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1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 2<html> 3<head> 4<title>Warning Messages</title> 5<link rel="stylesheet" type="text/css" href="style.css"> 6</head> 7 8<body bgcolor="#ffffff"> 9<H1><a name="Warnings"></a>14 Warning Messages</H1> 10<!-- INDEX --> 11<div class="sectiontoc"> 12<ul> 13<li><a href="#Warnings_nn2">Introduction</a> 14<li><a href="#Warnings_suppression">Warning message suppression</a> 15<li><a href="#Warnings_nn4">Enabling extra warnings</a> 16<li><a href="#Warnings_nn5">Issuing a warning message</a> 17<li><a href="#Warnings_symbolic_symbols">Symbolic symbols</a> 18<li><a href="#Warnings_nn6">Commentary</a> 19<li><a href="#Warnings_nn7">Warnings as errors</a> 20<li><a href="#Warnings_nn8">Message output format</a> 21<li><a href="#Warnings_nn9">Warning number reference</a> 22<ul> 23<li><a href="#Warnings_nn10">Deprecated features (100-199)</a> 24<li><a href="#Warnings_nn11">Preprocessor (200-299)</a> 25<li><a href="#Warnings_nn12">C/C++ Parser (300-399)</a> 26<li><a href="#Warnings_nn13">Types and typemaps (400-499) </a> 27<li><a href="#Warnings_nn14">Code generation (500-599)</a> 28<li><a href="#Warnings_nn15">Language module specific (700-899) </a> 29<li><a href="#Warnings_nn16">User defined (900-999)</a> 30</ul> 31<li><a href="#Warnings_nn17">History</a> 32</ul> 33</div> 34<!-- INDEX --> 35 36 37 38<H2><a name="Warnings_nn2"></a>14.1 Introduction</H2> 39 40 41<p> 42During compilation, SWIG may generate a variety of warning messages. For example: 43</p> 44 45<div class="shell"> 46<pre> 47example.i:16: Warning 501: Overloaded declaration ignored. bar(double) 48example.i:15: Warning 501: Previous declaration is bar(int) 49</pre> 50</div> 51 52<p> 53Typically, warning messages indicate non-fatal problems with the input 54where the generated wrapper code will probably compile, but it may not 55work like you expect. 56</p> 57 58<H2><a name="Warnings_suppression"></a>14.2 Warning message suppression</H2> 59 60 61<p> 62All warning messages have a numeric code that is shown in the warning message itself. 63To suppress the printing of a warning message, a number of techniques can be used. 64First, you can run SWIG with the <tt>-w</tt> command line option. For example: 65</p> 66 67<div class="shell"> 68<pre> 69% swig -python -w501 example.i 70% swig -python -w501,505,401 example.i 71</pre> 72</div> 73 74<p> 75Alternatively, warnings can be suppressed by inserting a special preprocessor pragma 76into the input file: 77</p> 78 79<div class="code"> 80<pre> 81%module example 82#pragma SWIG nowarn=501 83#pragma SWIG nowarn=501,505,401 84</pre> 85</div> 86 87<p> 88Finally, code-generation warnings can be disabled on a declaration by declaration basis using 89the <tt>%warnfilter</tt> directive. For example: 90</p> 91 92<div class="code"> 93<pre> 94%module example 95%warnfilter(501) foo; 96... 97int foo(int); 98int foo(double); // Silently ignored. 99</pre> 100</div> 101 102<p> 103The <tt>%warnfilter</tt> directive has the same semantics as other declaration modifiers like 104<tt>%rename</tt>, <tt>%ignore</tt> and <tt>%feature</tt>, see the 105<a href="Customization.html#Customization_features">%feature directive</a> section. For example, if you wanted to 106suppress a warning for a method in a class hierarchy, you could do this: 107</p> 108 109<div class="code"> 110<pre> 111%warnfilter(501) Object::foo; 112class Object { 113public: 114 int foo(int); 115 int foo(double); // Silently ignored 116 ... 