Merge topic 'generalize-importedtargets-behavior'

fb88d2b5 Help: Add notes for topic 'generalize-importedtargets-behavior'
494906a8 Add support for IMPORTED GLOBAL targets to be aliased
fe4b25ec Teach target_* commands to set INTERFACE properties of IMPORTED targets
e40fd9fd cmTargetPropCommandBase: Fix typo in error message

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Henry Schreiner <henryschreineriii@gmail.com>
Merge-request: !1264

40 files changed, 236 insertions, 129 deletions

diff --git a/Help/command/add_executable.rst b/Help/command/add_executable.rst
index 6763620..c7a30d7 100644
--- a/Help/command/add_executable.rst
+++ b/Help/command/add_executable.rst
@@ -74,8 +74,9 @@ properties for more information.
 Creates an :ref:`Alias Target <Alias Targets>`, such that ``<name>`` can
 be used to refer to ``<target>`` in subsequent commands.  The ``<name>``
 does not appear in the generated buildsystem as a make target.  The
-``<target>`` may not be an :ref:`Imported Target <Imported Targets>` or an
-``ALIAS``.  ``ALIAS`` targets can be used as targets to read properties
+``<target>`` may not be a non-``GLOBAL``
+:ref:`Imported Target <Imported Targets>` or an ``ALIAS``.
+``ALIAS`` targets can be used as targets to read properties
 from, executables for custom commands and custom targets.  They can also be
 tested for existence with the regular :command:`if(TARGET)` subcommand.
 The ``<name>`` may not be used to modify properties of ``<target>``, that
diff --git a/Help/command/add_library.rst b/Help/command/add_library.rst
index 78b316d..4e85d8c 100644
--- a/Help/command/add_library.rst
+++ b/Help/command/add_library.rst
@@ -125,7 +125,8 @@ Alias Libraries
 Creates an :ref:`Alias Target <Alias Targets>`, such that ``<name>`` can be
 used to refer to ``<target>`` in subsequent commands.  The ``<name>`` does
 not appear in the generated buildsystem as a make target.  The ``<target>``
-may not be an :ref:`Imported Target <Imported Targets>` or an ``ALIAS``.
+may not be a non-``GLOBAL`` :ref:`Imported Target <Imported Targets>` or an
+``ALIAS``.
 ``ALIAS`` targets can be used as linkable targets and as targets to
 read properties from.  They can also be tested for existence with the
 regular :command:`if(TARGET)` subcommand.  The ``<name>`` may not be used
diff --git a/Help/command/target_compile_definitions.rst b/Help/command/target_compile_definitions.rst
index 8bd3233..3709e7a 100644
--- a/Help/command/target_compile_definitions.rst
+++ b/Help/command/target_compile_definitions.rst
@@ -12,14 +12,15 @@ Add compile definitions to a target.
 Specify 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:`Imported Target <Imported Targets>`.
+:ref:`ALIAS target <Alias Targets>`.
 
 The ``INTERFACE``, ``PUBLIC`` and ``PRIVATE`` keywords are required to
 specify the scope of the following arguments.  ``PRIVATE`` and ``PUBLIC``
 items will populate the :prop_tgt:`COMPILE_DEFINITIONS` property of
 ``<target>``. ``PUBLIC`` and ``INTERFACE`` items will populate the
-:prop_tgt:`INTERFACE_COMPILE_DEFINITIONS` property of ``<target>``.  The
-following arguments specify compile definitions.  Repeated calls for the
+:prop_tgt:`INTERFACE_COMPILE_DEFINITIONS` property of ``<target>``.
+(:ref:`IMPORTED targets <Imported Targets>` only support ``INTERFACE`` items.)
+The following arguments specify compile definitions.  Repeated calls for the
 same ``<target>`` append items in the order called.
 
 Arguments to ``target_compile_definitions`` may use "generator expressions"
diff --git a/Help/command/target_compile_features.rst b/Help/command/target_compile_features.rst
index b66a4ec..bf413bf 100644
--- a/Help/command/target_compile_features.rst
+++ b/Help/command/target_compile_features.rst
@@ -18,12 +18,13 @@ The ``INTERFACE``, ``PUBLIC`` and ``PRIVATE`` keywords are required to
 specify the scope of the features.  ``PRIVATE`` and ``PUBLIC`` items will
 populate the :prop_tgt:`COMPILE_FEATURES` property of ``<target>``.
 ``PUBLIC`` and ``INTERFACE`` items will populate the
-:prop_tgt:`INTERFACE_COMPILE_FEATURES` property of ``<target>``.  Repeated
-calls for the same ``<target>`` append items.
+:prop_tgt:`INTERFACE_COMPILE_FEATURES` property of ``<target>``.
+(:ref:`IMPORTED targets <Imported Targets>` only support ``INTERFACE`` items.)
+Repeated calls for the same ``<target>`` append items.
 
 The named ``<target>`` must have been created by a command such as
-:command:`add_executable` or :command:`add_library` and must not be
-an ``IMPORTED`` target.
+:command:`add_executable` or :command:`add_library` and must not be an
+:ref:`ALIAS target <Alias Targets>`.
 
 Arguments to ``target_compile_features`` may use "generator expressions"
 with the syntax ``$<...>``.
diff --git a/Help/command/target_compile_options.rst b/Help/command/target_compile_options.rst
index 73e01e7..3e7dc47 100644
--- a/Help/command/target_compile_options.rst
+++ b/Help/command/target_compile_options.rst
@@ -12,8 +12,10 @@ Add compile options to a target.
 Specify compile options 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:`IMPORTED Target <Imported Targets>`.  If ``BEFORE`` is specified,
-the content will be prepended to the property instead of being appended.
+:ref:`ALIAS target <Alias Targets>`.
+
+If ``BEFORE`` is specified, the content will be prepended to the property
+instead of being appended.
 
