ALIAS: Add support for target_* commands

Now that set_property and set_target_properties support ALIAS targets,
we need to extend support to all the target_* type commands that modify
target properties.

Relaxes target_compile_definitions, target_compile_features,
target_compile_options, target_include_directories,
target_link_directories, target_link_libraries, target_link_options,
target_precompile_headers, and target_sources to now accept ALIAS
targets. These commands set properties on the target which the alias
references.

Help/command/add_executable.rst

@@ -115,12 +115,10 @@ tested for existence with the regular :command:`if(TARGET)` subcommand.
 An ``ALIAS`` target may not be installed or exported.
 
 .. versionchanged:: 4.5
-  The ``<name>`` may be used as the operand of :command:`set_property` and
-  :command:`set_target_properties` to modify properties of ``<target>``.  It
-  may not be used with the commands :command:`target_link_libraries`,
-  :command:`target_compile_definitions` etc.  CMake 4.4 and earlier did not
-  allow the ``<name>`` to modify properties of ``<target>`` with
-  :command:`set_property` and :command:`set_target_properties`.
+  The ``<name>`` may be used as the operand of :command:`set_property`,
+  :command:`set_target_properties`, :command:`target_link_libraries`, etc. to
+  modify properties of ``<target>``.  CMake 4.4 and earlier did not allow the
+  ``<name>`` to modify properties of ``<target>``.
 
 See Also
 ^^^^^^^^

Help/command/add_library.rst

@@ -321,12 +321,10 @@ regular :command:`if(TARGET)` subcommand.  An ``ALIAS`` target may not be
 installed or exported.
 
 .. versionchanged:: 4.5
-  The ``<name>`` may be used as the operand of :command:`set_property` and
-  :command:`set_target_properties` to modify properties of ``<target>``.  It
-  may not be used with the commands :command:`target_link_libraries`,
-  :command:`target_compile_definitions` etc.  CMake 4.4 and earlier did not
-  allow the ``<name>`` to modify properties of ``<target>`` with
-  :command:`set_property` and :command:`set_target_properties`.
+  The ``<name>`` may be used as the operand of :command:`set_property`,
+  :command:`set_target_properties`, :command:`target_link_libraries`, etc. to
+  modify properties of ``<target>``.  CMake 4.4 and earlier did not allow the
+  ``<name>`` to modify properties of ``<target>``.
 
 See Also
 ^^^^^^^^

Help/command/target_compile_definitions.rst

@@ -11,8 +11,11 @@ Add compile definitions to a target.
 
 Specifies compile definitions to use when compiling a given ``<target>``.  The
 named ``<target>`` must have been created by a command such as
-:command:`add_executable` or :command:`add_library` and must not be an
-:ref:`ALIAS target <Alias Targets>`.
+:command:`add_executable` or :command:`add_library`.
+
+.. versionchanged:: 4.5
+  If ``<target>`` is an :ref:`Alias Target <Alias Targets>`, the command
+  operates on the target which the alias references.
 
 The ``INTERFACE``, ``PUBLIC`` and ``PRIVATE`` keywords are required to
 specify the :ref:`scope <Target Command Scope>` of the following arguments.

Help/command/target_compile_features.rst

@@ -29,8 +29,11 @@ Repeated calls for the same ``<target>`` append items.
   Allow setting ``INTERFACE`` items on :ref:`IMPORTED targets <Imported Targets>`.
 
 The named ``<target>`` must have been created by a command such as
-:command:`add_executable` or :command:`add_library` and must not be an
-:ref:`ALIAS target <Alias Targets>`.
+:command:`add_executable` or :command:`add_library`.
+
+.. versionchanged:: 4.5
+  If ``<target>`` is an :ref:`Alias Target <Alias Targets>`, the command
+  operates on the target which the alias references.
 
