ccache support sets incompatible compiler

[landonf (Landon Fuller)]

Prior to the introduction of ccache-specific functionality, ccache could be enabled by setting the binpath in macports.conf. This would result in standard compiler names being found in /opt/local/libexec/ccache.

With the introduction of ccache-specific functionality -- in of itself a layering violation -- the compiler is now munged at configure-time:

CC=ccache /usr/bin/gcc-4.0

This "two word" CC command breaks some otherwise valid Makefile that expect CC to be a single command. An example:

ifndef $(CXX)
    CXX = c++
endif

Results in:

Makefile:8: *** invalid syntax in conditional.  Stop.

[raimue (Rainer Müller)]

As MacPorts explicitly sets CC and CXX to the full path to the compiler in the build environment, extending binpath is not a possible solution for using ccache. Also, it will not work with the different compilers we allow to select by configure.compiler.

If a port does only accept real paths for CC or CXX or does not understand more than one word, add configure.ccache no to the port, which will disable ccache for it.

[tobypeterson]

Milestone MacPorts base bugs deleted

[cooljeanius (Eric Gallager)]

Cc Me!

[raimue (Rainer Müller)]

If we wanted to use wrapper scripts for compilers to avoid such problems, this should be a general decision and is not specific to ccache.