recognise gcc with appended version

[PaulPrice]

$CC may be something like "gcc-4.8", which needs to be recognised as gcc.
Note also that "gcc-4.8 --version" produces something like:

gcc-4.8 (Homebrew gcc48 4.8.4) 4.8.4

so we have to deal with that additional "-4.8".

[mjuric]

Looks OK to me; merge it!

PS: ... though I'd argue this is a fundamentally wrong way to query compiler properties -- compiling a probe that tests the https://gcc.gnu.org/onlinedocs/cpp/Common-Predefined-Macros.html (and analogs in other compilers) is probably better

[jhoblitt]

@PaulPrice No objection to merging this but I think the behavior with respect to env variables is surprising. My general expectation is that if CC or CXX is set in the env that the build tooling would use those values verbatim.

[timj]

so this regexp no longer matches gcc ? Maybe I'm missing some earlier context.

[PaulPrice]

Yeah, that's not right. Let me check...

[PaulPrice]

Removed this. Dunno what I was smoking…

[RobertLuptonTheGood]

scons cc=clang is the preferred way to do this as it sets all appropriate variables, is explicit rather than dependent on the vagaries of your environment, and also turns on and off appropriate flags. I'd be willing to see a warning about trying to use CC and CXX. In fact, if you want to use them enough there's a setenv flag to sconsUtils.