1 .\" Process with groff -man -Tascii file.3
2 .TH GMQCC 1 2012-07-12 "" "gmqcc Manual"
4 gmqcc \- A Quake C compiler built from the NIH realm of sarcastic wit
7 [\fIOPTIONS\fR] [\fIfiles...\fR]
9 Traditionally, a QC compiler reads the file \fIprogs.src\fR which
10 in its first line contains the output filename, and the rest is a
11 list of QC source files that are to be compiled in order.
12 \fBgmqcc\fR optionally takes options to specify the output and
13 input files on the commandline, and also accepts assembly files.
15 \fBgmqcc\fR mostly tries to mimick gcc's commandline handling, though
16 there are also traditional long-options available.
19 Show a usage message and exit.
22 Turn on some compiler debugging mechanisms.
25 Turn on compiler mem-check. (Shows allocations and checks for leaks.)
27 .BI "-o, --output=" filename
28 Specify the output filename. Defaults to progs.dat. This will overwrite
29 the output file listed in a \fIprogs.src\fR file in case such a file is used.
32 Specify the optimization level
35 Highest optimization level
37 Default optimization level
39 Minimal optimization level
41 Disable optimization entirely
44 .BI "-O" name "\fR, " "" -Ono- name
45 Enable or disable a specific optimization. Note that these options
46 must be used after setting the optimization level, otherwise they'll
50 List all possible optimizations and the optimization level they're
53 .BI -W warning "\fR, " "" -Wno- warning
54 Enable or disable a warning.
57 Enable all warnings. Overrides preceding -W parameters.
59 .BR -Werror ", " -Wno-error
60 Controls whether or not all warnings should be treated as errors.
62 .BI -Werror- warning "\fR, " "" -Wno-error- warning
63 Controls whether a specific warning should be an error.
66 List all possible warn flags.
68 .BI -f flag "\fR, " "" -fno- flag
69 Enable or disable a specific compile flag. See the list of flags
73 List all possible compile flags.
76 Disables colored output
79 Use an ini file to read all the -O, -W and -f flag from. See the
80 CONFIG section about the file format.
83 Redirects standard output to a \fIfile\fR
86 Redirects standard error to a \fIfile\fR
89 Use the specified standard for parsing QC code. The following standards
91 .IR gmqcc , qcc , fteqcc
92 Selecting a standard also implies some -f options and behaves as if
93 those options have been written right after the -std option, meaning
94 if you changed them before the -std option, you're now overwriting
97 .BR -std=gmqcc " includes:"
99 -fadjust-vector-fields
101 .BR -std=qcc " includes:"
104 -fassign-function-types
105 -f\fIno-\fRadjust-vector-fields
108 .BR -std=fteqcc " includes:"
112 -ftranslatable-strings
113 -fassign-function-types
115 -f\fIno-\fRadjust-vector-fields
116 -f\fIno-\fRcorrect-ternary
122 Generate a warning about variables which are declared but never used.
123 This can be avoided by adding the \fInoref\fR keyword in front of the
124 variable declaration. Additionally a complete section of unreferenced
125 variables can be opened using \fI#pragma noref 1\fR, and closed via
126 \fI#pragma noref 0\fR.
128 .B -Wused-uninitialized
129 Generate a warning if it is possible that a variable can be used
130 without prior initialization. Note that this warning is not
131 necessarily reliable if the initialization happens only under certain
132 conditions. The other way is \fInot\fR possible: that the warning is
133 \fInot\fR generated when uninitialized use \fIis possible\fR.
135 .B -Wunknown-control-sequence
136 Generate an error when an unrecognized control sequence in a string is
137 used. Meaning: when there's a character after a backslash in a string
138 which has no known meaning.
141 Warn when using special extensions which are not part of the selected
144 .B -Wfield-redeclared
145 Generally QC compilers ignore redeclaration of fields. Here you can
146 optionally enable a warning.
148 .B -Wmissing-return-values
149 Functions which aren't of type \fIvoid\fR will warn if it possible to
150 reach the end without returning an actual value.
