Lazarus FAQ: what changed

Revision 1 to 2. Removed lines have a minus sign; added lines have a plus sign.

Old	New		Line
1	1		> Note: This FAQ may be outdated in certain parts.
2	2
3	3		## General
4	4
5	5		### What is Lazarus?
6	6
7	7		Lazarus is a cross-platform integrated development environment (IDE) that lets you create visual (GUI) and non-visual Object [[Pascal]] programs, and uses the Free Pascal compiler to generate your executable. Its aim is write once, compile anywhere: you should be able to just recompile your program source code with Lazarus running on another operating system (or a cross compiler) and get a program that runs on that operating system.
8	8
9	9		For more details see [[Overview of Free Pascal and Lazarus]]
10	10
11	11		### Why are the generated binaries so big?
12	12
13	13		The binaries are big because they include a lot of debug information necessary for using gdb (GNU Debugger). A debugger is a program that is used to test your code. It uses the extra-information stored in your binary to test it. But once your program is working well, you may delete those infos and reduce the size of the binary.
14	14
15	15		Quick guide to Lazarus/FPC application size reduction
16	16
17	17		- 1\. Project\\|Compiler Options\\|Code\\|Smart Linkable (-CX) -\> Checked
18	18		- 2\. Project\\|Compiler Options\\|Linking\\|Debugging\\| Uncheck all except Strip Symbols From Executable (-Xs)
19	19		- 3\. Project\\|Compiler Options\\|Linking\\|Link Style\\|Link Smart (-XX) -\> Checked
20	20
21	21		> Note: only do this if you don't need to run the debugger. For more details, see [[Size Matters]]
22	22
23	23		Lazarus executable size starts big, but grows very slowly, because of the way the LCL is designed, and its use of certain Free Pascal features (RTTI). Projects that don't use the LCL are much smaller (this is similar to some non-GUI C++ frameworks). This typically requires more manual coding though.
24	24
25	25		Exclude image readers See [[Lazarus 1.10.0 release notes\|Lazarus 1.10.0 release notes#LCL Changes]] If your app does not use images compressed in one of those formats, then you can exclude it.
26	26
27	27		### Do I need ppc386.cfg or fpc.cfg?
28	28
29	29		You only need fpc.cfg. This way the compiler knows where to find the libraries.
30	30
31	31		### How do I compile Lazarus?
32	32
33	33		Do something like this:
34	34
35	35		``` bash
36	36		cd lazarus
37	37		make clean all
38	38		```
39	39
40	40		If you want to build Lazarus for different widgetset eg. Qt (supported on Linux, Windows and OSX) then use the LCL_PLATFORM argument:
41	41
42	42		``` bash
43	43		cd lazarus
44	44		make clean all LCL_PLATFORM=qt
45	45		```
46	46
47	47		### Is it possible to build Lazarus projects without the Lazarus IDE?
48	48
49	49		See [[Using the LCL without Lazarus]]
50	50
51	51		### How do I build other Free Pascal programs that use LCL without the Lazarus IDE?
52	52
53	53		See [[Using the LCL without Lazarus]]
54	54
55	55		### What version of FPC is required?
56	56
57	57		Any Lazarus version compiles and works with 2 latest FPC release versions. FPC release cycle is slow and 2 latest versions typically span over few years.
58	58
59	59		Lazarus trunk also supports FPC trunk.
60	60
61	61		- Lazarus 1.0.8 requires at least FPC 2.6.2.
62	62		- Lazarus 1.0 requires at least FPC 2.6.0.
63	63		- Lazarus 2.x requires at least FPC 3.0.0
64	64		- Lazarus 3.0 requires at least FPC 3.2.0
65	65
66	66		### I can't compile Lazarus
67	67
68	68		1. Check if the compiler is the correct version
69	69		2. Check if the (fpc) libraries are from the same version
70	70		3. Check if the compiler installation path has spaces in it. Make sure it doesn't!
71	71		4. Check if you have a fpc.cfg and no old ppc386.cfg
72	72		5. Check also the OS-dependent FAQs
73	73		6. If you're still stuck, ask on the forum or Lazarus mailing list
74	74
75	75		### How to embed a small file in the executable, without the need of a separate file? How to embed a resource?
76	76
77	77		Both Lazarus resource and Windows-type/FPC resources are supported. See [[Lazarus Resources]].
78	78
79	79		### What is the meaning of the various file extensions used by Lazarus?
80	80
81	81		The [[Lazarus Tutorial\|Lazarus Tutorial#The Lazarus files]] explains some extensions by an example. Here is a brief list:
82	82
83		-	~~<table>~~
84	83		<thead>
85		-	~~<tr>~~
86		-	~~<th>extension</th>~~
87		-	~~<th>filetype</th>~~
88		-	~~<th>description</th>~~
89		-	~~</tr>~~
	84	+
90	85		</thead>
91	86		<tbody>
92		-	~~<tr>~~
93		-	~~<td><code>.lpi</code></td>~~
94		-	~~<td>Lazarus Project Information</td>~~
95		-	~~<td>contains project-specific settings like compiler settings and needed packages. stored in XML</td>~~
96		-	~~</tr>~~
97		-	~~<tr>~~
98		-	~~<td><code>.lps</code></td>~~
99		-	~~<td>Lazarus Program Session</td>~~
100		-	~~<td>Personal data like cursor positions, source editor files, personal build modes. stored in XML</td>~~
101		-	~~</tr>~~
102		-	~~<tr>~~
103		-	~~<td><code>.lpr</code></td>~~
104		-	~~<td>Lazarus Program</td>~~
105		-	~~<td>Pascal source of main program.</td>~~
106		-	~~</tr>~~
107		-	~~<tr>~~
108		-	~~<td><code>.lfm</code></td>~~
109		-	~~<td>Lazarus Form</td>~~
110		-	<td>Form configuration information for all objects on a form (stored in a Lazarus-specific textual format, similar to Delphi dfm; the actions are described by Pascal source code in a corresponding <code>*.pas</code> file)</td>
111		-	~~</tr>~~
112		-	~~<tr>~~
113		-	~~<td><code>.pas</code><br />~~
	87	+
114	88		<code>.pp</code><br />
115	89		<code>.p</code></td>
116		-	~~<td>Pascal code</td>~~
117		-	~~<td>Pascal code typically for a form stored in a corresponding <code>*.lfm</code> file</td>~~
118		-	~~</tr>~~
119		-	~~<tr>~~
120		-	~~<td><code>.lrs</code></td>~~
121		-	~~<td>Lazarus Resource</td>~~
122		-	<td>Generated Lazarus Resource file; not to be confused with a Windows resource file. This file can be created with lazres tool (in directory Lazarus/Tools) using commandline: lazres myfile.lrs myfile.lfm</td>
123		-	~~</tr>~~
124		-	~~<tr>~~
125		-	~~<td><code>.ppu</code></td>~~
126		-	~~<td>Compiled unit</td>~~
127		-	~~<td>Compiled source code created by the Free Pascal compiler for each unit and program.</td>~~
128		-	~~</tr>~~
129		-	~~<tr>~~
130		-	~~<td><code>.o</code></td>~~
131		-	~~<td>Object file</td>~~
132		-	~~<td>created by the compiler, every ppu file has a corresponding o file, needed by the linker.</td>~~
133		-	~~</tr>~~
134		-	~~<tr>~~
135		-	~~<td><code>.lpk</code></td>~~
136		-	~~<td>Lazarus package information</td>~~
137		-	~~<td>package-specific settings, like compiler settings and needed packages; stored in XML</td>~~
138		-	~~</tr>~~
139		-	~~<tr>~~
140		-	~~<td><code>.lrt</code></td>~~
141		-	~~<td>Lazarus Resourcestring table</td>~~
142		-	~~<td>Lazarus Resourcestring table created when saving a lfm file and i18n is enabled. It contains the TTranslateString properties of the lfm. Do not edit them, they are overwritten.</td>~~
143		-	~~</tr>~~
144		-	~~<tr>~~
145		-	~~<td><code>.rst</code></td>~~
146		-	~~<td>Resourcestring table</td>~~
147		-	~~<td>Resourcestring table created by the compiler for every unit with a resourcestring section. Do not edit them, they are overwritten.</td>~~
148		-	~~</tr>~~
149		-	~~<tr>~~
150		-	~~<td><code>.po</code></td>~~
151		-	~~<td>gnu gettext messages</td>~~
152		-	~~<td>When [[i18n]] is enabled the IDE creates/updated the .po files with the resourcestrings from the rst and lrt files.</td>~~
153		-	~~</tr>~~
	90	+
154	91		</tbody>
155		-	~~</table>~~
156	92
157	93		### Why are TForm.ClientWidth/ClientHeight the same as TForm.Width/Height
158	94
159	95		The TForm.Width/Height do no include the frame, because there was no way to retrieve the frame size on all platforms. Without a reliable way, the LCL would move the forms around on the screen or resize them endlessly.
