Since commit c16acd35b3 (GenEx: Add support for custom transitive link
properties, 2024-05-09, v3.30.0-rc1~82^2) evaluation of
`TRANSITIVE_LINK_PROPERTIES` by `install(EXPORT)` enables discovery of
missing dependencies on INTERFACE libraries that we did not previously
diagnose. This regressed existing projects that relied on such
non-diagnosis. Although commit 2fc9e482a9 (Evaluation of
TRANSITIVE_LINK_PROPERTIES isn't considered a usage, 2024-07-05) fixed
this, it also made a significant change to the `UseTo` infrastructure
that may have other subtle effects. Replace the fix with an approach
that explicitly models suppression of the relevant diagnostics.
Fixes: #26108
Link line construction starts with `LINK_LIBRARIES` and appends
dependencies from the transitive closure of `INTERFACE_LINK_LIBRARIES`.
Only the entries of `LINK_LIBRARIES` are considered direct link
dependencies. In some advanced use cases, particularly involving static
libraries and static plugins, usage requirements need to update the list
of direct link dependencies. This may mean adding new items, removing
existing items, or both.
Add target properties to encode these usage requirements:
* INTERFACE_LINK_LIBRARIES_DIRECT
* INTERFACE_LINK_LIBRARIES_DIRECT_EXCLUDE
Fixes: #22496
The only purpose of `cmLinkImplItem`'s `FromGenex` member is to decide
whether to check CMP0027. That won't be needed for link items added by
new interfaces in the future. Clarify the name to indicate that we do
not always need to know if the item came from a generator expression.
Linkers always use object files explicitly specified on the command line
regardless of where they appear. Move them to the front of the list of
linked libraries in so that symbols required by the object files can be
resolved by any library.
Issue: #22149
#pragma once is a widely supported compiler pragma, even though it is
not part of the C++ standard. Many of the issues keeping #pragma once
from being standardized (distributed filesystems, build farms, hard
links, etc.) do not apply to CMake - it is easy to build CMake on a
single machine. CMake also does not install any header files which can
be consumed by other projects (though cmCPluginAPI.h has been
deliberately omitted from this conversion in case anyone is still using
it.) Finally, #pragma once has been required to build CMake since at
least August 2017 (7f29bbe6 enabled server mode unconditionally, which
had been using #pragma once since September 2016 (b13d3e0d)). The fact
that we now require C++11 filters out old compilers, and it is unlikely
that there is a compiler which supports C++11 but does not support
#pragma once.
Report in `cmLinkImplementationLibraries` and `cmLinkInterfaceLibraries`
whether the list of libraries depends on a genex referencing the
configuration. We already track whether a genex references the head
target.
Suppress some cases in `Source/cmGeneratorExpressionNode.cxx` and
`Source/cmUVHandlePtr.h` where a few older compilers require a
user-defined default constructor (with `{}`).
Carry a backtrace on every link item, not just link implementation
items. For now the non-impl items will still have empty backtraces at
runtime, but this will allow us to introduce values over time.
Avoid exposing the item name implicitly as std::string. When the item
is a target, avoid storing a second copy of its name.
Most link item construction is paired with calls to `FindTargetToLink`
to get the possible target pointer. Rename these methods to
`ResolveLinkItem` and refactor them to construct the entire item.
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.
Run the `Utilities/Scripts/clang-format.bash` script to update
all our C++ code to a new style defined by `.clang-format`.
Use `clang-format` version 3.8.
* If you reached this commit for a line in `git blame`, re-run the blame
operation starting at the parent of this commit to see older history
for the content.
* See the parent commit for instructions to rebase a change across this
style transition commit.