152 .B -Wtoo-few-parameters
153 Warn about a function call with fewer parameters than the function
157 Warn when a locally declared variable shadows variable.
160 Warn when the initialization of a local variable turns the variable
161 into a constant. This is default behaviour unless
162 \fI-finitialized-nonconstants\fR is used.
165 There are only 2 known global variables of type void: end_sys_globals
166 and end_sys_fields. Any other void-variable will warn.
168 .B -Wimplicit-function-pointer
169 A global function which is not declared with the \fIvar\fR keyword is
170 expected to have an implementing body, or be a builtin. If neither is
171 the case, it implicitly becomes a function pointer, and a warning is
174 .B -Wvariadic-function
175 Currently there's no way for an in QC implemented function to access
176 variadic parameters. If a function with variadic parameters has an
177 implementing body, a warning will be generated.
180 Generate warnings about \fI$frame\fR commands, for instance about
181 duplicate frame definitions.
183 .B -Weffectless-statement
184 Warn about statements which have no effect. Any expression which does
185 not call a function or assigns a variable.
188 The \fIend_sys_fields\fR variable is supposed to be a global variable
189 of type \fIvoid\fR. It is also recognized as a \fIfield\fR but this
190 will generate a warning.
192 .B -Wassign-function-types
193 Warn when assigning to a function pointer with an unmatching
194 signature. This usually happens in cases like assigning the null
195 function to an entity's .think function pointer.
198 Enable warnings coming from the preprocessor. Like duplicate macro
199 declarations. This warning triggers when there's a problem with the
200 way the preprocessor has been used, it will \fBnot\fR affect warnings
201 generated with the '#warning' directive. See -Wcpp.
204 Show warnings created using the preprocessor's '#warning' directive.
207 Warn if there's a preprocessor \fI#if\fR spanning across several
210 .B -Wdouble-declaration
211 Warn about multiple declarations of globals. This seems pretty common
212 in QC code so you probably do not want this unless you want to clean
216 The combination of \fIconst\fR and \fIvar\fR is not illegal, however
217 different compilers may handle them differently. We were told, the
218 intention is to create a function-pointer which is not assignable.
219 This is exactly how we interpret it. However for this interpretation
220 the \fIvar\fR keyword is considered superfluous (and philosophically
221 wrong), so it is possible to generate a warning about this.
223 .B -Wmultibyte-character
224 Warn about multibyte character constants, they do not work right now.
226 .B -Wternary-precedence
227 Warn if a ternary expression which contains a comma operator is used
228 without enclosing parenthesis, since this is most likely not what you
229 actually want. We recommend the \fI-fcorrect-ternary\fR option.
232 Warn when encountering an unrecognized \fI#pragma\fR line.
234 .B -Wunreachable-code
235 Warn about unreachable code. That is: code after a return statement,
236 or code after a call to a function marked as 'noreturn'.
239 Enable some warnings added in order to help debugging in the compiler.
241 .B -Wunknown-attribute
242 Warn on an unknown attribute. The warning will inlclude only the first
243 token inside the enclosing attribute-brackets. This may change when
244 the actual attribute syntax is better defined.
248 Allow local variables to overlap with each other if they don't
249 interfer with each other. (Not implemented right now)
251 .B -fdarkplaces-string-table-bug
252 Add some additional characters to the string table in order to
253 compensate for a wrong boundcheck in some specific version of the
256 .B -fadjust-vector-fields
257 When assigning to field pointers of type \fI.vector\fR the common
258 behaviour in compilers like \fIfteqcc\fR is to only assign the
259 x-component of the pointer. This means that you can use the vector as
260 such, but you cannot use its y and z components directly. This flag
261 fixes this behaviour. Before using it make sure your code does not
262 depend on the buggy behaviour.
265 Enable a partially fteqcc-compatible preprocessor. It supports all the
266 features used in the Xonotic codebase. If you need more, write a
270 Allow switch cases to use non constant variables.
273 Perform early out in logical AND and OR expressions. The final result
274 will be either a 0 or a 1, see the next flag for more possibilities.