 This command can be used to add any options, but
 alternative commands exist to add preprocessor definitions
@@ -27,8 +29,9 @@ The ``INTERFACE``, ``PUBLIC`` and ``PRIVATE`` keywords are required to
 specify the scope of the following arguments.  ``PRIVATE`` and ``PUBLIC``
 items will populate the :prop_tgt:`COMPILE_OPTIONS` property of
 ``<target>``.  ``PUBLIC`` and ``INTERFACE`` items will populate the
-:prop_tgt:`INTERFACE_COMPILE_OPTIONS` property of ``<target>``.  The
-following arguments specify compile options.  Repeated calls for the same
+:prop_tgt:`INTERFACE_COMPILE_OPTIONS` property of ``<target>``.
+(:ref:`IMPORTED targets <Imported Targets>` only support ``INTERFACE`` items.)
+The following arguments specify compile options.  Repeated calls for the same
 ``<target>`` append items in the order called.
 
 Arguments to ``target_compile_options`` may use "generator expressions"
diff --git a/Help/command/target_include_directories.rst b/Help/command/target_include_directories.rst
index 30ec2cb..e71be64 100644
--- a/Help/command/target_include_directories.rst
+++ b/Help/command/target_include_directories.rst
@@ -12,7 +12,7 @@ Add include directories to a target.
 Specify 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
-:prop_tgt:`IMPORTED` target.
+:ref:`ALIAS target <Alias Targets>`.
 
 If ``BEFORE`` is specified, the content will be prepended to the property
 instead of being appended.
@@ -21,9 +21,9 @@ The ``INTERFACE``, ``PUBLIC`` and ``PRIVATE`` keywords are required to specify
 the scope of the following arguments.  ``PRIVATE`` and ``PUBLIC`` items will
 populate the :prop_tgt:`INCLUDE_DIRECTORIES` property of ``<target>``.
 ``PUBLIC`` and ``INTERFACE`` items will populate the
-:prop_tgt:`INTERFACE_INCLUDE_DIRECTORIES`
-property of ``<target>``.  The following arguments specify include
-directories.
+:prop_tgt:`INTERFACE_INCLUDE_DIRECTORIES` property of ``<target>``.
+(:ref:`IMPORTED targets <Imported Targets>` only support ``INTERFACE`` items.)
+The following arguments specify include directories.
 
 Specified include directories may be absolute paths or relative paths.
 Repeated calls for the same <target> append items in the order called.  If
diff --git a/Help/command/target_link_libraries.rst b/Help/command/target_link_libraries.rst
index 30d69f2..2ec8744 100644
--- a/Help/command/target_link_libraries.rst
+++ b/Help/command/target_link_libraries.rst
@@ -19,7 +19,8 @@ All of them have the general form::
   target_link_libraries(<target> ... <item>... ...)
 
 The named ``<target>`` must have been created in the current directory by
-a command such as :command:`add_executable` or :command:`add_library`.
+a command such as :command:`add_executable` or :command:`add_library` and
+must not be an :ref:`ALIAS target <Alias Targets>`.
 Repeated calls for the same ``<target>`` append items in the order called.
 Each ``<item>`` may be:
 
diff --git a/Help/command/target_sources.rst b/Help/command/target_sources.rst
index d6f148d..a4f5196 100644
--- a/Help/command/target_sources.rst
+++ b/Help/command/target_sources.rst
@@ -12,14 +12,15 @@ Add sources to a target.
 Specify sources 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:`IMPORTED Target <Imported Targets>`.
+:ref:`ALIAS target <Alias Targets>`.
 
 The ``INTERFACE``, ``PUBLIC`` and ``PRIVATE`` keywords are required to
 specify the scope of the following arguments.  ``PRIVATE`` and ``PUBLIC``
 items will populate the :prop_tgt:`SOURCES` property of
 ``<target>``.  ``PUBLIC`` and ``INTERFACE`` items will populate the
-:prop_tgt:`INTERFACE_SOURCES` property of ``<target>``.  The
-following arguments specify sources.  Repeated calls for the same
+:prop_tgt:`INTERFACE_SOURCES` property of ``<target>``.
+(:ref:`IMPORTED targets <Imported Targets>` only support ``INTERFACE`` items.)
+The following arguments specify sources.  Repeated calls for the same
 ``<target>`` append items in the order called.
 
