[FR] Support LLVM toolchain on Windows in prebuilt SDK

[triplef]

[REQUIRED] Please fill in the following fields:

• Pre-built SDK from the website or open-source from this repo: pre-built from website
• Firebase C++ SDK version: 8.8.0
• Problematic Firebase Component: App, Auth
• Other Firebase Components in use: –
• Platform you are using the C++ SDK on: Windows
• Platform you are targeting: Windows

[REQUIRED] Please describe the issue here:

Using the LLVM toolchain (specifically lld-link) instead of MSVC (link.exe) results in linker errors "relocation against symbol in discarded section: ..." from lld-link (see logs below).

Using link.exe instead of lld-link works fine, and it does not matter whether the source was built with MSVC or clang-cl.

As we have technical requirements to use lld-link in our projects and this is blocking us from using the Firebase C++ SDK.

Steps to reproduce with sample project:

1. Download Visual Studio sample project: FirebaseCppTest.zip
2. Build app

Steps to reproduce manually:

1. Create new C++ project in Visual Studio
2. Select "LLVM (clang-cl)" as Platform Toolset in project settings
3. Link against at least firebase_app.lib and optionally firebase_auth.lib (linking both results in more errors of the same kind)
4. Add some minimal code to reference these projects, e.g.

    App *app = App::Create();
    if (app) {
        Auth *auth = Auth::GetAuth(app);
        printf("Created auth: %p", auth);
    }

