Code::Blocks - User contributions [en]

FAQ-Compiling (errors)

2011-12-08T21:53:13Z

Zabzonk: /* Q: My simple C++ program throws up lots of errors - what's going on? */

[[Category:Code::Blocks Documentation]]
__TOC__
Return to '''[[FAQ]]'''.

----

==== Q: My simple C++ program throws up lots of errors - what is going on? ====

If you have a C++ program like this:

#include <iostream>
int main() {
std::cout << "hello world\n";
}

and when you compile it you get errors like this:

fatal error: iostream: No such file or directory

then you have probably given your source file a .c extension. If you do that, the GCC compiler (and others) will probably attempt to compile the file as a C program, not as C++. You should always give your C++ source files the extension .cpp to make sure the compiler handles them correctly.

==== Q: How do I troubleshoot a compiler problem? ====

'''A:''' I would start by turning on full Compiler logging.

This is done by selecting the "Full command line" option Under menu "Settings" -> "Compiler and Debugger" -> Global compiler settings -> [the compiler you use] -> "Other Setting" tab, "Compiler logging".

This option will make Code::Blocks output the exact commands it uses to compile your code.

Things to remember:

* You should review all the commands and their options;
* If you don't know what an option or a command does please read the documentation for the compiler/linker you're using;
* Look for missing commands;
* For every source file (<tt>.cpp</tt>; <tt>.c</tt>; <tt>.d</tt>; etc) in your project, you must have at least one command in the log. This command must produce an object file (file extension <tt>.o</tt> if using gcc/g++ and <tt>.obj</tt> if using Visual Studio);
* Every object file should be linked in the final executable, if not there are undefined symbols errors;
* Remember the file extension matters: <tt>*.c</tt> is compiled as C file, <tt>*.cpp</tt> is compiled as C++ file. [http://www.parashift.com/c++-faq-lite/mixing-c-and-cpp.html Read more]

==== Q: I imported a MSVCToolkit project/workspace, but Code::Blocks insists on trying to use GCC. What's wrong? ====

'''A:''' A little documentation problem ^^;. The "default compiler" is usually GCC, so when you imported it with "the default compiler", you told it to use GCC. To fix this situation, go to "Project", "Build Options" and select VC++ Toolkit as your compiler.

Another possibility is to put the Microsoft compiler as the default one. To do this, choose '''''Settings - Compiler''''', choose the Microsoft compiler in the '''''Selected Compiler''''' section (top of dialog box) and press the '''''Set as default''''' button.

From now onwards, for all new projects the Microsoft compiler will be taken by default.

==== Q: When compiling a wxWidgets project, I get several "variable 'vtable for xxxx' can't be auto-imported". What's wrong? ====

'''A:''' You need to add WXUSINGDLL in "Project->Build options->Compiler #defines" and rebuild your project (or create a new project and use the "Using wxWidgets DLL" project option which adds "-DWXUSINGDLL" to Project->Build options->Other options).
Other errors with the same resolution are:
'unresolved external symbol "char const * const wxEmptyString" (?wxEmptyString@@3PBDB)' or similar.
If you were using 1.0-finalbeta and were trying to build a statically linked wxWidgets project, the cause of the problem was some faulty templates. But that's fixed now.

==== Q: I can't compile a multithreaded app with VC Toolkit! Where are the libraries? ====

'''A:''' Sorry, no fix for your problem...

Your problem doesn't come from CodeBlocks. It exists, because the free VC toolkit (VCTK) doesn't provide all the libraries and tools which come with Visual C++ (VC) which isn't free, unfortunately.