 Arguments to ``target_sources`` may use "generator expressions"
diff --git a/Help/release/dev/generalize-importedtargets-behavior.rst b/Help/release/dev/generalize-importedtargets-behavior.rst
new file mode 100644
index 0000000..c6f4523
--- /dev/null
+++ b/Help/release/dev/generalize-importedtargets-behavior.rst
@@ -0,0 +1,25 @@
+generalize-importedtargets-behavior
+-----------------------------------
+
+* The :command:`target_compile_definitions` command learned to set the
+  :prop_tgt:`INTERFACE_COMPILE_DEFINITIONS` property on
+  :ref:`Imported Targets`.
+
+* The :command:`target_compile_features` command learned to set the
+  :prop_tgt:`INTERFACE_COMPILE_FEATURES` property on :ref:`Imported Targets`.
+
+* The :command:`target_compile_options` command learned to set the
+  :prop_tgt:`INTERFACE_COMPILE_OPTIONS` property on :ref:`Imported Targets`.
+
+* The :command:`target_include_directories` command learned to set the
+  :prop_tgt:`INTERFACE_INCLUDE_DIRECTORIES` property on
+  :ref:`Imported Targets`.
+
+* The :command:`target_sources` command learned to set the
+  :prop_tgt:`INTERFACE_SOURCES` property on :ref:`Imported Targets`.
+
+* The :command:`target_link_libraries` command learned to set the
+  :prop_tgt:`INTERFACE_LINK_LIBRARIES` property on :ref:`Imported Targets`.
+
+* :ref:`Alias Targets` may now alias :ref:`Imported Targets` that are
+  created with the ``GLOBAL`` option to :command:`add_library`.
diff --git a/Source/cmAddExecutableCommand.cxx b/Source/cmAddExecutableCommand.cxx
index 262e3a1..053e34c 100644
--- a/Source/cmAddExecutableCommand.cxx
+++ b/Source/cmAddExecutableCommand.cxx
@@ -140,8 +140,7 @@ bool cmAddExecutableCommand::InitialPass(std::vector<std::string> const& args,
     if (!aliasedTarget) {
       std::ostringstream e;
       e << "cannot create ALIAS target \"" << exename << "\" because target \""
-        << aliasedName << "\" does not already "
-                          "exist.";
+        << aliasedName << "\" does not already exist.";
       this->SetError(e.str());
       return false;
     }
@@ -149,15 +148,15 @@ bool cmAddExecutableCommand::InitialPass(std::vector<std::string> const& args,
     if (type != cmStateEnums::EXECUTABLE) {
       std::ostringstream e;
       e << "cannot create ALIAS target \"" << exename << "\" because target \""
-        << aliasedName << "\" is not an "
-                          "executable.";
+        << aliasedName << "\" is not an executable.";
       this->SetError(e.str());
       return false;
     }
-    if (aliasedTarget->IsImported()) {
+    if (aliasedTarget->IsImported() &&
+        !aliasedTarget->IsImportedGloballyVisible()) {
       std::ostringstream e;
       e << "cannot create ALIAS target \"" << exename << "\" because target \""
-        << aliasedName << "\" is IMPORTED.";
+        << aliasedName << "\" is imported but not globally visible.";
       this->SetError(e.str());
       return false;
     }
diff --git a/Source/cmAddLibraryCommand.cxx b/Source/cmAddLibraryCommand.cxx
index 31c2ecf..9129047 100644
--- a/Source/cmAddLibraryCommand.cxx
+++ b/Source/cmAddLibraryCommand.cxx
@@ -256,13 +256,6 @@ bool cmAddLibraryCommand::InitialPass(std::vector<std::string> const& args,
       this->SetError(e.str());
       return false;
     }
-    if (aliasedTarget->IsImported()) {
-      std::ostringstream e;
-      e << "cannot create ALIAS target \"" << libName << "\" because target \""
-        << aliasedName << "\" is IMPORTED.";
-      this->SetError(e.str());
-      return false;
-    }
     this->Makefile->AddAlias(libName, aliasedName);
     return true;
   }
diff --git a/Source/cmTargetCompileDefinitionsCommand.cxx b/Source/cmTargetCompileDefinitionsCommand.cxx
index d159d41..bd4121d 100644
--- a/Source/cmTargetCompileDefinitionsCommand.cxx
+++ b/Source/cmTargetCompileDefinitionsCommand.cxx
@@ -17,15 +17,6 @@ bool cmTargetCompileDefinitionsCommand::InitialPass(
   return this->HandleArguments(args, "COMPILE_DEFINITIONS");
 }
 
-void cmTargetCompileDefinitionsCommand::HandleImportedTarget(
-  const std::string& tgt)
-{
-  std::ostringstream e;
-  e << "Cannot specify compile definitions for imported target \"" << tgt
-    << "\".";
-  this->Makefile->IssueMessage(cmake::FATAL_ERROR, e.str());
-}
-
 void cmTargetCompileDefinitionsCommand::HandleMissingTarget(
   const std::string& name)
 {
@@ -56,5 +47,5 @@ bool cmTargetCompileDefinitionsCommand::HandleDirectContent(
   cmTarget* tgt, const std::vector<std::string>& content, bool, bool)
 {
   tgt->AppendProperty("COMPILE_DEFINITIONS", this->Join(content).c_str());
-  return true;
+  return true; // Successfully handled.
 }
diff --git a/Source/cmTargetCompileDefinitionsCommand.h b/Source/cmTargetCompileDefinitionsCommand.h
index f910452..d41483a 100644
--- a/Source/cmTargetCompileDefinitionsCommand.h
+++ b/Source/cmTargetCompileDefinitionsCommand.h
@@ -30,7 +30,6 @@ public:
                    cmExecutionStatus& status) override;
 
 private:
-  void HandleImportedTarget(const std::string& tgt) override;
   void HandleMissingTarget(const std::string& name) override;
 
   bool HandleDirectContent(cmTarget* tgt,
diff --git a/Source/cmTargetCompileFeaturesCommand.cxx b/Source/cmTargetCompileFeaturesCommand.cxx
index 722bbe5..f58e404 100644
--- a/Source/cmTargetCompileFeaturesCommand.cxx
+++ b/Source/cmTargetCompileFeaturesCommand.cxx
@@ -17,15 +17,6 @@ bool cmTargetCompileFeaturesCommand::InitialPass(
   return this->HandleArguments(args, "COMPILE_FEATURES", NO_FLAGS);
 }
 