5. Build app

Error Logs

1>lld-link : error : relocation against symbol in discarded section: $LN10
1>>>> referenced by C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.29.30133\include\vector:803
1>>>>               firebase_auth.lib(a9003852461049443285ecfe94112265_firebase_auth.dir_Debug_auth_request.obj):(__catch$??$_Emplace_reallocate@AEBQEAUNamespace@f_b_flatbuffers@@@?$vector@PEAUNamespace@f_b_flatbuffers@@V?$allocator@PEAUNamespace@f_b_flatbuffers@@@std@@@std@@QEAAPEAPEAUNamespace@f_b_flatbuffers@@QEAPEAU23@AEBQEAU23@@Z$0)
1>
1>lld-link : error : relocation against symbol in discarded section: $LN10
1>>>> referenced by C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.29.30133\include\vector:803
1>>>>               firebase_app.lib(d94e1bff3c0e8414a6679ea91c3e103e_firebase_app.dir_Debug_variant_util.obj):(__catch$??$_Emplace_reallocate@AEBQEAUNamespace@f_b_flatbuffers@@@?$vector@PEAUNamespace@f_b_flatbuffers@@V?$allocator@PEAUNamespace@f_b_flatbuffers@@@std@@@std@@QEAAPEAPEAUNamespace@f_b_flatbuffers@@QEAPEAU23@AEBQEAU23@@Z$0)
1>
1>lld-link : error : relocation against symbol in discarded section: $LN10
1>>>> referenced by C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.29.30133\include\vector:803
1>>>>               firebase_auth.lib(a9003852461049443285ecfe94112265_firebase_auth.dir_Debug_set_account_info_result.obj):(__catch$??$_Emplace_reallocate@AEBUUserInfoImpl@auth@firebase@@@?$vector@UUserInfoImpl@auth@firebase@@V?$allocator@UUserInfoImpl@auth@firebase@@@std@@@std@@QEAAPEAUUserInfoImpl@auth@firebase@@QEAU234@AEBU234@@Z$0)
1>
1>lld-link : error : relocation against symbol in discarded section: $LN36
1>>>> referenced by C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.29.30133\include\vector:1050
1>>>>               firebase_app.lib(d94e1bff3c0e8414a6679ea91c3e103e_firebase_app.dir_Debug_variant_util.obj):($LN34)
1>
1>lld-link : error : relocation against symbol in discarded section: $LN9
1>>>> referenced by C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.29.30133\include\xtree:1679
1>>>>               firebase_auth.lib(a9003852461049443285ecfe94112265_firebase_auth.dir_Debug_get_additional_user_info.obj):(__catch$??$_Copy_nodes@U_Copy_tag@?$_Tree@V?$_Tmap_traits@VVariant@firebase@@V12@U?$less@VVariant@firebase@@@std@@V?$allocator@U?$pair@$$CBVVariant@firebase@@V12@@std@@@4@$0A@@std@@@std@@@?$_Tree@V?$_Tmap_traits@VVariant@firebase@@V12@U?$less@VVariant@firebase@@@std@@V?$allocator@U?$pair@$$CBVVariant@firebase@@V12@@std@@@4@$0A@@std@@@std@@IEAAPEAU?$_Tree_node@U?$pair@$$CBVVariant@firebase@@V12@@std@@PEAX@1@PEAU21@0U_Copy_tag@01@@Z$0)
1>
1>lld-link : error : relocation against symbol in discarded section: $LN9
1>>>> referenced by C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.29.30133\include\xtree:1679
1>>>>               firebase_auth.lib(a9003852461049443285ecfe94112265_firebase_auth.dir_Debug_auth_util.obj):(__catch$??$_Copy_nodes@U_Copy_tag@?$_Tree@V?$_Tmap_traits@VVariant@firebase@@V12@U?$less@VVariant@firebase@@@std@@V?$allocator@U?$pair@$$CBVVariant@firebase@@V12@@std@@@4@$0A@@std@@@std@@@?$_Tree@V?$_Tmap_traits@VVariant@firebase@@V12@U?$less@VVariant@firebase@@@std@@V?$allocator@U?$pair@$$CBVVariant@firebase@@V12@@std@@@4@$0A@@std@@@std@@IEAAPEAU?$_Tree_node@U?$pair@$$CBVVariant@firebase@@V12@@std@@PEAX@1@PEAU21@0U_Copy_tag@01@@Z$0)
1>
1>lld-link : error : relocation against symbol in discarded section: $LN9
1>>>> referenced by C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.29.30133\include\xtree:1679
1>>>>               firebase_auth.lib(a9003852461049443285ecfe94112265_firebase_auth.dir_Debug_authentication_result.obj):(__catch$??$_Copy_nodes@U_Copy_tag@?$_Tree@V?$_Tmap_traits@VVariant@firebase@@V12@U?$less@VVariant@firebase@@@std@@V?$allocator@U?$pair@$$CBVVariant@firebase@@V12@@std@@@4@$0A@@std@@@std@@@?$_Tree@V?$_Tmap_traits@VVariant@firebase@@V12@U?$less@VVariant@firebase@@@std@@V?$allocator@U?$pair@$$CBVVariant@firebase@@V12@@std@@@4@$0A@@std@@@std@@IEAAPEAU?$_Tree_node@U?$pair@$$CBVVariant@firebase@@V12@@std@@PEAX@1@PEAU21@0U_Copy_tag@01@@Z$0)
1>
1>lld-link : error : relocation against symbol in discarded section: $LN10
