15 files changed, 137 insertions, 59 deletions
diff --git a/Help/command/add_subdirectory.rst b/Help/command/add_subdirectory.rst
index fe17b56..ae063e6 100644
--- a/Help/command/add_subdirectory.rst
+++ b/Help/command/add_subdirectory.rst
@@ -7,16 +7,16 @@ Add a subdirectory to the build.
 
   add_subdirectory(source_dir [binary_dir] [EXCLUDE_FROM_ALL] [SYSTEM])
 
-Adds a subdirectory to the build.  The source_dir specifies the
-directory in which the source CMakeLists.txt and code files are
-located.  If it is a relative path it will be evaluated with respect
+Adds a subdirectory to the build.  The ``source_dir`` specifies the
+directory in which the source ``CMakeLists.txt`` and code files are
+located.  If it is a relative path, it will be evaluated with respect
 to the current directory (the typical usage), but it may also be an
 absolute path.  The ``binary_dir`` specifies the directory in which to
-place the output files.  If it is a relative path it will be evaluated
+place the output files.  If it is a relative path, it will be evaluated
 with respect to the current output directory, but it may also be an
 absolute path.  If ``binary_dir`` is not specified, the value of
 ``source_dir``, before expanding any relative path, will be used (the
-typical usage).  The CMakeLists.txt file in the specified source
+typical usage).  The ``CMakeLists.txt`` file in the specified source
 directory will be processed immediately by CMake before processing in
 the current input file continues beyond this command.
 
@@ -28,9 +28,9 @@ meant for use when the subdirectory contains a separate part of the
 project that is useful but not necessary, such as a set of examples.
 Typically the subdirectory should contain its own :command:`project`
 command invocation so that a full build system will be generated in the
-subdirectory (such as a VS IDE solution file).  Note that inter-target
-dependencies supersede this exclusion.  If a target built by the
-parent project depends on a target in the subdirectory, the dependee
+subdirectory (such as a Visual Studio IDE solution file).  Note that
+inter-target dependencies supersede this exclusion.  If a target built by
+the parent project depends on a target in the subdirectory, the dependee
 target will be included in the parent project build system to satisfy
 the dependency.
 
@@ -38,6 +38,4 @@ the dependency.
   If the ``SYSTEM`` argument is provided, the :prop_dir:`SYSTEM` directory
   property of the subdirectory will be set to true.  This property is
   used to initialize the :prop_tgt:`SYSTEM` property of each non-imported
-  target created in that subdirectory.  The include directories of targets
-  with :prop_tgt:`SYSTEM` set to true will be treated as ``SYSTEM`` when
-  compiling consumers.
+  target created in that subdirectory.
diff --git a/Help/command/configure_file.rst b/Help/command/configure_file.rst
index 7fa2941..adc2a66 100644
--- a/Help/command/configure_file.rst
+++ b/Help/command/configure_file.rst
@@ -58,7 +58,7 @@ or
   #define VAR 1
 
 Input lines of the form ``#cmakedefine01 VAR ...`` will expand
-as ``#cmakedefine01 VAR ... 0`` or ``#cmakedefine01 VAR ... 0``,
+as ``#cmakedefine01 VAR ... 0`` or ``#cmakedefine01 VAR ... 1``,
 which may lead to undefined behavior.
 
 .. versionadded:: 3.10
diff --git a/Help/manual/cmake-buildsystem.7.rst b/Help/manual/cmake-buildsystem.7.rst
index 0990320..9e467bf 100644
--- a/Help/manual/cmake-buildsystem.7.rst
+++ b/Help/manual/cmake-buildsystem.7.rst
@@ -672,14 +672,14 @@ This is equivalent to appending ``${CMAKE_INSTALL_PREFIX}/include`` to the
 