-void cmTargetCompileFeaturesCommand::HandleImportedTarget(
-  const std::string& tgt)
-{
-  std::ostringstream e;
-  e << "Cannot specify compile features for imported target \"" << tgt
-    << "\".";
-  this->Makefile->IssueMessage(cmake::FATAL_ERROR, e.str());
-}
-
 void cmTargetCompileFeaturesCommand::HandleMissingTarget(
   const std::string& name)
 {
@@ -49,8 +40,8 @@ bool cmTargetCompileFeaturesCommand::HandleDirectContent(
     std::string error;
     if (!this->Makefile->AddRequiredTargetFeature(tgt, it, &error)) {
       this->SetError(error);
-      return false;
+      return false; // Not (successfully) handled.
     }
   }
-  return true;
+  return true; // Successfully handled.
 }
diff --git a/Source/cmTargetCompileFeaturesCommand.h b/Source/cmTargetCompileFeaturesCommand.h
index 444d260..45240a5 100644
--- a/Source/cmTargetCompileFeaturesCommand.h
+++ b/Source/cmTargetCompileFeaturesCommand.h
@@ -22,7 +22,6 @@ class cmTargetCompileFeaturesCommand : public cmTargetPropCommandBase
                    cmExecutionStatus& status) override;
 
 private:
-  void HandleImportedTarget(const std::string& tgt) override;
   void HandleMissingTarget(const std::string& name) override;
 
   bool HandleDirectContent(cmTarget* tgt,
diff --git a/Source/cmTargetCompileOptionsCommand.cxx b/Source/cmTargetCompileOptionsCommand.cxx
index 1b4056d..4df3630 100644
--- a/Source/cmTargetCompileOptionsCommand.cxx
+++ b/Source/cmTargetCompileOptionsCommand.cxx
@@ -18,21 +18,12 @@ bool cmTargetCompileOptionsCommand::InitialPass(
   return this->HandleArguments(args, "COMPILE_OPTIONS", PROCESS_BEFORE);
 }
 
-void cmTargetCompileOptionsCommand::HandleImportedTarget(
-  const std::string& tgt)
-{
-  std::ostringstream e;
-  e << "Cannot specify compile options for imported target \"" << tgt << "\".";
-  this->Makefile->IssueMessage(cmake::FATAL_ERROR, e.str());
-}
-
 void cmTargetCompileOptionsCommand::HandleMissingTarget(
   const std::string& name)
 {
   std::ostringstream e;
   e << "Cannot specify compile options for target \"" << name
-    << "\" "
-       "which is not built by this project.";
+    << "\" which is not built by this project.";
   this->Makefile->IssueMessage(cmake::FATAL_ERROR, e.str());
 }
 
@@ -47,5 +38,5 @@ bool cmTargetCompileOptionsCommand::HandleDirectContent(
 {
   cmListFileBacktrace lfbt = this->Makefile->GetBacktrace();
   tgt->InsertCompileOption(this->Join(content), lfbt);
-  return true;
+  return true; // Successfully handled.
 }
diff --git a/Source/cmTargetCompileOptionsCommand.h b/Source/cmTargetCompileOptionsCommand.h
index 3fab238..6fb151a 100644
--- a/Source/cmTargetCompileOptionsCommand.h
+++ b/Source/cmTargetCompileOptionsCommand.h
@@ -30,7 +30,6 @@ public:
                    cmExecutionStatus& status) override;
 
 private:
-  void HandleImportedTarget(const std::string& tgt) override;
   void HandleMissingTarget(const std::string& name) override;
 
   bool HandleDirectContent(cmTarget* tgt,
diff --git a/Source/cmTargetIncludeDirectoriesCommand.cxx b/Source/cmTargetIncludeDirectoriesCommand.cxx
index 4646c7e..dcec830 100644
--- a/Source/cmTargetIncludeDirectoriesCommand.cxx
+++ b/Source/cmTargetIncludeDirectoriesCommand.cxx
@@ -21,22 +21,12 @@ bool cmTargetIncludeDirectoriesCommand::InitialPass(
                                ArgumentFlags(PROCESS_BEFORE | PROCESS_SYSTEM));
 }
 
-void cmTargetIncludeDirectoriesCommand::HandleImportedTarget(
-  const std::string& tgt)
-{
-  std::ostringstream e;
-  e << "Cannot specify include directories for imported target \"" << tgt
-    << "\".";
-  this->Makefile->IssueMessage(cmake::FATAL_ERROR, e.str());
-}
-
 void cmTargetIncludeDirectoriesCommand::HandleMissingTarget(
   const std::string& name)
 {
   std::ostringstream e;
   e << "Cannot specify include directories for target \"" << name
-    << "\" "
-       "which is not built by this project.";
+    << "\" which is not built by this project.";
   this->Makefile->IssueMessage(cmake::FATAL_ERROR, e.str());
 }
 
@@ -79,7 +69,7 @@ bool cmTargetIncludeDirectoriesCommand::HandleDirectContent(
     }
     tgt->AddSystemIncludeDirectories(sdirs);
   }
-  return true;
+  return true; // Successfully handled.
 }
 
 void cmTargetIncludeDirectoriesCommand::HandleInterfaceContent(
diff --git a/Source/cmTargetIncludeDirectoriesCommand.h b/Source/cmTargetIncludeDirectoriesCommand.h
index 27a2f43..57bf8fc 100644
--- a/Source/cmTargetIncludeDirectoriesCommand.h
+++ b/Source/cmTargetIncludeDirectoriesCommand.h
@@ -30,7 +30,6 @@ public:
                    cmExecutionStatus& status) override;
 
 private:
-  void HandleImportedTarget(const std::string& tgt) override;
   void HandleMissingTarget(const std::string& name) override;
 