117}; 118 119class Derived : public Object { 120public: 121 int foo(int); 122 int foo(double); // Silently ignored 123 ... 124}; 125</pre> 126</div> 127 128<p> 129Warnings can be suppressed for an entire class by supplying a class name. For example: 130</p> 131 132<div class="code"> 133<pre> 134%warnfilter(501) Object; 135 136class Object { 137public: 138 ... // All 501 warnings ignored in class 139}; 140</pre> 141</div> 142 143<p> 144There is no option to suppress all SWIG warning messages. The warning messages are there 145for a reason---to tell you that something may be <em>broken</em> in 146your interface. Ignore the warning messages at your own peril. 147</p> 148 149 150<H2><a name="Warnings_nn4"></a>14.3 Enabling extra warnings</H2> 151 152 153<p> 154Some warning messages are disabled by default and are generated only 155to provide additional diagnostics. These warnings can be turned on using the 156<tt>-Wextra</tt> option. For example: 157</p> 158 159<div class="shell"> 160<pre> 161% swig -Wextra -python example.i 162</pre> 163</div> 164 165<p> 166To selectively turn on extra warning messages, you can use the directives and options in the 167previous section--simply add a "+" to all warning numbers. For example: 168</p> 169 170<div class="shell"> 171<pre> 172% swig -w+309,+452 example.i 173</pre> 174</div> 175 176<p> 177or in your interface file use either 178</p> 179 180<div class="code"> 181<pre> 182#pragma SWIG nowarn=+309,+452 183</pre> 184</div> 185 186<p> 187or 188</p> 189 190<div class="code"> 191<pre> 192%warnfilter(+309,+452) foo; 193</pre> 194</div> 195 196<p> 197Note: selective enabling of warnings with <tt>%warnfilter</tt> overrides any global settings you might have 198made using <tt>-w</tt> or <tt>#pragma</tt>. 199</p> 200 201<p> 202You can of course also enable all warnings and suppress a select few, for example: 203</p> 204 205<div class="shell"> 206<pre> 207% swig -Wextra -w309,452 example.i 208</pre> 209</div> 210 211<p> 212The warnings on the right take precedence over the warnings on the left, so in the above example <tt>-Wextra</tt> adds numerous warnings including 452, but then <tt>-w309,452</tt> overrides this and so 452 is suppressesed. 213</p> 214 215<p> 216If you would like all warnings to appear, regardless of the warning filters used, then use the <tt>-Wall</tt> option. 217The <tt>-Wall</tt> option also turns on the extra warnings that <tt>-Wextra</tt> adds, however, it is subtely different. 218When <tt>-Wall</tt> is used, it also disables all other warning filters, 219that is, any warnings suppressed or added in <tt>%warnfilter</tt>, <tt>#pragma SWIG nowarn</tt> 220or the <tt>-w</tt> option. 221</p> 222 223<H2><a name="Warnings_nn5"></a>14.4 Issuing a warning message</H2> 224 225 226<p> 227Warning messages can be issued from an interface file using a number of directives. The 228<tt>%warn</tt> directive is the most simple: 229</p> 230 231<div class="code"> 232<pre> 233%warn "900:This is your last warning!" 234</pre> 235</div> 236 237<p> 238All warning messages are optionally prefixed by the warning number to use. If you are generating 239your own warnings, make sure you don't use numbers defined in the table at the end of this section. 240</p> 241 242<p> 243The <tt>%ignorewarn</tt> directive is the same as <tt>%ignore</tt> except that it issues a 244warning message whenever a matching declaration is found. For example: 245</p> 246 247<div class="code"> 248<pre> 249%ignorewarn("362:operator= ignored") operator=; 250</pre> 251</div> 252 253<p> 254Warning messages can be associated with typemaps using the 255<tt>warning</tt> attribute of a typemap declaration. For example: 256</p> 257 258<div class="code"> 259<pre> 260%typemap(in, warning="901:You are really going to regret this usage of $1_type $1_name") blah * { 261 ... 