Try buying a full-fledged VC++, or even better, download [http://www.mingw.org/ MinGW]

The libraries that can be obtained free of charge are:

Paths:
(VCT3) Visual C++ Toolkit 2003 - C:\Program Files\Microsoft Visual C++ Toolkit 2003\lib
(PSDK) Platform SDK - C:\Program Files\Microsoft Platform SDK\Lib
(NSDK) .NET 1.1 SDK - C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\lib

C runtime libs:
LIBC.LIB Single-threaded, static link (VCT3, NSDK)
LIBCMT.LIB Multithreaded, static link (VCT3, NSDK)
MSVCRT.LIB Multithreaded, dynamic link (import library for MSVCR71.DLL) (NSDK)
LIBCD.LIB Single-threaded, static link (debug) (VCT3, NSDK)
LIBCMTD.LIB Multithreaded, static link (debug) (NSDK)
MSVCRTD.LIB Multithreaded, dynamic link (import library for MSVCR71D.DLL) (debug) (NSDK)

C++ libs:
LIBCP.LIB Single-threaded, static link (VCT3, PSDK)
LIBCPMT.LIB Multithreaded, static link (VCT3)
MSVCPRT.LIB Multithreaded, dynamic link (import library for MSVCP71.dll) (none)
LIBCPD.LIB Single-threaded, static link (debug) (VCT3)
LIBCPMTD.LIB Multithreaded, static link (debug) (none)
MSVCPRTD.LIB Multithreaded, dynamic link (import library for MSVCP71D.DLL) (debug) (none)

Try setting the library linker directories to:
C:\Program Files\Microsoft Visual C++ Toolkit 2003\lib
C:\Program Files\Microsoft Platform SDK\Lib
C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\lib
in that order.

The ones listed as (none) above are actually present in the IA64 and AMD64 subdirectories of the PSDK lib directory. Not sure if these would work on 32-bit windows, however, they may if they are
meant to work in 32-bit compatibility mode on the 64-bit processors. Worth a try. Otherwise, you
can link statically to the C++ library instead of using MSVCP71.dll. If you really want to link against MSVCP71.dll you can try to create MSVCP71.LIB from the dll using lib.exe and sed. Search google for "exports.sed" for detailed steps.

See also: [http://wiki.tcl.tk/2435 tclsh script to extract import .lib from (any?) DLL (MinGW)]

See also: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vclib/html/_crt_c_run.2d.time_libraries.asp

See also: http://sapdb.2scale.net/moin.cgi/MS_20C_2b_2b_20Toolkit

==== Q: I get this error when compiling: Symbol "isascii" was not found in "codeblocks.dll" ====

'''A:''' Make sure you didn't mix up the MSVC headers or libs with the MinGW ones.

==== Q: My build fails with multiple ''undefined reference'' errors? ====

''Example:''
undefined reference to `WSACleanup@8
undefined reference to `WSACleanup@0

'''A:''' Most of the time it is because the required library is not linked with your project. Go to ''Project->Build options...->Linker settings (tab)'' and add the required library or libraries.

If the error includes a line number, it is likely that this is a problem with your code. Track down down your function declarations and implementations. Ensure they all match up, are spelled correctly, and have the correct scope resolution.

==== Q: My build fails in the compile/link/run step with a ''Permission denied'' error? ====

'''A:''' There are several possible causes for this:

# The output directory does not have read/write access.
#* Either change control settings on the output directory, or move the project to different location.
# A previous instance of the executable failed to terminate properly.
#* Open your system's equivalent of Process/Task Manager, search the list for the name of the executable Code::Blocks is trying to output, and terminate it.
#* Logging off or rebooting will achieve the same effect.
# The executable is open.
#* If the executable is open in a hex-editor or actively being run, close it.
# Security software is interfering.
#* The target file is locked while an antivirus programming is scanning it; either wait a few seconds for the antivirus scan to finish, set an exception in the antivirus settings, or (temporarily) disable the antivirus program.
#* Firewalls with very strict settings sometimes block execution; try reducing the firewall's settings or adding an exception.
#* Switching security software may have left traces behind that are interfering; hunt down the remnants of the old antivirus/firewall software and remove them.
# The file/library cannot be found.
#* Double check all of the compiler and linker [[FAQ-Compiling (general)#Q: I would like to compile a project using some non-standard libraries. How can I indicate to CodeBlocks that these libraries and include files exist?|search directories]] (including any [[Global compiler variables|variables]] they may be using) are properly setup.
# Code::Blocks was improperly installed.
#* Mixing binaries from a stable release and a nightly build (or even two different nightly builds) is highly likely to cause a slew of problems; [[Installing Code::Blocks|reinstall Code::Blocks]] in an empty directory.
# Multiple installed compilers are interfering with each other.
#* If they are not required to keep, completely remove all but the most used compiler.
#* If several compilers are required, ensure that '''none''' of them are in the ''system'' path (this is so that Code::Blocks will be able to manage all paths).
#* Also, do not place any compilers in their default installation path (for example <tt>C:\MinGW</tt>), as some compilers are hard-coded to look for headers in a default path ''before'' searching their own respective directories.