   bool HandleDirectContent(cmTarget* tgt,
diff --git a/Source/cmTargetLinkLibrariesCommand.cxx b/Source/cmTargetLinkLibrariesCommand.cxx
index dda0464..37bcb70 100644
--- a/Source/cmTargetLinkLibrariesCommand.cxx
+++ b/Source/cmTargetLinkLibrariesCommand.cxx
@@ -40,6 +40,16 @@ bool cmTargetLinkLibrariesCommand::InitialPass(
     this->Makefile->GetCMakeInstance()->GetGlobalGenerator()->FindTarget(
       args[0]);
   if (!this->Target) {
+    const std::vector<cmTarget*>& importedTargets =
+      this->Makefile->GetOwnedImportedTargets();
+    for (cmTarget* importedTarget : importedTargets) {
+      if (importedTarget->GetName() == args[0]) {
+        this->Target = importedTarget;
+        break;
+      }
+    }
+  }
+  if (!this->Target) {
     cmake::MessageType t = cmake::FATAL_ERROR; // fail by default
     std::ostringstream e;
     e << "Cannot specify link libraries for target \"" << args[0] << "\" "
@@ -228,7 +238,7 @@ bool cmTargetLinkLibrariesCommand::InitialPass(
     } else {
       // Lookup old-style cache entry if type is unspecified.  So if you
       // do a target_link_libraries(foo optimized bar) it will stay optimized
-      // and not use the lookup.  As there maybe the case where someone has
+      // and not use the lookup.  As there may be the case where someone has
       // specifed that a library is both debug and optimized.  (this check is
       // only there for backwards compatibility when mixing projects built
       // with old versions of CMake and new)
@@ -299,6 +309,14 @@ bool cmTargetLinkLibrariesCommand::HandleLibrary(const std::string& lib,
       "target_link_libraries");
     return false;
   }
+  if (this->Target->IsImported() &&
+      this->CurrentProcessingState != ProcessingKeywordLinkInterface) {
+    this->Makefile->IssueMessage(
+      cmake::FATAL_ERROR,
+      "IMPORTED library can only be used with the INTERFACE keyword of "
+      "target_link_libraries");
+    return false;
+  }
 
   cmTarget::TLLSignature sig =
     (this->CurrentProcessingState == ProcessingPlainPrivateInterface ||
@@ -355,6 +373,16 @@ bool cmTargetLinkLibrariesCommand::HandleLibrary(const std::string& lib,
     cmTarget* t =
       this->Makefile->FindLocalNonAliasTarget(this->Target->GetName());
     if (!t) {
+      const std::vector<cmTarget*>& importedTargets =
+        this->Makefile->GetOwnedImportedTargets();
+      for (cmTarget* importedTarget : importedTargets) {
+        if (importedTarget->GetName() == this->Target->GetName()) {
+          t = importedTarget;
+          break;
+        }
+      }
+    }
+    if (!t) {
       std::ostringstream e;
       e << "Attempt to add link library \"" << lib << "\" to target \""
         << this->Target->GetName()
diff --git a/Source/cmTargetPropCommandBase.cxx b/Source/cmTargetPropCommandBase.cxx
index 45fe430..9a8fd96 100644
--- a/Source/cmTargetPropCommandBase.cxx
+++ b/Source/cmTargetPropCommandBase.cxx
@@ -17,11 +17,11 @@ bool cmTargetPropCommandBase::HandleArguments(
     return false;
   }
 
-  // Lookup the target for which libraries are specified.
   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->GetCMakeInstance()->GetGlobalGenerator()->FindTarget(
       args[0]);
@@ -84,16 +84,13 @@ bool cmTargetPropCommandBase::ProcessContentArgs(
     this->SetError("called with invalid arguments");
     return false;
   }
-
-  if (this->Target->IsImported()) {
-    this->HandleImportedTarget(args[0]);
-    return false;
-  }
-
   if (this->Target->GetType() == cmStateEnums::INTERFACE_LIBRARY &&
       scope != "INTERFACE") {
-    this->SetError("may only be set INTERFACE properties on INTERFACE "
-                   "targets");
+    this->SetError("may only set INTERFACE properties on INTERFACE targets");
+    return false;
+  }
+  if (this->Target->IsImported() && scope != "INTERFACE") {
+    this->SetError("may only set INTERFACE properties on IMPORTED targets");
     return false;
   }
 
diff --git a/Source/cmTargetPropCommandBase.h b/Source/cmTargetPropCommandBase.h
index 46a2f6b..3c736fc 100644
--- a/Source/cmTargetPropCommandBase.h
+++ b/Source/cmTargetPropCommandBase.h
@@ -35,7 +35,6 @@ protected:
                                       bool prepend, bool system);
 
 private:
-  virtual void HandleImportedTarget(const std::string& tgt) = 0;
   virtual void HandleMissingTarget(const std::string& name) = 0;
 
   virtual bool HandleDirectContent(cmTarget* tgt,
diff --git a/Source/cmTargetSourcesCommand.cxx b/Source/cmTargetSourcesCommand.cxx
index 058659a..3dd3748 100644
--- a/Source/cmTargetSourcesCommand.cxx
+++ b/Source/cmTargetSourcesCommand.cxx
@@ -17,13 +17,6 @@ bool cmTargetSourcesCommand::InitialPass(std::vector<std::string> const& args,
   return this->HandleArguments(args, "SOURCES");
 }
 
