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, 8 insertions, 5 deletions

diff --git a/src/dev/arm/pl111.cc b/src/dev/arm/pl111.cc
index 263a3b620..d416ab31f 100644
--- a/src/dev/arm/pl111.cc
+++ b/src/dev/arm/pl111.cc
@@ -50,6 +50,10 @@
 #include "mem/packet.hh"
 #include "mem/packet_access.hh"
 
+// clang complains about std::set being overloaded with Packet::set if
+// we open up the entire namespace std
+using std::vector;
+
 using namespace AmbaDev;
 
 // initialize clcd registers
@@ -69,11 +73,12 @@ Pl111::Pl111(const Params *p)
 
     pic = simout.create(csprintf("%s.framebuffer.bmp", sys->name()), true);
 
-    dmaBuffer = new uint8_t[LcdMaxWidth * LcdMaxHeight * sizeof(uint32_t)];
+    const int buffer_size = LcdMaxWidth * LcdMaxHeight * sizeof(uint32_t);
+    dmaBuffer = new uint8_t[buffer_size];
 
     memset(lcdPalette, 0, sizeof(lcdPalette));
     memset(cursorImage, 0, sizeof(cursorImage));
-    memset(dmaBuffer, 0, sizeof(dmaBuffer));
+    memset(dmaBuffer, 0, buffer_size);
 
     if (vncserver)
         vncserver->setFramebufferAddr(dmaBuffer);
diff --git a/src/dev/arm/pl111.hh b/src/dev/arm/pl111.hh
index b2dc1f640..e0a03641c 100644
--- a/src/dev/arm/pl111.hh
+++ b/src/dev/arm/pl111.hh
@@ -53,8 +53,6 @@
 #include "params/Pl111.hh"
 #include "sim/serialize.hh"
 
-using namespace std;
-
 class Gic;
 class VncServer;
 class Bitmap;
@@ -304,7 +302,7 @@ class Pl111: public AmbaDmaDevice
     EventWrapper<Pl111, &Pl111::fillFifo> fillFifoEvent;
 
     /** DMA done event */
-    vector<EventWrapper<Pl111, &Pl111::dmaDone> > dmaDoneEvent;
+    std::vector<EventWrapper<Pl111, &Pl111::dmaDone> > dmaDoneEvent;
 
     /** Wrapper to create an event out of the interrupt */
     EventWrapper<Pl111, &Pl111::generateInterrupt> intEvent;