----

Return to '''[[FAQ]]'''.

FAQ

2011-12-08T21:52:32Z

Zabzonk: /* Compiling (errors) */

[[Category:Code::Blocks Documentation]]

== [[FAQ-General|General]] ==

* '''[[FAQ-General#Q: What is Code::Blocks?|What is Code::Blocks?]]'''
* '''[[FAQ-General#Q: What Code::Blocks is not?|What Code::Blocks is not?]]'''
* '''[[FAQ-General#Q: What license is Code::Blocks released under?|What license is Code::Blocks released under?]]'''
* '''[[FAQ-General#Q: Is it possible to integrate the win32-help as in dev-cpp, to get help on the items under the caret?|Is it possible to integrate the win32-help as in dev-cpp, to get help on the items under the caret?]]'''

== [[FAQ-Compiling (general)|Compiling (general)]] ==

* '''[[FAQ-Compiling (general)#Q: What compiler can I use with Code::Blocks?|What compiler can I use with Code::Blocks?]]'''
* '''[[FAQ-Compiling (general)#Q: My project should be compiled with a custom makefile. Is it possible with Code::Blocks?|My project should be compiled with a custom makefile. Is it possible with Code::Blocks?]]'''
* '''[[FAQ-Compiling (general)#Q: I have downloaded MS VC++ Toolkit 2003 for a compiler. How do I tell Code::Blocks that it is my compiler?|I have downloaded MS VC++ Toolkit 2003 for a compiler. How do I tell Code::Blocks that it is my compiler?]]'''
* '''[[FAQ-Compiling (general)#Q: Microsoft calls MSVCRT.DLL a "Known DLL." How do I know if I can/should use it?|Microsoft calls MSVCRT.DLL a "Known DLL." How do I know if I can/should use it?]]'''
* '''[[FAQ-Compiling (general)#Q: How can I use a DLL without DEF or LIB files?|How can I use a DLL without DEF or LIB files?]]'''
* '''[[FAQ-Compiling (general)#Q: Where are the libraries for the OpenGL, Ogre3D, SDL, QT, wxWidgets etc. projects?|Where are the libraries for the OpenGL, Ogre3D, SDL, QT, wxWidgets etc. projects?]]'''
* '''[[FAQ-Compiling (general)#Q: Is it possible to use Visual C++ 6.0 with Code::Blocks?|Is it possible to use Visual C++ 6.0 with Code::Blocks?]]'''
* '''[[FAQ-Compiling (general)#Q: I would like to compile a project using some non-standard libraries. How can I indicate to CodeBlocks that these libraries and include files exist?|I would like to compile a project using some non-standard libraries. How can I indicate to CodeBlocks that these libraries and include files exist?]]'''
* '''[[FAQ-Compiling (general)#Q: How do I use both Debug and Release builds of wx libraries?|How do I use both Debug and Release builds of wx libraries?]]'''
* '''[[FAQ-Compiling (general)#Q: How do I add version information to windows executables and dll's?|How do I add version information to windows executables and dll's?]]'''
* '''[[FAQ-Compiling (general)#Q: Code::Blocks does not force relink if the library is changed?|Code::Blocks does not force relink if the library is changed?]]'''
* '''[[FAQ-Compiling (general)#Q: How do I report a compilation problem on the forums?|How do I report a compilation problem on the forums?]]'''
* '''[[FAQ-Compiling (general)#Q: All of the Build related options are grayed out?|All of the Build related options are grayed out?]]'''