-void cmTargetSourcesCommand::HandleImportedTarget(const std::string& tgt)
-{
-  std::ostringstream e;
-  e << "Cannot specify sources for imported target \"" << tgt << "\".";
-  this->Makefile->IssueMessage(cmake::FATAL_ERROR, e.str());
-}
-
 void cmTargetSourcesCommand::HandleMissingTarget(const std::string& name)
 {
   std::ostringstream e;
@@ -43,5 +36,5 @@ bool cmTargetSourcesCommand::HandleDirectContent(
   cmTarget* tgt, const std::vector<std::string>& content, bool, bool)
 {
   tgt->AppendProperty("SOURCES", this->Join(content).c_str());
-  return true;
+  return true; // Successfully handled.
 }
diff --git a/Source/cmTargetSourcesCommand.h b/Source/cmTargetSourcesCommand.h
index 0639e98..ea8776a 100644
--- a/Source/cmTargetSourcesCommand.h
+++ b/Source/cmTargetSourcesCommand.h
@@ -30,7 +30,6 @@ public:
                    cmExecutionStatus& status) override;
 
 private:
-  void HandleImportedTarget(const std::string& tgt) override;
   void HandleMissingTarget(const std::string& name) override;
 
   bool HandleDirectContent(cmTarget* tgt,
diff --git a/Tests/RunCMake/add_library/UNKNOWNwithNoSourcesButLinkObjects-stderr.txt b/Tests/RunCMake/add_library/UNKNOWNwithNoSourcesButLinkObjects-stderr.txt
deleted file mode 100644
index adcd3a2..0000000
--- a/Tests/RunCMake/add_library/UNKNOWNwithNoSourcesButLinkObjects-stderr.txt
+++ /dev/null
@@ -1,5 +0,0 @@
-^CMake Error at UNKNOWNwithNoSourcesButLinkObjects.cmake:[0-9]+ \(target_link_libraries\):
-  Cannot specify link libraries for target \"TestUnknownLibWithoutSources\"
-  which is not built by this project.
-Call Stack \(most recent call first\):
-  CMakeLists.txt:[0-9]+ \(include\)$
diff --git a/Tests/RunCMake/add_library/UNKNOWNwithNoSourcesButLinkObjects.cmake b/Tests/RunCMake/add_library/UNKNOWNwithNoSourcesButLinkObjects.cmake
index 8e014c2..a977d42 100644
--- a/Tests/RunCMake/add_library/UNKNOWNwithNoSourcesButLinkObjects.cmake
+++ b/Tests/RunCMake/add_library/UNKNOWNwithNoSourcesButLinkObjects.cmake
@@ -2,4 +2,4 @@ enable_language(CXX)
 add_library(ObjectLibDependency OBJECT test.cpp)
 
 add_library(TestUnknownLibWithoutSources UNKNOWN IMPORTED)
-target_link_libraries(TestUnknownLibWithoutSources PUBLIC $<TARGET_OBJECTS:ObjectLibDependency>)
+target_link_libraries(TestUnknownLibWithoutSources INTERFACE $<TARGET_OBJECTS:ObjectLibDependency>)
diff --git a/Tests/RunCMake/alias_targets/RunCMakeTest.cmake b/Tests/RunCMake/alias_targets/RunCMakeTest.cmake
index 9a5eaaf..dded248 100644
--- a/Tests/RunCMake/alias_targets/RunCMakeTest.cmake
+++ b/Tests/RunCMake/alias_targets/RunCMakeTest.cmake
@@ -6,6 +6,7 @@ run_cmake(exclude-from-all)
 run_cmake(imported)
 run_cmake(invalid-name)
 run_cmake(invalid-target)
+run_cmake(imported-global-target)
 run_cmake(imported-target)
 run_cmake(alias-target)
 run_cmake(set_property)
diff --git a/Tests/RunCMake/alias_targets/imported-global-target-stderr.txt b/Tests/RunCMake/alias_targets/imported-global-target-stderr.txt
new file mode 100644
index 0000000..8259c80
--- /dev/null
+++ b/Tests/RunCMake/alias_targets/imported-global-target-stderr.txt
@@ -0,0 +1,2 @@
+^'alias-test-exe' is an alias for 'test-exe' and its name-property contains 'test-exe'.
+'alias-test-lib' is an alias for 'test-lib' and its name-property contains 'test-lib'.$
diff --git a/Tests/RunCMake/alias_targets/imported-global-target.cmake b/Tests/RunCMake/alias_targets/imported-global-target.cmake
new file mode 100644
index 0000000..12c4e0a
--- /dev/null
+++ b/Tests/RunCMake/alias_targets/imported-global-target.cmake
@@ -0,0 +1,46 @@
+
+enable_language(CXX)
+
+
+add_executable(test-exe IMPORTED GLOBAL)
+add_executable(alias-test-exe ALIAS test-exe)
+
+if(TARGET alias-test-exe)
+  get_target_property(aliased-target alias-test-exe ALIASED_TARGET)
+  if("${aliased-target}" STREQUAL "test-exe")
+    get_target_property(aliased-name alias-test-exe NAME)
+    if("${aliased-name}" STREQUAL "test-exe")
+      message("'alias-test-exe' is an alias for '${aliased-target}'"
+              " and its name-property contains '${aliased-name}'.")
+    else()
+      message("'alias-test-exe' is an alias for '${aliased-target}'"
+              " but its name-property contains '${aliased-name}'!?")
+    endif()
+  else()
+    message("'alias-test-exe' is something but not a real target!?")
+  endif()
+else()
+    message("'alias-test-exe' does not exist!?")
+endif()
+
+
+add_library(test-lib SHARED IMPORTED GLOBAL)
+add_library(alias-test-lib ALIAS test-lib)
+
+if(TARGET alias-test-lib)
+  get_target_property(aliased-target alias-test-lib ALIASED_TARGET)
+  if("${aliased-target}" STREQUAL "test-lib")
+    get_target_property(aliased-name alias-test-lib NAME)
+    if("${aliased-name}" STREQUAL "test-lib")
+      message("'alias-test-lib' is an alias for '${aliased-target}'"
+              " and its name-property contains '${aliased-name}'.")
+    else()
+      message("'alias-test-lib' is an alias for '${aliased-target}'"
+              " but its name-property contains '${aliased-name}'!?")
+    endif()
+  else()
+    message("'alias-test-lib' is something but not a real target!?")
+  endif()
+else()
+    message("'alias-test-lib' does not exist!?")
+endif()
diff --git a/Tests/RunCMake/alias_targets/imported-target-stderr.txt b/Tests/RunCMake/alias_targets/imported-target-stderr.txt
index bbff29a..12ffbc2 100644
--- a/Tests/RunCMake/alias_targets/imported-target-stderr.txt
+++ b/Tests/RunCMake/alias_targets/imported-target-stderr.txt
@@ -1,5 +1,9 @@
-CMake Error at imported-target.cmake:6 \(add_library\):
-  add_library cannot create ALIAS target "alias" because target "foo" is
-  IMPORTED.
+^CMake Error at imported-target.cmake:[0-9]+ \(add_executable\):
+  add_executable cannot create ALIAS target \"alias-test-exe\" because target
+  \"test-exe\" is imported but not globally visible.
 Call Stack \(most recent call first\):
-  CMakeLists.txt:3 \(include\)
+  CMakeLists.txt:[0-9]+ \(include\)
+
+
+'alias-test-exe' does not exist![?]
+'alias-test-lib' does not exist![?]$
diff --git a/Tests/RunCMake/alias_targets/imported-target.cmake b/Tests/RunCMake/alias_targets/imported-target.cmake
index 7259ab0..bb682fe 100644
--- a/Tests/RunCMake/alias_targets/imported-target.cmake
+++ b/Tests/RunCMake/alias_targets/imported-target.cmake
@@ -1,6 +1,46 @@
 
