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, 3 insertions, 3 deletions

diff --git a/src/cpu/simple/base.hh b/src/cpu/simple/base.hh
index 56e5e5608..3535539d0 100644
--- a/src/cpu/simple/base.hh
+++ b/src/cpu/simple/base.hh
@@ -92,7 +92,7 @@ namespace Trace {
     class InstRecord;
 }
 
-class BaseSimpleCPUParams;
+struct BaseSimpleCPUParams;
 
 
 class BaseSimpleCPU : public BaseCPU
@@ -189,8 +189,8 @@ class BaseSimpleCPU : public BaseCPU
     void postExecute();
     void advancePC(Fault fault);
 
-    virtual void deallocateContext(int thread_num);
-    virtual void haltContext(int thread_num);
+    virtual void deallocateContext(ThreadID thread_num);
+    virtual void haltContext(ThreadID thread_num);
 
     // statistics
     virtual void regStats();