clang/gcc: Fix compilation issues with clang 3.0 and gcc 4.6

This patch addresses a number of minor issues that cause problems when
compiling with clang >= 3.0 and gcc >= 4.6. Most importantly, it
avoids using the deprecated ext/hash_map and instead uses
unordered_map (and similarly so for the hash_set). To make use of the
new STL containers, g++ and clang has to be invoked with "-std=c++0x",
and this is now added for all gcc versions >= 4.6, and for clang >=
3.0. For gcc >= 4.3 and <= 4.5 and clang <= 3.0 we use the tr1
unordered_map to avoid the deprecation warning.

The addition of c++0x in turn causes a few problems, as the
compiler is more stringent and adds a number of new warnings. Below,
the most important issues are enumerated:

1) the use of namespaces is more strict, e.g. for isnan, and all
   headers opening the entire namespace std are now fixed.

2) another other issue caused by the more stringent compiler is the
   narrowing of the embedded python, which used to be a char array,
   and is now unsigned char since there were values larger than 128.

3) a particularly odd issue that arose with the new c++0x behaviour is
   found in range.hh, where the operator< causes gcc to complain about
   the template type parsing (the "<" is interpreted as the beginning
   of a template argument), and the problem seems to be related to the
   begin/end members introduced for the range-type iteration, which is
   a new feature in c++11.

As a minor update, this patch also fixes the build flags for the clang
debug target that used to be shared with gcc and incorrectly use
"-ggdb".

4 files changed, 115 insertions, 15 deletions

diff --git a/src/base/hashmap.hh b/src/base/hashmap.hh
index e3a72bcf5..ce9325881 100644
--- a/src/base/hashmap.hh
+++ b/src/base/hashmap.hh
@@ -1,4 +1,16 @@
 /*
+ * Copyright (c) 2012 ARM Limited
+ * All rights reserved
+ *
+ * The license below extends only to copyright in the software and shall
+ * not be construed as granting a license to any other intellectual
+ * property including but not limited to intellectual property relating
+ * to a hardware implementation of the functionality of the software
+ * licensed hereunder.  You may use the software subject to the license
+ * terms below provided that you ensure that this notice is replicated
+ * unmodified and in its entirety in all distributions of the software,
+ * modified or unmodified, in source code or in binary form.
+ *
  * Copyright (c) 2003-2005 The Regents of The University of Michigan
  * All rights reserved.
  *
@@ -26,29 +38,106 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  * Authors: Nathan Binkert
+ *          Andreas Hansson
  */
 
 #ifndef __HASHMAP_HH__
 #define __HASHMAP_HH__
 
-#if defined(__GNUC__) && __GNUC__ >= 3
+#if defined(__GNUC__)
+
+// for compilers that deprecate ext/hash_map, i.e. gcc >= 4.3 and
+// clang, use unordered_map
+
+// we need to determine what is available, as in the non-c++0x case,
+// e.g. gcc >= 4.3 and <= 4.5, the containers are in the std::tr1
+// namespace, and only gcc >= 4.6 (with -std=c++0x) adds the final
+// container implementation in the std namespace
+
+#if defined(__clang__)
+// align with -std=c++0x only for clang >= 3.0 in CCFLAGS and also
+// check if the header is present as this depends on what clang was
+// built against, using XCode clang 3.1, for example, the header is
+// not present without adding -stdlib=libc++
+#if (__clang_major__ >= 3 && __has_include(<unordered_map>))
+#define HAVE_STD_UNORDERED_MAP 1
+#else
+// we only support clang versions above 2.9 and these all have the tr1
+// unordered_map
+#define HAVE_STD_TR1_UNORDERED_MAP 1
+#endif
+#else
+// align with -std=c++0x only for gcc >= 4.6 in CCFLAGS, contrary to
+// clang we can rely entirely on the compiler version
+#if ((__GNUC__ == 4 && __GNUC_MINOR__ >= 6) || __GNUC__ > 4)
+#define HAVE_STD_UNORDERED_MAP 1
+#else
+#define HAVE_STD_TR1_UNORDERED_MAP 1
+#endif
+#endif
+
+// set a default value of 0
+#ifndef HAVE_STD_UNORDERED_MAP
+#define HAVE_STD_UNORDERED_MAP 0
+#endif
+
+// set a default value of 0
+#ifndef HAVE_STD_TR1_UNORDERED_MAP
+#define HAVE_STD_TR1_UNORDERED_MAP 0
+#endif
+
+// now we are ready to deal with the actual includes based on what is
+// available
+#if (HAVE_STD_UNORDERED_MAP || HAVE_STD_TR1_UNORDERED_MAP)
+
+#define hash_map unordered_map
+#define hash_multimap unordered_multimap
+#define hash_set unordered_set
+#define hash_multiset unordered_multiset
+
+// these versions also have an existing hash function for strings
+#define HAVE_STRING_HASH 1
+
+#if HAVE_STD_UNORDERED_MAP
+
+// clang or gcc >= 4.6
+#include <unordered_map>
+#include <unordered_set>
+// note that this assumes that -std=c++0x is added to the command line
+// which is done in the SConstruct CXXFLAGS for gcc >= 4.6 and clang
+// >= 3.0
+#define __hash_namespace std
+#define __hash_namespace_begin namespace std {
+#define __hash_namespace_end }
+#else
+// clang <= 3.0, gcc >= 4.3 and < 4.6
+#include <tr1/unordered_map>
+#include <tr1/unordered_set>
+#define __hash_namespace std::tr1
+#define __hash_namespace_begin namespace std { namespace tr1 {
+#define __hash_namespace_end } }
+#endif
+#else
+// gcc < 4.3
 #include <ext/hash_map>
 #include <ext/hash_set>
+#define __hash_namespace __gnu_cxx
+#define __hash_namespace_begin namespace __gnu_cxx {
+#define __hash_namespace_end }
+#endif
 #else
+// non GNU compiler
 #include <hash_map>
 #include <hash_set>
+#define __hash_namsepace std
+#define __hash_namespace_begin namespace std {
+#define __hash_namespace_end }
 #endif
 