262} 263</pre> 264</div> 265 266<p> 267In this case, the warning message will be printed whenever the typemap is actually used and the <a href="Typemaps.html#Typemaps_special_variables">special variables</a> will be expanded as appropriate, for example: 268</p> 269 270<div class="shell"> 271<pre> 272example.i:23: Warning 901: You are really going to regret this usage of blah * self 273example.i:24: Warning 901: You are really going to regret this usage of blah * stuff 274</pre> 275</div> 276 277<H2><a name="Warnings_symbolic_symbols"></a>14.5 Symbolic symbols</H2> 278 279 280<p> 281The <tt>swigwarn.swg</tt> file that is installed with SWIG contains symbol constants that could also be 282used in <tt>%warnfilter</tt> and <tt>#pragma SWIG nowarn</tt>. 283For example this file contains the following line: 284</p> 285 286<div class="code"> 287<pre> 288%define SWIGWARN_TYPE_UNDEFINED_CLASS 401 %enddef 289</pre> 290</div> 291 292<p> 293so <tt>SWIGWARN_TYPE_UNDEFINED_CLASS</tt> could be used instead of 401, for example: 294</p> 295 296<div class="code"> 297<pre> 298#pragma SWIG nowarn=SWIGWARN_TYPE_UNDEFINED_CLASS 299</pre> 300</div> 301 302<p> 303or 304</p> 305 306<div class="code"> 307<pre> 308%warnfilter(SWIGWARN_TYPE_UNDEFINED_CLASS) Foo; 309</pre> 310</div> 311 312<H2><a name="Warnings_nn6"></a>14.6 Commentary</H2> 313 314 315<p> 316The ability to suppress warning messages is really only provided for 317advanced users and is not recommended in normal use. You are advised 318to modify your interface to fix the problems highlighted by the warnings 319wherever possible instead of suppressing warnings. 320</p> 321 322<p> 323Certain types of SWIG problems are errors. These usually arise due to 324parsing errors (bad syntax) or semantic problems for which there is 325no obvious recovery. There is no mechanism for suppressing error 326messages. 327</p> 328 329<H2><a name="Warnings_nn7"></a>14.7 Warnings as errors</H2> 330 331 332<p> 333Warnings can be handled as errors by using the <tt>-Werror</tt> command line 334option. This will cause SWIG to exit with a non successful exit code if a 335warning is encountered. 336</p> 337 338<H2><a name="Warnings_nn8"></a>14.8 Message output format</H2> 339 340 341<p> 342The output format for both warnings and errors can be selected for 343integration with your favourite IDE/editor. Editors and IDEs can usually parse 344error messages and if in the appropriate format will easily take you 345directly to the source of the error. The standard format is used by 346default except on Windows where the Microsoft format is used by default. 347These can be overridden using command line options, for example: 348</p> 349 350<div class="shell"><pre> 351$ swig -python -Fstandard example.i 352example.i:4: Syntax error in input. 353$ swig -python -Fmicrosoft example.i 354example.i(4) : Syntax error in input. 355</pre></div> 356 357<H2><a name="Warnings_nn9"></a>14.9 Warning number reference</H2> 358 359 360<H3><a name="Warnings_nn10"></a>14.9.1 Deprecated features (100-199)</H3> 361 362 363<ul> 364<li>101. Deprecated <tt>%extern</tt> directive. 365<li>102. Deprecated <tt>%val</tt> directive. 366<li>103. Deprecated <tt>%out</tt> directive. 367<li>104. Deprecated <tt>%disabledoc</tt> directive. 368<li>105. Deprecated <tt>%enabledoc</tt> directive. 