Laszlo, I have the same concern on final image sizes. I have done some evaluation:
GCC5 OVMF X64 DEBUG without -whole-archive ========================================== FV Space Information SECFV [19%Full] 212992 total, 42000 used, 170992 free FVMAIN_COMPACT [33%Full] 3440640 total, 1162760 used, 2277880 free DXEFV [38%Full] 10485760 total, 4024024 used, 6461736 free PEIFV [19%Full] 917504 total, 180648 used, 736856 free Total used = 5409432 GCC5 OVMF X64 DEBUG with -whole-archive ======================================= FV Space Information SECFV [19%Full] 212992 total, 41936 used, 171056 free FVMAIN_COMPACT [33%Full] 3440640 total, 1158304 used, 2282336 free DXEFV [38%Full] 10485760 total, 4029656 used, 6456104 free PEIFV [19%Full] 917504 total, 181352 used, 736152 free Total used = 5411248 Total used difference = 1816 bytes larger with -whole-archive I was also able to do a MSFT VS2015 build with /WHOLEARCHIVE set and it also catches the same duplicate symbol error now. error C2220: warning treated as error - no 'executable' file generated warning C4744: 'mMemoryDiscoveredNotifyList' has different type in 'd:\work\github\tianocore\edk2\mdemodulepkg\core\dxeiplpeim\dxeload.c' and 'd:\work\github\tianocore\edk2\sourceleveldebugpkg\library\debugagent\secpeidebugagent\secpeidebugagentlib.c': 'struct (12 bytes)' and 'array (12 bytes)' DxeIpl.lib(DxeLoad.obj) : error LNK2005: _mMemoryDiscoveredNotifyList already defined in SecPeiDebugAgentLib.lib(SecPeiDebugAgentLib.obj) d:\work\github\tianocore\edk2\Build\OvmfIa32\DEBUG_VS2015x86\IA32\MdeModulePkg\Core\DxeIplPeim\DxeIpl\DEBUG\DxeIpl.dll : fatal error LNK1169: one or more multiply defined symbols found VS2015 OVMF X64 DEBUG without /WHOLEARCHIVE =========================================== FV Space Information SECFV [22%Full] 212992 total, 48560 used, 164432 free FVMAIN_COMPACT [33%Full] 3440640 total, 1147464 used, 2293176 free DXEFV [39%Full] 10485760 total, 4163888 used, 6321872 free PEIFV [22%Full] 917504 total, 204840 used, 712664 free Total used = 5564752 VS2015 OVMF X64 DEBUG with /WHOLEARCHIVE =========================================== FV Space Information SECFV [23%Full] 212992 total, 50384 used, 162608 free FVMAIN_COMPACT [33%Full] 3440640 total, 1147424 used, 2293216 free DXEFV [42%Full] 10485760 total, 4422992 used, 6062768 free PEIFV [27%Full] 917504 total, 255528 used, 661976 free Total used = 5875338 Total used difference = 310586 bytes larger with /WHOLEARCHIVE For tool chains that do have size impacts, one option is to have a "test" build that enables the linker flags to detect duplicate symbols. For example the following could be added to a DSC file. May want to disable GenFds stage when doing this type of build. [BuildOptions] !ifdef $(DETECT_DUPLICATE_SYMBOLS) MSFT:*_VS2015_*_DLINK_FLAGS = /WHOLEARCHIVE !endif Best regards, Mike > -----Original Message----- > From: Laszlo Ersek [mailto:[email protected]] > Sent: Thursday, May 25, 2017 11:07 AM > To: Kinney, Michael D <[email protected]>; Ard Biesheuvel > <[email protected]>; Andrew Fish ([email protected]) <[email protected]> > Cc: Wu, Hao A <[email protected]>; [email protected]; Fan, Jeff > <[email protected]> > Subject: Re: [edk2] [Patch] SourceLevelDebugPkg/SecPeiDebugAgentLib: Fix > duplicate > symbol > > On 05/25/17 19:38, Kinney, Michael D wrote: > > Laszlo, > > > > I think the equivalent flag for GCC builds is --whole-archive. > > > > I tried adding that flag to DLINK_FLAGS in GCC5, and I get the > > following error building OVMF from edk2/master with > > -D SOURCE_DEBUG_ENABLE set. > > > > DxeLoad.obj (symbol from plugin): In function > > `InstallIplPermanentMemoryPpis': > > (.text+0x0): multiple definition of `mMemoryDiscoveredNotifyList' > > SecPeiDebugAgentLib.obj (symbol from plugin):(.text+0x0): first defined here > > collect2: error: ld returned 1 exit status > > Great find! That's the error message we should get. > > Unfortunately, after reading the "ld" manual on "--whole-archive", it > seems that the complete object files will actually be copied into the > resultant binary, even if several of their symbols will remain unused. I > think that's quite sub-optimal. (I haven't verified this though.) What > we'd like to get is (a) the full verification at link time, and (b) > inclusion of *only* those symbols that are actually necessary. > > In your testing, when you build OVMF with and without "--whole-archive", > do you see a difference in, say, the DXEFV footprint, when the build > completes? > > (If so, then I wonder if we should add "--whole-archive" only to the > NOOPT build... Not sure.) > > > Visual Studio 2015 Update 2 has also added a new linker flag called > > /WHOLEARCHIVE. I am working on evaluating that flag to see if it > > catches the same issue. > > Thanks! > Laszlo > > >> -----Original Message----- > >> From: Laszlo Ersek [mailto:[email protected]] > >> Sent: Thursday, May 25, 2017 9:09 AM > >> To: Kinney, Michael D <[email protected]>; Ard Biesheuvel > >> <[email protected]>; Andrew Fish ([email protected]) > >> <[email protected]> > >> Cc: Wu, Hao A <[email protected]>; [email protected]; Fan, Jeff > >> <[email protected]> > >> Subject: Re: [edk2] [Patch] SourceLevelDebugPkg/SecPeiDebugAgentLib: Fix > >> duplicate > >> symbol > >> > >> On 05/25/17 03:47, Kinney, Michael D wrote: > >>> Andrew, > >>> > >>> I think I have found an alternate fix for this XCODE5 specific > >>> build failure. Since there appears to be a difference in the > >>> linker behavior between MSFT/GCC/XCODE tool chains, I reviewed > >>> the 'ld' command line options used in XCODE5 tool chain in > >>> tools_def.txt. > >>> > >>> There is a flag set call '-all_load'. The description of this > >>> flag is 'Loads all members of static archive libraries.'. > >>> > >>> I tried removing this flag from the XCODE5 specific SLINK_FLAGS > >>> and DLINK_FLAGS statements in tools_def.txt, and the duplicate > >>> symbol build failure is no longer present. I am able to build > >>> and boot OVMF with XCODE5 with -D SOURCE_DEBUG_ENABLE flag set. > >>> > >>> This seems to make XCODE5 linker behavior match the MSFT and GCC > >>> linker behavior. > >>> > >>> Do you know why '-all_load' is used in XCODE5 and what impacts > >>> there may be from removing it? > >> > >> Please don't remove -all_load from there; instead we should figure out > >> if the same can be brought to MSFT and GCC. > >> > >> The error message that XCODE5 emitted caught a real bug (undefined > >> behavior according to ISO C, see my previous email), and so we should > >> keep that detection enabled (we should even extend it to other > >> toolchains, if that's possible). > >> > >> As for docs, I found this: > >> > >> http://www.manpages.info/macosx/ld.1.html > >> > >>> -all_load > >>> Loads all members of static archive libraries. This option does > >>> not apply to dynamic shared libraries. > >> > >> > >> Thanks > >> Laszlo _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