160	96
161	97		Eventually it will be changed when there is a reliable way to get the size and position of a window with its frame on all platforms. To keep compatibility with older LCL forms, a version number and some extra methods will be added.
162	98
163	99		## Errors
164	100
165	101		Platform specific errors/problems are also covered in sections below.
166	102
167	103		### 'Fatal: Circular unit reference between a and b'
168	104
169	105		A common thing happened to a new user when one wants to create two forms referencing each other's properties. The error above only happens to uses clause of interface section, thus it's OK to put it in implementation section. Example:
170	106
171	107		This one causes error:
172	108
173	109		``` pascal
174	110		unit a;
175	111
176	112		interface
177	113
178	114		uses b;
179	115
180	116		implementation
181	117
182	118		end.
183	119		```
184	120
185	121		``` pascal
186	122		unit b;
187	123
188	124		interface
189	125
190	126		uses a;
191	127
192	128		implementation
193	129
194	130		end.
195	131		```
196	132
197	133		But this one doesn't:
198	134
199	135		``` pascal
200	136		unit a;
201	137
202	138		interface
203	139
204	140		implementation
205	141
206	142		uses b;
207	143
208	144		end.
209	145		```
210	146
211	147		``` pascal
212	148		unit b;
213	149
214	150		interface
215	151
216	152		implementation
217	153
218	154		uses a;
219	155
220	156		end.
221	157		```
222	158
223	159		In some cases the minimal base class method might be suitable.
224	160
225	161		Separate one class into a minimal base class (what the other needs) and derive it for the rest of the implementation.
226	162
227	163		unita: uses unitb
228	164
229	165		``` pascal
230	166		type
231	167		ClassA = class(BaseClassA)
232	168		// rest of ClassA
233	169		end;
234	170		```
235	171
236	172		unitb:
237	173
238	174		``` pascal
239	175		type
240	176		ClassB = class; //forward declaration
241	177
242	178		BaseClassA = class
243	179		// references ClassB
244	180		end;
245	181
246	182		ClassB = class
247	183		// references BaseClassA
248	184		end;
249	185		```
250	186
251	187		Discussion: <https://forum.lazarus.freepascal.org/index.php/topic,25667.msg156115.html#msg156115>
252	188
253	189		### When I do var mytext: text; to declare a text file, I get "Unit1.pas(32,15) Error: Error in type definition". How can I fix this?
254	190
255	191		The TControl class has a [[doc:lcl/controls/tcontrol.text.html\|Text]] property. In a method of a form, that has higher visibility, the [[doc:rtl/system/text.html\|Text]] type from the system unit. You can use the [[doc:rtl/system/textfile.html\|TextFile]] type, which is just an alias for the Text type or you can add the unit to the type definition.
256	192
257	193		``` pascal
258	194		var
259	195		MyTextFile: TextFile;
260	196		MyText: System.Text;
261	197		```
262	198
263	199		A similar name clash exists with assigning and closing a text file. TForm has a assign and a [[doc:lcl/forms/tcustomform.close.html\|Close]] method. You can use [[doc:rtl/objpas/assignfile.html\|AssignFile]] and [[doc:rtl/objpas/closefile.html\|CloseFile]] or add the unit name System.
264	200
265	201		### I get an error when using Printer.BeginDoc
266	202
267	203		The unit Printers must be added to the uses section and the Printer4Lazarus package must be added to your project requirement in the IDE under: Project \> Project Inspector \> Add \> New Requirement \> Package Name.
268	204
269	205		If the Printer4Lazarus package is not in the list when opening the dropdown box it must be installed. The package is part of the Lazarus installation and can be found in: \[lazarus installed directory\]\[/\\|\\\]components\[/\\|\\\]printers.
270	206
271	207		If you used the default installation directories \[lazarus installed directory\] is:
272	208
273	209		\| Operating system \| Lazarus installed directory \|
274	210		\|------------------\|-----------------------------\|
275	211		\| FreeBSD \| /usr/local/share/lazarus \|
276	212		\| Linux \| /usr/lib/lazarus \|
277	213		\| macOS \| /Library/Lazarus/ \|
278	214		\| Windows \| c:\lazarus \|
279	215
280	216		The same solution also applies to the exception you can get when referencing Printer.Printers.
281	217
282	218		### When I try to compile a project, I get an error message "Cannot find Unit ..."
283	219
284	220		Please see [[Unit not found - How to find units]]
285	221
286	222		For information on the error "Cannot find unit interfaces", see the next section.
287	223
288	224		### When I try to compile a project, I get an error message "Cannot find Unit interfaces"
289	225
290	226		This error means that the compiler can not find the file 'interfaces.ppu' or the file was found, but it is wrong or outdated (the .ppu file date code is older than the date code of the compiler itself). Testing the compiler option settings can help debug these issues, via Project: Compiler Options... (use the Test button at the bottom of the dialog). This test also lets you check that the {TargetCPU} and {TargetOS} variables are set properly.
291	227
292	228		The interfaces unit can be found in {LazarusDir}\lcl\units\\{TargetCPU}-{TargetOS}\\{LCLWidgetSet}\interfaces.ppu. For example: /home/username/lazarus/lcl/units/i386-linux/gtk/interfaces.ppu.
293	229
294	230		It is normal to have multiple versions of interfaces.ppu (in the proper directories) to allow compiling with different widgets.
295	231
296	232		If the interface.ppu file is in the folder matching the OS and CPU you selected in the project preferences, and you get this error, you are using a different compiler / RTL for compiling your project than you used for compiling your Lazarus IDE, or the libraries need to be recompiled to give the .ppu files newer compilation dates.