1>>>> referenced by C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.29.30133\include\vector:803
1>>>>               firebase_auth.lib(a9003852461049443285ecfe94112265_firebase_auth.dir_Debug_set_account_info_request.obj):(__catch$??$_Emplace_reallocate@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@?$vector@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@V?$allocator@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@2@@std@@QEAAPEAV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@1@QEAV21@$$QEAV21@@Z$0)
1>
1>lld-link : error : relocation against symbol in discarded section: $LN10
1>>>> referenced by C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.29.30133\include\vector:803
1>>>>               firebase_auth.lib(a9003852461049443285ecfe94112265_firebase_auth.dir_Debug_get_account_info_result.obj):(__catch$??$_Emplace_reallocate@AEBUUserInfoImpl@auth@firebase@@@?$vector@UUserInfoImpl@auth@firebase@@V?$allocator@UUserInfoImpl@auth@firebase@@@std@@@std@@QEAAPEAUUserInfoImpl@auth@firebase@@QEAU234@AEBU234@@Z$0)
1>
1>lld-link : error : relocation against symbol in discarded section: $LN10
1>>>> referenced by C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.29.30133\include\vector:803
1>>>>               firebase_app.lib(d94e1bff3c0e8414a6679ea91c3e103e_firebase_app.dir_Debug_variant_util.obj):(__catch$??$_Emplace_reallocate@AEBUValue@Builder@f_b_flexbuffers@@@?$vector@UValue@Builder@f_b_flexbuffers@@V?$allocator@UValue@Builder@f_b_flexbuffers@@@std@@@std@@QEAAPEAUValue@Builder@f_b_flexbuffers@@QEAU234@AEBU234@@Z$0)
1>
1>lld-link : error : relocation against symbol in discarded section: $LN10
1>>>> referenced by C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.29.30133\include\vector:803
1>>>>               firebase_app.lib(d7017cfa2b4147331b16a451ec58c76c_firebase_rest_lib.dir_Debug_response.obj):(__catch$??$_Emplace_reallocate@AEBV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@?$vector@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@V?$allocator@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@2@@std@@QEAAPEAV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@1@QEAV21@AEBV21@@Z$0)
1>
1>lld-link : error : relocation against symbol in discarded section: $LN9
1>>>> referenced by C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.29.30133\include\xtree:1679
1>>>>               firebase_app.lib(d94e1bff3c0e8414a6679ea91c3e103e_firebase_app.dir_Debug_variant.obj):(__catch$??$_Copy_nodes@U_Copy_tag@?$_Tree@V?$_Tmap_traits@VVariant@firebase@@V12@U?$less@VVariant@firebase@@@std@@V?$allocator@U?$pair@$$CBVVariant@firebase@@V12@@std@@@4@$0A@@std@@@std@@@?$_Tree@V?$_Tmap_traits@VVariant@firebase@@V12@U?$less@VVariant@firebase@@@std@@V?$allocator@U?$pair@$$CBVVariant@firebase@@V12@@std@@@4@$0A@@std@@@std@@IEAAPEAU?$_Tree_node@U?$pair@$$CBVVariant@firebase@@V12@@std@@PEAX@1@PEAU21@0U_Copy_tag@01@@Z$0)
1>
1>lld-link : error : relocation against symbol in discarded section: $LN10
1>>>> referenced by C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.29.30133\include\vector:803
1>>>>               firebase_auth.lib(a9003852461049443285ecfe94112265_firebase_auth.dir_Debug_sign_in_flow.obj):(__catch$??$_Emplace_reallocate@AEBQEAUNamespace@f_b_flatbuffers@@@?$vector@PEAUNamespace@f_b_flatbuffers@@V?$allocator@PEAUNamespace@f_b_flatbuffers@@@std@@@std@@QEAAPEAPEAUNamespace@f_b_flatbuffers@@QEAPEAU23@AEBQEAU23@@Z$0)
1>
1>lld-link : error : relocation against symbol in discarded section: $LN10
1>>>> referenced by C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.29.30133\include\vector:803
1>>>>               firebase_app.lib(d94e1bff3c0e8414a6679ea91c3e103e_firebase_app.dir_Debug_variant_util.obj):(__catch$??$_Emplace_reallocate@E@?$vector@EV?$allocator@E@std@@@std@@QEAAPEAEQEAE$$QEAE@Z$0)
1>
1>lld-link : error : relocation against symbol in discarded section: $LN10
1>>>> referenced by C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.29.30133\include\vector:803
1>>>>               firebase_app.lib(d94e1bff3c0e8414a6679ea91c3e103e_firebase_app.dir_Debug_variant_util.obj):(__catch$??$_Emplace_reallocate@UValue@Builder@f_b_flexbuffers@@@?$vector@UValue@Builder@f_b_flexbuffers@@V?$allocator@UValue@Builder@f_b_flexbuffers@@@std@@@std@@QEAAPEAUValue@Builder@f_b_flexbuffers@@QEAU234@$$QEAU234@@Z$0)