 enable_language(CXX)
 
-add_library(foo SHARED IMPORTED)
 
-add_library(alias ALIAS foo)
+add_executable(test-exe IMPORTED)
+add_executable(alias-test-exe ALIAS test-exe)
+
+if(TARGET alias-test-exe)
+  get_target_property(aliased-target alias-test-exe ALIASED_TARGET)
+  if("${aliased-target}" STREQUAL "test-exe")
+    get_target_property(aliased-name alias-test-exe NAME)
+    if("${aliased-name}" STREQUAL "test-exe")
+      message("'alias-test-exe' is an alias for '${aliased-target}'"
+              " and its name-property contains '${aliased-name}'.")
+    else()
+      message("'alias-test-exe' is an alias for '${aliased-target}'"
+              " but its name-property contains '${aliased-name}'!?")
+    endif()
+  else()
+    message("'alias-test-exe' is something but not a real target!?")
+  endif()
+else()
+    message("'alias-test-exe' does not exist!?")
+endif()
+
+
+add_library(test-lib SHARED IMPORTED)
+add_library(alias-test-lib ALIAS test-lib)
+
+if(TARGET alias-test-lib)
+  get_target_property(aliased-target alias-test-lib ALIASED_TARGET)
+  if("${aliased-target}" STREQUAL "test-lib")
+    get_target_property(aliased-name alias-test-lib NAME)
+    if("${aliased-name}" STREQUAL "test-lib")
+      message("'alias-test-lib' is an alias for '${aliased-target}'"
+              " and its name-property contains '${aliased-name}'.")
+    else()
+      message("'alias-test-lib' is an alias for '${aliased-target}'"
+              " but its name-property contains '${aliased-name}'!?")
+    endif()
+  else()
+    message("'alias-test-lib' is something but not a real target!?")
+  endif()
+else()
+    message("'alias-test-lib' does not exist!?")
+endif()
diff --git a/Tests/RunCMake/interface_library/target_commands-stderr.txt b/Tests/RunCMake/interface_library/target_commands-stderr.txt
index be11b77..9362a75 100644
--- a/Tests/RunCMake/interface_library/target_commands-stderr.txt
+++ b/Tests/RunCMake/interface_library/target_commands-stderr.txt
@@ -23,25 +23,25 @@ Call Stack \(most recent call first\):
   CMakeLists.txt:3 \(include\)
 +
 CMake Error at target_commands.cmake:9 \(target_include_directories\):
-  target_include_directories may only be set INTERFACE properties on
-  INTERFACE targets
+  target_include_directories may only set INTERFACE properties on INTERFACE
+  targets
 Call Stack \(most recent call first\):
   CMakeLists.txt:3 \(include\)
 +
 CMake Error at target_commands.cmake:10 \(target_include_directories\):
-  target_include_directories may only be set INTERFACE properties on
-  INTERFACE targets
+  target_include_directories may only set INTERFACE properties on INTERFACE
+  targets
 Call Stack \(most recent call first\):
   CMakeLists.txt:3 \(include\)
 +
 CMake Error at target_commands.cmake:12 \(target_compile_definitions\):
-  target_compile_definitions may only be set INTERFACE properties on
-  INTERFACE targets
+  target_compile_definitions may only set INTERFACE properties on INTERFACE
+  targets
 Call Stack \(most recent call first\):
   CMakeLists.txt:3 \(include\)
 +
 CMake Error at target_commands.cmake:13 \(target_compile_definitions\):
-  target_compile_definitions may only be set INTERFACE properties on
-  INTERFACE targets
+  target_compile_definitions may only set INTERFACE properties on INTERFACE
+  targets
 Call Stack \(most recent call first\):
   CMakeLists.txt:3 \(include\)
diff --git a/Tests/RunCMake/target_compile_features/imported_target-stderr.txt b/Tests/RunCMake/target_compile_features/imported_target-stderr.txt
index 7a07427..afad537 100644
--- a/Tests/RunCMake/target_compile_features/imported_target-stderr.txt
+++ b/Tests/RunCMake/target_compile_features/imported_target-stderr.txt
@@ -1,4 +1,5 @@
-CMake Error at imported_target.cmake:[0-9]+ \(target_compile_features\):
-  Cannot specify compile features for imported target "main".
+^CMake Error at imported_target.cmake:[0-9]+ \(target_compile_features\):
+  target_compile_features may only set INTERFACE properties on INTERFACE
+  targets
 Call Stack \(most recent call first\):
-  CMakeLists.txt:3 \(include\)
+  CMakeLists.txt:3 \(include\)$
diff --git a/Tests/RunCMake/target_compile_features/imported_target.cmake b/Tests/RunCMake/target_compile_features/imported_target.cmake
index e886ce9..e410ace 100644
--- a/Tests/RunCMake/target_compile_features/imported_target.cmake
+++ b/Tests/RunCMake/target_compile_features/imported_target.cmake
@@ -1,4 +1,10 @@
 enable_language(CXX)
 