369<li>106. Deprecated <tt>%doconly</tt> directive. 370<li>107. Deprecated <tt>%style</tt> directive. 371<li>108. Deprecated <tt>%localstyle</tt> directive. 372<li>109. Deprecated <tt>%title</tt> directive. 373<li>110. Deprecated <tt>%section</tt> directive. 374<li>111. Deprecated <tt>%subsection</tt> directive. 375<li>112. Deprecated <tt>%subsubsection</tt> directive. 376<li>113. Deprecated <tt>%addmethods</tt> directive. 377<li>114. Deprecated <tt>%readonly</tt> directive. 378<li>115. Deprecated <tt>%readwrite</tt> directive. 379<li>116. Deprecated <tt>%except</tt> directive. 380<li>117. Deprecated <tt>%new</tt> directive. 381<li>118. Deprecated <tt>%typemap(except)</tt>. 382<li>119. Deprecated <tt>%typemap(ignore)</tt>. 383<li>120. Deprecated command line option (-runtime, -noruntime). 384<li>121. Deprecated <tt>%name</tt> directive. 385</ul> 386 387<H3><a name="Warnings_nn11"></a>14.9.2 Preprocessor (200-299)</H3> 388 389 390<ul> 391<li>201. Unable to find <em>filename</em>. 392<li>202. Could not evaluate expression <em>expr</em>. 393<li>203. Both includeall and importall are defined: using includeall. 394<li>204. CPP #warning, "<em>warning</em>". 395<li>205. CPP #error, "<em>error</em>". 396<li>206. Unexpected tokens after #<em>directive</em> directive. 397</ul> 398 399<H3><a name="Warnings_nn12"></a>14.9.3 C/C++ Parser (300-399)</H3> 400 401 402<ul> 403<li>301. <tt>class</tt> keyword used, but not in C++ mode. 404<li>302. Identifier '<em>name</em>' redefined (ignored). 405<li>303. <tt>%extend</tt> defined for an undeclared class '<em>name</em>'. 406<li>304. Unsupported constant value (ignored). 407<li>305. Bad constant value (ignored). 408<li>306. '<em>identifier</em>' is private in this context. 409<li>307. Can't set default argument value (ignored) 410<li>308. Namespace alias '<em>name</em>' not allowed here. Assuming '<em>name</em>' 411<li>309. [private | protected] inheritance ignored. 412<li>310. Template '<em>name</em>' was already wrapped as '<em>name</em>' (ignored) 413<li>312. Unnamed nested class not currently supported (ignored). 414<li>313. Unrecognized extern type "<em>name</em>" (ignored). 415<li>314. '<em>identifier</em>' is a <em>lang</em> keyword. 416<li>315. Nothing known about '<em>identifier</em>'. 417<li>316. Repeated %module directive. 418<li>317. Specialization of non-template '<em>name</em>'. 419<li>318. Instantiation of template '<em>name</em>' is ambiguous, instantiation <em>templ</em> used, instantiation <em>templ</em> ignored. 420<li>319. No access specifier given for base class <em>name</em> (ignored). 421<li>320. Explicit template instantiation ignored. 422<li>321. <em>identifier</em> conflicts with a built-in name. 423<li>322. Redundant redeclaration of '<em>name</em>'. 424<li>323. Recursive scope inheritance of '<em>name</em>'. 425<li>324. Named nested template instantiations not supported. Processing as if no name was given to %template(). 426<li>325. Nested class not currently supported (<em>name</em> ignored). 427<li>350. operator new ignored. 428<li>351. operator delete ignored. 429<li>352. operator+ ignored. 430<li>353. operator- ignored. 431<li>354. operator* ignored. 432<li>355. operator/ ignored. 433<li>356. operator% ignored. 434<li>357. operator^ ignored. 435<li>358. operator& ignored. 436<li>359. operator| ignored. 437<li>360. operator~ ignored. 438<li>361. operator! ignored. 439<li>362. operator= ignored. 440<li>363. operator< ignored. 441<li>364. operator> ignored. 442<li>365. operator+= ignored. 443<li>366. operator-= ignored. 444<li>367. operator*= ignored. 