 .. |command_name| replace:: ``target_compile_features``
 .. |more_see_also| replace:: See the :manual:`cmake-compile-features(7)`

Help/command/target_compile_options.rst

@@ -13,7 +13,11 @@ Adds options to the :prop_tgt:`COMPILE_OPTIONS` or
 :prop_tgt:`INTERFACE_COMPILE_OPTIONS` target properties. These options
 are used when compiling the given ``<target>``, which must have been
 created by a command such as :command:`add_executable` or
-:command:`add_library` and must not be an :ref:`ALIAS target <Alias Targets>`.
+:command:`add_library`.
+
+.. versionchanged:: 4.5
+  If ``<target>`` is an :ref:`Alias Target <Alias Targets>`, the command
+  operates on the target which the alias references.
 
 .. note::
 

Help/command/target_include_directories.rst

@@ -11,8 +11,11 @@ Add include directories to a target.
 
 Specifies include directories to use when compiling a given target.
 The named ``<target>`` must have been created by a command such
-as :command:`add_executable` or :command:`add_library` and must not be an
-:ref:`ALIAS target <Alias Targets>`.
+as :command:`add_executable` or :command:`add_library`.
+
+.. versionchanged:: 4.5
+  If ``<target>`` is an :ref:`Alias Target <Alias Targets>`, the command
+  operates on the target which the alias references.
 
 By using ``AFTER`` or ``BEFORE`` explicitly, you can select between appending
 and prepending, independent of the default.

Help/command/target_link_directories.rst

@@ -17,8 +17,11 @@ with the latter being interpreted as relative to the current source
 directory.  These items will be added to the link command.
 
 The named ``<target>`` must have been created by a command such as
-:command:`add_executable` or :command:`add_library` and must not be an
-:ref:`ALIAS target <Alias Targets>`.
+:command:`add_executable` or :command:`add_library`.
+
+.. versionchanged:: 4.5
+  If ``<target>`` is an :ref:`Alias Target <Alias Targets>`, the command
+  operates on the target which the alias references.
 
 The ``INTERFACE``, ``PUBLIC`` and ``PRIVATE`` keywords are required to
 specify the :ref:`scope <Target Command Scope>` of the items that follow

Help/command/target_link_libraries.rst

@@ -21,16 +21,19 @@ All of them have the general form
   target_link_libraries(<target> ... <item>... ...)
 
 The named ``<target>`` must have been created by a command such as
-:command:`add_executable` or :command:`add_library` and must not be an
-:ref:`ALIAS target <Alias Targets>`.  If policy :policy:`CMP0079` is not
-set to ``NEW`` then the target must have been created in the current
-directory.  Repeated calls for the same ``<target>`` append items in
-the order called.
+:command:`add_executable` or :command:`add_library`.  If policy
+:policy:`CMP0079` is not set to ``NEW``, then the target must have been
+created in the current directory.  Repeated calls for the same ``<target>``
+append items in the order called.
 
 .. versionadded:: 3.13
   The ``<target>`` doesn't have to be defined in the same directory as the
   ``target_link_libraries`` call.
 
+.. versionchanged:: 4.5
+  If ``<target>`` is an :ref:`Alias Target <Alias Targets>`, the command
+  operates on the target which the alias references.
+
 Each ``<item>`` may be:
 
 * **A library target name**: The generated link line will have the

Help/command/target_link_options.rst

@@ -13,8 +13,11 @@ library target.
     [{INTERFACE|PUBLIC|PRIVATE} <item>...]...)
 
 The named ``<target>`` must have been created by a command such as
-:command:`add_executable` or :command:`add_library` and must not be an
-:ref:`ALIAS target <Alias Targets>`.
+:command:`add_executable` or :command:`add_library`.
+
+.. versionchanged:: 4.5
+  If ``<target>`` is an :ref:`Alias Target <Alias Targets>`, the command
+  operates on the target which the alias references.
 
 This command can be used to add any link options, but alternative commands
 exist to add libraries (:command:`target_link_libraries` or

Help/command/target_precompile_headers.rst

@@ -21,8 +21,11 @@ Main Form
 The command adds header files to the :prop_tgt:`PRECOMPILE_HEADERS` and/or
 :prop_tgt:`INTERFACE_PRECOMPILE_HEADERS` target properties of ``<target>``.
 The named ``<target>`` must have been created by a command such as
-:command:`add_executable` or :command:`add_library` and must not be an
-:ref:`ALIAS target <Alias Targets>`.
+:command:`add_executable` or :command:`add_library`.
+
+.. versionchanged:: 4.5
+  If ``<target>`` is an :ref:`Alias Target <Alias Targets>`, the command
+  operates on the target which the alias references.
 