-add_library(main INTERFACE IMPORTED)
-target_compile_features(main INTERFACE cxx_delegating_constructors)
+add_library(lib1-interface INTERFACE IMPORTED)
+target_compile_features(lib1-interface INTERFACE cxx_delegating_constructors)
+
+add_library(lib2-interface INTERFACE IMPORTED)
+target_compile_features(lib2-interface PUBLIC cxx_delegating_constructors)
+
+add_library(lib-shared SHARED IMPORTED)
+target_compile_features(lib-shared INTERFACE cxx_delegating_constructors)
diff --git a/Tests/RunCMake/target_compile_features/invalid_args_on_interface-stderr.txt b/Tests/RunCMake/target_compile_features/invalid_args_on_interface-stderr.txt
index 3708998..23a8eeb 100644
--- a/Tests/RunCMake/target_compile_features/invalid_args_on_interface-stderr.txt
+++ b/Tests/RunCMake/target_compile_features/invalid_args_on_interface-stderr.txt
@@ -1,5 +1,5 @@
 CMake Error at invalid_args_on_interface.cmake:[0-9]+ \(target_compile_features\):
-  target_compile_features may only be set INTERFACE properties on INTERFACE
+  target_compile_features may only set INTERFACE properties on INTERFACE
   targets
 Call Stack \(most recent call first\):
   CMakeLists.txt:3 \(include\)
diff --git a/Tests/RunCMake/target_link_libraries/ImportedTarget.cmake b/Tests/RunCMake/target_link_libraries/ImportedTarget.cmake
new file mode 100644
index 0000000..e5ec3f6
--- /dev/null
+++ b/Tests/RunCMake/target_link_libraries/ImportedTarget.cmake
@@ -0,0 +1,2 @@
+add_library(UnknownImportedGlobal UNKNOWN IMPORTED GLOBAL)
+target_link_libraries(UnknownImportedGlobal INTERFACE z)
diff --git a/Tests/RunCMake/add_library/UNKNOWNwithNoSourcesButLinkObjects-result.txt b/Tests/RunCMake/target_link_libraries/ImportedTargetFailure-result.txt
index d00491f..d00491f 100644
--- a/Tests/RunCMake/add_library/UNKNOWNwithNoSourcesButLinkObjects-result.txt
+++ b/Tests/RunCMake/target_link_libraries/ImportedTargetFailure-result.txt
diff --git a/Tests/RunCMake/target_link_libraries/ImportedTargetFailure-stderr.txt b/Tests/RunCMake/target_link_libraries/ImportedTargetFailure-stderr.txt
new file mode 100644
index 0000000..1cafa5b
--- /dev/null
+++ b/Tests/RunCMake/target_link_libraries/ImportedTargetFailure-stderr.txt
@@ -0,0 +1,5 @@
+^CMake Error at ImportedTargetFailure.cmake:[0-9]+ \(target_link_libraries\):
+  IMPORTED library can only be used with the INTERFACE keyword of
+  target_link_libraries
+Call Stack \(most recent call first\):
+  CMakeLists\.txt:[0-9]+ \(include\)$
diff --git a/Tests/RunCMake/target_link_libraries/ImportedTargetFailure.cmake b/Tests/RunCMake/target_link_libraries/ImportedTargetFailure.cmake
new file mode 100644
index 0000000..3ac0aa9
--- /dev/null
+++ b/Tests/RunCMake/target_link_libraries/ImportedTargetFailure.cmake
@@ -0,0 +1,2 @@
+add_library(UnknownImportedGlobal UNKNOWN IMPORTED GLOBAL)
+target_link_libraries(UnknownImportedGlobal PRIVATE z)
diff --git a/Tests/RunCMake/target_link_libraries/RunCMakeTest.cmake b/Tests/RunCMake/target_link_libraries/RunCMakeTest.cmake
index b1c9435..97b0888 100644
--- a/Tests/RunCMake/target_link_libraries/RunCMakeTest.cmake
+++ b/Tests/RunCMake/target_link_libraries/RunCMakeTest.cmake
@@ -4,6 +4,8 @@ run_cmake(CMP0023-WARN)
 run_cmake(CMP0023-NEW)
 run_cmake(CMP0023-WARN-2)
 run_cmake(CMP0023-NEW-2)
+run_cmake(ImportedTarget)
+run_cmake(ImportedTargetFailure)
 run_cmake(MixedSignature)
 run_cmake(Separate-PRIVATE-LINK_PRIVATE-uses)
 run_cmake(SubDirTarget)