Revert "Remove erroneous uses of CXX / CXX_target / CXX_host from gyp."

build/toolchain.gypi

Index: build/toolchain.gypi
diff --git a/build/toolchain.gypi b/build/toolchain.gypi
index 6cad1e2d0a2c233a0642a06e92a39cf3ffbf6b7f..d7c52ea38670eb3958045d00d2fa96ec6ac83f9c 100644
--- a/build/toolchain.gypi
+++ b/build/toolchain.gypi
@@ -31,7 +31,7 @@
   'variables': {
     'msvs_use_common_release': 0,
     'gcc_version%': 'unknown',
-    'clang%': 0,
+    'CXX%': '${CXX:-$(which g++)}',  # Used to assemble a shell command.
     'v8_target_arch%': '<(target_arch)',
     # Native Client builds currently use the V8 ARM JIT and
     # arm/simulator-arm.cc to defer the significant effort required
@@ -83,27 +83,6 @@
     # Allow to suppress the array bounds warning (default is no suppression).
     'wno_array_bounds%': '',
   },
-  'conditions': [
-    ['host_arch=="ia32" or host_arch=="x64" or clang==1', {
-      'variables': {
-        'host_cxx_is_biarch%': 1,
-       },
-     }, {
-      'variables': {
-        'host_cxx_is_biarch%': 0,
-      },
-    }],
-    ['target_arch=="ia32" or target_arch=="x64" or target_arch=="x87" or \
-      clang==1', {
-      'variables': {
-        'target_cxx_is_biarch%': 1,
-       },
-     }, {
-      'variables': {
-        'target_cxx_is_biarch%': 0,
-      },
-    }],
-  ],
   'target_defaults': {
     'conditions': [
       ['v8_target_arch=="arm"', {
@@ -142,9 +121,11 @@
         ],
         'target_conditions': [
           ['_toolset=="host"', {
+            'variables': {
+              'armcompiler': '<!($(echo ${CXX_host:-$(which g++)}) -v 2>&1 | grep -q "^Target: arm" && echo "yes" || echo "no")',
+            },
             'conditions': [
-              ['v8_target_arch==host_arch', {
-                # Host built with an Arm CXX compiler.
+              ['armcompiler=="yes"', {
                 'conditions': [
                   [ 'arm_version==7', {
                     'cflags': ['-march=armv7-a',],
@@ -167,8 +148,7 @@
                   }],
                 ],
               }, {
-                # 'v8_target_arch!=host_arch'
-                # Host not built with an Arm CXX compiler (simulator build).
+                # armcompiler=="no"
                 'conditions': [
                   [ 'arm_float_abi=="hard"', {
                     'defines': [
@@ -185,9 +165,11 @@
             ],
           }],  # _toolset=="host"
           ['_toolset=="target"', {
+            'variables': {
+              'armcompiler': '<!($(echo ${CXX_target:-<(CXX)}) -v 2>&1 | grep -q "^Target: arm" && echo "yes" || echo "no")',
+            },
             'conditions': [
-              ['v8_target_arch==target_arch', {
-                # Target built with an Arm CXX compiler.
+              ['armcompiler=="yes"', {
                 'conditions': [
                   [ 'arm_version==7', {
                     'cflags': ['-march=armv7-a',],
@@ -210,8 +192,7 @@
                   }],
                 ],
               }, {
-                # 'v8_target_arch!=target_arch'
-                # Target not built with an Arm CXX compiler (simulator build).
+                # armcompiler=="no"
                 'conditions': [
                   [ 'arm_float_abi=="hard"', {
                     'defines': [
@@ -249,9 +230,11 @@
         'defines': [
           'V8_TARGET_ARCH_MIPS',
         ],
+        'variables': {
+          'mipscompiler': '<!($(echo <(CXX)) -v 2>&1 | grep -q "^Target: mips" && echo "yes" || echo "no")',
+        },
         'conditions': [
-          ['v8_target_arch==target_arch', {
-            # Target built with a Mips CXX compiler.
+          ['mipscompiler=="yes"', {
             'target_conditions': [
               ['_toolset=="target"', {
                 'cflags': ['-EB'],
@@ -298,9 +281,11 @@
         'defines': [
           'V8_TARGET_ARCH_MIPS',
         ],
+        'variables': {
+          'mipscompiler': '<!($(echo <(CXX)) -v 2>&1 | grep -q "^Target: mips" && echo "yes" || echo "no")',
+        },
         'conditions': [
-          ['v8_target_arch==target_arch', {
-            # Target built with a Mips CXX compiler.
+          ['mipscompiler=="yes"', {
             'target_conditions': [
               ['_toolset=="target"', {
                 'cflags': ['-EL'],
@@ -353,9 +338,11 @@
         'defines': [
           'V8_TARGET_ARCH_MIPS64',
         ],
+        'variables': {
+          'mipscompiler': '<!($(echo <(CXX)) -v 2>&1 | grep -q "^Target: mips" && echo "yes" || echo "no")',
+        },
         'conditions': [
-          ['v8_target_arch==target_arch', {
-            # Target built with a Mips CXX compiler.
