1 .\" Please adjust this date whenever revising the manpage.
9 .Op Fl c | S | E | -print-ast
10 .Op Fl -print-implicit-cast
11 .Op Fl -print-parenthesis
12 .Op Fl std= Ns Ar standard
13 .Op Fl - Ns Oo Cm no- Oc Ns Cm gcc
14 .Op Fl - Ns Oo Cm no- Oc Ns Cm ms
17 .Op Fl W Ns Oo Cm no- Oc Ns Oo Cm error= Oc Ns Ar warning
21 .Op Fl D Ns Ar macro Ns Op Ar =defn
24 .Op Fl finput-charset= Ns Ar encoding
29 .Op Fl Wl, Ns Ar option
30 .Op Fl Wp, Ns Ar option
34 is a C compiler, which can parse C90 and C99 as well as many GCC and some MSC extensions.
35 It also provides many useful analyses for warnings and generates concise messages in case of error.
36 It uses libFIRM for optimization and code generation.
37 The compiler driver is largely compatible with GCC.
41 Compile the input files to object files.
42 The default output filename is the input filename with the extension replaced by .o.
44 Compile the input files to assembler.
45 The default output filename is the input filename with the extension replaced by .s.
47 Preprocess the input file only.
48 By default the result is output to stdout.
50 Output the abstract syntax tree of the parsed input file as C again.
51 .It Fl -print-implicit-cast
54 show casts, which are inserted by the semantic checks.
55 .It Fl -print-parenthesis
58 show all expressions fully parenthesized.
59 .It Fl std= Ns Ar standard
60 Select the language standard.
62 .Bl -tag -compact -width "iso9899:1990"
68 ISO C90 with GCC extensions
73 ISO C99 with GCC extensions
78 ISO C++ 1998 with GCC extensions.
81 .It Fl - Ns Oo Cm no- Oc Ns Cm gcc
82 Disable/enable GCC extensions.
83 This switch supersedes
85 .It Fl - Ns Oo Cm no- Oc Ns Cm ms
86 Disable/enable MSC extensions.
88 When compiling C files, add debug information in
93 Select the optimization level.
94 Sensible values are between 0 and 4, inclusive.
96 .It Fl W Ns Ar warning
97 Enable the specified warning.
98 .It Fl Wno- Ns Ar warning
99 Disable the specified warning.
100 .It Fl Werror= Ns Ar warning
101 Enable the specified warning and turn it into an error.
102 .It Fl Wno-error= Ns Ar warning
103 Force the specified warning to only be a warning, even in the presence of
105 This neither enables nor disables the warning itself.
107 Warn about suspicious use of addresses, like using the address of a function or variable as boolean condition or comparing with the address of a string literal.
108 .It Fl Waggregate-return
109 Warn about defining or calling a function, which returns a struct or union by value.
111 Activate most warnings.
112 In particular these are
115 .Fl Wchar-subscripts ,
117 .Fl Wempty-statement ,
119 .Fl Wimplicit-function-declaration ,
126 .Fl Wredundant-decls ,
130 .Fl Wstrict-prototypes ,
132 .Fl Wunknown-pragmas ,
133 .Fl Wunreachable-code ,
134 .Fl Wunused-function ,
136 .Fl Wunused-parameter ,
138 .Fl Wunused-variable .
140 Warn whenever a pointer cast removes qualifiers from the pointed-to type, e.g. casting a const char* to char*.
141 .It Fl Wchar-subscripts
142 Warn about using an expression of type char as array subscript, e.g. char\ c; arr[c].
143 .It Fl Wdeclaration-after-statement
144 Warn about mixing declarations and statements, which is not allowed prior to C99.
146 Warn about compile-time integer division by zero.
147 .It Fl Wempty-statement
148 Warn about empty statements, i.e. statements which only consist of a single
150 Use {} as replacement to avoid this warning.
152 Treat warnings as errors, i.e. do not continue after parsing when a warning is encountered.
156 Activate some more warnings.
157 In particular these are
158 .Fl Wempty-statement ,
160 .Fl Wunused-parameter ,
163 Immediately abort compilation when encountering an error.
165 Check format strings of char and wchar_t functions.
168 .Fl Wimplicit-function-declaration ,
170 .It Fl Wimplicit-function-declaration
171 Warn about calling a function without a prior declaration.
173 Warn about declarations whose declaration specifiers do not include a type specifier.
175 Warn about uninitialized variables which are initialized with themselves.
183 is suspicious, i.e. if it is not a non-static function declared as either int\ main(void), int\ main(int,\ char**) or, as an extension, int\ main(int,\ char**,\ char**).
