[Olena-patches] [Olena] #241: Have Qmake honor CXX and adjust its parameters according to the compiler's abilities

#241: Have Qmake honor CXX and adjust its parameters according to the compiler's abilities ----------------------+----------------------------------------------------- Reporter: levill_r | Owner: Olena Team Type: defect | Status: new Priority: major | Milestone: Component: Olena | Version: 1.0 Keywords: | ----------------------+----------------------------------------------------- Context: qmake is used by `configure` to set flags like `QT_CXXFLAGS`, `QT_LDFLAGS`, etc. (thanks to `autotroll.m4`). Qmake does not set compiler/linker flags based on tests on the tools themselves; instead, it queries the environment and sets variables according to some recipe (the « `spec` »). This is annoying on Mac OS X, since the `spec` detected and used by Qmake on this OS (`macx-g++`) adds Apple-specific flags to `QT_CXXFLAGS`, `QT_LDFLAGS`, etc., namely « `-arch x86_64 -Xarch_x86_64` » on Intel64 hosts. This prevents Qt-dependent components from being built with a non Apple compiler (e.g., `g++` 4.5 from the !MacPorts). We cannot really solve this problem entirely because it implies patching qmake. We can however write some workaround in `autotroll.m4` for known cases (like this one). In the current case, if non-standard flags `-arch` and/or `-Xarch` are detected in the `Makefile` generated by qmake, we should try to run `make` in the `conftest.dir` directory with CXX set to the value found ealier by `configure`. If this fails, try again with `-arch` and/or `-Xarch` removed from `QT_CXXFLAGS`, `QT_LDFLAGS`, etc. -- Ticket URL: <https://trac.lrde.org/olena/ticket/241> Olena <http://olena.lrde.epita.fr> Olena, a generic and efficient C++ image processing library.