277 In many languages, logical expressions perform early out in a special
278 way: If the left operand of an AND yeilds true, or the one of an OR
279 yields false, the complete expression evaluates to the right side.
280 Thus \fItrue && 5\fI evaluates to 5 rather than 1.
282 .B -ftranslatable-strings
283 Enable the underscore intrinsic: Using \fI_("A string constant")\fR
284 will cause the string immediate to get a name with a "dotranslate_"
285 prefix. The darkplaces engine recognizes these and translates them in
286 a way similar to how gettext works.
288 .B -finitialized-nonconstants
289 Don't implicitly convert initialized variables to constants. With this
290 flag, the \fIconst\fR keyword is required to make a constant.
292 .B -fassign-function-types
293 If this flag is not set, (and it is set by default in the qcc and
294 fteqcc standards), assigning function pointers of mismatching
295 signatures will result in an error rather than a warning.
298 Produce a linenumber file along with the output .dat file.
301 Use C's operator precedence for ternary expressions. Unless your code
302 depends on fteqcc-compatible behaviour, you'll want to use thi
305 .B -fsingle-vector-defs
306 Normally vectors generate 4 defs, once for the vector, and once for
307 its components with _x, _y, _z suffixes. This option
308 prevents components from being listed.
311 Most QC compilers translate if(a_vector) directly as an IF on the
312 vector, which means only the x-component is checked. This causes
313 vectors to be cast to actual booleans via a NOT_V and, if necessary, a
317 if (a_vector) // becomes
320 a = a_vector && a_float // becomes
321 a = !!a_vector && a_float
325 .B -ftrue-empty-strings
326 An empty string is considered to be true everywhere. The NOT_S
327 instruction usually considers an empty string to be false, this option
328 effectively causes the unary not in strings to use NOT_F instead.
330 .B -ffalse-empty-strings
331 An empty string is considered to be false everywhere. This means loops
332 and if statements which depend on a string will perform a NOT_S
333 instruction on the string before using it.
336 Enable utf8 characters. This allows utf-8 encoded character constants,
337 and escape sequence codepoints in the valid utf-8 range. Effectively
338 enabling escape sequences like '\\{x2211}'.
342 Some general peephole optimizations. For instance the code `a = b + c`
343 typically generates 2 instructions, an ADD and a STORE. This
344 optimization removes the STORE and lets the ADD write directly into A.
347 Tail recursive function calls will be turned into loops to avoid the
348 overhead of the CALL and RETURN instructions.
351 Make all functions which use neither local arrays nor have locals
352 which are seen as possibly uninitialized use the same local section.
353 This should be pretty safe compared to other compilers which do not
354 check for uninitialized values properly. The problem is that there's
355 QC code out there which really doesn't initialize some values. This is
356 fine as long as this kind of optimization isn't used, but also, only
357 as long as the functions cannot be called in a recursive manner. Since
358 it's hard to know whether or not an array is actually fully
359 initialized, especially when initializing it via a loop, we assume
360 functions with arrays to be too dangerous for this optimization.
362 The configuration file is similar to regular .ini files. Comments
363 start with hashtags or semicolons, sections are written in square
364 brackets and in each section there can be arbitrary many key-value
367 There are 3 sections currently:
368 .IR flags ", " warnings ", and " optimizations .
369 They contain a list of boolean values of the form `VARNAME = true` or
370 `VARNAME = false`. The variable names are the same as for the
371 corresponding -W, -f or -O flag written with only capital letters and
372 dashes replaced by underscores.
377 # a GMQCC configuration file
380 ADJUST_VECTOR_FIELDS = false
384 UNUSED_VARIABLE = false
385 USED_UNINITIALIZED = true
389 TAIL_RECURSION = true
393 Please report bugs on <http://github.com/graphitemaster/gmqcc/issues>,
394 or see <http://graphitemaster.github.com/gmqcc> on how to contact us.
398 A documented example for a gmqcc.ini file.
402 See <http://graphitemaster.github.com/gmqcc>.