 When the :prop_tgt:`INTERFACE_INCLUDE_DIRECTORIES` of an
 :ref:`imported target <Imported targets>` is consumed, the entries in the
-property are treated as ``SYSTEM`` include directories, as if they were
-listed in the :prop_tgt:`INTERFACE_SYSTEM_INCLUDE_DIRECTORIES` of the
-dependency. This can result in omission of compiler warnings for headers
-found in those directories.  This behavior for :ref:`imported targets` may
-be controlled by setting the :prop_tgt:`NO_SYSTEM_FROM_IMPORTED` target
-property on the *consumers* of imported targets, or by setting the
-:prop_tgt:`IMPORTED_NO_SYSTEM` target property on the imported targets
-themselves.
+property may be treated as system include directories.  The effects of that
+are toolchain-dependent, but one common effect is to omit compiler warnings
+for headers found in those directories.  The :prop_tgt:`SYSTEM` property of
+the installed target determines this behavior (see the
+:prop_tgt:`EXPORT_NO_SYSTEM` property for how to modify the installed value
+for a target).  It is also possible to change how consumers interpret the
+system behavior of consumed imported targets by setting the
+:prop_tgt:`NO_SYSTEM_FROM_IMPORTED` target property on the *consumer*.
 
 If a binary target is linked transitively to a macOS :prop_tgt:`FRAMEWORK`, the
 ``Headers`` directory of the framework is also treated as a usage requirement.
diff --git a/Help/manual/cmake-configure-log.7.rst b/Help/manual/cmake-configure-log.7.rst
index 7f395f5..f909717 100644
--- a/Help/manual/cmake-configure-log.7.rst
+++ b/Help/manual/cmake-configure-log.7.rst
@@ -73,6 +73,16 @@ they do not understand:
 * If an existing build tree is re-configured with a different version of
   CMake, the log may contain different versions of the same event kind.
 
+* If :manual:`cmake-file-api(7)` queries request one or more
+  :ref:`configureLog <file-api configureLog>` object versions,
+  the log may contain multiple entries for the same event, each
+  with a different version of its event kind.
+
+IDEs should write a :manual:`cmake-file-api(7)` query requesting a
+specific :ref:`configureLog <file-api configureLog>` object version,
+before running CMake, and then read the configure log only as described
+by the file-api reply.
+
 Text Block Encoding
 -------------------
 
diff --git a/Help/manual/cmake-file-api.7.rst b/Help/manual/cmake-file-api.7.rst
index cdc86ec..7ff9728 100644
--- a/Help/manual/cmake-file-api.7.rst
+++ b/Help/manual/cmake-file-api.7.rst
@@ -1298,6 +1298,45 @@ elsewhere in the containing object.  The backtrace graph object members are:
   directory then the path is specified relative to that directory.
   Otherwise the path is absolute.
 
+.. _`file-api configureLog`:
+
+Object Kind "configureLog"
+--------------------------
+
+The ``configureLog`` object kind describes the location and contents of
+a :manual:`cmake-configure-log(7)` file.
+
+There is only one ``configureLog`` object major version, version 1.
+
+"configureLog" version 1
+^^^^^^^^^^^^^^^^^^^^^^^^
+
+``configureLog`` object version 1 is a JSON object:
+
+.. code-block:: json
+
+  {
+    "kind": "configureLog",
+    "version": { "major": 1, "minor": 0 },
+    "path": "/path/to/top-level-build-dir/CMakeFiles/CMakeConfigureLog.yaml",
+    "eventKindNames": [ "try_compile-v1", "try_run-v1" ]
+  }
+
+The members specific to ``configureLog`` objects are:
+
+``path``
+  A string specifying the path to the configure log file.
+  Clients must read the log file from this path, which may be
+  different than the path documented by :manual:`cmake-configure-log(7)`.
+  The log file may not exist if no events are logged.
+
+``eventKindNames``
+  A JSON array whose entries are each a JSON string naming one
+  of the :manual:`cmake-configure-log(7)` versioned event kinds.
+  At most one version of each configure log event kind will be listed.
+  Although the configure log may contain other (versioned) event kinds,
+  clients must ignore those that are not listed in this field.
+
 Object Kind "cache"
 -------------------
 
diff --git a/Help/prop_tgt/EXPORT_NO_SYSTEM.rst b/Help/prop_tgt/EXPORT_NO_SYSTEM.rst
index 61f0a8d..f86abd3 100644
--- a/Help/prop_tgt/EXPORT_NO_SYSTEM.rst
+++ b/Help/prop_tgt/EXPORT_NO_SYSTEM.rst
@@ -3,8 +3,10 @@ EXPORT_NO_SYSTEM
 
 .. versionadded:: 3.25
 
-Specifies that :command:`install(EXPORT)` and :command:`export` commands will
-generate an imported target with :prop_tgt:`SYSTEM` property `OFF`.
+This property affects the behavior of the :command:`install(EXPORT)` and
+:command:`export` commands when they install or export the target respectively.
+When ``EXPORT_NO_SYSTEM`` is set to true, those commands generate an imported
+target with :prop_tgt:`SYSTEM` property set to false.
 
