Failure building x86_64-w64-mingw32 triplet of clang on Windows

Clang Frontend
1

I was successful building a 32-bit version clang from source on Windows using gcc-5.3. When I try to build a 64-bit version of clang on Windows with the triplet x86_64-w64-mingw32 and the 64-bit version of gcc-5.3 I get as an error:

[482/563] Linking CXX executable bin\c-index-test.exe
FAILED: bin/c-index-test.exe
cmd.exe /C "cd . && C:\utilities\mingw-w64\x86_64-5.3.0-posix-seh-rt_v4-rev0\min
gw64\bin\c++.exe -Wall -W -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wn
o-missing-field-initializers -pedantic -Wno-long-long -Wno-maybe-uninitialized -
Wdelete-non-virtual-dtor -Wno-comment -Werror=date-time -std=gnu++11 -fno-common
-Woverloaded-virtual -fno-strict-aliasing -O2 tools/clang/tools/c-index-test
/CMakeFiles/c-index-test.dir/c-index-test.c.obj tools/clang/tools/c-index-test/C
MakeFiles/c-index-test.dir/core_main.cpp.obj -o bin\c-index-test.exe -Wl,--out-
implib,lib\libc-index-test.dll.a -Wl,--major-image-version,0,--minor-image-versi
on,0 lib/libLLVMSupport.a lib/liblibclang.dll.a lib/libclangAST.a lib/libclangB
asic.a lib/libclangFrontend.a lib/libclangIndex.a C:/utilities/libxml/lib/libxml
2.lib lib/libclangFrontend.a lib/libclangDriver.a -lversion lib/libclangParse.a
lib/libLLVMMCParser.a lib/libclangSerialization.a lib/libclangSema.a lib/libclan
gEdit.a lib/libclangAnalysis.a lib/libLLVMBitReader.a lib/libLLVMOption.a lib/li
bLLVMProfileData.a lib/libclangFormat.a lib/libclangToolingCore.a lib/libclangAS
T.a lib/libclangRewrite.a lib/libclangLex.a lib/libclangBasic.a lib/libLLVMCore.
a lib/libLLVMMC.a lib/libLLVMSupport.a -lpsapi -lshell32 -lole32 -luuid -lkernel
32 -luser32 -lgdi32 -lwinspool -lshell32 -lole32 -loleaut32 -luuid -lcomdlg32 -l
advapi32 && cd ."
tools/clang/tools/c-index-test/CMakeFiles/c-index-test.dir/c-index-test.c.obj:c-
index-test.c:(.text+0x3066): undefined reference to `xmlRelaxNGNewParserCtxt'
tools/clang/tools/c-index-test/CMakeFiles/c-index-test.dir/c-index-test.c.obj:c-
index-test.c:(.text+0x307a): undefined reference to `xmlRelaxNGParse'
tools/clang/tools/c-index-test/CMakeFiles/c-index-test.dir/c-index-test.c.obj:c-
index-test.c:(.text+0x3085): undefined reference to `xmlParseDoc'
tools/clang/tools/c-index-test/CMakeFiles/c-index-test.dir/c-index-test.c.obj:c-
index-test.c:(.text+0x3099): undefined reference to `xmlRelaxNGNewValidCtxt'
tools/clang/tools/c-index-test/CMakeFiles/c-index-test.dir/c-index-test.c.obj:c-
index-test.c:(.text+0x30a7): undefined reference to `xmlRelaxNGValidateDoc'
tools/clang/tools/c-index-test/CMakeFiles/c-index-test.dir/c-index-test.c.obj:c-
index-test.c:(.text+0x30bb): undefined reference to `xmlGetLastError'
tools/clang/tools/c-index-test/CMakeFiles/c-index-test.dir/c-index-test.c.obj:c-
index-test.c:(.text+0x30d3): undefined reference to `xmlRelaxNGFreeValidCtxt'
tools/clang/tools/c-index-test/CMakeFiles/c-index-test.dir/c-index-test.c.obj:c-
index-test.c:(.text+0x30db): undefined reference to `xmlFreeDoc'
tools/clang/tools/c-index-test/CMakeFiles/c-index-test.dir/c-index-test.c.obj:c-
index-test.c:(.text+0x30e3): undefined reference to `xmlRelaxNGFree'
tools/clang/tools/c-index-test/CMakeFiles/c-index-test.dir/c-index-test.c.obj:c-
index-test.c:(.text+0x30eb): undefined reference to `xmlRelaxNGFreeParserCtxt'
tools/clang/tools/c-index-test/CMakeFiles/c-index-test.dir/c-index-test.c.obj:c-
index-test.c:(.text+0x3452): undefined reference to `xmlGetLastError'
tools/clang/tools/c-index-test/CMakeFiles/c-index-test.dir/c-index-test.c.obj:c-
index-test.c:(.text.startup+0x23): undefined reference to `xmlCheckVersion'
collect2.exe: error: ld returned 1 exit status

Anyone know what I have to do to correct this problem ?

