diff options
Diffstat (limited to 'qmake/generators/makefile.h')
| -rw-r--r-- | qmake/generators/makefile.h | 34 |
1 files changed, 31 insertions, 3 deletions
diff --git a/qmake/generators/makefile.h b/qmake/generators/makefile.h index 0b3bdfa..85510ea 100644 --- a/qmake/generators/makefile.h +++ b/qmake/generators/makefile.h @@ -249,9 +249,37 @@ public: virtual bool openOutput(QFile &, const QString &build) const; virtual bool isWindowsShell() const { return Option::target_mode == Option::TARG_WIN_MODE; } - // This is to avoid having SymbianCommonGenerator as a virtually inherited class - // of this class. Instead it is without a base class (avoiding the virtual - // inheritance problem), and is allowed to use functions defined in here. + /* The next one is to avoid having SymbianCommonGenerator as a virtually + inherited class of this class. Instead it is without a base class + (avoiding the virtual inheritance problem), and is allowed to use + functions defined in here. + + To illustrate: + +-------------------+ + | MakefileGenerator | + +-------------------+ + ^ ^ + | | + | X <-- Avoid this inheritance + | | + +------------------------+ +------------------------+ + | UnixMakefileGenerator | | SymbianCommonGenerator | + | or | | | + | NmakeMakefileGenerator | | | + +------------------------+ +------------------------+ + ^ ^ + | | + | | + | | + +-----------------------------+ + | SymbianMakefileTemplate<> | + +-----------------------------+ + + We want to avoid the famous diamond problem, because if we have that, we need + virtual inheritance, which not all compilers like. Therefore, we break the + link as illustrated. Instead, we have a pointer to MakefileGenerator inside + SymbianCommonGenerator, and allows full access by making it a friend here. + */ friend class SymbianCommonGenerator; }; |