609188 - MSVC warnings in mozalloc about C4273: 'std::moz_Xinvalid_argument' : inconsistent dll linkage warnings in msvc_raise_wrappers.h

Status: RESOLVED WORKSFORME

(Core :: XPCOM, defect)

Description

[Ryan VanderMeulen [:RyanVM]]

c:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\INCLUDE\xutility(3408) : warning C4273: 'std::moz_Xinvalid_argument' : inconsistent dll linkage
        c:\mozbuild\mozilla-central\objdir-fx\dist\include\mozilla\msvc_raise_wrappers.h(59) : see previous definition of 'moz_Xinvalid_argument'
c:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\INCLUDE\xutility(3409) : warning C4273: 'std::moz_Xlength_error' : inconsistent dll linkage
        c:\mozbuild\mozilla-central\objdir-fx\dist\include\mozilla\msvc_raise_wrappers.h(60) : see previous definition of 'moz_Xlength_error'
c:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\INCLUDE\xutility(3410) : warning C4273: 'std::moz_Xout_of_range' : inconsistent dll linkage
        c:\mozbuild\mozilla-central\objdir-fx\dist\include\mozilla\msvc_raise_wrappers.h(61) : see previous definition of 'moz_Xout_of_range'
c:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\INCLUDE\xutility(3411) : warning C4273: 'std::moz_Xoverflow_error' : inconsistent dll linkage
        c:\mozbuild\mozilla-central\objdir-fx\dist\include\mozilla\msvc_raise_wrappers.h(62) : see previous definition of 'moz_Xoverflow_error'
c:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\INCLUDE\xutility(3412) : warning C4273: 'std::moz_Xruntime_error' : inconsistent dll linkage
        c:\mozbuild\mozilla-central\objdir-fx\dist\include\mozilla\msvc_raise_wrappers.h(63) : see previous definition of 'moz_Xruntime_error'

This code was added by bug 560723 and generates warning spam with numerous files on MSVC builds due to mozalloc being used throughout the tree.

Comment 1

[Ryan VanderMeulen [:RyanVM]]

Any insight on this one would be appreciated, Chris.

Comment 2

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

Not sure about this one ... the xutility symbols are declared __declspec(noreturn) along with some other indecipherable gunk.  Might be __declspec(noreturn), but a preprocessed version of the decls in xutility would confirm (make -C $objdir/some_file_triggering_warning.i).

Comment 3

[Ryan VanderMeulen [:RyanVM]]

Stupid question, but all I see is .obj files, not .i files.

Comment 4

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

Oh sorry --- I was referring to explicitly making a preprocessed version of a file.  To get a preprocessed version of a file foo/bar/Baz.cpp, just run
  make -C $objdir/foo/bar/Baz.i

which spits out the preprocessed file as foo/bar/Baz.i.  Then we can look for the std::moz_X* decls and compare them.

Comment 5

[Ryan VanderMeulen [:RyanVM]]

$ python build/pymake/make.py -C objdir-fx/browser/components/migration/src/nsIEProfileMigrator.i
make.py[0]: Entering directory 'c:\mozbuild\mozilla-central\objdir-fx/browser/components/migration/src/nsIEProfileMigrator.i'
No makefile found

Comment 6

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

Arrg, sorry:

$ python build/pymake/make.py -C
objdir-fx/browser/components/migration/src nsIEProfileMigrator.i

Note the space between "src" and "ns".  (-C is "change to this directory", and nsFoo.i is the target to make.)

Comment 7

[Ryan VanderMeulen [:RyanVM]]

Hopefully this is what you are looking for. I have the entire .i file, but it's over 4MB. Let me know if you want other info from it.

 #line 3400 "c:\\Program Files (x86)\\Microsoft Visual Studio 10.0\\VC\\INCLUDE\\xutility"
		_Myptr = 0;
		}
	_Elem *_Myptr;	// pointer to allocated string
	_Elem _Nul;		// nul terminator for unallocated string
	};
 __declspec(noreturn) void __cdecl moz_Xinvalid_argument(   const char *);
 __declspec(noreturn) void __cdecl moz_Xlength_error(   const char *);
 __declspec(noreturn) void __cdecl moz_Xout_of_range(   const char *);
 __declspec(noreturn) void __cdecl moz_Xoverflow_error(   const char *);
 __declspec(noreturn) void __cdecl moz_Xruntime_error(   const char *);
}

#line 52 "c:\\mozbuild\\mozilla-central\\objdir-fx\\dist\\include\\mozilla\\msvc_raise_wrappers.h"
namespace std {
// NB: user code is not supposed to touch the std:: namespace.  We're
// doing this after careful review because we want to define our own
// exception throwing semantics.  Don't try this at home!

__declspec(dllimport) __declspec(noreturn) void moz_Xinvalid_argument(const char*);
__declspec(dllimport) __declspec(noreturn) void moz_Xlength_error(const char*);
__declspec(dllimport) __declspec(noreturn) void moz_Xout_of_range(const char*);
__declspec(dllimport) __declspec(noreturn) void moz_Xoverflow_error(const char*);
__declspec(dllimport) __declspec(noreturn) void moz_Xruntime_error(const char*);
} // namespace std

Comment 8

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

OK, it's not __declspec(noreturn); looks like __declspec(dllimport) is the problem.  Our code is adding this exactly as I understand it should be added; I don't know why the VS header tries to declare these symbols without dllimport.  Next we would want to know why the VS header is lacking this apparently necessary declspec: is the declspec just missing or is the definition of these symbols provided inline somewhere?

