Why do we have a dependency on msvcr90 if compiling with MINGW?

[cowo78]

I see from 146e2ed that msvcr90 is brought in as a dependency when compiling with MINGW.

Could it be clarified what are the dependencies that we have from msvcr?

Why is msvcr90 (Visual Studio 2008) hardcoded? Shouldn't we link to whatever is available on the system?

[mariuszmaximus]

in my opinion this is a mistake,

I use MSYS2 clang 15.0.5 and MINGW is True
I remove lines

	if(MINGW)
	    set(MINGW_MSVCR_LIBRARY "msvcr90$<$<CONFIG:DEBUG>>" CACHE STRING "Mingw MSVC runtime import library")
	    list(APPEND _BACKWARD_LIBRARIES ${MINGW_MSVCR_LIBRARY})
	endif()

then:
[ctest] 100% tests passed, 0 tests failed out of 5

[bombela]

The pull request #234 states:

msvcr90 was needed because backward-cpp uses _set_abort_behavior.

[bombela]

It is used there:

backward-cpp/backward.hpp

Line 4338 in dc8b8c7

_set_abort_behavior(0, _WRITE_ABORT_MSG | _CALL_REPORTFAULT);

Maybe MinGW didn't implements this before? Or it behaves differently? Clearly it seems to compile fine for you.

[mariuszmaximus]

I'm programming in C++ very little, I'm not an expert(I've used Delphi all my life) , but MinGW is broad concept.
It is included in it:

• MinGW (I don't think anyone uses it anymore)
• Cygwin
• Mingw-w64
• MSYS2-mingw32
• MSYS2-mingw64
• MSYS2-clang32
• MSYS2-clang64
• other ?

In MSYS2-mingw64 and MSYS2-clang64 _set_abort_behavior exists and msvcr90 is unnecessary

[cowo78]

As far as I understand _set_abort_behaviour is available in MSYS import libraries that in turn refer to native DLLs (i.e. ucrtbase, msvcr90 ...). Such import libraries are distributed inside mingw-*-crt*.

In our case the problem is that I don't see why it's necessary to hardcode a specific redistributable dependency. The same should be obtained by finding whatever is available on the system.

As far as I know there's no import library for debug MSVC libraries, so I would suggest to change set(MINGW_MSVCR_LIBRARY "msvcr90$<$<CONFIG:DEBUG>:d>" CACHE STRING "Mingw MSVC runtime import library") to find_library(MINGW_MSVCR_LIBRARY ucrtbase msvcr140 msvcr120 msvcr110 msvcr100 msvcr90 REQUIRED DOC "Mingw MSVC runtime import library").

I can provide a PR for that if you see the point.

[cowo78]

In MSYS2-mingw64 and MSYS2-clang64 _set_abort_behavior exists and msvcr90 is unnecessary

AFAIK import libraries exist but the target EXE is dynamically linked to msvcr* or ucrtbase where the symbol is really defined.

[madebr]

I see the missing __imp__set_abort_behavior symbol error again in current master when I build for mingw with -DBUILD_SHARED_LIBS=ON.
The following fixes it for me:

--- a/BackwardConfig.cmake
+++ b/BackwardConfig.cmake
@@ -215,10 +215,9 @@ if(WIN32)
                if(SUPPORT_WINDOWS_DEBUG_INFO)
                        set(CMAKE_EXE_LINKER_FLAGS "-Wl,--pdb= ")
                        add_compile_options(-gcodeview)
-               else()
-                       set(MINGW_MSVCR_LIBRARY "msvcr90$<$<CONFIG:DEBUG>:d>" CACHE STRING "Mingw MSVC runtime import library")
-                       list(APPEND _BACKWARD_LIBRARIES ${MINGW_MSVCR_LIBRARY})
                endif()
+               set(MINGW_MSVCR_LIBRARY "msvcr90$<$<CONFIG:DEBUG>:d>" CACHE STRING "Mingw MSVC runtime import library")
+               list(APPEND _BACKWARD_LIBRARIES ${MINGW_MSVCR_LIBRARY})
        endif() 
 endif()
 

[mariuszmaximus]

@madebr
which mingw ?

• https://sourceforge.net/projects/mingw/ here is gcc 6.x
• https://www.mingw-w64.org/downloads/ I do not know what to choose, too much choice
• https://sourceforge.net/projects/mingw-w64/ maybe this one?

could you send link to your mingw compiler, version and CMakeCache.txt from build ?

on my msys2 when I turn on BACKWARD_SHARED=YES then I must add -lDbghelp

I will look at the problem globally

[madebr]

When I build with -DBACKWARD_SHARED=YES, I additionally get a __imp_SymGetModuleBase64 missing symbol.
Looks like the order of libraries is wrong: -ldbghelp must be after backward.cpp.obj, not before.

Here's my CMakeCache.txt, configured on top of current main (without any patch applied).

I'm using a mingw toolchain, provided by my Linux distribution (Fedora 38).
It provides a gcc toolchain with version 12.2.1, using mingw64 10.0.0.

I will look at the problem globally

It might be interesting to link with MSVC using -nodefaultlib (while debugging, don't push this upstream). This will force you to explicitly add every library as a link argument (including the c, c++ and windows libraries).

[mariuszmaximus]

In my opinion better solution,
compatible with Linux and msys2

if(WIN32)
    list(APPEND _BACKWARD_LIBRARIES dbghelp psapi)
    if(MINGW)
        if(CMAKE_HOST_SYSTEM_NAME STREQUAL "Linux")
            # mingw on Linux platform
            set(MINGW_MSVCR_LIBRARY "msvcr90$<$<CONFIG:DEBUG>:d>" CACHE STRING "Mingw MSVC runtime import library")
            list(APPEND _BACKWARD_LIBRARIES ${MINGW_MSVCR_LIBRARY})
        else()
            # mingw on msys2
            include(CheckCXXCompilerFlag)
            check_cxx_compiler_flag(-gcodeview SUPPORT_WINDOWS_DEBUG_INFO)  
            if(SUPPORT_WINDOWS_DEBUG_INFO)
                set(CMAKE_EXE_LINKER_FLAGS "-Wl,--pdb= ")
                add_compile_options(-gcodeview)
            endif()
        endif()
    endif() 
endif()

[madebr]

Or do a check_c_source_compiles test on all mingw/win32 platforms?

Also, the --codeview test should run on all mingw toolchains.
I don't see why the __imp__set_abort_behavior symbol issue and the -gcodeview check are mutually exclusive.

[cowo78]

Please note also #307 regarding the usage of fixed msvcr90. Better use whatever is available on the system IMO.

[cowo78]

As of 51f0700 there are no unresolved symbols when building with ninja/-DBACKWARD_SHARED=YES/gcc 12.2

[cowo78]

Or do a check_c_source_compiles test on all mingw/win32 platforms?

Also, the --codeview test should run on all mingw toolchains. I don't see why the __imp__set_abort_behavior symbol issue and the -gcodeview check are mutually exclusive.

_set_abort_behavior sets if we want to show a windows error report message or print some text (on the console if any I guess).
-gcodeview produces debug info in CodeView format (compatible with visual c++).

I don't understand why we should use -gcodeview option. If we build on windows with MINGW we will not be able to use the binary with MSVC anyway so I don't understand why we should produce a MSVC debug info. I see this was introduced in af4436f by @mariuszmaximus so maybe you want to shed some light?