I use CMake, ninja, and mingw-64/gcc-5.3. I have not downloaded the optional 'extra' and 'compiler-rt' projects as part of LLVM on Windows.

2

I was successful building a 32-bit version clang from source on Windows
using gcc-5.3. When I try to build a 64-bit version of clang on Windows
with the triplet x86_64-w64-mingw32 and the 64-bit version of gcc-5.3 I get
as an error:

[482/563] Linking CXX executable bin\c-index-test.exe

FAILED: bin/c-index-test.exe
cmd.exe /C "cd . &&
C:\utilities\mingw-w64\x86_64-5.3.0-posix-seh-rt_v4-rev0\min
gw64\bin\c++.exe -Wall -W -Wno-unused-parameter -Wwrite-strings
-Wcast-qual -Wn
o-missing-field-initializers -pedantic -Wno-long-long
-Wno-maybe-uninitialized -
Wdelete-non-virtual-dtor -Wno-comment -Werror=date-time -std=gnu++11
-fno-common
-Woverloaded-virtual -fno-strict-aliasing -O2
tools/clang/tools/c-index-test
/CMakeFiles/c-index-test.dir/c-index-test.c.obj
tools/clang/tools/c-index-test/C
MakeFiles/c-index-test.dir/core_main.cpp.obj -o bin\c-index-test.exe
-Wl,--out-
implib,lib\libc-index-test.dll.a
-Wl,--major-image-version,0,--minor-image-versi
on,0 lib/libLLVMSupport.a lib/liblibclang.dll.a lib/libclangAST.a
lib/libclangB
asic.a lib/libclangFrontend.a lib/libclangIndex.a
C:/utilities/libxml/lib/libxml
2.lib lib/libclangFrontend.a lib/libclangDriver.a -lversion
lib/libclangParse.a
lib/libLLVMMCParser.a lib/libclangSerialization.a lib/libclangSema.a
lib/libclan
gEdit.a lib/libclangAnalysis.a lib/libLLVMBitReader.a lib/libLLVMOption.a
lib/li
bLLVMProfileData.a lib/libclangFormat.a lib/libclangToolingCore.a
lib/libclangAS
T.a lib/libclangRewrite.a lib/libclangLex.a lib/libclangBasic.a
lib/libLLVMCore.
a lib/libLLVMMC.a lib/libLLVMSupport.a -lpsapi -lshell32 -lole32 -luuid
-lkernel
32 -luser32 -lgdi32 -lwinspool -lshell32 -lole32 -loleaut32 -luuid
-lcomdlg32 -l
advapi32 && cd ."

tools/clang/tools/c-index-test/CMakeFiles/c-index-test.dir/c-index-test.c.obj:c-
index-test.c:(.text+0x3066): undefined reference to
`xmlRelaxNGNewParserCtxt'

tools/clang/tools/c-index-test/CMakeFiles/c-index-test.dir/c-index-test.c.obj:c-
index-test.c:(.text+0x307a): undefined reference to `xmlRelaxNGParse'

tools/clang/tools/c-index-test/CMakeFiles/c-index-test.dir/c-index-test.c.obj:c-
index-test.c:(.text+0x3085): undefined reference to `xmlParseDoc'

tools/clang/tools/c-index-test/CMakeFiles/c-index-test.dir/c-index-test.c.obj:c-
index-test.c:(.text+0x3099): undefined reference to
`xmlRelaxNGNewValidCtxt'

tools/clang/tools/c-index-test/CMakeFiles/c-index-test.dir/c-index-test.c.obj:c-
index-test.c:(.text+0x30a7): undefined reference to
`xmlRelaxNGValidateDoc'

tools/clang/tools/c-index-test/CMakeFiles/c-index-test.dir/c-index-test.c.obj:c-
index-test.c:(.text+0x30bb): undefined reference to `xmlGetLastError'

tools/clang/tools/c-index-test/CMakeFiles/c-index-test.dir/c-index-test.c.obj:c-
index-test.c:(.text+0x30d3): undefined reference to
`xmlRelaxNGFreeValidCtxt'

tools/clang/tools/c-index-test/CMakeFiles/c-index-test.dir/c-index-test.c.obj:c-
index-test.c:(.text+0x30db): undefined reference to `xmlFreeDoc'

