Per-source copyright/license notice headers that spell out copyright holder
names and years are hard to maintain and often out-of-date or plain wrong.
Precise contributor information is already maintained automatically by the
version control tool. Ultimately it is the receiver of a file who is
responsible for determining its licensing status, and per-source notices are
merely a convenience. Therefore it is simpler and more accurate for
each source to have a generic notice of the license name and references to
more detailed information on copyright holders and full license terms.
Our `Copyright.txt` file now contains a list of Contributors whose names
appeared source-level copyright notices. It also references version control
history for more precise information. Therefore we no longer need to spell
out the list of Contributors in each source file notice.
Replace CMake per-source copyright/license notice headers with a short
description of the license and links to `Copyright.txt` and online information
available from "https://cmake.org/licensing". The online URL also handles
cases of modules being copied out of our source into other projects, so we
can drop our notices about replacing links with full license text.
Run the `Utilities/Scripts/filter-notices.bash` script to perform the majority
of the replacements mechanically. Manually fix up shebang lines and trailing
newlines in a few files. Manually update the notices in a few files that the
script does not handle.
Since commit v3.1.0-rc1~564^2 (OS X: Use -iframework for system
framework directories, 2014-05-05) we test the version of Clang is smaller
that 3.1 to see if it supports -iframework.
Considering that "iframework" support has been added in clang@r142418
(Frontend: Support -iframework.) prior to clang 3.1, this made sense.
That said, considering that support for multiple -iframework parameters
has been added later in clang@r164607 (-iframework should allow separate
arguments. ) prior to clang 3.2, this commit updates the check to enable
framework support only if version is >= 3.2
Just like -I flag has its -isystem counterpart which marks an include
directory as a system directory and prevents unwanted warnings, on Apple
systems there is -iframework -- a system directory replacement for -F.
Use this flag to implement include_directories(SYSTEM) for frameworks.
We detect the implicit link directories for the toolchain by adding a
flag to get verbose output from the compiler front-end while linking the
ABI detection binary. Newer OS X toolchains based on Clang do not add
the implicit link directories with -L options to their internal
invocation of "ld". Instead they use a linker that comes with the
toolchain and is already configured with the proper directories.
Add the "-Wl,-v" option to ask "ld" to print its implicit directories.
It displays them in a block such as:
Library search paths:
/...
Parse this block to extract the implicit link directories.
While at it, remove the checks introduced by commit efaf335b (Skip
implicit link information on Xcode, 2009-07-23) and commit 5195a664
(Skip implicit link info for multiple OS X archs, 2009-09-22). Discard
the non-system link directories added by Xcode. Discard all detected
implicit libraries in the multi-architecture case but keep the
directories. The directories are still useful without the libraries
just to suppress addition of explicit -L options for them.
Drop the last use of CMAKE_OSX_SYSROOT_DEFAULT. Replace internal
platform variable CMAKE_${lang}_HAS_ISYSROOT with a more general
CMAKE_${lang}_SYSROOT_FLAG variable. If the -isysroot flag exists and
CMAKE_OSX_SYSROOT points to an SDK (not "/") then always add it to
compiler command lines. This is already done in the Xcode IDE.
Clang has the same interface as GNU except that we do not need to test
for the deployment target and sysroot flags. Simply set variables
CMAKE_${lang}_HAS_ISYSROOT
CMAKE_${lang}_OSX_DEPLOYMENT_TARGET_FLAG
to true because every version of Clang available on OS X supports these
flags.
Brad King
Jean-Christophe Fillion-Robin
Mikołaj Siedlarek