445<li>368. operator/= ignored. 446<li>369. operator%= ignored. 447<li>370. operator^= ignored. 448<li>371. operator&= ignored. 449<li>372. operator|= ignored. 450<li>373. operator<< ignored. 451<li>374. operator>>ignored. 452<li>375. operator<<= ignored. 453<li>376. operator>>= ignored. 454<li>377. operator== ignored. 455<li>378. operator!= ignored. 456<li>379. operator<= ignored. 457<li>380. operator>= ignored. 458<li>381. operator&& ignored. 459<li>382. operator|| ignored. 460<li>383. operator++ ignored. 461<li>384. operator-- ignored. 462<li>385. operator, ignored. 463<li>386. operator-<* ignored. 464<li>387. operator-< ignored. 465<li>388. operator() ignored. 466<li>389. operator[] ignored. 467<li>390. operator+ ignored (unary). 468<li>391. operator- ignored (unary). 469<li>392. operator* ignored (unary). 470<li>393. operator& ignored (unary). 471<li>394. operator new[] ignored. 472<li>395. operator delete[] ignored. 473</ul> 474 475<H3><a name="Warnings_nn13"></a>14.9.4 Types and typemaps (400-499) </H3> 476 477 478<ul> 479<li>401. Nothing known about class 'name'. Ignored. 480<li>402. Base class 'name' is incomplete. 481<li>403. Class 'name' might be abstract. 482<li>450. Deprecated typemap feature ($source/$target). 483<li>451. Setting const char * variable may leak memory. 484<li>452. Reserved 485<li>453. Can't apply (pattern). No typemaps are defined. 486<li>460. Unable to use type <em>type</em> as a function argument. 487<li>461. Unable to use return type <em>type</em> in function <em>name</em>. 488<li>462. Unable to set variable of type <em>type</em>. 489<li>463. Unable to read variable of type <em>type</em>. 490<li>464. Unsupported constant value. 491<li>465. Unable to handle type <em>type</em>. 492<li>466. Unsupported variable type <em>type</em>. 493<li>467. Overloaded <em>declaration</em> not supported (no type checking rule for '<em>type</em>') 494<li>468. No 'throw' typemap defined for exception type <em>type</em> 495<li>469. No or improper directorin typemap defined for <em>type</em> 496<li>470. Thread/reentrant unsafe wrapping, consider returning by value instead. 497<li>471. Unable to use return type <em>type</em> in director method 498<li>474. Method <em>method</em> usage of the optimal attribute ignored in the out typemap as the following cannot be used to generate optimal code: <em>code</em> 499<li>475. Multiple calls to <em>method</em> might be generated due to optimal attribute usage in the out typemap. 500</ul> 501 502 503 504<H3><a name="Warnings_nn14"></a>14.9.5 Code generation (500-599)</H3> 505 506 507<ul> 508<li>501. Overloaded declaration ignored. <em>decl</em>. Previous declaration is <em>decl</em>. 509<li>502. Overloaded constructor ignored. <em>decl</em>. Previous declaration is <em>decl</em>. 510<li>503. Can't wrap '<em>identifier</em>' unless renamed to a valid identifier. 511<li>504. Function <em>name</em> must have a return type. Ignored. 512<li>505. Variable length arguments discarded. 513<li>506. Can't wrap varargs with keyword arguments enabled. 514<li>507. Adding native function <em>name</em> not supported (ignored). 515<li>508. Declaration of '<em>name</em>' shadows declaration accessible via operator->(), previous declaration of'<em>declaration</em>'. 516<li>509. Overloaded method <em>declaration</em> effectively ignored, as it is shadowed by <em>declaration</em>. 517<li>510. Friend function '<em>name</em>' ignored. 518<li>511. Can't use keyword arguments with overloaded functions. 519<li>512. Overloaded method <em>declaration</em> ignored, using non-const method <em>declaration</em> instead. 