clang: Enable compiling gem5 using clang 2.9 and 3.0

This patch adds the necessary flags to the SConstruct and SConscript
files for compiling using clang 2.9 and later (on Ubuntu et al and OSX
XCode 4.2), and also cleans up a bunch of compiler warnings found by
clang. Most of the warnings are related to hidden virtual functions,
comparisons with unsigneds >= 0, and if-statements with empty
bodies. A number of mismatches between struct and class are also
fixed. clang 2.8 is not working as it has problems with class names
that occur in multiple namespaces (e.g. Statistics in
kernel_stats.hh).

clang has a bug (http://llvm.org/bugs/show_bug.cgi?id=7247) which
causes confusion between the container std::set and the function
Packet::set, and this is currently addressed by not including the
entire namespace std, but rather selecting e.g. "using std::vector" in
the appropriate places.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/cpu/simple/atomic.hh b/src/cpu/simple/atomic.hh
index 77a9d6b0d..f677ed49b 100644
--- a/src/cpu/simple/atomic.hh
+++ b/src/cpu/simple/atomic.hh
@@ -112,8 +112,8 @@ class AtomicSimpleCPU : public BaseSimpleCPU
     void switchOut();
     void takeOverFrom(BaseCPU *oldCPU);
 
-    virtual void activateContext(int thread_num, int delay);
-    virtual void suspendContext(int thread_num);
+    virtual void activateContext(ThreadID thread_num, int delay);
+    virtual void suspendContext(ThreadID thread_num);
 
     Fault readMem(Addr addr, uint8_t *data, unsigned size, unsigned flags);