How to turn off default setting of user defined macro in DLL compilation

Clipper52a · Sep 30, 2015#12015-09-30T14:02+00:00

This question regards to user defined macro in DLL file compilation.

Assuming I have the following codes in a DLL file:

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#ifndef USERMACRO_DECL
	# define USERMACRO_DECL
#endif

When I build the DLL file, I have the following message:

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warning: "USERMACRO_DECL" redefined [enabled by default]

This is fine for most needs, I am just wondering where in UEStudio I can turn this off, as sometimes we may choose to not define the macro for different build requirements.

Thanks again.

Mofi · Oct 01, 2015#22015-10-01T05:54+00:00

First of all, a macro already defined should not be redefined. If this must be done, then the code should be:

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#ifdef USERMACRO_DECL
#undef USERMACRO_DECL
#define USERMACRO_DECL whatever
#endif

See also Undefining and Redefining Macros in GCC online documentation. There are always one or more pretty methods to avoid a warning. It would be also possible to use a diagnostic pragma to avoid a specific warning in a specific file. I don't recommend to disable any warning. I suggest the opposite, enable all warnings supported by a compiler, especially for new projects, i.e use -Wall -Wextra for GCC/MinGW.

The GCC page about Warning Options lists all basic options related to warnings and contains the links to the other warning options.

I can see in the configuration files for MinGW compiler that some of those options were made customizable via the Build - Set Compiler Options dialog. And there is an additional Warnings = in group COMPILER OPTIONS to add additional warning options not explicitly listed in group C/C++ Warning Options. GCC respectively its Windows port MinGW usually outputs on a warning also the option which can be used to suppress this warning. Add this option on Warnings = in compiler options dialog. I suppose the option for this warning is -Wno-macro-redefined, but I have not studied GCC documentation to verify my assumption.

Clipper52a · Oct 01, 2015#32015-10-01T08:27+00:00

Thank you for your generous comments as always.

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