== [[FAQ-Compiling (errors)|Compiling (errors)]] ==

* '''[[FAQ-Compiling (errors)#Q: My simple C++ program throws up lots of errors - what is going on?|Q: My simple C++ program throws up lots of errors - what is going on?]]'''
* '''[[FAQ-Compiling (errors)#Q: How do I troubleshoot a compiler problem?|How do I troubleshoot a compiler problem?]]'''
* '''[[FAQ-Compiling (errors)#Q: I imported a MSVCToolkit project/workspace, but Code::Blocks insists on trying to use GCC. What's wrong?|I imported a MSVCToolkit project/workspace, but Code::Blocks insists on trying to use GCC. What's wrong?]]'''
* '''[[FAQ-Compiling (errors)#Q: When compiling a wxWidgets project, I get several "variable 'vtable for xxxx' can't be auto-imported". What's wrong?|When compiling a wxWidgets project, I get several "variable 'vtable for xxxx' can't be auto-imported". What's wrong?]]'''
* '''[[FAQ-Compiling (errors)#Q: I can't compile a multithreaded app with VC Toolkit! Where are the libraries?|I can't compile a multithreaded app with VC Toolkit! Where are the libraries?]]'''
* '''[[FAQ-Compiling (errors)#Q: I get this error when compiling: Symbol "isascii" was not found in "codeblocks.dll"|I get this error when compiling: Symbol "isascii" was not found in "codeblocks.dll"]]'''
* '''[[FAQ-Compiling (errors)#Q: My build fails with multiple undefined reference errors?|My build fails with multiple ''undefined reference'' errors?]]'''
* '''[[FAQ-Compiling (errors)#Q: My build fails in the compile/link/run step with a Permission denied error?|My build fails in the compile/link/run step with a ''Permission denied'' error?]]'''

== [[FAQ-Settings|Settings]] ==

* '''[[FAQ-Settings#Q: How do I get Code Completion to work?|How do I get Code Completion to work?]]'''
* '''[[FAQ-Settings#Q: How do I make Code::Blocks portable?|How do I make Code::Blocks portable?]]'''
* '''[[FAQ-Settings#Q: Code::Blocks option xyz is missing?|Code::Blocks option ''xyz'' is missing?]]'''

== [[FAQ-Issues and Workarounds|Issues and Workarounds]] ==

* '''[[FAQ-Issues and Workarounds#Q: Sometime, in the text editor, space bar triggers Code Completion, how do I fix that?|Sometime, in the text editor, space bar triggers Code Completion, how do I fix that?]]'''
* '''[[FAQ-Issues and Workarounds#Q: IDE is drawing the text from Right to Left?|IDE is drawing the text from Right to Left?]]'''
* '''[[FAQ-Issues and Workarounds#Q: All the options in the debug menu are grayed out?|All the options in the debug menu are grayed out?]]'''
* '''[[FAQ-Issues and Workarounds#Q: My project works everywhere except one computer?|My project works everywhere except one computer?]]'''
* '''[[FAQ-Issues and Workarounds#Q: Syntax highlighting is broken; how do I fix it?|Syntax highlighting is broken; how do I fix it?]]'''
* '''[[FAQ-Issues and Workarounds#Q: I posted on the forums that Code::Blocks was not working, but no one could help me?|I posted on the forums that Code::Blocks was not working, but no one could help me?]]'''
* '''[[FAQ-Issues and Workarounds#Q: I cannot find any text in my Code::Blocks logs?|I cannot find any text in my Code::Blocks logs?]]'''
* '''[[FAQ-Issues and Workarounds#Q: Scrolling causes gray areas/distortions to obscure my code in the editor?|Scrolling causes gray areas/distortions to obscure my code in the editor?]]'''

FAQ-Compiling (errors)

2011-12-08T21:27:49Z

Zabzonk:

[[Category:Code::Blocks Documentation]]
__TOC__
Return to '''[[FAQ]]'''.

----

==== Q: My simple C++ program throws up lots of errors - what's going on? ====

If you have a C++ program like this:

#include <iostream>
int main() {
std::cout << "hello world\n";
}

and when you compile it you get errors like this:

fatal error: iostream: No such file or directory

then you have probably given your source file a .c extension. If you do that, the GCC compiler (and others) will probably attempt to compile the file as a C program, not as C++. You should always give your C++ source files the extension .cpp to make sure the compiler handles them correctly.

