Enable debug builds with some optimizations turned on.

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index dbb33a867bfb9abd6aaeb88a542aa69b168c082d..79a74b7ece64b1ecce54fe7dd6b7515de629a9aa 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -490,6 +490,7 @@
       'Debug': {
         'variables': {
           'v8_enable_extra_checks%': 1,
+          'v8_full_debug%': 1,
         },
         'defines': [
           'DEBUG',
@@ -498,29 +499,39 @@
           'OBJECT_PRINT',
           'VERIFY_HEAP',
         ],
-        'msvs_settings': {
-          'VCCLCompilerTool': {
-            'Optimization': '0',
-
-            'conditions': [
-              ['OS=="win" and component=="shared_library"', {
-                'RuntimeLibrary': '3',  # /MDd
-              }, {
-                'RuntimeLibrary': '1',  # /MTd
-              }],
-            ],
-          },
-          'VCLinkerTool': {
-            'LinkIncremental': '2',
-          },
-        },
         'conditions': [
           ['v8_enable_extra_checks==1', {
             'defines': ['ENABLE_EXTRA_CHECKS',],
           }],
+          ['OS=="win"', {
+            'msvs_settings': {

[Jakob Kummerow, 2013/07/09 16:47:07]

Keeping the msvs_settings section where it was saves two levels of indentation.
It's safe to have it outside an OS=="win" conditional, since the section is
ignored by other GYP generators anyway.
I don't feel strongly about this though.

+              'VCCLCompilerTool': {
+                'conditions': [
+                  ['component=="shared_library"', {
+                    'RuntimeLibrary': '3',  # /MDd
+                  }, {
+                    'RuntimeLibrary': '1',  # /MTd
+                  }],
+                  ['v8_full_debug==0', {
+                    'Optimization': '1',
+                  }, {
+                    'Optimization': '0',
+                  }]

[Jakob Kummerow, 2013/07/09 16:47:07]

nit: trailing comma (not necessary for correctness, but we're pretty consistent
about putting it in nevertheless).

+                ],
+              },
+              'VCLinkerTool': {
+                'LinkIncremental': '2',
+              },
+            },
+          }],  # OS=="win"
           ['OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="netbsd"', {
             'cflags': [ '-Wall', '<(werror)', '-W', '-Wno-unused-parameter',
                         '-Wnon-virtual-dtor', '-Woverloaded-virtual' ],
+            'conditions': [
+              ['v8_full_debug==0', {
+                'cflags': [ '-O1' ],
+              }]

[Jakob Kummerow, 2013/07/09 16:47:07]

nit: trailing comma

+            ],
           }],
           ['OS=="linux" and v8_enable_backtrace==1', {
             # Support for backtrace_symbols.
@@ -542,7 +553,13 @@
           }],
           ['OS=="mac"', {
             'xcode_settings': {
-              'GCC_OPTIMIZATION_LEVEL': '0',  # -O0
+              'conditions': [
+                ['v8_full_debug==0', {
+                  'GCC_OPTIMIZATION_LEVEL': '1',  # -O1
+                }, {
+                  'GCC_OPTIMIZATION_LEVEL': '0',  # -O0
+                }]

[Jakob Kummerow, 2013/07/09 16:47:07]

nit: trailing comma

+              ],
             },
           }],
         ],
@@ -613,7 +630,7 @@
                 'FavorSizeOrSpeed': '0',
                 'StringPooling': 'true',
                 'conditions': [
-                  ['OS=="win" and component=="shared_library"', {
+                  ['component=="shared_library"', {
                     'RuntimeLibrary': '2',  #/MD
                   }, {
                     'RuntimeLibrary': '0',  #/MT