297	233
298	234		You can do one of the following:
299	235
300	236		1. Set the compiler in the Environment Options to the one you used to compile Lazarus. Also look carefully in the Environment Options to see if you are using the correct paths for the Lazarus directory and the FPC sources directory. Check that there is only one version of the compiler configuration file fpc.cfg - it should reside in /etc/ for Linux/Unix systems or in the same directory as the fpc compiler for Windows systems. Try to run "fpc -vt bogus" to check which fpc.cfg is being used in your system. Rogue copies often creep in if you have updated your compiler to a new version; they may be found in your home directory or in the same directory as the one in which you built your new compiler. DELETE THESE!
301	237		2. Rebuild the LCL (or Lazarus completely) with the compiler selected in the Environmnent Options. You can do this with Tools -\> Build Lazarus. Before doing this, check the current settings in Tools -\> Configure Build Lazarus.
302	238		3. You may also try to change the widgetset currently selected for the project. For example, the sample project "objectinspector" that comes with Lazarus is set to gtk by default. Compiling this project will surely give you "Can't find unit interfaces" in Windows platform. Changing widgetset to default(Win32) in [[IDE Window: Compiler Options\|Project Options \| Compiler Options...]] should fix this issue.
303	239
304	240		### When I compile a project, that uses a LCL unit, I get a linker error
305	241
306	242		Here is an example for such a linker error:
307	243
308	244		`` /path/to/lazarus/lcl/units/x86_64-linux/wsimglist.o: In function `REGISTERCUSTOMIMAGELIST': ``\
309	245		`` /path/to/lazarus/lcl//widgetset/wsimglist.pp:266: undefined reference to `WSRegisterCustomImageList' ``
310	246
311	247		- Make sure yor project uses the package LCL. You can check this in the project inspector.
312	248		- Make sure unit "interfaces" is used as one of the first units of your program.
313	249
314	250		> Note: These functions are implemented by the LCL backends. By adding the unit interfaces, you link a LCL backend into your program.
315	251
316	252		### At the line :{\$R *.DFM} How can I solve this problem (Lazarus with FPC \< 2.4.0)?
317	253
318	254		Lazarus (or better Linux) doesn't know about resources, so you can't use them in the way Delphi/Win32 does. However Lazarus uses a method pretty compatible with this. You can still use your Delphi layouts (.dfm files) if you use the following steps:
319	255
320		-	- You need a textual version of the .dfm files. D5 and higher are doing this by default. If you have older files: <span class="kbd">Alt</span>+<span class="kbd">F12</span> to see the layout as text and paste/copy. When you have a text .dfm file, just copy it to a .lfm file.
	256	+	- You need a textual version of the .dfm files. D5 and higher are doing this by default. If you have older files: `Alt`+`F12` to see the layout as text and paste/copy. When you have a text .dfm file, just copy it to a .lfm file.
321	257		- Create a file with lazres (in lazarus/tools) lazres yourform.lrs yourform.lfm
322	258		- Add the following initialization section to
323	259
324	260		``` pascal
325	261		initialization
326	262		{$I yourform.lrs}
327	263		```
328	264
329	265		Please keep in mind that not all properties in the dfm are supported yet by Lazarus, so you might get a crash.
330	266
331	267		Edit: Since FPC 2.4.0, Delphi style resources are supported, so you don't need to change anything. Even Lazarus SVN already uses it as default projects. Note: it's still advised that you use Lazarus' Delphi project converter as there might still be unsupported properties.
332	268
333	269		### 'Identifier not found LazarusResources'
334	270
335	271		When creating a form Lazarus automaticaly add some extra units to the uses section of your form unit. During the conversion of a delphi unit to a Lazarus unit this does not happen. So you need to add LResources to the Uses section of your form unit.
336	272
337	273		### When accessing events of objects, e.g., the onclick event of a button, I get the following error. ERROR unit not found: stdCtrls
338	274
339	275		Make sure, in the Project -\> Project Inspector, that your project depends on the package "LCL" and that you have installed the FPC sources.
340	276
341	277		Lazarus is the IDE and the visual components library LCL. All other stuff, like IO, Database, FCL and RTL are provided by FPC. The IDE needs the paths to all sources.
342	278
343	279		The FPC source path can be set via: Environment -\> Environment Options -\> Files -\> FPC source directory
344	280
345	281		### 'Fatal: Internal error XXXXYYZZW'
346	282
347	283		An internal error is a compiler error that is not expected to happen (but is prepared to easily track down the problem if happens by giving code XXXXYYZZW). Every internal error is a bug, thus it's advised to report to the bugtracker (with small example that can demonstrate the internal error) when one gets it.
348	284
349	285		=== Fatal: Cannot find \[...\] used by \[...\], incompatible ppu=\[filename\], package \[package name\] ===
350	286
351	287		When the compiler gives the message "Cannot find A used by B", Lazarus checks what pas/pp/ppu files are in the search path, and if there is a ppu file it inserts "incompatible ppu=filename, package".''
352	288
353	289		Explanation: FPC cannot use this ppu for one of these reasons:
354	290
355	291		- it was compiled with another FPC version;
356	292		- it was compiled with (depends on) some other ppu files that are not in the search path;
357	293		- you misconfigured some search path(s).
358	294
359	295		Without knowing how you installed FPC + Lazarus, I'd be tempted to delete both and start again (make sure to delete the fpc.cfg file).
360	296
361	297		### Lazarus cannot open a project if last character of the path to it is a space
362	298
363	299		If you try to open a project like `/home/bart/space /test.lpi` (note the space just before /test.lpi), the Lazarus IDE will give an error saying it cannot find `/home/bart/space /test.lpi`.
364	300
365	301		This is a known limit of the IDE, which is caused by the fact that the IDE a.o. has to handle paths that users have supplied in edit controls, which have to be stripped from surrounding spaces. This limitation in no way affects user programs written in FPC/Lazarus. Avoid such pathnames for projects.
366	302
367	303		### strToFloat - EConvertError: "0.nnn" is an invalid float
368	304
369	305		The "0.nnn" can be any floating point number. The problem is that your locale settings (eg DE Germany) are expecting a comma to be the decimal separator in numbers and not a decimal point. The solution is to add this to your code: `DefaultFormatSettings.decimalSeparator := '.';` to override your locale's decimal separator. Alternatively, instead of strToFloat and floatToStr, use the Pascal intrinsics val and str - they always need a decimal point.
370	306
371	307		## Debugger
372	308
373	309		See also [[GDB Debugger Tips]].
374	310
375	311		### How do I set up/configure for debugging
376	312
377	313		[[Debugger Setup\|Setup the debugger]]
378	314
379	315		### How can I inspect properties?
380	316
381	317		You have to use FPC 2.4 or newer.
382	318
383	319		If you compile your application using -gw (dwarf debug info), you should be able to inspect properties.
384	320
385	321		> Note: This is only true for properties that map directly to a variable (the "read" declaration points to a member, not a function).
386	322
387	323		If your property returns the value of a function it is very dangerous to evaluate/inspect it. It would require this function to be called, and very often it would change the values of some of your variables. This would mean it would alter the state of your application in the debugger, and any further code-execution, debugging or inspections would return incorrect results.
