1CCOM(1) BSD General Commands Manual CCOM(1)
2
4 ccom — C compiler
5
7 ccom [-gkpsv] [-f features] [-m options] [-W warnings] [-X flags]
8 [-x settings] [-Z flags] [infile] [outfile]
9
11 The ccom utility provides a C compiler. The frontend is usually pcc(1).
12 It is not intended to be run directly. ccom reads the C source from
13 infile or standard input and writes the assembler source to outfile or to
14 standard output.
15 The options are as follows:
17 -f feature
19 Enable language features. Multiple -f options can be given, the
20 following features are supported:
21 stack-protector
23 Enable stack smashing protection. Currently the same as
24 stack-protector-all.
25 stack-protector-all
27 Enable stack smashing protection for all functions.
28 pack-struct[=n]
30 Specify maximum alignment for structure members, similar
31 to a #pragma pack statement at the start of the file. If
32 no value is given, the default is 1.
33 freestanding
35 Emit code for a freestanding environment. Currently not
36 implemented.
37 -g Include debugging information in the output code for use by sym‐
39 bolic and source-level debuggers. Currently this uses the stabs
40 format, encoding information in symbol table entries.
41 -k Generate PIC code.
43 -m option
45 Target-specific options, used in machine-dependent code. Multi‐
46 ple -m options can be given, the following options are supported:
47 AMD64
49 ARM little-endian, big-endian, fpe=fpa, fpe=vpf, soft-float,
51 arch=armv1, arch=armv2, arch=armv2a, arch=armv3,
52 arch=armv4, arch=armv4t, arch=armv4tej, arch=armv5,
53 arch=armv5te, arch=armv5tej, arch=armv6, arch=armv6t2,
54 arch=armv6kz, arch=armv6k & arch=armv7.
55 HPPA
57 i386
59 M16C
61 MIPS little-endian & big-endian.
63 NOVA
65 PDP-10
67 PDP-11
69 PowerPC little-endian, big-endian, soft-float & hard-float.
71 Sparc64
73 VAX
75 -p Generate profiling code.
77 -s Print statistics to standard error when complete. This includes:
79 name table entries, name string size, permanent allocated memory,
80 temporary allocated memory, lost memory, argument list unions,
81 dimension/function unions, struct/union/enum blocks, inline node
82 count, inline control blocks, and permanent symtab entries.
83 -v Display version.
85 -W warning
87 Do some basic checks and emit warnings about possible coding
88 problems. Multiple -W options can be given, the following warn‐
89 ings are supported:
90 error[=warning]
92 Enable warning, and treat it as an error condition. If a
93 specific warning is not given, producing any warning will
94 cause an error.
95 deprecated-declarations
97 Report whenever a symbol marked with the ‘deprecated’
98 attribute is used. This warning is enabled by default.
99 implicit-function-declaration
101 (TODO) Require explicit prototypes for all called func‐
102 tions.
103 implicit-int
105 (TODO) Warn when a function declaration lacks a type.
106 missing-prototypes
108 Require explicit prototypes for all global function defi‐
109 nitions.
110 pointer-sign
112 Warn when pointer operations are done with mismatched
113 signed and unsigned values.
114 sign-compare
116 (TODO) Warn about comparisons between signed and unsigned
117 values.
118 strict-prototypes
120 (TODO) Require that function prototypes are strictly C99.
121 shadow Report when a local variable shadows something from a
123 higher scope.
124 truncate
126 Report when integer values may be implicitly truncated to
127 fit a smaller type.
128 unknown-pragmas
130 Report unhandled pragma statements.
131 unreachable-code
133 Report statements that cannot be executed.
134 Any of the above may be prefixed with “no-” in order to disable
136 the effect.
137 -X flags
139 C specific debugging where flags is one or more of the following:
140 b Building of parse trees
142 d Declarations (using multiple d flags gives more output)
143 e Pass1 trees at exit
144 i Initializations
145 n Memory allocations
146 o Turn off optimisations
147 p Prototypes
148 s Inlining
149 t Type conversions
150 x Target-specific flag, used in machine-dependent code
151 -x setting
153 Enable setting in the compiler. Multiple -x options can be
154 given, the following settings are supported:
155 ccp Apply sparse conditional constant propagation techniques
157 for optimization. Currently not implemented.
158 dce Do dead code elimination.
160 deljumps
162 Delete redundant jumps and dead code.
163 gnu89
165 gnu99 Use GNU C semantics rather than C99 for some things.
167 Currently only inline.
168 inline Replace calls to functions marked with an inline speci‐
170 fier with a copy of the actual function.
171 ssa Convert statements into static single assignment form for
173 optimization. Not yet finished.
174 tailcall
176 Enable optimization of tail-recursion functions. Cur‐
177 rently not implemented.
178 temps Locate automatic variables into registers where possible,
180 for further optimization by the register allocator.
181 uchar Treat character constants as unsigned values.
