The commit "Consider link dependencies for link language" taught CMake
to propagate linker language preference from languages compiled into
libraries linked by a target. It turns out this should only be done for
some languages, such as C++, because normally the language of the
program entry point (main) should be used.
We introduce variable CMAKE_<LANG>_LINKER_PREFERENCE_PROPAGATES to tell
CMake whether a language should propagate its linker preference across
targets. Currently it is true only for C++.
This factors the decision logic out of cmTarget::ComputeLinkClosure into
dedicated class cmTargetSelectLinker. We replace several local
variables with a single object instance, and organize code into methods.
All global generator CreateLocalGenerator methods automatically
initialize the local generator instances with SetGlobalGenerator. In
several places we were calling SetGlobalGenerator again after receiving
the return value from CreateLocalGenerator. The double-initializations
leaked the resources allocated by the first call to SetGlobalGenerator.
This fix removes the unnecessary calls.
We list implicit link items of languages linked into a target but filter
them by the implicit libraries known to be passed by the main linker
language. Implicit link flags like "-z..." should not be filtered out
because they are not libraries.
In cmComputeLinkInformation we recognize link options that look like
library file names, but pass flags starting in '-' through untouched.
This fixes the ordering of the check to recognize '-' flags first in
case the rest of the option looks like a library file name, as in the
case of "-l:libfoo.a".
In cmComputeLinkInformation we construct regular expressions to
recognize library file names. This fixes the expressions to not allow a
colon (':') in the file name so that "-l:libfoo.a" is left alone.
Some AIX/gcc version combinations the <cstdio> header breaks when large
file support is enabled. See this GCC issue for details:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20366
We work around the problem by enhancing the configuration check for
large file support to include <cstdio> when available. This will cause
LFS to be disabled when the above problem occurs.
This adds implicit libraries and search directories for languages linked
into a target other than the linker language to its link line. For
example, when linking an executable containing both C++ and Fortran code
the C++ linker is used but we need to add the Fortran libraries.
The variables
CMAKE_<LANG>_IMPLICIT_LINK_LIBRARIES
CMAKE_<LANG>_IMPLICIT_LINK_DIRECTORIES
contain the implicit libraries and directories for each language.
Entries for the linker language are known to be implicit in the
generated link line. Entries for other languages that do not appear in
the known implicit set are listed explicitly at the end of the link
line.
The "Keep only FinalPass commands in memory" commit caused instances of
this command to be deleted after the InitialPass. Even though the
variable_watch command does not have a final pass, it does need to stay
alive because it owns the callback information.
In cmMakefile we save all invoked commands so that FinalPass can be
called on them later. Most commands have no final pass, so we should
keep only the few that do.
This teaches CMake to detect implicit link information for C, C++, and
Fortran compilers. We detect the implicit linker search directories and
implicit linker options for UNIX-like environments using verbose output
from compiler front-ends. We store results in new variables called
CMAKE_<LANG>_IMPLICIT_LINK_LIBRARIES
CMAKE_<LANG>_IMPLICIT_LINK_DIRECTORIES
The implicit libraries can contain linker flags as well as library
names.
This teaches the command to recognize full windows paths when built on
UNIX. CollapseFullPath knows when the input path is relative better
than FileIsFullPath because the latter is only meant for paths from the
host platform.
Previously each new variable scope (subdirectory or function call) in
the CMake language created a complete copy of the key->value definition
map. This avoids the copy using transitive lookups up the scope stack.
Results of queries answered by parents are stored locally to maintain
locality of reference.
The class cmDefinitions replaces cmMakefile::DefinitionsMap, and is
aware of its enclosing scope. Each scope stores only the definitions
set (or unset!) inside it relative to the enclosing scope.
Generated makefiles for try-compile projects should never use color
output. On MSYS the color escapes end up in the try-compile output text
because there is no way to identify whether the output is going to a
color-capable terminal. Instead we should just always skip color for
try-compile projects.
Brad King
KWSys Robot
Bill Hoffman
Dave Partyka
David Cole
Mathieu Malaterre
Clinton Stimpson