Trap hidden in debug gyp settings

[dothebart]

toolchain.gypi contains this setting:

          ['OS=="linux" and disable_glibcxx_debug==0', {
            # Enable libstdc++ debugging facilities to help catch problems
            # early, see http://crbug.com/65151 .
                        'defines': ['_GLIBCXX_DEBUG=1',],
          }],

which will increase the size of std::vector, and make this assert in V8 spaces.cc fail:

void Space::CheckOffsetsAreConsistent() const {
  DCHECK_EQ(Space::kIdOffset, OFFSET_OF(Space, id_));
}

# Debug check failed: Space::kIdOffset == (reinterpret_cast<intptr_t>(&(reinterpret_cast<Space*>(16)->id_)) - 16) (72 vs. 104).

[addaleax]

@nodejs/v8

[richardlau]

We do set by default:

node/common.gypi

Lines 33 to 35 in a350d8b

	# Some STL containers (e.g. std::vector) do not preserve ABI compatibility
	# between debug and non-debug mode.
	'disable_glibcxx_debug': 1,

but maybe we should just removed the section from toolchain.gypi if it's not going to work.

[bnoordhuis]

Untested but I think this should fix it:

diff --git a/common.gypi b/common.gypi
index 78a57d9291..49cfee48b2 100644
--- a/common.gypi
+++ b/common.gypi
@@ -32,7 +32,7 @@
 
     # Some STL containers (e.g. std::vector) do not preserve ABI compatibility
     # between debug and non-debug mode.
-    'disable_glibcxx_debug': 1,
+    'disable_glibcxx_debug%': 1,
 
     # Don't use ICU data file (icudtl.dat) from V8, we use our own.
     'icu_use_data_file_flag%': 0,

toolchain.gypi also defines disable_glibcxx_debug (but sets it to zero) and that takes precedence unless common.gypi defines it as "global".