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 Ar warn
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"
67 ISO C90 with GCC extensions
72 ISO C99 with GCC extensions
77 ISO C++ 1998 with GCC extensions.
80 .It Fl - Ns Oo Cm no- Oc Ns Cm gcc
81 Disable/enable GCC extensions.
82 This switch supersedes
84 .It Fl - Ns Oo Cm no- Oc Ns Cm ms
85 Disable/enable MSC extensions.
87 When compiling C files, add debug information in
92 Select the optimization level.
93 Sensible values are between 0 and 4, inclusive.
94 .It Fl W Ns Oo Cm no- Oc Ns Ar warn
96 Disable/enable a specific warning.
97 Every warning option has a corresponding
99 switch to deactivate it.
101 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.
102 .It Fl Waggregate-return
103 Warn about defining or calling a function, which returns a struct or union by value.
105 Activate most warnings.
106 In particular these are
109 .Fl Wchar-subscripts ,
111 .Fl Wempty-statement ,
113 .Fl Wimplicit-function-declaration ,
120 .Fl Wredundant-decls ,
124 .Fl Wstrict-prototypes ,
126 .Fl Wunknown-pragmas ,
127 .Fl Wunreachable-code ,
128 .Fl Wunused-function ,
130 .Fl Wunused-parameter ,
132 .Fl Wunused-variable .
134 Warn whenever a pointer cast removes qualifiers from the pointed-to type, e.g. casting a const char* to char*.
135 .It Fl Wchar-subscripts
136 Warn about using an expression of type char as array subscript, e.g. char\ c; arr[c].
137 .It Fl Wdeclaration-after-statement
138 Warn about mixing declarations and statements, which is not allowed prior to C99.
140 Warn about compile-time integer division by zero.
141 .It Fl Wempty-statement
142 Warn about empty statements, i.e. statements which only consist of a single
144 Use {} as replacement to avoid this warning.
146 Treat warnings as errors, i.e. do not continue after parsing when a warning is encountered.
147 .It Fl Werror-implicit-function-declaration
148 Generate an error, when calling a function without a prior declaration.
152 Activate some more warnings.
153 In particular these are
154 .Fl Wempty-statement ,
156 .Fl Wunused-parameter ,
159 Immediately abort compilation when encountering an error.
161 Check format strings of char and wchar_t functions.
164 .Fl Wimplicit-function-declaration ,
166 .It Fl Wimplicit-function-declaration
167 Warn about calling a function without a prior declaration.
169 Warn about declarations whose declaration specifiers do not include a type specifier.
171 Warn about uninitialized variables which are initialized with themselves.
179 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**).
180 .It Fl Wmissing-declarations
181 Warn if a non-static function or a global variable without a storage class is defined without a prior declaration.
182 This is typically a sign of a missing #include or that the object should be static.
183 .It Fl Wmissing-noreturn
184 Warn about functions, which are candidates for the attribute
186 .It Fl Wmissing-prototypes
187 Warn if a global function is defined without a previous prototype declaration.
189 Warn if a multicharacter constant
192 .It Fl Wnested-externs
195 declaration is encountered within a function.
197 Warn if parentheses are omitted in certain contexts.
198 Warn if an assignment is used as condition, e.g. if\ (x\ =\ 23).
199 Warn if && without parentheses is used within ||, e.g. if\ (x\ ||\ y\ &&\ z).
200 Warn if it there may be confusion which
204 -branch belongs to, e.g. if\ (x)\ if\ (y)\ {}\ else\ {}.
205 Warn if cascaded comparisons appear which do not have their mathematical meaning, e.g. if\ (23\ <=\ x\ <\ 42).
206 Warn if + or - is used as operand of << or >>, e.g. x\ +\ y\ <<\ z.
207 .It Fl Wredundant-decls
208 Warn about redundant declarations, i.e. multiple declarations of the same object or static forward declarations which have no use before their definition.
210 Warn when a new declaration shadows another declaration with the same name in an outer scope.
214 but only warn if the shadowed declaration is not global, e.g. a local variable shadows a parameter or another local variable.
215 .It Fl Wunreachable-code
216 Warn when the compiler determines that a statement (or in some cases a part thereof) will never be executed.
219 .Fl Wunused-function ,
221 .Fl Wunused-parameter ,
223 .Fl Wunused-variable .
224 .It Fl Wunused-parameter
225 Warn when a parameter is never used or only ever read to calculate its own new value, e.g. x\ =\ x\ +\ 1.
226 .It Fl Wunused-variable
227 Warn when a variable is never used or only ever read to calculate its own new value, e.g. x\ =\ x\ +\ 1.
229 Suppress all warnings.
233 to the paths to be searched for include files.
237 to the paths to be searched for libraries.
239 Define the preprocessor macro
241 which will expand to 1.
242 .It Fl D Ns Ar macro=defn
243 Define the preprocessor macro
245 and set its expanded value to
248 Undefine the preprocessor macro
251 Set a frontend or optimizer option.
254 to get a list of supported optimizer options.
255 .It Fl finput-charset= Ns Ar encoding
256 Select the encoding of the input.
285 .It Fl f Ns Oo Cm no- Oc Ns Cm show-column
286 Show the column number in diagnostic messages.
290 to have the same range, representation and behaviour as
292 .It Fl funsigned-char
295 to have the same range, representation and behaviour as
298 Set a backend option.
301 to get a list of supported options.
303 Link with the specified library.
305 Specify the output filename.
306 This is only valid when using a single input filename.
308 as filename uses stdout for output.
310 Overwrite the language auto-detection for the following filenames by the
313 Supported values are:
314 .Bl -tag -compact -width "assembler-with-cpp"
317 .It Cm assembler-with-cpp
318 Assembler file, which needs to be preprocessed
326 Revert to auto-detection
328 .It Fl Wl, Ns Ar option
332 .It Fl Wp, Ns Ar option
339 http://www.libfirm.org/
341 Probably many - if you hit one, please report it.
344 needs to support more switches for better GCC compatibility.
346 This manual page is incomplete.
352 .Aq matze@braunis.de ,
354 .Aq christoph.mallon@gmx.de