 The ``INTERFACE``, ``PUBLIC`` and ``PRIVATE`` keywords are required to
 specify the :ref:`scope <Target Command Scope>` of the following arguments.

Help/command/target_sources.rst

@@ -14,13 +14,16 @@ Add sources to a target.
 Specifies sources to use when building a target and/or its dependents.
 The named ``<target>`` must have been created by a command such as
 :command:`add_executable` or :command:`add_library` or
-:command:`add_custom_target` and must not be an
-:ref:`ALIAS target <Alias Targets>`.  The ``<items>`` may use
+:command:`add_custom_target`.  The ``<items>`` may use
 :manual:`generator expressions <cmake-generator-expressions(7)>`.
 
 .. versionadded:: 3.20
   ``<target>`` can be a custom target.
 
+.. versionchanged:: 4.5
+  If ``<target>`` is an :ref:`Alias Target <Alias Targets>`, the command
+  operates on the target which the alias references.
+
 The ``INTERFACE``, ``PUBLIC`` and ``PRIVATE`` keywords are required to
 specify the :ref:`scope <Target Command Scope>` of the source file paths
 (``<items>``) that follow them.  ``PRIVATE`` and ``PUBLIC`` items will

Help/release/dev/alias-transparency.rst

@@ -5,4 +5,11 @@ alias-transparency
   now accept :ref:`Alias Targets`. Properties are set on the target which
   the alias references.
 
+* The :command:`target_compile_definitions`, :command:`target_compile_features`,
+  :command:`target_compile_options`, :command:`target_include_directories`,
+  :command:`target_link_directories`, :command:`target_link_libraries`,
+  :command:`target_link_options`, :command:`target_precompile_headers`,
+  and :command:`target_sources` commands now accept :ref:`Alias Targets`.
+  The commands operate on the target which the alias references.
+
 * The :prop_tgt:`ALIASED_TARGET` target property is now read-only.

Source/cmTargetLinkLibrariesCommand.cxx

@@ -78,12 +78,6 @@ bool cmTargetLinkLibrariesCommand(std::vector<std::string> const& args,
 
   cmMakefile& mf = status.GetMakefile();
 
-  // Alias targets cannot be on the LHS of this command.
-  if (mf.IsAlias(args[0])) {
-    status.SetError("can not be used on an ALIAS target.");
-    return false;
-  }
-
   // Lookup the target for which libraries are specified.
   cmTarget* target = mf.GetGlobalGenerator()->FindTarget(args[0]);
   if (!target) {

Source/cmTargetPropCommandBase.cxx

@@ -29,10 +29,6 @@ bool cmTargetPropCommandBase::HandleArguments(
     return false;
   }
 
-  if (this->Makefile->IsAlias(args[0])) {
-    this->SetError("can not be used on an ALIAS target.");
-    return false;
-  }
   // Lookup the target for which property-values are specified.
   this->Target = this->Makefile->GetGlobalGenerator()->FindTarget(args[0]);
   if (!this->Target) {

Tests/RunCMake/alias_targets/RunCMakeTest.cmake

@@ -17,7 +17,14 @@ run_cmake(get_property)
 run_cmake(set_target_properties)
 run_cmake(set_target_properties-ALIAS_GLOBAL)
 run_cmake(target_link_libraries)
+run_cmake(target_compile_definitions)
+run_cmake(target_compile_features)
+run_cmake(target_compile_options)
 run_cmake(target_include_directories)
+run_cmake(target_link_directories)
+run_cmake(target_link_options)
+run_cmake(target_precompile_headers)
+run_cmake(target_sources)
 run_cmake(export)
 run_cmake(install-export)
 run_cmake(name-conflict)

