aix: build failure with linker error in debug mode

[gireeshpunathil]

• Version: v9.0.0-pre
• Platform: AIX
• Subsystem: build

ld: 0711-317 ERROR: Undefined symbol: vtable for v8::base::PosixTimezoneCache
ld: 0711-345 Use the -bloadmap or -bnoquiet option to obtain more information.
collect2: error: ld returned 8 exit status
gmake: *** [node/out/Debug/mksnapshot] Error 1
rm e593a2578c78c7c5200c07a18c22644588ff3c6e.intermediate

[gireeshpunathil]

-bnoquiet flag produced this info:

ld: 0711-318 ERROR: Undefined symbols were found.
        The following symbols are in error:
 Symbol                    Inpndx  TY CL Source-File(Object-File) OR Import-File{Shared-object}
                              RLD: Address  Section  Rld-type Referencing Symbol
 ----------------------------------------------------------------------------------------------
 vtable for v8::base::PosixTimezoneCache [136]   ER PR ../deps/v8/src/base/platform/platform-aix.cc(node/out/Debug/obj.target/deps/v8/src/libv8_libbase.a[platform-aix.o])
                                   00005820 .data    R_POS    [4730]  <_ZTVN2v84base18PosixTimezoneCacheE.P16>
ER: The return code is 8.
ld: 0711-317 ERROR: Undefined symbol: vtable for v8::base::PosixTimezoneCache
collect2: error: ld returned 8 exit status

[gireeshpunathil]

-O3 build fine, while -O0 throws up the above error.
Self-assigning, but feel free to jump in.

[gireeshpunathil]

smallest code that reproduces the error, with the class heirarchy retained:

class TimezoneCache {
 public:
  virtual void foo() = 0;
  virtual ~TimezoneCache() {}
};

class PosixTimezoneCache : public TimezoneCache {
 public:
  void foo() override;
  ~PosixTimezoneCache() override {}
};

class AIXTimezoneCache : public PosixTimezoneCache {
  void foo() override;
  ~AIXTimezoneCache() override {}
};

void AIXTimezoneCache::foo() {}

int main() {
}

Resolution of the function foo is what causes the issue - looks like PosixTimezoneCache is deemed abstract and no vtable is created for it.

This code fails in Linux too with similar linker error:

/tmp/ccW4gs0R.o: In function `PosixTimezoneCache::~PosixTimezoneCache()':
a.cc:(.text._ZN18PosixTimezoneCacheD2Ev[_ZN18PosixTimezoneCacheD5Ev]+0x13): undefined reference to `vtable for PosixTimezoneCache'
/tmp/ccW4gs0R.o:(.rodata._ZTI16AIXTimezoneCache[_ZTI16AIXTimezoneCache]+0x10): undefined reference to `typeinfo for PosixTimezoneCache'
collect2: error: ld returned 1 exit status

But I guess the scenario does not affect Linux, as it uses PosixTimezoneCache, with no next level inheritance.

If I define foo inline within the AIXTimezoneCache class the problem goes away, don't know what it means.

[gireeshpunathil]

-fno-rtti flag took away the first problem -
undefined reference to vtable for PosixTimezoneCache'

[bnoordhuis]

Can this be closed?

[gireeshpunathil]

@bnoordhuis - no I guess, @jbajwa is working on this with v8

[jbajwa]

@gireeshpunathil
Hi Gireesh, as per the v8 bug, the fix is in 6.1 CL and the backport to 6.0/5.9 was rejected. So the only option is to float the patch in node (not sure what the process for that is) until v8 is upgraded to 6.1.

[bnoordhuis]

@jbajwa Cherry-pick the patch to deps/v8 and open a PR. See git log deps/v8 for what the commit log should look like. Ping me here or on Slack (if I'm around) if you need assistance.

[jbajwa]

@bnoordhuis
Thank you, I will do that now.

[gibfahn]

@jbajwa FWIW I think this is the relevant section of the guide: https://github.com/nodejs/node/blob/master/doc/guides/maintaining-V8.md#backporting-to-abandoned-branches

[richardlau]

This was fixed by 8096791.