388	324
389	325		The optional ability to explicitly inspect the results of functions (with the risks described), and therefore calling code from the debugger is not yet implemented
390	326
391	327		### Why does the debugger not show some Variables/Structures ("no such symbol"/"incomplete type")
392	328
393	329		For problems debugging:
394	330
395	331		- properties
396	332		- Array of ... (Dynamic Array)
397	333		- Variables in Nested Procedures
398	334		- "no such symbol in context"
399	335		- "incomplete type"
400	336
401	337		Please see [[GDB Debugger Tips]] and the and [[FpDebug\|FpDebug#Properties]]
402	338
403	339		### How can I debug FCL components from packages with Lazarus
404	340
405	341		FCL components and classes are built without debug information by default and as a result, gdb cannot access component methods or properties. To build package components they must be rebuilt with a debug-line information "-gl" switch.
406	342
407	343		This example assumes you have a Linux distribution with /usr/local/ installation prefix and that the Database package fcl-db is what is needed to contain debug-line information. While the fcl-db is used in this example, you may issue this make command from ANY of the included packages.
408	344
409	345		Before you begin, you need to locate your FPC path by examining your FPC configuration file. The file (fpc.cfg) is located at /etc/fpc.cfg. Display the contents of fpc.cfg and find your fpc installation path. Look for a line starting with -Fu in the fpc.cfg:
410	346
411	347		`-Fu/usr/local/lib/fpc/$fpcversion/units/$fpctarget/*`
412	348
413	349		Make scripts are installing units into INSTALL_PATH/lib/fpc/\$fpcversion/units/\$fpctarget/, so you must be sure that /usr/local is the installation path, and should be assigned to INSTALL_PREFIX, otherwise the Make scripts will place units where they don't belong or the Make script will fail.
414	350
415	351		1. Open a shell terminal
416	352		2. cd /user/local/share/src/fpc-2.3.1/fpc/fcl-db/
417	353		3. sudo make clean all install INSTALL_PREFIX=/usr/local OPT=-gl
418	354
419	355		> Note: INSTALL_PREFIX parameter should be properly configured for units to be installed.
420	356
421	357		In the sample below /usr/local is a default fpc path for Linux, but may vary on other OSes.
422	358
423	359		``` bash
424	360		make clean all install INSTALL_PREFIX=/usr/local OPT=-gl
425	361		```
426	362
427	363		Finally, after rebuilding any FCL units you may want to rebuild LCL as well.
428	364
429	365		### Problems with GDB on Mac
430	366
431	367		Lazarus has now support for lldb on Mac. See [[Installing Lazarus on macOS\|Configuring the lldb debugger]].
432	368
433	369		If you want to use gdb, you can find some info here: [[GDB Debugger Tips\|GDB tips for Mac]]
434	370
435	371		### How can I use a log file for debugging?
436	372
437	373		Lazarus provides a basic log framework (style [[DebugLn\|debugln(...)]] ) in the unit [[LazLogger]]. See that page for more details.
438	374
439	375		### How can I use a Log-file for debugging the IDE itself?
440	376
441	377		Lazarus itself uses [[LazLogger]].
442	378
443	379		This means that you can run Lazarus with
444	380
445	381		``` bash
446	382		--debug-log=lazarusdebuglog.txt
447	383		```
448	384
449	385		If this is not sufficient: in the IDE the extent of the information that is logged can be controlled with `--debug-enable`. See `--help` for a list of keywords, or install the package IdeLazLogger.
450	386
451	387		If you want output on a console (most useful for Windows), add the option -WC in the Tools / Configure "Build Lazarus" options. Then rebuild Lazarus.
452	388
453	389		See also [[Console Mode Pascal\|Console Mode Pascal#Run in IDE with redirected output]]
454	390
455	391		## Contributing / Making Changes to Lazarus
456	392
457	393		### I created a Patch to dock the IDE Messages form on the "Source Code Editor" form (at bottom)
458	394
459	395		Such patches will not be applied, because they only implement a small part of the needed docking. The goal is to create a complete dock manager and use that. A complete dock manager can dock all IDE windows and it allows to let the user define how to dock. For example dock the messages window above or below the source editor — or not at all. For instance,
460	396
461	397		`+-------------------++--+`\
462	398		`\|menu \|\| \|`\
463	399		`+-------------------+\| \|`\
464	400		`+--++---------------+\| \|`\
465	401		`\|PI\|\| Source Editor \|\|CE\|`\
466	402		`+--+\| \|\| \|`\
467	403		`+--+\| \|\| \|`\
468	404		`\| \|+---------------++--+`\
469	405		`\|OI\|+-------------------+`\
470	406		`\| \|\|messages \|`\
471	407		`+--++-------------------+`
472	408
473	409		The dock manager can store the layout and restore it on next load. Preferably the dock manager can dock in pages too. The dock manager does not need to use drag and drop. All patches implementing docking without a dock manager makes it harder to implement a real dock manager and will be rejected.
474	410
475	411		An example for such a dock manager is the package [[anchordockdsgn]]
476	412
477	413		### I have fixed/improved Lazarus. How can I add my changes to the official Lazarus source?
478	414
479	415		Create a patch and send it to the developers. For details, see [[Creating A Patch]].
480	416
481	417		### How can I install more than one copy of Lazarus?
482	418
483	419		Please see [[Multiple Lazarus]]
484	420
485	421		### How can I become a Lazarus developer and access management in the SVN and bug-tracker?
486	422
487	423		First of all, you must learn about Lazarus, to prove your knowledge and skill. Start by reading the [[Lazarus Documentation]] wiki article, read the Lazarus source code, giving a look at the [Lazarus Bug-Tracker](https://gitlab.com/freepascal.org/lazarus/lazarus/-/issues/), fix some bugs, and if you think you are ready, contact the developers on the [mailing list](https://www.mail-archive.com/lazarus@miraclec.com/).
488	424
489	425		## Where is ... defined
490	426
491	427		### Virtual key constants
492	428
493		-	~~Virtual key constants are defined in [[doc:lcl/lcltype\|LCLType]]. Add LCLtype to your <b>uses</b>.~~
	429	+	Virtual key constants are defined in [[doc:lcl/lcltype\|LCLType]]. Add LCLtype to your uses.
494	430
495	431		## Using the IDE
496	432
497	433		### How can I use "identifier completion"?
498	434
499	435		You can invoke identifier completion by pressing \[ctrl\]\[space\]. Under the menu item Environment -\> Editor Options -\> Code Tools -\> Automatic Features you can set how quick this should happen automatically.
500	436
501	437		### Can I change the code editor font and colours?
502	438
503	439		Yes, see the menu item Tools -\> Options and use the Editor/Display and Colors sections. On Windows you may find that the default Courier (and some other typefaces) are either too sharp or too soft, either selecting/deselecting 'Disable anti-aliasing'. TrueType fonts are an improvement, such as the free "Bitstream Vera Sans Mono" font available from [1](https://download.gnome.org/sources/ttf-bitstream-vera/1.10/). (To install a new font, unzip and copy the files into a suitable folder. In Windows XP you will need to use the Fonts section of the Control Panel. In Windows 7 you may select all the font files, right-click and find an Install option in the pop-up menu)
504	440
505	441		### How can I disable specific compiler warning messages?