==== Q: How do I troubleshoot a compiler problem? ====

'''A:''' I would start by turning on full Compiler logging.

This is done by selecting the "Full command line" option Under menu "Settings" -> "Compiler and Debugger" -> Global compiler settings -> [the compiler you use] -> "Other Setting" tab, "Compiler logging".

This option will make Code::Blocks output the exact commands it uses to compile your code.

Things to remember:

* You should review all the commands and their options;
* If you don't know what an option or a command does please read the documentation for the compiler/linker you're using;
* Look for missing commands;
* For every source file (<tt>.cpp</tt>; <tt>.c</tt>; <tt>.d</tt>; etc) in your project, you must have at least one command in the log. This command must produce an object file (file extension <tt>.o</tt> if using gcc/g++ and <tt>.obj</tt> if using Visual Studio);
* Every object file should be linked in the final executable, if not there are undefined symbols errors;
* Remember the file extension matters: <tt>*.c</tt> is compiled as C file, <tt>*.cpp</tt> is compiled as C++ file. [http://www.parashift.com/c++-faq-lite/mixing-c-and-cpp.html Read more]

==== Q: I imported a MSVCToolkit project/workspace, but Code::Blocks insists on trying to use GCC. What's wrong? ====

'''A:''' A little documentation problem ^^;. The "default compiler" is usually GCC, so when you imported it with "the default compiler", you told it to use GCC. To fix this situation, go to "Project", "Build Options" and select VC++ Toolkit as your compiler.

Another possibility is to put the Microsoft compiler as the default one. To do this, choose '''''Settings - Compiler''''', choose the Microsoft compiler in the '''''Selected Compiler''''' section (top of dialog box) and press the '''''Set as default''''' button.

From now onwards, for all new projects the Microsoft compiler will be taken by default.

==== Q: When compiling a wxWidgets project, I get several "variable 'vtable for xxxx' can't be auto-imported". What's wrong? ====

'''A:''' You need to add WXUSINGDLL in "Project->Build options->Compiler #defines" and rebuild your project (or create a new project and use the "Using wxWidgets DLL" project option which adds "-DWXUSINGDLL" to Project->Build options->Other options).
Other errors with the same resolution are:
'unresolved external symbol "char const * const wxEmptyString" (?wxEmptyString@@3PBDB)' or similar.
If you were using 1.0-finalbeta and were trying to build a statically linked wxWidgets project, the cause of the problem was some faulty templates. But that's fixed now.

==== Q: I can't compile a multithreaded app with VC Toolkit! Where are the libraries? ====

'''A:''' Sorry, no fix for your problem...

Your problem doesn't come from CodeBlocks. It exists, because the free VC toolkit (VCTK) doesn't provide all the libraries and tools which come with Visual C++ (VC) which isn't free, unfortunately.

Try buying a full-fledged VC++, or even better, download [http://www.mingw.org/ MinGW]

The libraries that can be obtained free of charge are:

Paths:
(VCT3) Visual C++ Toolkit 2003 - C:\Program Files\Microsoft Visual C++ Toolkit 2003\lib
(PSDK) Platform SDK - C:\Program Files\Microsoft Platform SDK\Lib
(NSDK) .NET 1.1 SDK - C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\lib

C runtime libs:
LIBC.LIB Single-threaded, static link (VCT3, NSDK)
LIBCMT.LIB Multithreaded, static link (VCT3, NSDK)
MSVCRT.LIB Multithreaded, dynamic link (import library for MSVCR71.DLL) (NSDK)
LIBCD.LIB Single-threaded, static link (debug) (VCT3, NSDK)
LIBCMTD.LIB Multithreaded, static link (debug) (NSDK)
MSVCRTD.LIB Multithreaded, dynamic link (import library for MSVCR71D.DLL) (debug) (NSDK)

