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.

2 files changed, 3 insertions, 3 deletions

diff --git a/src/arch/alpha/tlb.cc b/src/arch/alpha/tlb.cc
index b211c4923..26d290a50 100644
--- a/src/arch/alpha/tlb.cc
+++ b/src/arch/alpha/tlb.cc
@@ -63,7 +63,7 @@ TLB::TLB(const Params *p)
     : BaseTLB(p), size(p->size), nlu(0)
 {
     table = new TlbEntry[size];
-    memset(table, 0, sizeof(TlbEntry[size]));
+    memset(table, 0, sizeof(TlbEntry) * size);
     flushCache();
 }
 
@@ -279,7 +279,7 @@ void
 TLB::flushAll()
 {
     DPRINTF(TLB, "flushAll\n");
-    memset(table, 0, sizeof(TlbEntry[size]));
+    memset(table, 0, sizeof(TlbEntry) * size);
     flushCache();
     lookupTable.clear();
     nlu = 0;
diff --git a/src/arch/alpha/tlb.hh b/src/arch/alpha/tlb.hh
index b6261769f..1d4b6c6f8 100644
--- a/src/arch/alpha/tlb.hh
+++ b/src/arch/alpha/tlb.hh
@@ -49,7 +49,7 @@ class ThreadContext;
 
 namespace AlphaISA {
 
-class TlbEntry;
+struct TlbEntry;
 
 class TLB : public BaseTLB
 {