506	442
507	443		To disable specific compiler warning messages you can either insert a {\$WARN number OFF} directive in your code or use FPC's option -vm\<x\>. You can find details for these in FPC's [Programmer's guide](https://www.freepascal.org/docs.html) and Appendix A of the [User's guide](https://www.freepascal.org/docs.html).
508	444
509	445		### What are the IDE command line options?
510	446
511	447		See [[Lazarus command line options]].
512	448
513	449		## Linux
514	450
515	451		### Typing in edit fields generate duplicate letters
516	452
517	453		This is more likely to happen under Ubuntu and Ubunto derived distros, and with GNOME Desktop but other distros/Desktop environments can be affected too.
518	454
519	455		The problem is originated by bugs in the ibus Input Method System. Unfortunately Ibus is the default input method of GNOME desktop.
520	456
521	457		If you don't know what an IM is, this means that you do not need it, and therefore the easiest way is to disable IM's at all.
522	458
523	459		In order to do that you have a number of options, namely:
524	460
525	461		- 1 - Disable (or set to "none") the Input Method in System Settings-\>Preferences-\>Input Method
526	462
527	463		- 2 - Add the three following lines in /etc/profile (system wide)
528	464
529	465		`export GTK_IM_MODULE=gtk-im-context-simple`\
530	466		`export QT_IM_MODULE=simple`\
531	467		`export XMODIFIERS=@im=none`
532	468
533	469		- 3 - Add a file named input_method.sh containing just the 3 lines above in /etc/profile.d (system wide)
534	470
535	471		- 4 - Add the 3 lines above in the home directory ~/.xprofile (per user). If there's no ~/.xprofile in your home directory, you should create one.
536	472
537	473		- 5 - Create a Lazarus launching script containing the same 3 lines. (affects only Lazarus)
538	474
539	475		Methods 1 and 2 may not survive after a system update, while 3,4 and 5 will.
540	476
541	477		Be aware that both GTK and QT applications may change dynamically the IM. If you experience the problem in an apparently random way, chances are good that some other application is enabling again an IM and fails to set to default when terminates. If such is the case method 5 is the only one suitable.
542	478
543	479		You may find more information about Input Methods, and how to deal with them in:
544	480
545	481		<https://fedoraproject.org/wiki/I18N/InputMethods> (This is Fedora specific but most informations apply in general)
546	482
547	483		<http://www.pinyinjoe.com/linux/ubuntu-12-chinese-setup.htm> (This is Ubuntu specific, but again most informations apply in general. It explains how to enable IM but the info can be used also to disable it)
548	484
549	485		### How can I debug on Linux without the IDE?
550	486
551	487		First of all you need a debugger. gdb is the standard debugger under linux and there are several GUI-frontends available. One common frontend is ddd, which is part of most common distributions. To compile lazarus/lcl with debug-information you should then use the following commands to start a debug session:
552	488
553	489		``` bash
554	490		make clean; make OPT=-dDEBUG
555	491		ddd lazarus
556	492		```
557	493
558	494		Be warned, however, that ddd is not as comfortable as, e.g., the Lazarus debugger, especially if it comes to view the contents of a variable you have to take into account that ddd/gdb are case sensitive whereas Pascal is case-insensitive. Therefore, you have to type all variable names in uppercase to see their contents. For more information see the fpc-manuals.
559	495
560	496		### I can debug now but ddd does not find my sources or complains that they contain no code. What's that?
561	497
562	498		This is a path-related problem with either gdb or ddd. You can avoid this by
563	499
564	500		- Use the "Change directory" command from the ddd menu and choose the directory where the sources are located. The drawback of this method is that you now can't use the source of the program you started with (e.g. lazarus). Thus it may be neccessary to change the directory multiple times.
565	501		- In ddd goto \[Edit\] \[gdb-settings\] and set the search-path
566	502		- Create a \$(HOME)/.gdbinit file like:
567	503
568	504		` directory /your/path/to/lazarus`\
569	505		` directory /your/path/to/lazarus/lcl`\
570	506		` directory /your/path/to/lazarus/lcl/include`
571	507
572	508		### I receive an error during the linking that states /usr/bin/ld: cannot find -l\<some lib\>
573	509
574	510		For example:
575	511
576	512		` /usr/bin/ld: cannot find -lgdk`
577	513
578	514		This means an external library was not found. In the above case under Linux it means the libgdk.so or libgdk.a was not found. Normally this means, you forgot to install the development package of this library. In the case of gdk the package is called under the Fedora Core distribution: 'gtk+-devel-1.2.10-33'.
579	515
580	516		Package Based Distributions
581	517		You need to install the package that provides the lib\<somelib\>.so or lib\<somelib\>.a files. Dynamic libs under linux have the extension .so, while static libs have the extension .a. On some Linux distro's you have installed the package (rpm, deb) \<packagename\> which provides \<some lib\>, but you also need the development package (rpm, deb), normally called \<packagename\>-dev, which contains the .a (static lib) and/or the .so (dynamic lib).
582	518
583	519
584	520		Some distributions have commands to find which package contains a file:
585	521
586	522		Mandriva
587	523
588	524		``` bash
589	525		urpmf lib<somelib>.so
590	526		```
591	527
592	528
593	529		will list all packages containing the file named lib\<somelib\>.so, you'll have to install those ending in -devel
594	530
595	531
596	532		Debian
597	533
598	534
599	535		install the apt-file utility (apt-get install apt-file) then
600	536
601	537		``` bash
602	538		apt-file search lib<somelib>.so
603	539		```
604	540
605	541
606	542		will list all packages containing the file named lib\<somelib\>.so, you'll have to install those ending in -dev
607	543
608	544
609	545		SuSE
610	546
611	547
612	548		SuSE installs the gtk devel libs under /opt/gnome/lib (or /opt/gnome/lib64 for 64 bits), which is not in the standard lib path. Simply add it to your /etc/fpc.cfg. (-Fl/opt/gnome/lib).
613	549
614	550		Source Based Distributions and Manual Compilation (LFS)
615	551		Make sure that there is a lib\<somelib\>.a in the path, and that it contains the right version. To let the linker find the dynamic library, create a symlink called lib\<some lib\>.so to lib\<some lib\>\<version\>-x,y.so if necessary (and/or for static lib; lib\<some lib\>.a to lib\<some lib\>\<version\>-x,y.a).
