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.

src/dev/alpha/tsunami_cchip.cc

@@ -53,7 +53,6 @@
 #include "params/TsunamiCChip.hh"
 #include "sim/system.hh"
 
-using namespace std;
 //Should this be AlphaISA?
 using namespace TheISA;
 

src/dev/alpha/tsunami_io.cc

@@ -54,7 +54,11 @@
 #include "mem/port.hh"
 #include "sim/system.hh"
 
-using namespace std;
+// clang complains about std::set being overloaded with Packet::set if
+// we open up the entire namespace std
+using std::string;
+using std::ostream;
+
 //Should this be AlphaISA?
 using namespace TheISA;
 

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);

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;

src/dev/copy_engine.cc

@@ -45,7 +45,6 @@
 #include "sim/system.hh"
 
 using namespace CopyEngineReg;
-using namespace std;
 
 CopyEngine::CopyEngine(const Params *p)
     : PciDev(p)

src/dev/disk_image.cc

@@ -170,12 +170,12 @@ CowDiskImage::CowDiskImage(const Params *p)
     : DiskImage(p), filename(p->image_file), child(p->child), table(NULL)
 {
     if (filename.empty()) {
-        init(p->table_size);
+        initSectorTable(p->table_size);
     } else {
         if (!open(filename)) {
             if (p->read_only)
                 fatal("could not open read-only file");
-            init(p->table_size);
+            initSectorTable(p->table_size);
         }
 
         if (!p->read_only)
@@ -270,7 +270,7 @@ CowDiskImage::open(const string &file)
 }
 
 void
-CowDiskImage::init(int hash_size)
+CowDiskImage::initSectorTable(int hash_size)
 {
     table = new SectorTable(hash_size);
 

src/dev/disk_image.hh

@@ -121,7 +121,7 @@ class CowDiskImage : public DiskImage
     CowDiskImage(const Params *p);
     ~CowDiskImage();
 
-    void init(int hash_size);
+    void initSectorTable(int hash_size);
     bool open(const std::string &file);
     void save();
     void save(const std::string &file);

src/dev/ide_ctrl.cc

@@ -32,7 +32,6 @@
 
 #include <string>
 
-#include "base/trace.hh"
 #include "cpu/intr_control.hh"
 #include "debug/IdeCtrl.hh"
 #include "dev/ide_ctrl.hh"
@@ -42,7 +41,9 @@
 #include "params/IdeController.hh"
 #include "sim/byteswap.hh"
 
-using namespace std;
+// clang complains about std::set being overloaded with Packet::set if
+// we open up the entire namespace std
+using std::string;
 
 // Bus master IDE registers
 enum BMIRegOffset {

src/dev/ns_gige.cc

@@ -50,6 +50,12 @@
 #include "params/NSGigE.hh"
 #include "sim/system.hh"
 
+// clang complains about std::set being overloaded with Packet::set if
+// we open up the entire namespace std
+using std::min;
+using std::ostream;
+using std::string;
+
 const char *NsRxStateStrings[] =
 {
     "rxIdle",
@@ -81,7 +87,6 @@ const char *NsDmaState[] =
     "dmaWriteWaiting"
 };
 
-using namespace std;
 using namespace Net;
 using namespace TheISA;
 
@@ -479,12 +484,12 @@ NSGigE::write(PacketPtr pkt)
 // all these #if 0's are because i don't THINK the kernel needs to
 // have these implemented. if there is a problem relating to one of
 // these, you may need to add functionality in.
+
+// grouped together and #if 0'ed to avoid empty if body and make clang happy
+#if 0
             if (reg & CFGR_TBI_EN) ;
             if (reg & CFGR_MODE_1000) ;
 
-            if (reg & CFGR_AUTO_1000)
-                panic("CFGR_AUTO_1000 not implemented!\n");
-
             if (reg & CFGR_PINT_DUPSTS ||
                 reg & CFGR_PINT_LNKSTS ||
                 reg & CFGR_PINT_SPDSTS)
@@ -494,22 +499,11 @@ NSGigE::write(PacketPtr pkt)
             if (reg & CFGR_MRM_DIS) ;
             if (reg & CFGR_MWI_DIS) ;
 
-            if (reg & CFGR_T64ADDR) ;
-            // panic("CFGR_T64ADDR is read only register!\n");
-
-            if (reg & CFGR_PCI64_DET)
-                panic("CFGR_PCI64_DET is read only register!\n");
-
             if (reg & CFGR_DATA64_EN) ;
             if (reg & CFGR_M64ADDR) ;
             if (reg & CFGR_PHY_RST) ;
             if (reg & CFGR_PHY_DIS) ;
 
-            if (reg & CFGR_EXTSTS_EN)
-                extstsEnable = true;
-            else
-                extstsEnable = false;
-
             if (reg & CFGR_REQALG) ;
             if (reg & CFGR_SB) ;
             if (reg & CFGR_POW) ;
@@ -518,6 +512,20 @@ NSGigE::write(PacketPtr pkt)
             if (reg & CFGR_BROM_DIS) ;
             if (reg & CFGR_EXT_125) ;
             if (reg & CFGR_BEM) ;
+
+            if (reg & CFGR_T64ADDR) ;
+            // panic("CFGR_T64ADDR is read only register!\n");
+#endif
+            if (reg & CFGR_AUTO_1000)
+                panic("CFGR_AUTO_1000 not implemented!\n");
+
+            if (reg & CFGR_PCI64_DET)
+                panic("CFGR_PCI64_DET is read only register!\n");
+
+            if (reg & CFGR_EXTSTS_EN)
+                extstsEnable = true;
+            else
+                extstsEnable = false;
             break;
 
           case MEAR:
@@ -541,9 +549,13 @@ NSGigE::write(PacketPtr pkt)
             eepromClk = reg & MEAR_EECLK;
 
             // since phy is completely faked, MEAR_MD* don't matter
+
+// grouped together and #if 0'ed to avoid empty if body and make clang happy
+#if 0
             if (reg & MEAR_MDIO) ;
             if (reg & MEAR_MDDIR) ;
             if (reg & MEAR_MDC) ;
+#endif
             break;
 
           case PTSCR:

src/dev/pciconfigall.cc

@@ -43,8 +43,6 @@
 #include "params/PciConfigAll.hh"
 #include "sim/system.hh"
 
-using namespace std;
-
 PciConfigAll::PciConfigAll(const Params *p)
     : PioDevice(p)
 {

src/dev/pcidev.cc

@@ -52,8 +52,6 @@
 #include "sim/byteswap.hh"
 #include "sim/core.hh"
 
-using namespace std;
-
 
 PciDev::PciConfigPort::PciConfigPort(PciDev *dev, int busid, int devid,
         int funcid, Platform *p)
@@ -341,7 +339,7 @@ PciDev::writeConfig(PacketPtr pkt)
 }
 
 void
-PciDev::serialize(ostream &os)
+PciDev::serialize(std::ostream &os)
 {
     SERIALIZE_ARRAY(BARSize, sizeof(BARSize) / sizeof(BARSize[0]));
     SERIALIZE_ARRAY(BARAddrs, sizeof(BARAddrs) / sizeof(BARAddrs[0]));