 See the :prop_tgt:`NO_SYSTEM_FROM_IMPORTED` target property to set this
 behavior on the target *consuming* the include directories rather than the
diff --git a/Help/prop_tgt/FOLDER.rst b/Help/prop_tgt/FOLDER.rst
index f6be9e6..3155d90 100644
--- a/Help/prop_tgt/FOLDER.rst
+++ b/Help/prop_tgt/FOLDER.rst
@@ -11,3 +11,6 @@ separating folder levels.
 
 This property is initialized by the value of the variable
 :variable:`CMAKE_FOLDER` if it is set when a target is created.
+
+The global property :prop_gbl:`USE_FOLDERS` must be set to ON, otherwise
+the ``FOLDER`` property is ignored.
diff --git a/Help/prop_tgt/IMPORTED_NO_SYSTEM.rst b/Help/prop_tgt/IMPORTED_NO_SYSTEM.rst
index 913d9f2..c8ec8b5 100644
--- a/Help/prop_tgt/IMPORTED_NO_SYSTEM.rst
+++ b/Help/prop_tgt/IMPORTED_NO_SYSTEM.rst
@@ -5,27 +5,31 @@ IMPORTED_NO_SYSTEM
 
 .. deprecated:: 3.25
 
-  ``IMPORTED_NO_SYSTEM`` is deprecated. Set :prop_tgt:`SYSTEM` to `OFF`
-  instead if you don't want target's include directories to be ``SYSTEM``
-  when compiling consumers. Set :prop_tgt:`EXPORT_NO_SYSTEM` to `ON` instead
-  if you don't want the include directories of the imported target generated
-  by :command:`install(EXPORT)` and :command:`export` commands to be
-  ``SYSTEM`` when compiling consumers.
+  ``IMPORTED_NO_SYSTEM`` is deprecated. Please use the following alternatives
+  instead:
 
-Specifies that an :ref:`Imported Target <Imported Targets>` is not
-a ``SYSTEM`` library.  This has the following effects:
+  * Set :prop_tgt:`SYSTEM` to false if you don't want a target's include
+    directories to be treated as system directories when compiling consumers.
+  * Set :prop_tgt:`EXPORT_NO_SYSTEM` to true if you don't want the include
+    directories of the imported target generated by :command:`install(EXPORT)`
+    and :command:`export` commands to be treated as system directories when
+    compiling consumers.
+
+Setting ``IMPORTED_NO_SYSTEM`` to true on an
+:ref:`imported target <Imported Targets>` specifies that it is not a
+system target.  This has the following effects:
 
 * Entries of :prop_tgt:`INTERFACE_INCLUDE_DIRECTORIES` are not treated
-  as ``SYSTEM`` include directories when compiling consumers (regardless of
+  as system include directories when compiling consumers (regardless of
   the value of the consumed target's :prop_tgt:`SYSTEM` property), as they
   would be by default.   Entries of
   :prop_tgt:`INTERFACE_SYSTEM_INCLUDE_DIRECTORIES` are not affected,
-  and will always be treated as ``SYSTEM`` include directories.
+  and will always be treated as system include directories.
 
 This property can also be enabled on a non-imported target.  Doing so does
 not affect the build system, but does tell the :command:`install(EXPORT)` and
 :command:`export` commands to enable it on the imported targets they generate.
 
 See the :prop_tgt:`NO_SYSTEM_FROM_IMPORTED` target property to set this
-behavior on the target consuming the include directories rather than
-providing them.
+behavior on the target *consuming* the include directories rather than
+the one *providing* them.
diff --git a/Help/prop_tgt/INTERFACE_SYSTEM_INCLUDE_DIRECTORIES.rst b/Help/prop_tgt/INTERFACE_SYSTEM_INCLUDE_DIRECTORIES.rst
index b37bb0c..2ded46f 100644
--- a/Help/prop_tgt/INTERFACE_SYSTEM_INCLUDE_DIRECTORIES.rst
+++ b/Help/prop_tgt/INTERFACE_SYSTEM_INCLUDE_DIRECTORIES.rst
@@ -8,17 +8,17 @@ which contain system headers, and therefore should not result in
 compiler warnings.  Additionally, system include directories are searched
 after normal include directories regardless of the order specified.
 