Comment 9

[Ryan VanderMeulen [:RyanVM]]

xutility defines them as such:
_CRTIMP2_PURE __declspec(noreturn) void __CLRCALL_PURE_OR_CDECL _Xinvalid_argument(_In_z_ const char *);
_CRTIMP2_PURE __declspec(noreturn) void __CLRCALL_PURE_OR_CDECL _Xlength_error(_In_z_ const char *);
_CRTIMP2_PURE __declspec(noreturn) void __CLRCALL_PURE_OR_CDECL _Xout_of_range(_In_z_ const char *);
_CRTIMP2_PURE __declspec(noreturn) void __CLRCALL_PURE_OR_CDECL _Xoverflow_error(_In_z_ const char *);
_CRTIMP2_PURE __declspec(noreturn) void __CLRCALL_PURE_OR_CDECL _Xruntime_error(_In_z_ const char *);

From searching around a bit, the only lead I found says that _CRTIMP2_PURE resolves to __declspec(dllimport) depending on how it's being linked (/MT v. /MD & _STATIC_CPPLIB macro) or to nothing for /clr:pure.

Comment 10

[Ryan VanderMeulen [:RyanVM]]

Ben, do you have any suggestions?

Comment 11

[(not currently active) Ted Mielczarek]

I fiddled with something similar when I was hacking on "link everything into libxul":
http://hg.mozilla.org/users/tmielczarek_mozilla.com/mq/file/73917dc87482/bigger-libxul-win32#l109

I was hitting errors linking against _Throw since it was declared dllimport, but I was linking statically to the definition in mozalloc. Looks like you're actually hitting the opposite here, but it's the same macro that I was dealing with.

Comment 12

[Ryan VanderMeulen [:RyanVM]]

Ted, is "link everything into libxul" still being planned for post-Fx4?

Comment 13

[(not currently active) Ted Mielczarek]

Yeah, bug 561842.

Comment 14

[Ryan VanderMeulen [:RyanVM]]

It seems that bug 561842 is on the back burner with the Win PGO linker address space issues. Now that m-c builds are using MSVC2010, this is a big source of warning spam on tinderbox builds as well. I'm still willing to work on this bug, but I don't really know where to go from the comments above.

Comment 15

[(not currently active) Ted Mielczarek]

Are we screwing something up with our wrapper headers that makes _CRTIMP2_PURE not get defined to dllimport? If so, we should fix that.

Does this warning occur everywhere in the tree, or are there particular places? I know we do statically link the CRT in a few places, but I would expect that wouldn't use mozalloc in those cases. Is the problem that we're trying to use a static CRT and mozalloc at the same time?

Comment 16

[Ryan VanderMeulen [:RyanVM]]

Looks like it only hits two directories:
xpcom/glue
intl/unicharutil/util

Comment 17

[Ed Morley [:emorley]]

Which are the only two locations that do:

> ifdef _MSC_VER
> # Don't include directives about which CRT to use
> OS_COMPILE_CXXFLAGS += -Zl
> OS_COMPILE_CFLAGS += -Zl
> DEFINES += -D_USE_ANSI_CPP
> endif

Comment 18

[Chris Peterson [:cpeterson]]

These dll linkage warnings are still reproducible:

https://tbpl.mozilla.org/php/getParsedLog.php?id=42816626&tree=Mozilla-Central&full=1

c:\\PROGRA~2\\MICROS~2.0\\vc\\include\xutility(3408) : warning C4273: 'std::moz_Xinvalid_argument' : inconsistent dll linkage
        c:\builds\moz2_slave\m-cen-w32-d-000000000000000000\build\obj-firefox\dist\include\mozilla\msvc_raise_wrappers.h(26) : see previous definition of 'moz_Xinvalid_argument'
c:\\PROGRA~2\\MICROS~2.0\\vc\\include\xutility(3409) : warning C4273: 'std::moz_Xlength_error' : inconsistent dll linkage
        c:\builds\moz2_slave\m-cen-w32-d-000000000000000000\build\obj-firefox\dist\include\mozilla\msvc_raise_wrappers.h(27) : see previous definition of 'moz_Xlength_error'
c:\\PROGRA~2\\MICROS~2.0\\vc\\include\xutility(3410) : warning C4273: 'std::moz_Xout_of_range' : inconsistent dll linkage
        c:\builds\moz2_slave\m-cen-w32-d-000000000000000000\build\obj-firefox\dist\include\mozilla\msvc_raise_wrappers.h(28) : see previous definition of 'moz_Xout_of_range'
c:\\PROGRA~2\\MICROS~2.0\\vc\\include\xutility(3411) : warning C4273: 'std::moz_Xoverflow_error' : inconsistent dll linkage
        c:\builds\moz2_slave\m-cen-w32-d-000000000000000000\build\obj-firefox\dist\include\mozilla\msvc_raise_wrappers.h(29) : see previous definition of 'moz_Xoverflow_error'
c:\\PROGRA~2\\MICROS~2.0\\vc\\include\xutility(3412) : warning C4273: 'std::moz_Xruntime_error' : inconsistent dll linkage
        c:\builds\moz2_slave\m-cen-w32-d-000000000000000000\build\obj-firefox\dist\include\mozilla\msvc_raise_wrappers.h(30) : see previous definition of 'moz_Xruntime_error'

Comment 19

[Ryan VanderMeulen [:RyanVM]]

msvc_raise_wrappers.h isn't a thing anymore