Tests/RunCMake/alias_targets/target_compile_definitions.cmake

@@ -0,0 +1,12 @@
+
+enable_language(CXX)
+
+add_library(foo empty.cpp)
+
+add_library(alias ALIAS foo)
+
+target_compile_definitions(alias PRIVATE MY_DEFINE)
+get_target_property(val foo COMPILE_DEFINITIONS)
+if(NOT "MY_DEFINE" STREQUAL "${val}")
+  message(SEND_ERROR "target_compile_definitions(): Target property 'COMPILE_DEFINITIONS' set on ALIAS 'alias' has wrong value on aliased target 'foo': '${val}' instead of 'MY_DEFINE'.")
+endif()

Tests/RunCMake/alias_targets/target_compile_features.cmake

@@ -0,0 +1,14 @@
+
+enable_language(CXX)
+
+add_library(foo empty.cpp)
+
+add_library(alias ALIAS foo)
+
+if("cxx_std_11" IN_LIST CMAKE_CXX_COMPILE_FEATURES)
+  target_compile_features(alias PRIVATE cxx_std_11)
+  get_target_property(val foo COMPILE_FEATURES)
+  if(NOT "cxx_std_11" IN_LIST val)
+    message(SEND_ERROR "target_compile_features(): Target property 'COMPILE_FEATURES' set on ALIAS 'alias' has wrong value on aliased target 'foo': '${val}' instead of 'cxx_std_11'.")
+  endif()
+endif()

Tests/RunCMake/alias_targets/target_compile_options.cmake

@@ -0,0 +1,12 @@
+
+enable_language(CXX)
+
+add_library(foo empty.cpp)
+
+add_library(alias ALIAS foo)
+
+target_compile_options(alias PRIVATE -Wall)
+get_target_property(val foo COMPILE_OPTIONS)
+if(NOT "-Wall" STREQUAL "${val}")
+  message(SEND_ERROR "target_compile_options(): Target property 'COMPILE_OPTIONS' set on ALIAS 'alias' has wrong value on aliased target 'foo': '${val}' instead of '-Wall'.")
+endif()

Tests/RunCMake/alias_targets/target_include_directories-result.txt

@@ -1 +0,0 @@
-1

Tests/RunCMake/alias_targets/target_include_directories-stderr.txt

@@ -1,4 +0,0 @@
-CMake Error at target_include_directories\.cmake:8 \(target_include_directories\):
-  target_include_directories can not be used on an ALIAS target\.
-Call Stack \(most recent call first\):
-  CMakeLists\.txt:3 \(include\)

Tests/RunCMake/alias_targets/target_include_directories.cmake

@@ -6,3 +6,7 @@ add_library(foo empty.cpp)
 add_library(alias ALIAS foo)
 
 target_include_directories(alias PRIVATE $<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}>)
+get_target_property(val foo INCLUDE_DIRECTORIES)
+if(NOT "$<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}>" STREQUAL "${val}")
+  message(SEND_ERROR "target_include_directories(): Target property 'INCLUDE_DIRECTORIES' set on ALIAS 'alias' has wrong value on aliased target 'foo': '${val}' instead of '$<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}>'.")
+endif()

Tests/RunCMake/alias_targets/target_link_directories.cmake

@@ -0,0 +1,12 @@
+
+enable_language(CXX)
+
+add_library(foo empty.cpp)
+
+add_library(alias ALIAS foo)
+
+target_link_directories(alias PRIVATE /usr/local/lib)
+get_target_property(val foo LINK_DIRECTORIES)
+if(NOT "/usr/local/lib" STREQUAL "${val}")
+  message(SEND_ERROR "target_link_directories(): Target property 'LINK_DIRECTORIES' set on ALIAS 'alias' has wrong value on aliased target 'foo': '${val}' instead of '/usr/local/lib'.")
+endif()

Tests/RunCMake/alias_targets/target_link_libraries-result.txt

@@ -1 +0,0 @@
-1

Tests/RunCMake/alias_targets/target_link_libraries-stderr.txt

@@ -1,4 +0,0 @@
-CMake Error at target_link_libraries\.cmake:9 \(target_link_libraries\):
-  target_link_libraries can not be used on an ALIAS target\.
-Call Stack \(most recent call first\):
-  CMakeLists\.txt:3 \(include\)

