project: Add variable CMAKE_PROJECT_<PROJECT-NAME>_INCLUDE_BEFORE

Follow up commit 0761186949 (project: Add variable
CMAKE_PROJECT_INCLUDE_BEFORE, 2019-03-28, v3.15.0-rc1~294^2) with a
project-specific variant.  This variable will be used similar to the
already existing `CMAKE_PROJECT_INCLUDE_BEFORE` and
`CMAKE_PROJECT_<PROJECT-NAME>_INCLUDE` variables.

Fixes: #19854

Help/command/project.rst

@@ -102,9 +102,12 @@ options are intended for use as default values in package metadata and documenta
 Code Injection
 ^^^^^^^^^^^^^^
 
-If the :variable:`CMAKE_PROJECT_INCLUDE_BEFORE` variable is set, the file
-pointed to by that variable will be included as the first step of the
+If the :variable:`CMAKE_PROJECT_INCLUDE_BEFORE` or
+:variable:`CMAKE_PROJECT_<PROJECT-NAME>_INCLUDE_BEFORE` variables are set,
+the files they point to will be included as the first step of the
 ``project()`` command.
+If both are set, then :variable:`CMAKE_PROJECT_INCLUDE_BEFORE` will be
+included before :variable:`CMAKE_PROJECT_<PROJECT-NAME>_INCLUDE_BEFORE`.
 
 If the :variable:`CMAKE_PROJECT_INCLUDE` or
 :variable:`CMAKE_PROJECT_<PROJECT-NAME>_INCLUDE` variables are set, the files

Help/manual/cmake-variables.7.rst

@@ -216,6 +216,7 @@ Variables that Change Behavior
    /variable/CMAKE_PROJECT_INCLUDE
    /variable/CMAKE_PROJECT_INCLUDE_BEFORE
    /variable/CMAKE_PROJECT_PROJECT-NAME_INCLUDE
+   /variable/CMAKE_PROJECT_PROJECT-NAME_INCLUDE_BEFORE
    /variable/CMAKE_SKIP_INSTALL_ALL_DEPENDENCY
    /variable/CMAKE_STAGING_PREFIX
    /variable/CMAKE_SUBLIME_TEXT_2_ENV_SETTINGS

Help/variable/CMAKE_PROJECT_INCLUDE.rst

@@ -5,5 +5,6 @@ A CMake language file or module to be included as the last step of all
 :command:`project` command calls.  This is intended for injecting custom code
 into project builds without modifying their source.
 
-See also the :variable:`CMAKE_PROJECT_<PROJECT-NAME>_INCLUDE` and
+See also the :variable:`CMAKE_PROJECT_<PROJECT-NAME>_INCLUDE`,
+:variable:`CMAKE_PROJECT_<PROJECT-NAME>_INCLUDE_BEFORE` and
 :variable:`CMAKE_PROJECT_INCLUDE_BEFORE` variables.

Help/variable/CMAKE_PROJECT_INCLUDE_BEFORE.rst

@@ -5,5 +5,6 @@ A CMake language file or module to be included as the first step of all
 :command:`project` command calls.  This is intended for injecting custom code
 into project builds without modifying their source.
 
-See also the :variable:`CMAKE_PROJECT_<PROJECT-NAME>_INCLUDE` and
+See also the :variable:`CMAKE_PROJECT_<PROJECT-NAME>_INCLUDE`,
+:variable:`CMAKE_PROJECT_<PROJECT-NAME>_INCLUDE_BEFORE` and
 :variable:`CMAKE_PROJECT_INCLUDE` variables.

Help/variable/CMAKE_PROJECT_PROJECT-NAME_INCLUDE.rst

@@ -6,5 +6,6 @@ A CMake language file or module to be included as the last step of any
 name.  This is intended for injecting custom code into project builds without
 modifying their source.
 
-See also the :variable:`CMAKE_PROJECT_INCLUDE` and
+See also the :variable:`CMAKE_PROJECT_<PROJECT-NAME>_INCLUDE_BEFORE`,
+:variable:`CMAKE_PROJECT_INCLUDE` and
 :variable:`CMAKE_PROJECT_INCLUDE_BEFORE` variables.

Help/variable/CMAKE_PROJECT_PROJECT-NAME_INCLUDE_BEFORE.rst

@@ -0,0 +1,11 @@
+CMAKE_PROJECT_<PROJECT-NAME>_INCLUDE_BEFORE
+-------------------------------------------
+
+A CMake language file or module to be included as the first step of any
+:command:`project` command calls that specify ``<PROJECT-NAME>`` as the project
+name.  This is intended for injecting custom code into project builds without
+modifying their source.
+
+See also the :variable:`CMAKE_PROJECT_<PROJECT-NAME>_INCLUDE`,
+:variable:`CMAKE_PROJECT_INCLUDE` and
+:variable:`CMAKE_PROJECT_INCLUDE_BEFORE` variables.

Source/cmProjectCommand.cxx

@@ -39,6 +39,11 @@ bool cmProjectCommand(std::vector<std::string> const& args,
 
   std::string const& projectName = args[0];
 
+  if (!IncludeByVariable(status,
+                         "CMAKE_PROJECT_" + projectName + "_INCLUDE_BEFORE")) {
+    return false;
+  }
+
   mf.SetProjectName(projectName);
 
   mf.AddCacheDefinition(projectName + "_BINARY_DIR",

Tests/CMakeOnly/CMakeLists.txt

@@ -75,6 +75,12 @@ add_test(CMakeOnly.ProjectIncludeAny ${CMAKE_CMAKE_COMMAND}
 
 add_test(CMakeOnly.ProjectIncludeBefore ${CMAKE_CMAKE_COMMAND}
   -DTEST=ProjectIncludeBefore
+  -DCMAKE_ARGS=-DCMAKE_PROJECT_ProjectInclude_INCLUDE_BEFORE=${CMAKE_CURRENT_SOURCE_DIR}/ProjectIncludeBefore/include.cmake
+  -P ${CMAKE_CURRENT_BINARY_DIR}/Test.cmake
+  )
+
+add_test(CMakeOnly.ProjectIncludeBeforeAny ${CMAKE_CMAKE_COMMAND}
+  -DTEST=ProjectIncludeBeforeAny
   -DCMAKE_ARGS=-DCMAKE_PROJECT_INCLUDE_BEFORE=${CMAKE_CURRENT_SOURCE_DIR}/ProjectIncludeBefore/include.cmake
   -P ${CMAKE_CURRENT_BINARY_DIR}/Test.cmake
   )

Tests/CMakeOnly/ProjectIncludeBeforeAny/CMakeLists.txt

@@ -0,0 +1,5 @@
+set(FOO TRUE)
+project(ProjectInclude LANGUAGES NONE)
+if(NOT AUTO_INCLUDE)
+  message(FATAL_ERROR "include file not found")
+endif()

Tests/CMakeOnly/ProjectIncludeBeforeAny/include.cmake

@@ -0,0 +1,9 @@
+if(NOT FOO)
+  message(FATAL_ERROR "FOO is not set")
+endif()
+
+if(NOT "${PROJECT_NAME}" STREQUAL "")
+  message(FATAL_ERROR "PROJECT_NAME should be empty")
+endif()
+
+set(AUTO_INCLUDE TRUE)