183 -Z flags
185 Code generator (pass2) specific debugging where flags is one or
186 more of the following:
187 b Basic block and SSA building
189 c Code printout
190 e Trees when entering pass2
191 f Instruction matcher, may provide much output
192 g Print flow graphs
193 n Memory allocation
194 o Instruction generator
195 r Register allocator
196 s Shape matching in instruction generator
197 t Type matching in instruction generator
198 u Sethi-Ullman computations
199 x Target-specific flag, used in machine-dependent code
200
202 Input lines starting with a “#pragma” directive can be used to modify be‐
203 haviour of ccom during compilation. All tokens up to the first unescaped
204 newline are considered part of the pragma command, with the following
205 operations being recognized:
206 STDC Standard C99 operator follows. Currently no C99 operations are
208 implemented, and any directives starting with this token will be
209 silently ignored.
210 GCC diagnostic effect "option"
212 GNU C compatibility. Alter the effects of compiler diagnostics.
213 The required effect should be stated as warning, error or
214 ignored, followed by the compiler diagnostic option in double
215 quotes. For example, to force unknown pragmas to always generate
216 an error, a standard header might include
217 #pragma GCC diagnostic error "-Wunknown-pragmas"
219 GCC poison identifier ...
221 GNU C compatibility. Cause an error if any of the following
222 identifiers subsequently appear in the code (but not in any macro
223 expansions). Currently not implemented.
224 GCC system_header
226 GNU C compatibility. Currently not implemented.
227 GCC visibility
229 GNU C compatibility. Currently not implemented.
230 pack([n])
232 Set the default maximum alignment for structures and unions, such
233 that members will have their natural alignment requirements
234 clamped at this value and may be stored misaligned. If n is not
235 given, the alignment is reset to the target default.
236 pack(push[, n])
238 Push the current pack setting onto an internal stack then, if n
239 is given, change the default alignment for structures and unions.
240 Currently not implemented.
241 pack(pop)
243 Change the pack setting to the most recently pushed value, and
244 remove that setting from the stack. Currently not implemented.
245 packed [n]
247 Set the maximum alignment for the structure or union defined in
248 the current statement. If n is not given, the default value of 1
249 is used. (Currently this works except n is not used)
250 aligned [n]
252 Set the minimum alignment for the structure or union defined in
253 the current statement.
254 rename name
256 Provide an alternative name which will be used to reference the
257 object declared in the current statement.
258 weak name[=alias]
260 Mark name as a weak rather than a global symbol, to allow its
261 definition to be overridden at link time. If an alias is given,
262 this will be used as the default value of name.
263 ident Currently not implemented.
265 and the following target-specific operations are handled by machine-
267 dependent code:
268 tls For AMD64 and i386 targets, the variable declared in the current
270 statement will be referenced via the “thread-local storage” mech‐
271 anism.
272 init For AMD64, ARM, HPPA, i386, MIPS and PowerPC targets, when the
274 current statement is a function declaration, generate a reference
275 in the .ctors section, enabling library code to call the function
276 prior to entering main().
277 fini For AMD64, ARM, HPPA, i386, MIPS and PowerPC targets, when the
279 current statement is a function declaration, generate a reference
280 in the .dtors section, enabling library code to call the function
281 when main() returns or the exit() function is called.
282 section name
284 For AMD64, ARM, HPPA and i386 targets, place the subsequent code
285 in the named section. (This is currently broken).
286 alias name
288 For AMD64, HPPA and i386 targets, emit assembler instructions
289 providing an alias for the symbol defined by the current state‐
290 ment.
291 stdcall
293 For i386 targets, enable “stdcall” semantics during code genera‐
294 tion, where function arguments are passed on the stack in right-
295 to-left order, and the callee is responsible for adjusting the
296 stack pointer before returning. Any function result is passed in
297 the EAX register. On win32, the function name is postfixed with
298 an “@” and the size of the stack adjustment.
299 cdecl For i386 targets, enable “cdecl” semantics during code genera‐
301 tion, where function arguments are passed on the stack in right-
302 to-left order, and the caller is responsible for cleaning up the
303 stack after the function returns. Any function result is passed
304 in the EAX register. This is the default.
305 fastcall
307 For i386-win32 targets, enable “fastcall” semantics during code
308 generation. (Currently this is equivalent to stdcall, which is
309 likely wrong).
310 dllimport
312 For i386-win32 targets, references to the external symbol defined
313 by the current statement will be made via indirect access through
314 a location identified by the symbol name prefixed with “__imp_”.
315 dllexport
317 For i386-win32 targets, the external symbol declared by the cur‐
318 rent statement will be exported as an indirect reference to be
319 accessed with dllimport. The global locator will be the symbol
320 name prefixed with “__imp_”. Currently this is not completely
321 implemented.
322 Any unknown “#pragma” directives will be ignored unless the
324 -Wunknown-pragmas diagnostic is in effect.
325
327 as(1), cpp(1), pcc(1)
328
330 The ccom compiler is based on the original Portable C Compiler by S. C.
331 Johnson, written in the late 70's. Even though much of the compiler has
332 been rewritten (about 50% of the frontend code and 80% of the backend),
333 some of the basics still remain. Most is written by Anders Magnusson,
334 with the exception of the data-flow analysis part and the SSA conversion
335 code which is written by Peter A Jonsson, and the Mips port that were
336 written as part of a project by undergraduate students at Lulea Univer‐
337 sity of Technology.
338 This product includes software developed or owned by Caldera Interna‐
340 tional, Inc.
341BSD March 22, 2012 BSD