated with the '#warning' directive. See -Wcpp. .TP .B -Wcpp Show warnings created using the preprocessor's '#warning' directive. .TP .B -Wmultifile-if Warn if there's a preprocessor \fI#if\fR spanning across several files. .TP .B -Wdouble-declaration Warn about multiple declarations of globals. This seems pretty common in QC code so you probably do not want this unless you want to clean up your code. .TP .B -Wconst-var The combination of \fIconst\fR and \fIvar\fR is not illegal, however different compilers may handle them differently. We were told, the intention is to create a function-pointer which is not assignable. This is exactly how we interpret it. However for this interpretation the \fIvar\fR keyword is considered superfluous (and philosophically wrong), so it is possible to generate a warning about this. .TP .B -Wmultibyte-character Warn about multibyte character constants, they do not work right now. .TP .B -Wternary-precedence Warn if a ternary expression which contains a comma operator is used without enclosing parenthesis, since this is most likely not what you actually want. We recommend the \fI-fcorrect-ternary\fR option. .TP .B -Wunknown-pragmas Warn when encountering an unrecognized \fI#pragma\fR line. .TP .B -Wunreachable-code Warn about unreachable code. That is: code after a return statement, or code after a call to a function marked as 'noreturn'. .TP .B -Wdebug Enable some warnings added in order to help debugging in the compiler. You won't need this. .SH Compile Flags .TP .B -foverlap-locals Allow local variables to overlap with each other if they don't interfer with each other. (Not implemented right now) .TP .B -fdarkplaces-string-table-bug Add some additional characters to the string table in order to compensate for a wrong boundcheck in some specific version of the darkplaces engine. .TP .B -fadjust-vector-fields When assigning to field pointers of type \fI.vector\fR the common behaviour in compilers like \fIfteqcc\fR is to only assign the x-component of the pointer. This means that you can use the vector as such, but you cannot use its y and z components directly. This flag fixes this behaviour. Before using it make sure your code does not depend on the buggy behaviour. .TP .B -fftepp Enable a partially fteqcc-compatible preprocessor. It supports all the features used in the Xonotic codebase. If you need more, write a ticket. .TP .B -frelaxed-switch Allow switch cases to use non constant variables. .TP .B -fshort-logic Perform early out in logical AND and OR expressions. The final result will be either a 0 or a 1, see the next flag for more possibilities. .TP .B -fperl-logic In many languages, logical expressions perform early out in a special way: If the left operand of an AND yeilds true, or the one of an OR yields false, the complete expression evaluates to the right side. Thus \fItrue && 5\fI evaluates to 5 rather than 1. .TP .B -ftranslatable-strings Enable the underscore intrinsic: Using \fI_("A string constant")\fR will cause the string immediate to get a name with a "dotranslate_" prefix. The darkplaces engine recognizes these and translates them in a way similar to how gettext works. .TP .B -finitialized-nonconstants Don't implicitly convert initialized variables to constants. With this flag, the \fIconst\fR keyword is required to make a constant. .TP .B -fassign-function-types If this flag is not set, (and it is set by default in the qcc and fteqcc standards), assigning function pointers of mismatching signatures will result in an error rather than a warning. .TP .B -flno Produce a linenumber file along with the output .dat file. .TP .B -fcorrect-ternary Use C's operator precedence for ternary expressions. Unless your code depends on fteqcc-compatible behaviour, you'll want to use thi soption. .TP .B -fsingle-vector-defs Normally vectors generate 4 defs, once for the vector, and once for its components with _x, _y, _z suffixes. This option prevents components from being listed. .TP .B -fcorrect-logic Most QC compilers translate if(a_vector) directly as an IF on the vector, which means only the x-component is checked. This causes all non-float types to use an appropriate NOT instruction on all logic operations and invert their use. .in +4 .nf if (a_vector) // becomes if not(!a_vector) // likewise a = a_vector && a_float // becomes a = !!a_vector && a_float .fi .in .TP .B -ftrue-empty-strings An empty string is considered to be true everywhere. The NOT_S instruction usually considers an empty string to be false, this option effectively causes the unary not in strings to use NOT_F instead. .TP .B -ffalse-empty-strings An empty string is considered to be false everywhere. This means loops and if statements which depend on a string will perform a NOT_S instruction on the string before using it. .SH CONFIG The configuration file is similar to regular .ini files. Comments start with hashtags or semicolons, sections are written in square brackets and in each section there can be arbitrary many key-value pairs. .sp There are 3 sections currently: .IR flags ", " warnings ", and " optimizations . They contain a list of boolean values of the form `VARNAME = true` or `VARNAME = false`. The variable names are the same as for the corresponding -W, -f or -O flag written with only capital letters and dashes replaced by underscores. .sp Here's an example: .in +4 .nf # a GMQCC configuration file [flags] FTEPP = true ADJUST_VECTOR_FIELDS = false LNO = true [warnings] UNUSED_VARIABLE = false USED_UNINITIALIZED = true [optimizations] PEEPHOLE = true TAIL_RECURSION = true .fi .in .SH BUGS Please report bugs on , or see on how to contact us. .SH FILES .TP 20 .B gmqcc.ini.example A documented example for a gmqcc.ini file. .SH SEE ALSO .IR qcvm (1) .SH AUTHOR See .