tools/clang/tools/c-index-test/CMakeFiles/c-index-test.dir/c-index-test.c.obj:c-
index-test.c:(.text+0x30e3): undefined reference to `xmlRelaxNGFree'

tools/clang/tools/c-index-test/CMakeFiles/c-index-test.dir/c-index-test.c.obj:c-
index-test.c:(.text+0x30eb): undefined reference to
`xmlRelaxNGFreeParserCtxt'

tools/clang/tools/c-index-test/CMakeFiles/c-index-test.dir/c-index-test.c.obj:c-
index-test.c:(.text+0x3452): undefined reference to `xmlGetLastError'

tools/clang/tools/c-index-test/CMakeFiles/c-index-test.dir/c-index-test.c.obj:c-
index-test.c:(.text.startup+0x23): undefined reference to
`xmlCheckVersion'
collect2.exe: error: ld returned 1 exit status

Anyone know what I have to do to correct this problem ?

You are failing to link against libxml2. I don't have any idea why that
would be the case. I would recommend that you look at the cake output and
see if it failed to find the 64-bit version of libxml2 on your installation.

3

Why is llvm/clang looking for libxml2 ? It's not a part of the mingw-64/gcc compiler being used to build llvm/clang.

4

I guess you are building on msys2 with external mingw-w64.
CMake picks up msys2’s libxml2, I guess.

Could you try overriding CMake and reconfigure?

-DCMAKE_LIBRARY_PATH=“C:/mingw-w64/x86_64-4.9.3-posix-seh-rt_v4-rev1/mingw64/x86_64-w64-mingw32/lib”

5

I guess you are building on msys2 with external mingw-w64.

No, I am not. Ninja is calling mingw-64/gcc-5.3 directly to build llvm/clang.

CMake picks up msys2's libxml2, I guess.

I do have a 32-bit libxml2 on my Windows PATH from the GnuWin32 package. But why is a build of llvm/clang requiring libxml2, whether a 32-bit or 64-bit version ?

Could you try overriding CMake and reconfigure?
-DCMAKE_LIBRARY_PATH="C:/mingw-w64/x86_64-4.9.3-posix-seh-rt_v4-rev1/mingw64/x86_64-w64-mingw32/lib"

Why would using gcc-4.9.3 make any difference ?

6

I guess you are building on msys2 with external mingw-w64.

No, I am not. Ninja is calling mingw-64/gcc-5.3 directly to build
llvm/clang

.

CMake picks up msys2’s libxml2, I guess.

I do have a 32-bit libxml2 on my Windows PATH from the GnuWin32 package.
But why is a build of llvm/clang requiring libxml2, whether a 32-bit or
64-bit version ?

I don’t know why CMake finds but doesn’t ignore it.
c-index-test uses libxml2 if available. libxml2 is not essential.

We could add extra checks if libxml2 would be really available.

Could you try overriding CMake and reconfigure?
-DCMAKE_LIBRARY_PATH=“C:/mingw-w64/x86_64-4.9.3-posix-seh-rt_v4-rev1/mingw64/x86_64-w64-mingw32/lib”

Why would using gcc-4.9.3 make any difference ?

Excuse me. It was just an example. Please substitute with your mingw-w64’s path.

7

libxml is optional library, used if found.
Maybe CMake finds your libxml2 but does not check if its 32 or 64 bit, just assumes it’s the right one?

8

libxml is optional library, used if found.

Where in the llvm/clang CMake files is libxml specified ?

Maybe CMake finds your libxml2 but does not check if its 32 or 64 bit,
just assumes it's the right one?

I queried this on the CMake mailing list and am awaiting some answer from them. But I expect that if I get one it will be to ask where llvm/clang specifies libxml in its CMakeLists.txt files.

9

clang calls CMake find_package(libxml2) to find libxml2.
This is implemented in the CMake standard module “/usr/share/cmake-3.5/Modules/FindLibXml2.cmake”.

10

clang calls CMake find_package(libxml2) to find libxml2.

Where in the clang source does "find_package(libxml2)" occur ? I could not find <g> it.

11

You need to work on your grep skills :slight_smile:

tools/clang/CMakeLists.txt
171:find_package(LibXml2 2.5.3 QUIET)
172:if (LIBXML2_FOUND)

ismail

12

Thanks I found it also just searching for 'libxml2' with case being ignored in all the .txt files in clang.

Evidently CMake cannot distinguish between finding a package that corresponds to the compiler 32-bit or 64-bit build that you are doing. This surprises me as it says that if I have a 32-bit version of a package and I am doing a 64-bit build, or vice-versa, CMake will act as if it has found the package even when the package cannot work with the build. I do not see this as correct behavior for a build system.