Merge topic 'target-sources-refactor'

5de63265 Genex: Only evaluate TARGET_OBJECTS to determine target sources.
aa0a3562 cmGeneratorTarget: Compute target objects on demand
042c1c83 cmTarget: Compute languages from object libraries on demand.
fdcefe3c cmGeneratorTarget: Compute consumed object libraries on demand.
c355d108 cmComputeTargetDepends: Track object library depends.
e5da9e51 cmTarget: Allow any generator expression in SOURCES property.
5702e106 cmTarget: Include TARGET_OBJECTS genex in target SOURCES property.
857d30b5 cmGlobalGenerator: Add interface to call ForceLinkerLanguages
28e1d2f8 cmStringCommand: Add GENEX_STRIP subcommand.
bf98cc25 Genex: Evaluate TARGET_OBJECTS as a normal expression.
8cd113ad cmTarget: Store strings instead of cmSourceFile* to represent SOURCES.
4959f341 cmSourceFileLocation: Collapse full path for directory comparisons.
fcc92878 cmSourceFileLocation: Remove unused Update method.
59e8740a cmTarget: Remove AddSourceFile method
26d494ba cmTarget: Use string API to add sources to cmTarget objects.
d38423ec cmTarget: Add a method to obtain list of filenames for sources.
...

8 files changed, 62 insertions, 4 deletions

diff --git a/Help/command/add_executable.rst b/Help/command/add_executable.rst
index 231eeed..4ed10e1 100644
--- a/Help/command/add_executable.rst
+++ b/Help/command/add_executable.rst
@@ -35,8 +35,11 @@ If ``EXCLUDE_FROM_ALL`` is given the corresponding property will be set on
 the created target.  See documentation of the :prop_tgt:`EXCLUDE_FROM_ALL`
 target property for details.
 
-See the :manual:`cmake-buildsystem(7)` manual for more on defining
-buildsystem properties.
+Source arguments to ``add_executable`` may use "generator expressions" with
+the syntax ``$<...>``.  See the :manual:`cmake-generator-expressions(7)`
+manual for available expressions.  See the :manual:`cmake-buildsystem(7)`
+manual for more on defining buildsystem properties.
+
 
 --------------------------------------------------------------------------
 
diff --git a/Help/command/add_library.rst b/Help/command/add_library.rst
index 0944269..e93ef53 100644
--- a/Help/command/add_library.rst
+++ b/Help/command/add_library.rst
@@ -39,8 +39,10 @@ If ``EXCLUDE_FROM_ALL`` is given the corresponding property will be set on
 the created target.  See documentation of the :prop_tgt:`EXCLUDE_FROM_ALL`
 target property for details.
 
-See the :manual:`cmake-buildsystem(7)` manual for more on defining buildsystem
-properties.
+Source arguments to ``add_library`` may use "generator expressions" with
+the syntax ``$<...>``.  See the :manual:`cmake-generator-expressions(7)`
+manual for available expressions.  See the :manual:`cmake-buildsystem(7)`
+manual for more on defining buildsystem properties.
 
 --------------------------------------------------------------------------
 
diff --git a/Help/command/string.rst b/Help/command/string.rst
index af18825..abde6ee 100644
--- a/Help/command/string.rst
+++ b/Help/command/string.rst
@@ -35,6 +35,7 @@ String operations.
   string(FIND <string> <substring> <output variable> [REVERSE])
   string(TIMESTAMP <output variable> [<format string>] [UTC])
   string(MAKE_C_IDENTIFIER <input string> <output variable>)
+  string(GENEX_STRIP <input string> <output variable>)
 
 REGEX MATCH will match the regular expression once and store the match
 in the output variable.
@@ -154,3 +155,7 @@ If no explicit <format string> is given it will default to:
 
