Only use -Wshadow with GCC > 4.6.0.

Prior to 4.6.0, -Wshadow would cause GCC to warn when variables shadowed
global functions. Since libc defines a number of functions with common
names, this is a problem. Also, without this change, we'll keep breaking
on older versions of GCC because we won't be testing with them.

OpenBSD, specifically is reported to have a problem:

(Note the test should really be >= 4.6.0, but CMake doesn't have a

Change-Id: I1aedda01ab629e138c8781e4319bfaaed0b236b0
Reviewed-by: Adam Langley <>
1 file changed