1>
1>lld-link : error : relocation against symbol in discarded section: $LN9
1>>>> referenced by C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.29.30133\include\xtree:1679
1>>>>               firebase_auth.lib(a9003852461049443285ecfe94112265_firebase_auth.dir_Debug_auth_desktop.obj):(__catch$??$_Copy_nodes@U_Copy_tag@?$_Tree@V?$_Tmap_traits@VVariant@firebase@@V12@U?$less@VVariant@firebase@@@std@@V?$allocator@U?$pair@$$CBVVariant@firebase@@V12@@std@@@4@$0A@@std@@@std@@@?$_Tree@V?$_Tmap_traits@VVariant@firebase@@V12@U?$less@VVariant@firebase@@@std@@V?$allocator@U?$pair@$$CBVVariant@firebase@@V12@@std@@@4@$0A@@std@@@std@@IEAAPEAU?$_Tree_node@U?$pair@$$CBVVariant@firebase@@V12@@std@@PEAX@1@PEAU21@0U_Copy_tag@01@@Z$0)
1>
1>lld-link : error : relocation against symbol in discarded section: $LN8
1>>>> referenced by C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.29.30133\include\vector:1252
1>>>>               firebase_auth.lib(a9003852461049443285ecfe94112265_firebase_auth.dir_Debug_auth_desktop.obj):(__catch$??$_Resize_reallocate@U_Value_init_tag@std@@@?$vector@V?$unique_ptr@UUserT@fbs@auth@firebase@@U?$default_delete@UUserT@fbs@auth@firebase@@@std@@@std@@V?$allocator@V?$unique_ptr@UUserT@fbs@auth@firebase@@U?$default_delete@UUserT@fbs@auth@firebase@@@std@@@std@@@2@@std@@AEAAX_KAEBU_Value_init_tag@1@@Z$0)
1>
1>lld-link : error : relocation against symbol in discarded section: $LN28
1>>>> referenced by C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.29.30133\include\vector:993
1>>>>               firebase_app.lib(d94e1bff3c0e8414a6679ea91c3e103e_firebase_app.dir_Debug_variant_util.obj):(__catch$??$_Insert_range@PEBE@?$vector@EV?$allocator@E@std@@@std@@AEAAXV?$_Vector_const_iterator@V?$_Vector_val@U?$_Simple_types@E@std@@@std@@@1@PEBE1Uforward_iterator_tag@1@@Z$0)
1>
1>lld-link : error : relocation against symbol in discarded section: $LN10
1>>>> referenced by C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.29.30133\include\vector:803
1>>>>               firebase_auth.lib(a9003852461049443285ecfe94112265_firebase_auth.dir_Debug_user_desktop.obj):(__catch$??$_Emplace_reallocate@AEBQEAUNamespace@f_b_flatbuffers@@@?$vector@PEAUNamespace@f_b_flatbuffers@@V?$allocator@PEAUNamespace@f_b_flatbuffers@@@std@@@std@@QEAAPEAPEAUNamespace@f_b_flatbuffers@@QEAPEAU23@AEBQEAU23@@Z$0)
1>
1>lld-link : error : relocation against symbol in discarded section: $LN32
1>>>> referenced by C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.29.30133\include\vector:1026
1>>>>               firebase_app.lib(d94e1bff3c0e8414a6679ea91c3e103e_firebase_app.dir_Debug_variant_util.obj):($LN30)
1>
1>lld-link : error : too many errors emitted, stopping now (use /errorlimit:0 to see all errors)

[triplef]

The issue can also be reproduced using the auth sample project from quickstart-cpp like this:

1. Ensure Visual Studio is set up with support for Clang (instructions)
2. Open "testapp" folder in Visual Studio
3. Select Project menu > CMake settings
4. Click "+" button and select "x64-Clang-Debug"
5. In "CMake command arguments" enter -DFIREBASE_CPP_SDK_DIR=<path-to-sdk>
6. Build project

[DellaBitta]

HI @triplef,

It's unclear if this is a build configuration mismatch between the toolchain used to precompile and link the Firebase C++ SDK libraries, and the toolchain you're using to link the final application. Or, it could be a bug in one of the toolchains.

The best way forward to resolve this issue is to build and link the libraries from the source in the repository using the same toolchain you're using in the final app.

I hope this helps!

[google-oss-bot]

Hey @triplef. We need more information to resolve this issue but there hasn't been an update in 5 weekdays. I'm marking the issue as stale and if there are no new updates in the next 5 days I will close it automatically.

If you have more information that will help us get to the bottom of this, just add a comment!

[triplef]

Thanks for your feedback @DellaBitta. I’ll try building from source and report back after the holidays.