616	552
617	553
618	554		FreeBSD : As source based distro's, and also make sure you have -Fl/usr/local/lib in your fpc.cfg and/or Lazarus library path. Keep in mind that GTK1.2 has "gtk12" as package name under FreeBSD. (same for glib) NOTE: This has changed as of late. Newest ports have gtk-12 and glib-12 as well. You might stumble on this problem, since FPC requires the "-less" ones, you will need to symlink them like this:
619	555
620	556		``` bash
621	557		# as root
622	558		cd /usr/local/lib && ln -s libglib-12.so libglib12.so
623	559		cd /usr/X11R6/lib && ln -s libgtk-12.so libgtk12.so
624	560		cd /usr/X11R6/lib && ln -s libgdk-12.so libgdk12.so
625	561		```
626	562
627	563
628	564		NetBSD : As source based distro's, and also make sure you have -Fl/usr/pkg/lib in your fpc.cfg and/or Lazarus library path
629	565
630	566
631	567		Fedora : In the "add/remove software" panel search for: "gtk2-devel", "glibc-devel" ([see here](https://www.mail-archive.com/lazarus@lists.lazarus.freepascal.org/msg03637.html)), "libx11-devel"
632	568
633	569		### I receive a warning during the linking that states: Warning: "crtbeginS.o" (or "crtendS.o") not found
634	570
635	571		The actual filename may also be "crtbegin.o" or "crtend.o"\
636	572		In most cases linking will not fail.\
637	573		Here's how to find where that file is (you need to have gcc installed, and gcc needs to target the same architecture as fpc), and tell the fpc (which tells the linker):
638	574
639	575		``` bash
640	576		bart@simenon ~ $ gcc --print-file-name crtbeginS.o
641	577		/usr/lib/gcc/x86_64-linux-gnu/5/crtbeginS.o
642	578		```
643	579
644	580		Add the path into fpc.cfg:
645	581
646	582		`# path to the gcclib`\
647	583		`#ifdef cpui386`\
648	584		`#-Fl/usr/lib/gcc/x86_64-linux-gnu/5 if you have a 32-bit fpc: fill in the correct path here`\
649	585		`#endif`\
650	586		`#ifdef cpux86_64`\
651	587		`-Fl/usr/lib/gcc/x86_64-linux-gnu/5`\
652	588		`#endif`
653	589
654	590		Note: On Linux the default (external) linker is ld. This is part of the linux distribution and not part of, or built with, FreePascal.
655	591
656	592		### How can I convert a Kylix 2 project into a Lazarus project?
657	593
658	594		Nearly the same way as converting a Kylix project into a Delphi/VCL project.
659	595
660	596		The LCL (Lazarus Component Library) tries to be compatible to Delphi's VCL. Kylix's CLX tries to be QT compatible. Here are some general hints:
661	597
662	598		- Rename all used CLX Q-units like QForms, QControls, QGraphics, ... into their VCL counterparts: Forms, Controls, Graphics, ...
663	599		- Add LResources to the uses section of every form source
664	600		- Rename or copy all .xfm files to .lfm files.
665	601		- Rename or copy .dpr file to .lpr file.
666	602		- Add "Interfaces" to the uses section in the .lpr file.
667	603		- Remove {\$R *.res} directive
668	604		- Remove {\$R *.xfm} directive
669	605		- Add {\$mode objfpc}{\$H+} or {\$mode delphi}{\$H+} directive to .pas and .lpr files
670	606		- Add an initialization section to the end of each form source and add an include directive for the .lrs file (Lazarus resource file):
671	607
672	608		``` pascal
673	609		initialization
674	610		{$I unit1.lrs}
675	611		```
676	612
677	613
678	614		The .lrs files can be created via the lazres tool in: (lazarusdir)/tools/lazres.
679	615
680	616		For example: ./lazres unit1.lrs unit1.lfm
681	617
682	618		- Fix the differences. The LCL does not yet support every property of the VCL and the CLX is not fully VCL compatible.
683	619
684	620		- To make it more platform independent, reduce unit libc (which is deprecated) references and substitute with native FPC units like baseunix/unix as much as possible. This will be necessary to support other targets than linux/x86 (including macOS, FreeBSD and Linux/x86_64)
685	621
686	622		### When compiling lazarus the compiler can not find a unit. e.g.: gtkint.pp(17,16) Fatal: Can't find unit GLIB
687	623
688	624		1\. Check a clean rebuild: do a 'make clean all'
689	625
690	626		2\. Check if the compiler has the correct version (2.0.4 or higher)
691	627
692	628		3\. Check if the compiler is using the right config file. The normal installation creates /etc/fpc.cfg. But fpc also searches for ~/.ppc386.cfg, ~/.fpc.cfg, /etc/ppc386.cfg and it uses only the first it finds.
693	629
694	630
695	631		Hint: You can see which config file is used with 'ppc386 -vt bogus'
696	632
697	633		Remove any ppc386.cfg as it is really obsolete.
698	634
699	635		4\. Check if the config file (/etc/fpc.cfg) contains the right paths to your fpc libs. There must be three lines like this:
700	636
701	637		` -Fu/usr/lib/fpc/$fpcversion/units/$fpctarget`\
702	638		` -Fu/usr/lib/fpc/$fpcversion/units/$fpctarget/rtl`\
703	639		` -Fu/usr/lib/fpc/$fpcversion/units/$fpctarget/*`
704	640
705	641
706	642		The first part of these paths (/usr/lib/fpc) depends on your system. On some systems this can be for example /usr/local/lib/fpc/... .
707	643
708	644		Hint: You can see your searchpaths with 'ppc386 -vt bogus'
709	645
710	646		5\. Check that the config file (/etc/fpc.cfg) does not contain search paths to the lcl source files (.pp, .pas):
711	647
712	648		` forbidden: -Fu(lazarus_source_directory)/lcl`\
713	649		` forbidden: -Fu(lazarus_source_directory)/lcl/interfaces/gtk`
714	650
715	651
716	652		If you want to add the lcl for all your fpc projects, make sure that the two paths look like the following and are placed after the above fpc lib paths:
717	653
718	654		` -Fu(lazarus_source_directory)/lcl/units/$fpctarget`\
719	655		` -Fu(lazarus_source_directory)/lcl/units/$fpctarget/gtk`
720	656
721	657		6\. Check if the missing unit (glib.ppu) exists in your fpc lib directory. For example the gtk.ppu can be found in /usr/lib/fpc/\$fpcversion/units/i386-linux/gtk/. If it does not exists, the fpc lib is corrupt and should be reinstalled.
722	658
723	659		7\. Check if the sources are in a NFS mounted directory. In some cases the NFS updates created files incorrectly. Please, try to move the sources into a non NFS directory and compile there.
724	660
725	661		8\. If you are still not succeeded try to use samplecfg script as follows:
726	662
727	663		\# cd /usr/lib/fpc/version/
728	664
729	665		\# sudo ./samplecfg /usr/lib/fpc/\\\$version /etc
730	666
731	667		> Note: Do not a slash ("/") after etc, because if you do, the system will create a folder `/etc/fpc.cfg/fpc.cfg`. In fact, we want samplecfg to make a file `/etc/fpc.cfg`, not the folder `/etc/fpc.cfg`.
