llvm dev - Feb 2014 - [LLVMdev] cmake/ninja build failing

A couple of llvm sub-projects have been failing to build for me for a while
(compiler-rt asan and util/unittests, at least). It turns out to be due to the
fact that some paths on my system include spaces and other special characters,
but the the build.ninja file was not generated with correctly quoted strings.
Specifically I'm on OS X and the command is setting -isysroot to a location
inside the Xcode.app, but Xcode is installed at a path which includes spaces and
parentheses.

I see the problem in the build.ninja commands, where FLAGS includes the
problematic setting of isysroot. The cause seems to come down to the line in the
compiler-rt CMakeLists.txt:
>   set(DARWIN_iossim_CFLAGS 
>    -mios-simulator-version-min=7.0 -isysroot ${IOSSIM_SDK_DIR})
where IOSSIM_SDK_DIR is the path including spaces and parens.

I'm not sure why these flags are finding their way into my build since
I'm not doing anything with iOS or the iOS simulator, but
DARWIN_iossim_CFLAGS is getting set based on "if(APPLE)", and for some
reason the iOS CFLAGS are making their way into the build.ninja file. Simply
deleting the cmake commands setting these iOS related variables fixes my build
errors but since I don't know why these variables are used on OS X in the
first place I can't say if removing them this way is the correct solution,
or if maybe the CMakeLists.txt files just needs to properly quote these strings.

Here's my shortened version of that whole `if(APPLE)` block:
> if(APPLE)
>  set(SANITIZER_COMMON_SUPPORTED_DARWIN_OS osx)
> 
>  if(COMPILER_RT_USES_LIBCXX)
>    set(SANITIZER_MIN_OSX_VERSION 10.7)
>  else()
>    set(SANITIZER_MIN_OSX_VERSION 10.6)
>  endif()
>  set(DARWIN_osx_CFLAGS -mmacosx-version-min=${SANITIZER_MIN_OSX_VERSION})
>  set(DARWIN_osx_LINKFLAGS)
> endif()

So, can anyone who's familiar with CMakeLists.txt comment on the correct way
to fix CMakeLists.txt and/or the generated build.ninja?

Thanks,
Seth

On 02/12/2014 02:04 AM, Seth Cantrell wrote:
>>   set(DARWIN_iossim_CFLAGS 
>>    -mios-simulator-version-min=7.0 -isysroot ${IOSSIM_SDK_DIR})
> 
> where IOSSIM_SDK_DIR is the path including spaces and parens.
It looks like the _CFLAGS values are used in the module
cmake/Modules/CompilerRTUtils.cmake:

 function(set_target_compile_flags target)
   foreach(arg ${ARGN})
     set(argstring "${argstring} ${arg}")
   endforeach()
   set_property(TARGET ${target} PROPERTY COMPILE_FLAGS
"${argstring}")
 endfunction()

but that makes no attempt to escape or quote anything.

The COMPILE_FLAGS target property was a very early CMake feature
and is treated as a raw string to put on the command line.  That
is why it needs manual escaping.

CMake 2.8.12 added the COMPILE_OPTIONS property and supporting command:

 http://www.cmake.org/cmake/help/v2.8.12/cmake.html#prop_tgt:COMPILE_OPTIONS
 http://www.cmake.org/cmake/help/v2.8.12/cmake.html#command:target_compile_options

The property holds a ;-list of options to be passed to the compiler.
CMake handles conversion to a command-line string with all needed
escaping.

-Brad

Well, I updated to cmake 2.8.12.2 but the result of changing that COMPILE_FLAGS
to COMPILE_OPTIONS is that quotes are applied incorrectly: quotes are added
surrounding the entire set of flags rather than around each individual item in
the list. Obviously the build doesn't work (with the compiler looking for
files named " -m64 ... ") but checking the relevant build command in
build.ninja at least shows me that the relevant path is indeed getting added via
set_target_compile_flags: the path is now part of one of these quoted strings.

On Feb 12, 2014, at 11:01 AM, Brad King <brad.king at kitware.com> wrote:
> On 02/12/2014 02:04 AM, Seth Cantrell wrote:
>>>  set(DARWIN_iossim_CFLAGS 
>>>   -mios-simulator-version-min=7.0 -isysroot ${IOSSIM_SDK_DIR})
>> 
>> where IOSSIM_SDK_DIR is the path including spaces and parens.
> 
> It looks like the _CFLAGS values are used in the module
> cmake/Modules/CompilerRTUtils.cmake:
> 
> function(set_target_compile_flags target)
>   foreach(arg ${ARGN})
>     set(argstring "${argstring} ${arg}")
>   endforeach()
>   set_property(TARGET ${target} PROPERTY COMPILE_FLAGS
"${argstring}")
> endfunction()
> 
> but that makes no attempt to escape or quote anything.
> 
> The COMPILE_FLAGS target property was a very early CMake feature
> and is treated as a raw string to put on the command line.  That
> is why it needs manual escaping.
> 
> CMake 2.8.12 added the COMPILE_OPTIONS property and supporting command:
> 
> http://www.cmake.org/cmake/help/v2.8.12/cmake.html#prop_tgt:COMPILE_OPTIONS
>
http://www.cmake.org/cmake/help/v2.8.12/cmake.html#command:target_compile_options
> 
> The property holds a ;-list of options to be passed to the compiler.
> CMake handles conversion to a command-line string with all needed
> escaping.
> 
> -Brad
>