build failure on mingw gcc 4.9.1

I encountered a new build failure (r227128) on my nightly build of LLVM for MinGW:

FAILED: cmd.exe /c cd . && D:\MinGW\x86_64-4.9.1-release-posix-seh-rt_v3-rev0\mingw64\bin\c++.exe -Wall -W -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=gnu++11 -g utils/not/CMakeFiles/not.dir/not.cpp.obj -o bin/not.exe -Wl,–major-image-version,0,–minor-image-version,0 lib/libLLVMSupportD.a -limagehlp -lpsapi -lshell32 -lkernel32 -luser32 -lgdi32 -lwinspool -lshell32 -lole32 -loleaut32 -luuid -lcomdlg32 -ladvapi32 && cd .

lib/libLLVMSupportD.a(Signals.cpp.obj): In function `llvm::sys::PrintStackTraceOnErrorSignal()’:

D:/Slave/llvm-mingw/build/lib/Support/Windows/Signals.inc:284: undefined reference to `__imp__set_abort_behavior’

D:/Slave/llvm-mingw/build/lib/Support/Windows/Signals.inc:286: undefined reference to `__imp__set_abort_behavior’

collect2.exe: error: ld returned 1 exit status

So, set**abort_behavior is not found. This should be solvable by specifying a newer MSVCRT version (see http://sourceforge.net/p/mingw/support-requests/153/ ). I’ll try it, and if it works, could we add that to the CMakeLists?

Adding -D__MSVCRT_VERSION__=0x900 (or higher) to CMAKE_CXX_FLAGS and -lmsvcr90 (or higher) to CMAKE_CXX_STANDARD_LIBRARIES appears to work. -lmsvcrt80 does not work, contrary to the comment on the MinGW bug tracker. However, if you do not have the runtimes installed, errors will occur later on in the build process, such as:

[215/1199] Building Intrinsics.gen…

FAILED: cmd.exe /c cd D:\Slave\llvm-mingw\buildMinGW\include\llvm\IR && D:\Slave\llvm-mingw\buildMinGW\bin\llvm-tblgen.exe -gen-intrinsic -I D:/Slave/llvm-mingw/build/include/llvm/IR -I D:/Slave/llvm-mingw/build/lib/Target -I D:/Slave/llvm-mingw/build/include D:/Slave/llvm-mingw/build/include/llvm/IR/Intrinsics.td -o D:/Slave/llvm-mingw/buildMinGW/include/llvm/IR/Intrinsics.gen.tmp

As I do not have administrative privileges on the machine, I switched to MSVCRT100, as those runtimes were already installed. Which leads me to the question: Should the exact MSVCRT version be selectable or should the lowest version necessary (9.0) be used?

Adding -D__MSVCRT_VERSION__=0x900 (or higher) to CMAKE_CXX_FLAGS and
-lmsvcr90 (or higher) to CMAKE_CXX_STANDARD_LIBRARIES appears to work.
-lmsvcrt80 does not work, contrary to the comment on the MinGW bug tracker.
However, if you do not have the runtimes installed, errors will occur later
on in the build process, such as:

[215/1199] Building Intrinsics.gen...

FAILED: cmd.exe /c cd D:\Slave\llvm-mingw\buildMinGW\include\llvm\IR &&
D:\Slave\llvm-mingw\buildMinGW\bin\llvm-tblgen.exe -gen-intrinsic -I
D:/Slave/llvm-mingw/build/include/llvm/IR -I
D:/Slave/llvm-mingw/build/lib/Target -I D:/Slave/llvm-mingw/build/include
D:/Slave/llvm-mingw/build/include/llvm/IR/Intrinsics.td -o
D:/Slave/llvm-mingw/buildMinGW/include/llvm/IR/Intrinsics.gen.tmp

As I do not have administrative privileges on the machine, I switched to
MSVCRT100, as those runtimes were already installed. Which leads me to the
question: Should the exact MSVCRT version be selectable or should the lowest
version necessary (9.0) be used?

Is there any way for CMake to detect which version of MSVCRT is
present? Otherwise there's really no default we can give. If not, then
we'll have to disable the error UI suppression on mingw.

- Michael Spencer

We could probably do a glob on C:/Windows/System32 to find all msvcr*.dll or something like that. But this seems excessively complicated. It might be better to just provide a variable MINGW_MSVCRT_VERSION which is set to 90 by default and can be set to 100 or 110 (or as soon as mingw supports it 120) as desired. None of these options require installing Visual C++, you only need to install the redistributables, so I think that requirement isn't too bad.

On MinGW, we could use GetProcAddress and GetModuleHandle(dllname) for all
dll names in { "msvcrt120", "msvcrt110", ... }, as horrible as that is.

That really is horrible…

Here’s basically the same thing but on the CMake side of things. It works but it ain’t pretty:

if(MINGW OR CYGWIN)

function(get_newest_msvcrt OUTVAR)

file(TO_CMAKE_PATH $ENV{WINDIR} WINDIR)

file(GLOB INSTALLED_MSVCRT_RUNTIMES “${WINDIR}/System32/msvcr*.dll”)

set(INSTALLED_MSVCRT_NAMES)

foreach(MSVCRT ${INSTALLED_MSVCRT_RUNTIMES})

get_filename_component(MSVCRT ${MSVCRT} NAME_WE)

list(APPEND INSTALLED_MSVCRT_NAMES ${MSVCRT})

endforeach()

foreach(VERSION 110 100 90) # try newest first

list(FIND INSTALLED_MSVCRT_NAMES “msvcr${VERSION}” INDEX)

if(INDEX GREATER -1)

set(${OUTVAR} ${VERSION} PARENT_SCOPE)

return()

endif()

endforeach()

message(FATAL_ERROR “No compatible MSVCRT runtime installed”)

endfunction()

get_newest_msvcrt(NEWEST_MSVCRT)

foreach(LANG C CXX)

set(CMAKE_${LANG}FLAGS "${CMAKE${LANG}FLAGS} -D__MSVCRT_VERSION_=0x${NEWEST_MSVCRT}0")

set(CMAKE_${LANG}STANDARD_LIBRARIES "${CMAKE${LANG}_STANDARD_LIBRARIES} -lmsvcr${NEWEST_MSVCRT}")

endforeach()

endif()

The MSVCRT version to use could also be an editable cache variable.

I could create a phabricator patch if you are ok with this solution.