732	668
733	669		### I have installed the binary version, but when compiling a simple project, Lazarus gives: Fatal: Can't find unit CONTROLS
734	670
735	671		Probably you are using a newer fpc package, than that used for building the lazarus binaries. The best solution is to download the sources and compile lazarus manually. You can download the source snapshot or get the source via svn:
736	672
737	673		``` bash
738	674		bash
739	675		svn checkout http://svn.freepascal.org/svn/lazarus/trunk lazarus
740	676		cd lazarus
741	677		make clean all
742	678		```
743	679
744	680		Make sure that Lazarus get the new source directory: Environment-\>General Options-\>Files-\>Lazarus Directory Top
745	681
746	682		### Lazarus compiles, but linking fails with: libgdk-pixbuf not found
747	683
748	684		Install the gdk-pixbuf library for gtk1.x:
749	685
750	686		Where to find the gdk-pixbuf library:
751	687
752	688		RPMs: <https://rpmfind.net/linux/rpm2html/search.php?query=gdk-pixbuf&submit=Search+>...&system=&arch=
753	689
754	690		Debian packages: libgdk-pixbuf-dev
755	691
756	692		Sources: <ftp://ftp.gnome.org/pub/gnome/unstable/sources/gdk-pixbuf/>
757	693
758	694		Ubuntu 8.10:
759	695
760	696		If you are compiling Lazarus with GTK 2.0 you'll get a "libgdk-pixbuf2.0" not found error. Just install libgtk2.0-dev using apt on this way:
761	697
762	698		``` bash
763	699		apt-get install libgtk2.0-dev
764	700		```
765	701
766	702		### I have SuSE and I get /usr/bin/ld: cannot find -lgtk Error: Error while linking
767	703
768	704		Older SuSE versions (before SuSE 11) install the gtk devel libs under /opt/gnome/lib (or /opt/gnome/lib64 for 64 bits), which is not in the standard lib path. Simply add it to your /etc/fpc.cfg (-Fl/opt/gnome/lib).
769	705
770	706		### I have Kubuntu and I get /usr/bin/ld: cannot find -lgtk-x11-2.0
771	707
772	708		You can either use the QT or the GTK2 backend. Default is GTK2. For GTK2 install the kubuntu package libgtk2.0-dev.
773	709
774	710		### Lazarus crashes with runtime error 211 after I installed a component
775	711
776	712		After I installed a component, Lazarus crashes with the following message:
777	713
778	714		`Threading has been used before cthreads was initialized.`\
779	715		`Make cthreads one of the first units in your uses clause.`\
780	716		`Runtime error 211 at $0066E188`
781	717
782	718		How can I fix this?
783	719
784	720		Your freshly installed component is using threads. FPC on *nix doesn't automatically include threading support, but it must be intialized. This initialization is done in the cthreads unit. Every application using the component needs to add this unit to the uses clause of the main program. Lazarus itself is no exception. This can be done in two ways:
785	721
786	722		1\) Open the package. In the package editor click on Options. Under page Usage add to the custom options -dUseCThreads. Then rebuild the IDE. This way the cthreads unit will be automatically used by the IDE under unix and the cthreads are initialized.
787	723
788	724		2\) In order to avoid modifying package, an FPC compiler option could be used directly. Open menu Tools-\>Configure "build Lazarus". "Configure build Lazarus" dialog will be shown; in field "Options:" type `-Facthreads` and then press "OK" button. The next step is to install the package. Lazarus will be built with option -Facthreads which means that it will treat main program as if unit cthreads where first in uses clause.
789	725
790	726		Hint: Maybe your old (non-crashing) Lazarus executable is stored as lazarus.old in the same directory as the crashing Lazarus executable.
791	727
792	728		See also [[Multithreaded Application Tutorial\|Multithreaded Application Tutorial#Units needed for a multithreaded application]]
793	729
794	730		### When I run a program with threads I get runtime error 232
795	731
796	732		The complete error message is:
797	733
798	734		`This binary has no thread support compiled in.`\
799	735		`Recompile the application with a thread-driver in the program uses`\
800	736		`clause before other units using thread.`\
801	737		`Runtime error 232`
802	738
803	739		Solution: Add cthreads as first unit to the uses clause of your main program, usually the .lpr-file.
804	740
805	741		### I have Ubuntu Breezy/Mandriva KDE3 and my fonts in Lazarus IDE look too big
806	742
807	743		If Lazarus is compiled with Gtk1.2, the settings in Gnome Preferences/Font don't have any effect as they are related to Gtk2. You could try this solution: Create a file named .gtkrc.mine in your home directory (if it's not already there) and add these lines to it:
808	744
809	745		`style "default-text" {`\
810	746		` fontset = "--arial-medium-r-normal---100-----iso8859-1,\`\
811	747		` --helvetica-medium-r-normal---100------"`\
812	748		`}`\
813		-	\
	749	+
814	750		`class "GtkWidget" style "default-text"`
815	751
816	752		If this is not enough try and create also a .gtkrc symlink to .gtkrc.mine . It worked in this way under Xubuntu 7.10, Mandriva 2009.0 KDE3.
817	753
818	754		### How can my gtk programs use custom rc files?
819	755
820	756		Option a) Name the rc file yourprogram.gtkrc and put it in the same directory where the executable is.
821	757
822	758		Option b) Use unit GtkInt and call GTKWidgetSet.SetRCFilename('your_preferred_rc_file'); Best done before Application.Initialize in the .lpr file with {\$IFDEF LCLGtk}.
823	759
824	760		Option c) Use unit gtk2 and call gtk_rc_parse('your_rc_file')); and gtk_rc_reparse_all;.
825	761
826	762		### I have Ubuntu and I cannot compile for Gtk2 due to missing libraries
827	763
828	764		Ubuntu has a problem with not creating all the symbolic links that you'll need even when the libraries are installed. Make sure that all missing libraries when trying to link for Gtk2 have their appropriate links. For instance, you might need to do:
829	765
830	766		``` bash
831	767		cd /usr/lib
832	768		sudo ln -s libgdk-x11-2.0.so.0 libgtk-x11-2.0.so
833	769		```
834	770
835	771		Make sure that the \[whatever\].so symbolic links are created and point to the actual libraries.
836	772
837	773		### Lazarus runs differently with Linux vs. Windows. What do I need to know?
838	774
839	775		If you use readln(); and writeln(); for your input and output the console window (sometimes called terminal window) is not going to pop up as it does with Windows. You will need to access this window with View - Debug Windows - Terminal Output. Unlike with Windows you can not use backspace to correct typing errors. The 'Enter' key on the numeric keypad may not work either, depending on the widgetset the IDE was built for. Type carefully!
840	776
841	777		Because Linux is case sensitive you will need to take care that you pay attention to case when referencing or accessing files.
842	778
843	779		## Windows
844	780
845	781		### When I cycle/rebuild the compiler, I get
846	782
847	783		#### The name specified is not recognized as an internal or external command, operable program or batch file.\>& was unexpected at this time
848	784
849	785		In the compiler directory there is an OS2 scriptfile named make.cmd. Different versions of Windows also see this as a script file, so remove it since what is needed for OS2 becomes a hindrance on Windows.
850	786
851	787		#### make\[3\]: ./ppc1.exe: Command not found
852	788
853	789		Somehow make has lost its path (reason unknown). Try to cycle with a basedir set like:
854	790
855	791		```dos
856	792		make cycle BASEDIR=your_fpc_source_dir_herecompiler
857	793		```
858	794
859	795		### When I try to make Lazarus I get:
860	796
861	797		#### make.exe: * * * interfaces: No such file or directory (ENOENT). Stop.make.exe: * * * \[interfaces_all\] Error 2
862	798
863	799		You need to upgrade your make.
864	800
865	801		#### makefile:27: *** You need the GNU utils package to use this Makefile. Stop.
866	802
867	803		Make sure you didn't install FPC in a path with spaces in the name. The Makefile doesn't support it.