 MAKE_C_IDENTIFIER will write a string which can be used as an
 identifier in C.
+
+``GENEX_STRIP`` will strip any
+:manual:`generator expressions <cmake-generator-expressions(7)>` from the
+``input string`` and store the result in the ``output variable``.
diff --git a/Help/manual/cmake-generator-expressions.7.rst b/Help/manual/cmake-generator-expressions.7.rst
index ac8c3f8..dfda8dc 100644
--- a/Help/manual/cmake-generator-expressions.7.rst
+++ b/Help/manual/cmake-generator-expressions.7.rst
@@ -188,3 +188,8 @@ property is non-empty::
   Content of ``...`` converted to upper case.
 ``$<MAKE_C_IDENTIFIER:...>``
   Content of ``...`` converted to a C identifier.
+``$<TARGET_OBJECTS:objLib>``
+  List of objects resulting from build of ``objLib``. ``objLib`` must be an
+  object of type ``OBJECT_LIBRARY``.  This expression may only be used in
+  the sources of :command:`add_library` and :command:`add_executable`
+  commands.
diff --git a/Help/manual/cmake-policies.7.rst b/Help/manual/cmake-policies.7.rst
index 8650a58..b763882 100644
--- a/Help/manual/cmake-policies.7.rst
+++ b/Help/manual/cmake-policies.7.rst
@@ -102,3 +102,4 @@ All Policies
    /policy/CMP0048
    /policy/CMP0049
    /policy/CMP0050
+   /policy/CMP0051
diff --git a/Help/policy/CMP0051.rst b/Help/policy/CMP0051.rst
new file mode 100644
index 0000000..7d85929
--- /dev/null
+++ b/Help/policy/CMP0051.rst
@@ -0,0 +1,24 @@
+CMP0051
+-------
+
+List TARGET_OBJECTS in SOURCES target property.
+
+CMake 3.0 and lower did not include the ``TARGET_OBJECTS``
+:manual:`generator expression <cmake-generator-expressions(7)>` when
+returning the :prop_tgt:`SOURCES` target property.
+
+Configure-time CMake code is not able to handle generator expressions.  If
+using the :prop_tgt:`SOURCES` target property at configure time, it may be
+necessary to first remove generator expressions using the
+:command:`string(STRIP_GENEX)` command.  Generate-time CMake code such as
+:command:`file(GENERATE)` can handle the content without stripping.
+
+The ``OLD`` behavior for this policy is to omit ``TARGET_OBJECTS``
+expressions from the :prop_tgt:`SOURCES` target property.  The ``NEW``
+behavior for this policy is to include ``TARGET_OBJECTS`` expressions
+in the output.
+
+This policy was introduced in CMake version 3.1.
+CMake version |release| warns when the policy is not set and uses
+``OLD`` behavior.  Use the :command:`cmake_policy` command to set it
+to ``OLD`` or ``NEW`` explicitly.
diff --git a/Help/release/dev/string-GENEX_STRIP.rst b/Help/release/dev/string-GENEX_STRIP.rst
new file mode 100644
index 0000000..b5b1074
--- /dev/null
+++ b/Help/release/dev/string-GENEX_STRIP.rst
@@ -0,0 +1,6 @@
+string-GENEX_STRIP
+------------------
+
+* The :command:`string` command learned a new ``GENEX_STRIP`` subcommand
+  which removes
+  :manual:`generator expression <cmake-generator-expressions(7)>`.
diff --git a/Help/release/dev/target-SOURCES-genex.rst b/Help/release/dev/target-SOURCES-genex.rst
new file mode 100644
index 0000000..9a65101
--- /dev/null
+++ b/Help/release/dev/target-SOURCES-genex.rst
@@ -0,0 +1,12 @@
+target-SOURCES-genex
+--------------------
+
+* The :prop_tgt:`SOURCES` target property now contains
+  :manual:`generator expression <cmake-generator-expressions(7)>`
+  such as ``TARGET_OBJECTS`` when read at configure time, if
+  policy :policy:`CMP0051` is ``NEW``.
+
+* The :prop_tgt:`SOURCES` target property now generally supports
+  :manual:`generator expression <cmake-generator-expressions(7)>`.  The
+  generator expressions may be used in the :command:`add_library` and
+  :command:`add_executable` commands.