520<li>513. Can't generate wrappers for unnamed struct/class. 521<li>514. 522<li>515. 523<li>516. Overloaded method <em>declaration</em> ignored, using <em>declaration</em> instead. 524<li>517. 525<li>518. Portability warning: File <em>file1</em> will be overwritten by <em>file2</em> on case insensitive filesystems such as Windows' FAT32 and NTFS unless the class/module name is renamed. 526<li>519. %template() contains no name. Template method ignored: <em>declaration</em> 527<li>520. <em>Base/Derived</em> class '<em>classname1</em>' of '<em>classname2</em>' is not similarly marked as a smart pointer. 528<li>521. Illegal destructor name <em>name</em>. Ignored. 529</ul> 530 531<H3><a name="Warnings_nn15"></a>14.9.6 Language module specific (700-899) </H3> 532 533 534<ul> 535<li>801. Wrong name (corrected to '<em>name</em>'). (Ruby). 536</ul> 537 538<ul> 539<li>810. No jni typemap defined for <em>type</em> (Java). 540<li>811. No jtype typemap defined for <em>type</em> (Java). 541<li>812. No jstype typemap defined for <em>type</em> (Java). 542<li>813. Warning for <em>classname</em>: Base <em>baseclass</em> ignored. Multiple inheritance is not supported in Java. (Java). 543<li>814. 544<li>815. No javafinalize typemap defined for <em>type</em> (Java). 545<li>816. No javabody typemap defined for <em>type</em> (Java). 546<li>817. No javaout typemap defined for <em>type</em> (Java). 547<li>818. No javain typemap defined for <em>type</em> (Java). 548<li>819. No javadirectorin typemap defined for <em>type</em> (Java). 549<li>820. No javadirectorout typemap defined for <em>type</em> (Java). 550<li>821. 551<li>822. Covariant return types not supported in Java. Proxy method will return <em>basetype</em> (Java). 552<li>823. No javaconstruct typemap defined for <em>type</em> (Java). 553<li>824. Missing JNI descriptor in directorin typemap defined for <em>type</em> (Java). 554</ul> 555 556<ul> 557<li>830. No ctype typemap defined for <em>type</em> (C#). 558<li>831. No cstype typemap defined for <em>type</em> (C#). 559<li>832. No cswtype typemap defined for <em>type</em> (C#). 560<li>833. Warning for <em>classname</em>: Base <em>baseclass</em> ignored. Multiple inheritance is not supported in C#. (C#). 561<li>834. 562<li>835. No csfinalize typemap defined for <em>type</em> (C#). 563<li>836. No csbody typemap defined for <em>type</em> (C#). 564<li>837. No csout typemap defined for <em>type</em> (C#). 565<li>838. No csin typemap defined for <em>type</em> (C#). 566<li>839. 567<li>840. 568<li>841. 569<li>842. Covariant return types not supported in C#. Proxy method will return <em>basetype</em> (C#). 570<li>843. No csconstruct typemap defined for <em>type</em> (C#). 571<li>844. C# exception may not be thrown - no $excode or excode attribute in <em>typemap</em> typemap. (C#). 572<li>845. Unmanaged code contains a call to a SWIG_CSharpSetPendingException method and C# code does not handle pending exceptions via the canthrow attribute. (C#). 573</ul> 574 575<ul> 576<li>870. Warning for <em>classname</em>: Base <em>baseclass</em> ignored. Multiple inheritance is not supported in PHP. 577<li>871. Unrecognized pragma <em>pragma</em>. (Php). 578</ul> 579 580<H3><a name="Warnings_nn16"></a>14.9.7 User defined (900-999)</H3> 581 582 583<p> 584These numbers can be used by your own application. 585</p> 586 587<H2><a name="Warnings_nn17"></a>14.10 History</H2> 588 589 590<p> 591The ability to control warning messages was first added to SWIG-1.3.12. 592</p> 593 594</body> 595</html>