On 4/6/2013 11:37, Geoff Worboys wrote: > Hi, > > I'm developing for Windows and recently started a project using > mingw (with gcc v4.7.2) - also tried mingw64 (with gcc v4.8.0). > I am getting some expected behaviour. To cut to the chase: > > with -Winline on the command line we get these warnings: > warning: function 'int B::fb()' can never be inlined because it > uses attributes conflicting with inlining [-Winline] > warning: inlining failed in call to 'int B::fb()': function not > inlinable [-Winline] (called from B::gb()) > > There is no warning that A::fa() will not be inlined (though > I think this is probably expected). > > > Notice that inline methods for class A and class B are NOT > being inlined inside the library (and the compiler does tell us > why in the case of B::fb()). > It is simple, there can only be one definition, if it is dllexported, it means there is no way to inline it since it has to be exported. > Having spent a long time developing with msvc, this behaviour > is quite unexpected. See discussion relating to msvc here: > http://msdn.microsoft.com/en-us/library/xa0d9ste.aspx > (Also, I ran the same code (after adjusting the c++11 > initialisation) through msvc v17.0 and can see that > all inline methods are being inlined.) > > I've asked this question on stackoverflow and on mingw64 forum, > (I really wasn't sure where I should be trying to report this), > but the only "solution" so far is to go with what you see in > class C. I can understand the arguments and discomfort that > people feel about class A and class B, especially when you read > about what is supposed to be possible with replacing the > implementation of exported functions, but consider also the > effects of requiring the class C style of declaration for all > shared library code. (I had hoped that the gcc option: > -fvisibility-inlines-hidden might be applicable in this case, > but it makes no difference to the problems shown above.) > Please do not compare ELF visibility to PE exports, ever. They are completely unrelated. > Take a look around at widely used code such as boost, Qt, ICU > and wxWidgets. These all use class declarations similar to > class A and class B. So in all these cases we can expect the > mingw/gcc builds of shared libraries for those products will > NOT inline the many simple accessor methods when used inside > the library (users of the library do get inlined). > > Do I report this as a bug, or am I missing something? > You can file an enhancement ticket.
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