868	804
869	805		### How can I give my program an XP look like Lazarus has?
870	806
871	807		Project -\> Project Options -\> Check 'Use manifest to enables themes'.
872	808
873	809		### When I run Windows program created in Lazarus it starts with a DOS window
874	810
875	811		Specify the -WG argument (Windows GUI) on the command line of the compiler or in the Lazarus IDE check the Windows GUI check box on the compiler options dialog box (Project menu -\> Compiler Options -\> Config and Target -\> target OS Specific options.
876	812
877	813		## macOS
878	814
879	815		### Why does compiling a project fail with 'unknown section attribute: no_dead_strip'?
880	816
881	817		Dead code stripping is not supported by the assembler and linker before Xcode 1.5 (available for macOS 10.3.9). Disable the compiler options:
882	818
883	819		- Code \> Unit style \> Smart linkable (-CX)
884	820		- and Linking \> Link Style \> Link smart (-XX)
885	821
886	822		### Xcode 3.1 and later
887	823
888	824		The macOS linker in Xcode 3.1 (2007, Leopard 10.5) and later does not support stripping the symbol table attached to the output of the assembler and link editor. The linker supported stripping, for 32 bit executables only, up to Xcode 2.5 (2005, Tiger 10.4).
889	825
890	826		You will need to manually run the strip command line utility instead after compiling your executable.
891	827
892	828		### Debugging
893	829
894	830		[[GDB Debugger Tips\|Please see here for debugger issues under macOS]]
895	831
896	832		## Licensing
897	833
898	834		### Can I make commercial applications with Lazarus?
899	835
900	836		Yes, the LCL is licensed under the [[FPC modified LGPL\|LGPL with an exception]], which allows you to link to it statically without releasing the source of your application. Modifications and enhancements to the LCL must be distributed with source. Lazarus, the IDE, is licensed under the GPL. The LCL consists only of the code in the directory named "lcl", other code may not be covered by this statement.
901	837
902	838		### Why are some components restricted from usage in commercial application?
903	839
904	840		Lazarus comes with additional components, that were developed by third parties. Those are under various other Licenses. If you wish to use them you need to see the License within the source files of those packages. Most of those 3rd party components are in the directory "components".
905	841
906	842		### How do I know if a Component is part of the LCL?
907	843
908	844		All LCL units are in the directory "lcl". A list of units belonging to the LCL can be found [here](https://lazarus-ccr.sourceforge.io/docs/lcl/). If your code uses units not listed on this page, you may have used a component that is not part of the LCL.
909	845
910	846		### Can I make commercial plug-ins for Lazarus?
911	847
912	848		Yes, the IDEIntf part of the IDE is licensed under the LGPL with the same exception, so that shared data structures in this part will not force you to license your plug-in or design-time package under the GPL. You are free to choose a plug-in of any license; we don't want to limit your choice. Therefore non-GPL compatible plug-ins are allowed. Note that it's not allowed to distribute a precompiled Lazarus with these non-GPL-compatible plugins included statically; however, we do not see this as a severe limitation, since recompiling Lazarus is easy.
913	849
914	850		## Using the Forum
915	851
916	852		### What is the correct way to ask questions in the forum?
917	853
918	854		First and most important: always mention which Lazarus version, Free Pascal version, Widgetset, CPU Architecture and Operating System (with full version) that you are using! Don't just say that you are using "the latest version"; please state the exact version number. For snapshots, the revision number and/or date are also important.
919	855
920	856		When asking a programming question, always try to include some source code which demonstrates the problem. Please surround your code with \[code=pascal\]...\[/code\] tags (or use the Insert code button in the forum post editor toolbar). You can attach complete programs as zip files if you want. Use Lazarus/Project/Publish Project to help with that.
921	857
922	858		If you get an error on your code, always specify what the error is. Simply copying what the compiler / debugger / your program said should be enough in most cases. If the error happens at runtime, use -gl and disable function inlining when compiling so your program can generate a proper backtrace.
923	859
924	860		Often an image is also very useful. You can host images in <https://imageshack.com/> and other similar websites and then post a link.
925	861
926	862		Try to provide both a high-level overview of the problem (what goal you want to achieve) as well as a more detailed view of the problem ('''how are you trying to achieve your goal'. Often, there is a much easier way of getting things done that you may not know about.
927	863
928	864		Finally, make sure you have searched/read the relevant documentation (e.g. the [[FPC documentation]] and Lazarus wiki, see e.g. [[Lazarus Documentation]]. You should also [search the forums](https://forum.lazarus.freepascal.org/index.php?action=search): other people with may already have found solutions to similar problems. If you indicate you have already done a bit of homework, people will in general be much more willing to help.
929	865
930	866		For more tips about asking questions the smart way, read this: <http://catb.org/esr/faqs/smart-questions.html>
931	867
932	868		See also: [[Forum\|How to use the forum]]
933	869
934	870		## Version numbering
935	871
936	872		See the [[Version Numbering]] page for an explanation of the branching and version numbering of Lazarus.
937	873
938	874		## Problems/issues with old Lazarus/FPC versions
939	875
940	876		Issues with old Lazarus/FPC versions and notes about upgrading are covered below.
941	877
942	878		Often, the best solution is to upgrade; please see the various [Release Notes](/wiki-category/Release%20Notes)
943	879
944	880		### Why is the linking so slow on Windows (Lazarus \< 0.9.24)?
945	881
946	882		> Note: This problem was fixed in FPC 2.2 and Lazarus 0.9.24. Please update your Lazarus if you can. For older versions read text below.
947	883
948	884		Generally speaking, compilation on Windows takes more time then other platforms because the GNU Linker utilized by Free Pascal is slow on this platform. This problem only affects Windows, and is only bad on relatively old computers (less then 1Ghz) and computers with little RAM (128MB or less).
949	885
950	886		Also, if you smartlink LCL the linking will be much slower. A study about this is located here: [[File size and smartlinking]]
951	887
952	888		Starting from FPC 2.2, an internal linker is used which decreases the linking time dramatically.
953	889
954	890		### Old Lazarus does not support Windows-style resources; converting lrs resources
955	891
956	892		Older versions of FPC (and Lazarus based on it) don't support Windows (.rc/.res) resources, but only LRS files (Lazarus Resource files). See [[Lazarus Resources]] Since 0.9.30 Lazarus can use fpc resources. That means you can delete the lrs files for forms and replace the include directives `{$I unit1.lrs}` with `{$R *.lfm}`.
957	893
958	894		### Antivirus
959	895
960	896		Excluding the Lazarus directory (and the directory/directories where your project/projects are) from on access virus scanning may help there.
961	897
962	898		## See also
963	899
964	900		- [[Mac Installation FAQ]] for macOS.
965	901		- [[Unit not found - How to find units]] information on what to do when you get "unit not found" messages.
966	902
967	903		---
968	904		From the Free Pascal wiki, page "Lazarus FAQ", as it stood on 2023-07-15 after a change by JuhaManninen, out of the wiki's dump of 2024-05-26. Copyright stays with the author who wrote it, according to the old wiki's [[Licensing]] page. If you have concerns about this material, [message the admin](/wiki-contact).
969	905		Category: FAQs
970	906		Category: Lazarus
971	907		Category: Troubleshooting

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