+          ['mipscompiler=="yes"', {
             'target_conditions': [
               ['_toolset=="target"', {
                 'cflags': ['-EL'],
@@ -452,28 +439,44 @@
           },
         },
       }],
-      ['(OS=="linux" or OS=="freebsd"  or OS=="openbsd" or OS=="solaris" \
+      ['OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="solaris" \
+         or OS=="netbsd" or OS=="qnx"', {
+        'conditions': [
+          [ 'v8_no_strict_aliasing==1', {
+            'cflags': [ '-fno-strict-aliasing' ],
+          }],
+        ],  # conditions
+      }],
+      ['OS=="solaris"', {
+        'defines': [ '__C99FEATURES__=1' ],  # isinf() etc.
+      }],
+      ['(OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="solaris" \
          or OS=="netbsd" or OS=="mac" or OS=="android" or OS=="qnx") and \
-        (v8_target_arch=="arm" or v8_target_arch=="ia32" or \
-         v8_target_arch=="x87" or v8_target_arch=="mips" or \
-         v8_target_arch=="mipsel")', {
+        (v8_target_arch=="arm" or v8_target_arch=="ia32" or v8_target_arch=="x87" or\
+         v8_target_arch=="mips" or v8_target_arch=="mipsel")', {
+        # Check whether the host compiler and target compiler support the
+        # '-m32' option and set it if so.
         'target_conditions': [
           ['_toolset=="host"', {
-            'conditions': [
-              ['host_cxx_is_biarch==1', {
-                'cflags': [ '-m32' ],
-                'ldflags': [ '-m32' ]
-              }],
-            ],
+            'variables': {
+              'm32flag': '<!(($(echo ${CXX_host:-$(which g++)}) -m32 -E - > /dev/null 2>&1 < /dev/null) && echo "-m32" || true)',
+            },
+            'cflags': [ '<(m32flag)' ],
+            'ldflags': [ '<(m32flag)' ],
             'xcode_settings': {
               'ARCHS': [ 'i386' ],
             },
           }],
           ['_toolset=="target"', {
+            'variables': {
+              'm32flag': '<!(($(echo ${CXX_target:-<(CXX)}) -m32 -E - > /dev/null 2>&1 < /dev/null) && echo "-m32" || true)',
+              'clang%': 0,
+            },
             'conditions': [
-              ['target_cxx_is_biarch==1 and nacl_target_arch!="nacl_x64"', {
-                'cflags': [ '-m32' ],
-                'ldflags': [ '-m32' ],
+              ['((OS!="android" and OS!="qnx") or clang==1) and \
+                nacl_target_arch!="nacl_x64"', {
+                'cflags': [ '<(m32flag)' ],
+                'ldflags': [ '<(m32flag)' ],
               }],
             ],
             'xcode_settings': {
@@ -484,35 +487,28 @@
       }],
       ['(OS=="linux" or OS=="android") and \
         (v8_target_arch=="x64" or v8_target_arch=="arm64")', {
+        # Check whether the host compiler and target compiler support the
+        # '-m64' option and set it if so.
         'target_conditions': [
           ['_toolset=="host"', {
+            'variables': {
+              'm64flag': '<!(($(echo ${CXX_host:-$(which g++)}) -m64 -E - > /dev/null 2>&1 < /dev/null) && echo "-m64" || true)',
+            },
+            'cflags': [ '<(m64flag)' ],
+            'ldflags': [ '<(m64flag)' ],
+          }],
+          ['_toolset=="target"', {
+            'variables': {
+              'm64flag': '<!(($(echo ${CXX_target:-<(CXX)}) -m64 -E - > /dev/null 2>&1 < /dev/null) && echo "-m64" || true)',
+            },
             'conditions': [
-              ['host_cxx_is_biarch==1', {
-                'cflags': [ '-m64' ],
-                'ldflags': [ '-m64' ]
+              ['((OS!="android" and OS!="qnx") or clang==1)', {
+                'cflags': [ '<(m64flag)' ],
+                'ldflags': [ '<(m64flag)' ],
               }],
-             ],
-           }],
-           ['_toolset=="target"', {
-             'conditions': [
-               ['target_cxx_is_biarch==1', {
-                 'cflags': [ '-m64' ],
-                 'ldflags': [ '-m64' ],
-               }],
-             ]
-           }],
-         ],
-      }],
-      ['OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="solaris" \
-         or OS=="netbsd" or OS=="qnx"', {
-        'conditions': [
-          [ 'v8_no_strict_aliasing==1', {
-            'cflags': [ '-fno-strict-aliasing' ],
-          }],
-        ],  # conditions
-      }],
-      ['OS=="solaris"', {
-        'defines': [ '__C99FEATURES__=1' ],  # isinf() etc.
+            ],
+          }]
+        ],
       }],
       ['OS=="freebsd" or OS=="openbsd"', {
         'cflags': [ '-I/usr/local/include' ],