184 .It Fl Wmissing-declarations
185 Warn if a non-static function or a global variable without a storage class is defined without a prior declaration.
186 This is typically a sign of a missing #include or that the object should be static.
187 .It Fl Wmissing-noreturn
188 Warn about functions, which are candidates for the attribute
190 .It Fl Wmissing-prototypes
191 Warn if a global function is defined without a previous prototype declaration.
193 Warn if a multicharacter constant
196 .It Fl Wnested-externs
199 declaration is encountered within a function.
201 Warn if parentheses are omitted in certain contexts.
202 Warn if an assignment is used as condition, e.g. if\ (x\ =\ 23).
203 Warn if && without parentheses is used within ||, e.g. if\ (x\ ||\ y\ &&\ z).
204 Warn if it there may be confusion which
208 -branch belongs to, e.g. if\ (x)\ if\ (y)\ {}\ else\ {}.
209 Warn if cascaded comparisons appear which do not have their mathematical meaning, e.g. if\ (23\ <=\ x\ <\ 42).
210 Warn if + or - is used as operand of << or >>, e.g. x\ +\ y\ <<\ z.
211 .It Fl Wredundant-decls
212 Warn about redundant declarations, i.e. multiple declarations of the same object or static forward declarations which have no use before their definition.
214 Warn when a new declaration shadows another declaration with the same name in an outer scope.
218 but only warn if the shadowed declaration is not global, e.g. a local variable shadows a parameter or another local variable.
219 .It Fl Wunreachable-code
220 Warn when the compiler determines that a statement (or in some cases a part thereof) will never be executed.
223 .Fl Wunused-function ,
225 .Fl Wunused-parameter ,
227 .Fl Wunused-variable .
228 .It Fl Wunused-parameter
229 Warn when a parameter is never used or only ever read to calculate its own new value, e.g. x\ =\ x\ +\ 1.
230 .It Fl Wunused-variable
231 Warn when a variable is never used or only ever read to calculate its own new value, e.g. x\ =\ x\ +\ 1.
233 Suppress all warnings.
237 to the paths to be searched for include files.
241 to the paths to be searched for libraries.
243 Define the preprocessor macro
245 which will expand to 1.
246 .It Fl D Ns Ar macro=defn
247 Define the preprocessor macro
249 and set its expanded value to
252 Undefine the preprocessor macro
255 Set a frontend or optimizer option.
258 to get a list of supported optimizer options.
259 .It Fl f Ns Oo Cm no- Oc Ns Cm diagnostics-show-option
260 Show the switch, which controls a warning, after each warning.
262 .It Fl finput-charset= Ns Ar encoding
263 Select the encoding of the input.
292 .It Fl f Ns Oo Cm no- Oc Ns Cm show-column
293 Show the column number in diagnostic messages.
297 to have the same range, representation and behaviour as
299 .It Fl funsigned-char
302 to have the same range, representation and behaviour as
305 Set a backend option.
308 to get a list of supported options.
310 Link with the specified library.
312 Specify the output filename.
313 This is only valid when using a single input filename.
315 as filename uses stdout for output.
317 Overwrite the language auto-detection for the following filenames by the
320 Supported values are:
321 .Bl -tag -compact -width "assembler-with-cpp"
324 .It Cm assembler-with-cpp
325 Assembler file, which needs to be preprocessed
333 Revert to auto-detection
335 .It Fl Wl, Ns Ar option
339 .It Fl Wp, Ns Ar option
346 http://www.libfirm.org/
348 Probably many - if you hit one, please report it.
351 needs to support more switches for better GCC compatibility.
353 This manual page is incomplete.
359 .Aq matze@braunis.de ,
361 .Aq christoph.mallon@gmx.de
projects / cparser / blob