Tests/RunCMake/alias_targets/target_link_libraries.cmake

@@ -6,4 +6,8 @@ add_library(bar empty.cpp)
 
 add_library(alias ALIAS foo)
 
-target_link_libraries(alias bar)
+target_link_libraries(alias PRIVATE bar)
+get_target_property(val foo LINK_LIBRARIES)
+if(NOT "bar" IN_LIST val)
+  message(SEND_ERROR "target_link_libraries(): Target property 'LINK_LIBRARIES' is missing value added to ALIAS 'alias' on aliased target 'foo': 'bar' not in '${val}'.")
+endif()

Tests/RunCMake/alias_targets/target_link_options.cmake

@@ -0,0 +1,12 @@
+
+enable_language(CXX)
+
+add_library(foo empty.cpp)
+
+add_library(alias ALIAS foo)
+
+target_link_options(alias PRIVATE LINKER:--test)
+get_target_property(val foo LINK_OPTIONS)
+if(NOT "LINKER:--test" STREQUAL "${val}")
+  message(SEND_ERROR "target_link_options(): Target property 'LINK_OPTIONS' set on ALIAS 'alias' has wrong value on aliased target 'foo': '${val}' instead of 'LINKER:--test'.")
+endif()

Tests/RunCMake/alias_targets/target_precompile_headers.cmake

@@ -0,0 +1,12 @@
+
+enable_language(CXX)
+
+add_library(foo empty.cpp)
+
+add_library(alias ALIAS foo)
+
+target_precompile_headers(alias PRIVATE <vector>)
+get_target_property(val foo PRECOMPILE_HEADERS)
+if(NOT "<vector>" IN_LIST val)
+  message(SEND_ERROR "target_precompile_headers(): Target property 'PRECOMPILE_HEADERS' is missing value added to ALIAS 'alias' on aliased target 'foo': '<vector>' not in '${val}'.")
+endif()

Tests/RunCMake/alias_targets/target_sources.cmake

@@ -0,0 +1,12 @@
+
+enable_language(CXX)
+
+add_library(foo)
+
+add_library(alias ALIAS foo)
+
+target_sources(alias PRIVATE empty.cpp)
+get_target_property(val foo SOURCES)
+if(NOT "empty.cpp" IN_LIST val)
+  message(SEND_ERROR "target_sources(): Target property 'SOURCES' is missing value added to ALIAS 'alias' on aliased target 'foo': 'empty.cpp' not in '${val}'.")
+endif()

Tests/RunCMake/target_compile_features/alias_target-result.txt

@@ -1 +0,0 @@
-1

Tests/RunCMake/target_compile_features/alias_target-stderr.txt

@@ -1,4 +0,0 @@
-CMake Error at alias_target\.cmake:[0-9]+ \(target_compile_features\):
-  target_compile_features can not be used on an ALIAS target\.
-Call Stack \(most recent call first\):
-  CMakeLists\.txt:[0-9]+ \(include\)

Tests/RunCMake/target_compile_features/alias_target.cmake

@@ -2,4 +2,11 @@ enable_language(CXX)
 
 add_executable(main empty.cpp)
 add_executable(Alias::Main ALIAS main)
-target_compile_features(Alias::Main PRIVATE cxx_delegating_constructors)
+
+if("cxx_delegating_constructors" IN_LIST CMAKE_CXX_COMPILE_FEATURES)
+  target_compile_features(Alias::Main PRIVATE cxx_delegating_constructors)
+  get_target_property(val main COMPILE_FEATURES)
+  if(NOT "cxx_delegating_constructors" IN_LIST val)
+    message(SEND_ERROR "target_compile_features(): Target property 'COMPILE_FEATURES' is missing value added to ALIAS 'Alias::Main' on aliased target 'main': 'cxx_delegating_constructors' not in '${val}'.")
+  endif()
+endif()