[LLVMdev] problems building googletest for 2.5

[Mike Stump]

On Feb 4, 2009, at 9:10 PM, Tanya Lattner wrote:
> Ideally, configure should detect what version of gcc you have and  
> either use those CPP FLAGS or not (it will output warnings with  
> 3.X). Or, we just disable building Google Test by default.

> Can anyone help with this?

Here is a Makefile fragment that will dynamically test gcc and add  
flags, if the flag is supported.  I'll leave it up to others to  
consider and/or integrate it and consider if /dev/null is portable  
enough.

FLAGS := $(shell gcc -Wall -fsyntax-only -xc /dev/null 2>/dev/null &&  
echo -Wall)
CFLAGS := $(shell gcc -Wallme -fsyntax-only -xc /dev/null 2>/dev/null  
&& echo -Wallme)
all:
	@echo flags are $(FLAGS)
	@echo flags are $(CFLAGS)

The down side, these execute every time the fragment is read.  If  
limited to just a few directories, it should be fine, Makefile.common  
would hurt.