C++ libs:
LIBCP.LIB Single-threaded, static link (VCT3, PSDK)
LIBCPMT.LIB Multithreaded, static link (VCT3)
MSVCPRT.LIB Multithreaded, dynamic link (import library for MSVCP71.dll) (none)
LIBCPD.LIB Single-threaded, static link (debug) (VCT3)
LIBCPMTD.LIB Multithreaded, static link (debug) (none)
MSVCPRTD.LIB Multithreaded, dynamic link (import library for MSVCP71D.DLL) (debug) (none)

Try setting the library linker directories to:
C:\Program Files\Microsoft Visual C++ Toolkit 2003\lib
C:\Program Files\Microsoft Platform SDK\Lib
C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\lib
in that order.

The ones listed as (none) above are actually present in the IA64 and AMD64 subdirectories of the PSDK lib directory. Not sure if these would work on 32-bit windows, however, they may if they are
meant to work in 32-bit compatibility mode on the 64-bit processors. Worth a try. Otherwise, you
can link statically to the C++ library instead of using MSVCP71.dll. If you really want to link against MSVCP71.dll you can try to create MSVCP71.LIB from the dll using lib.exe and sed. Search google for "exports.sed" for detailed steps.

See also: [http://wiki.tcl.tk/2435 tclsh script to extract import .lib from (any?) DLL (MinGW)]

See also: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vclib/html/_crt_c_run.2d.time_libraries.asp

See also: http://sapdb.2scale.net/moin.cgi/MS_20C_2b_2b_20Toolkit

==== Q: I get this error when compiling: Symbol "isascii" was not found in "codeblocks.dll" ====

'''A:''' Make sure you didn't mix up the MSVC headers or libs with the MinGW ones.

==== Q: My build fails with multiple ''undefined reference'' errors? ====

''Example:''
undefined reference to `WSACleanup@8
undefined reference to `WSACleanup@0

'''A:''' Most of the time it is because the required library is not linked with your project. Go to ''Project->Build options...->Linker settings (tab)'' and add the required library or libraries.

If the error includes a line number, it is likely that this is a problem with your code. Track down down your function declarations and implementations. Ensure they all match up, are spelled correctly, and have the correct scope resolution.

==== Q: My build fails in the compile/link/run step with a ''Permission denied'' error? ====

'''A:''' There are several possible causes for this:

# The output directory does not have read/write access.
#* Either change control settings on the output directory, or move the project to different location.
# A previous instance of the executable failed to terminate properly.
#* Open your system's equivalent of Process/Task Manager, search the list for the name of the executable Code::Blocks is trying to output, and terminate it.
#* Logging off or rebooting will achieve the same effect.
# The executable is open.
#* If the executable is open in a hex-editor or actively being run, close it.
# Security software is interfering.
#* The target file is locked while an antivirus programming is scanning it; either wait a few seconds for the antivirus scan to finish, set an exception in the antivirus settings, or (temporarily) disable the antivirus program.
#* Firewalls with very strict settings sometimes block execution; try reducing the firewall's settings or adding an exception.
#* Switching security software may have left traces behind that are interfering; hunt down the remnants of the old antivirus/firewall software and remove them.
# The file/library cannot be found.
#* Double check all of the compiler and linker [[FAQ-Compiling (general)#Q: I would like to compile a project using some non-standard libraries. How can I indicate to CodeBlocks that these libraries and include files exist?|search directories]] (including any [[Global compiler variables|variables]] they may be using) are properly setup.
# Code::Blocks was improperly installed.
#* Mixing binaries from a stable release and a nightly build (or even two different nightly builds) is highly likely to cause a slew of problems; [[Installing Code::Blocks|reinstall Code::Blocks]] in an empty directory.
# Multiple installed compilers are interfering with each other.
#* If they are not required to keep, completely remove all but the most used compiler.
#* If several compilers are required, ensure that '''none''' of them are in the ''system'' path (this is so that Code::Blocks will be able to manage all paths).
#* Also, do not place any compilers in their default installation path (for example <tt>C:\MinGW</tt>), as some compilers are hard-coded to look for headers in a default path ''before'' searching their own respective directories.

----

Return to '''[[FAQ]]'''.