-The :command:`target_include_directories(SYSTEM)` command signature
-populates this property with values given to the ``PUBLIC`` and
-``INTERFACE`` keywords.
+When the :command:`target_include_directories` command is given the
+``SYSTEM`` keyword, it populates this property with values provided after the
+``PUBLIC`` and ``INTERFACE`` keywords.
 
 Projects may also get and set the property directly, but must be aware that
 adding directories to this property does not make those directories used
 during compilation.  Adding directories to this property marks directories
-as ``SYSTEM`` which otherwise would be used in a non-``SYSTEM`` manner.  This
-can appear similar to 'duplication', so prefer the
-high-level :command:`target_include_directories(SYSTEM)` command and avoid
-setting the property by low-level means.
+as system directories which otherwise would be used in a non-system manner.
+This can appear similar to duplication, so prefer the high-level
+:command:`target_include_directories` command with the ``SYSTEM`` keyword
+and avoid setting the property directly.
 
 When target dependencies are specified using :command:`target_link_libraries`,
 CMake will read this property from all target dependencies to mark the
diff --git a/Help/prop_tgt/NO_SYSTEM_FROM_IMPORTED.rst b/Help/prop_tgt/NO_SYSTEM_FROM_IMPORTED.rst
index 39a13ee..a4c9b9f 100644
--- a/Help/prop_tgt/NO_SYSTEM_FROM_IMPORTED.rst
+++ b/Help/prop_tgt/NO_SYSTEM_FROM_IMPORTED.rst
@@ -2,19 +2,27 @@ NO_SYSTEM_FROM_IMPORTED
 -----------------------
 
 Do not treat include directories from the interfaces of consumed
-:ref:`imported targets` as ``SYSTEM``.
+:ref:`imported targets` as system directories.
 
 The contents of the :prop_tgt:`INTERFACE_INCLUDE_DIRECTORIES` target property
-of imported targets are treated as ``SYSTEM`` includes by default.  If this
-property is enabled on a target, compilation of sources in that target will
-not treat the contents of the ``INTERFACE_INCLUDE_DIRECTORIES`` of consumed
-imported targets as system includes.  Either way, entries of
-:prop_tgt:`INTERFACE_SYSTEM_INCLUDE_DIRECTORIES` are not affected,
-and will always be treated as ``SYSTEM`` include directories.
+are treated as system includes when the consumed target's :prop_tgt:`SYSTEM`
+property is set to true.  By default, :prop_tgt:`SYSTEM` is true for imported
+targets and false for other target types.  If the ``NO_SYSTEM_FROM_IMPORTED``
+property is set to true on a *consuming* target, compilation of sources in that
+consuming target will not treat the contents of the
+:prop_tgt:`INTERFACE_INCLUDE_DIRECTORIES` of consumed imported targets as
+system includes, even if that imported target's :prop_tgt:`SYSTEM` property
+is false.
+
+Directories listed in the :prop_tgt:`INTERFACE_SYSTEM_INCLUDE_DIRECTORIES`
+property of consumed targets are not affected by ``NO_SYSTEM_FROM_IMPORTED``.
+Those directories will always be treated as system include directories by
+consumers.
 
 This property is initialized by the value of the
 :variable:`CMAKE_NO_SYSTEM_FROM_IMPORTED` variable if it is set when a target
 is created.
 
-See the :prop_tgt:`IMPORTED_NO_SYSTEM` target property to set this behavior
-on the target providing the include directories rather than consuming them.
+See the :prop_tgt:`EXPORT_NO_SYSTEM` target property to set this behavior
+on the target providing the include directories rather than the target
+consuming them.
diff --git a/Help/prop_tgt/SYSTEM.rst b/Help/prop_tgt/SYSTEM.rst
index 6399d24..c7ae27e 100644
--- a/Help/prop_tgt/SYSTEM.rst
+++ b/Help/prop_tgt/SYSTEM.rst
@@ -3,20 +3,20 @@ SYSTEM
 
 .. versionadded:: 3.25
 
-Specifies that a target is a ``SYSTEM`` library.  This has the following
+Specifies that a target is a system target.  This has the following
 effects:
 
 * Entries of :prop_tgt:`INTERFACE_INCLUDE_DIRECTORIES` are treated as
-  ``SYSTEM`` include directories when compiling consumers.
+  system include directories when compiling consumers.
   Entries of :prop_tgt:`INTERFACE_SYSTEM_INCLUDE_DIRECTORIES` are not
-  affected, and will always be treated as ``SYSTEM`` include directories.
+  affected, and will always be treated as system include directories.
 
