Bug 158672 – Asserts-enabled builds fails because JSC::JSCell::inherits is not defined

• Status: NEW
• Component: JavaScriptCore

[Jeremy Huddleston Sequoia]

Recent master (r201265, b077d8fac8360fe5406bf13a44bbeff9acb0f9ea) fails to build with the following link error:

Undefined symbols for architecture x86_64:
  "JSC::JSCell::inherits(JSC::ClassInfo const*) const", referenced from:
      JSC::CodeBlock::ownerScriptExecutable() const in FTLCapabilities.cpp.o
ld: symbol(s) not found for architecture x86_64

We see the usage here:

bytecode/CodeBlock.h:
ScriptExecutable* ownerScriptExecutable() const { return jsCast<ScriptExecutable*>(m_ownerExecutable.get()); }

with jsCast implemented here, showing the JSC::JSCell::inherits call 

runtime/JSCell.h:
template<typename To, typename From>
inline To jsCast(From* from)
{
    ASSERT_WITH_SECURITY_IMPLICATION(!from || from->JSCell::inherits(std::remove_pointer<To>::type::info()));
    return static_cast<To>(from);
}

If asserts are disabled and SECURITY_ASSERTIONS are disabled, ASSERT_WITH_SECURITY_IMPLICATION is a no-op, and this could go unnoticed, but if the assertions are enabled, the build fails because JSCell.cpp does not implement JSC::JSCell::inherits(JSC::ClassInfo const*) const.

[Jeremy Huddleston Sequoia]

I'm updating to a newer revision, but looking at code changes, I suspect this to still be an issue.

[Jeremy Huddleston Sequoia]

You can reproduce this by configuring using cmake with the following options:
    -DCMAKE_C_FLAGS_RELEASE="-UNDEBUG" -DCMAKE_CXX_FLAGS_RELEASE="-UNDEBUG"

Or likely by using the Debug conifg.

[Jeremy Huddleston Sequoia]

Looks like it's a missing include of JSCellInlines.h

[Alexey Proskuryakov]

FWIW, mainline debug build succeeds - we have CI that verifies it all the time.

Lacking an include sounds feasible - my guess is that your port doesn't enable some feature, and thus doesn't get the include for free.

[Jeremy Huddleston Sequoia]

This is webkit-gtk, building straight from master.

[Jeremy Huddleston Sequoia]

And shouldn't there be a non-inline version of this function provided in JSCell.cpp anyways for cases where JSCellInlines.h is not included?