 #include <string>
 
 #include "base/types.hh"
 
-#if defined(__GNUC__) && __GNUC__ >= 3
-    #define __hash_namespace __gnu_cxx
-#else
-    #define __hash_namespace std
-#endif
-
 namespace m5 {
     using ::__hash_namespace::hash_multimap;
     using ::__hash_namespace::hash_multiset;
@@ -62,8 +151,8 @@ namespace m5 {
 // Some default Hashing Functions
 //
 
-namespace __hash_namespace {
-#if defined(__APPLE__) || !defined(__LP64__) && !defined(__alpha__) && !defined(__SUNPRO_CC)
+__hash_namespace_begin
+#if !defined(__LP64__) && !defined(__alpha__) && !defined(__SUNPRO_CC)
     template<>
     struct hash<uint64_t> {
         size_t operator()(uint64_t r) const {
@@ -79,6 +168,9 @@ namespace __hash_namespace {
     };
 #endif
 
+// if the hash functions for strings are not already defined, then
+// declare them here
+#if !defined(HAVE_STRING_HASH)
     template<>
     struct hash<std::string> {
         size_t operator()(const std::string &s) const {
@@ -92,6 +184,7 @@ namespace __hash_namespace {
             return (__stl_hash_string(r.first.c_str())) ^ r.second;
         }
     };
-} // namespace __hash_namespace
+#endif
+__hash_namespace_end
 
 #endif // __HASHMAP_HH__
diff --git a/src/base/inifile.cc b/src/base/inifile.cc
index 451198033..91e37f327 100644
--- a/src/base/inifile.cc
+++ b/src/base/inifile.cc
@@ -29,6 +29,7 @@
  *          Steve Reinhardt
  */
 
+#include <algorithm>
 #include <fstream>
 #include <iostream>
 #include <string>
diff --git a/src/base/range.hh b/src/base/range.hh
index d9542c0ca..ac64a37f9 100644
--- a/src/base/range.hh
+++ b/src/base/range.hh
@@ -316,7 +316,13 @@ template <class T, class U>
 inline bool
 operator<(const Range<T> &range, const U &pos)
 {
-    return range.end < pos;
+  // with -std=gnu++0x, gcc and clang get confused when range.end is
+  // compared to pos using the operator "<", and the parser expects it
+  // to be the opening bracket for a template parameter,
+  // i.e. range.end<pos>(...);, the reason seems to be the range-type
+  // iteration introduced in c++11 where begin and end are members
+  // that return iterators
+    return operator<(range.end, pos);
 }
 
 /**
diff --git a/src/base/stats/text.cc b/src/base/stats/text.cc
index 8fb49dc59..28541ff59 100644
--- a/src/base/stats/text.cc
+++ b/src/base/stats/text.cc
@@ -166,7 +166,7 @@ ValueToString(Result value, int precision)
 {
     stringstream val;
 
-    if (!isnan(value)) {
+    if (!std::isnan(value)) {
         if (precision != -1)
             val.precision(precision);
         else if (value == rint(value))
@@ -211,15 +211,15 @@ void
 ScalarPrint::operator()(ostream &stream) const
 {
     if ((flags.isSet(nozero) && value == 0.0) ||
-        (flags.isSet(nonan) && isnan(value)))
+        (flags.isSet(nonan) && std::isnan(value)))
         return;
 
     stringstream pdfstr, cdfstr;
 
-    if (!isnan(pdf))
+    if (!std::isnan(pdf))
         ccprintf(pdfstr, "%.2f%%", pdf * 100.0);
 
-    if (!isnan(cdf))
+    if (!std::isnan(cdf))
         ccprintf(cdfstr, "%.2f%%", cdf * 100.0);
 
     ccprintf(stream, "%-40s %12s %10s %10s", name,