 For imported targets, this property defaults to true, which means
 that their :prop_tgt:`INTERFACE_INCLUDE_DIRECTORIES` are treated
-as ``SYSTEM`` by default. If their ``SYSTEM`` property is false,
+as system directories by default.  If their ``SYSTEM`` property is false,
 then their :prop_tgt:`INTERFACE_INCLUDE_DIRECTORIES` will not be
-treated as ``SYSTEM``, regardless of the value of the
-:prop_tgt:`IMPORTED_NO_SYSTEM` property.
+treated as system.  Use the :prop_tgt:`EXPORT_NO_SYSTEM` property to change
+how a target's ``SYSTEM`` property is set when it is installed.
 
 For non-imported targets, this target property is initialized from
 the :prop_dir:`SYSTEM` directory property when the target is created.
diff --git a/Help/release/3.25.rst b/Help/release/3.25.rst
index e76a308..dea8de8 100644
--- a/Help/release/3.25.rst
+++ b/Help/release/3.25.rst
@@ -159,9 +159,10 @@ Properties
 Modules
 -------
 
-* The :module:`FetchContent` module :command:`FetchContent_Declare`
-  command gained a ``SYSTEM`` option to enable the :prop_dir:`SYSTEM`
-  directory property in the subdirectory.
+* The :module:`FetchContent` module's :command:`FetchContent_Declare`
+  command gained a ``SYSTEM`` option which sets the :prop_dir:`SYSTEM`
+  directory property on subdirectories created by
+  :command:`FetchContent_MakeAvailable`.
 
 * The :module:`FindCUDAToolkit` module now provides a target for
   :ref:`nvtx3 <cuda_toolkit_nvtx3>` for CUDA 10.0+, which supersedes
diff --git a/Help/release/dev/configure-log.rst b/Help/release/dev/configure-log.rst
index 8518b21..34b8fb3 100644
--- a/Help/release/dev/configure-log.rst
+++ b/Help/release/dev/configure-log.rst
@@ -3,3 +3,6 @@ Configure Log
 
 * CMake now writes a YAML log of configure-time checks.
   See the :manual:`cmake-configure-log(7)` manual.
+
+* The :manual:`cmake-file-api(7)` gained a new "configureLog" object kind
+  that enables stable access to the :manual:`cmake-configure-log(7)`.
diff --git a/Help/release/dev/frontend-variant-always.rst b/Help/release/dev/frontend-variant-always.rst
new file mode 100644
index 0000000..111175c
--- /dev/null
+++ b/Help/release/dev/frontend-variant-always.rst
@@ -0,0 +1,6 @@
+frontend-variant-always
+-----------------------
+
+* The :variable:`CMAKE_<LANG>_COMPILER_FRONTEND_VARIANT` variable is now
+  set for ``GNU``, ``MSVC``, and ``AppleClang`` compilers that have only
+  one frontend variant.
diff --git a/Help/variable/CMAKE_LANG_COMPILER_FRONTEND_VARIANT.rst b/Help/variable/CMAKE_LANG_COMPILER_FRONTEND_VARIANT.rst
index 128b1fb..a414463 100644
--- a/Help/variable/CMAKE_LANG_COMPILER_FRONTEND_VARIANT.rst
+++ b/Help/variable/CMAKE_LANG_COMPILER_FRONTEND_VARIANT.rst
@@ -16,3 +16,7 @@ the compiler whose frontend it resembles.
 .. note::
   In other words, this variable describes what command line options
   and language extensions the compiler frontend expects.
+
+.. versionchanged:: 3.26
+  This variable is set for ``GNU``, ``MSVC``, and ``AppleClang``
+  compilers that have only one frontend variant.