install: Teach CODE,SCRIPT modes to evaluate generator expressions

This also introduces CMP0087 which will keep the OLD behaviour of not
evaluating generator expressions

Fixes: #15785

9 files changed, 44 insertions, 0 deletions

diff --git a/Tests/RunCMake/install/CMP0087-NEW-check.cmake b/Tests/RunCMake/install/CMP0087-NEW-check.cmake
new file mode 100644
index 0000000..422c532
--- /dev/null
+++ b/Tests/RunCMake/install/CMP0087-NEW-check.cmake
@@ -0,0 +1,7 @@
+execute_process(COMMAND ${CMAKE_COMMAND} -P ${RunCMake_TEST_BINARY_DIR}/cmake_install.cmake
+  OUTPUT_VARIABLE out ERROR_VARIABLE err)
+if(NOT out MATCHES "-- Install configuration: .*-- codegenexlib")
+  string(REGEX REPLACE "\n" "\n  " out "  ${out}")
+  string(APPEND RunCMake_TEST_FAILED
+      "\"-- codegenexlib\" was not found:\n${out}")
+endif()
diff --git a/Tests/RunCMake/install/CMP0087-NEW.cmake b/Tests/RunCMake/install/CMP0087-NEW.cmake
new file mode 100644
index 0000000..0177960
--- /dev/null
+++ b/Tests/RunCMake/install/CMP0087-NEW.cmake
@@ -0,0 +1,3 @@
+# Need a new directory scope, not just a new policy scope
+# to test this correctly
+add_subdirectory(CMP0087-NEW)
diff --git a/Tests/RunCMake/install/CMP0087-NEW/CMakeLists.txt b/Tests/RunCMake/install/CMP0087-NEW/CMakeLists.txt
new file mode 100644
index 0000000..07b4589
--- /dev/null
+++ b/Tests/RunCMake/install/CMP0087-NEW/CMakeLists.txt
@@ -0,0 +1,7 @@
+# Note that it is the policy settings at the end of the directory
+# scope that will be used when deciding whether or not generator
+# expressions should be evaluated in the installed code.
+cmake_policy(VERSION 3.13)
+cmake_policy(SET CMP0087 NEW)
+add_library( codegenexlib INTERFACE )
+install(CODE "message( STATUS \"$<TARGET_PROPERTY:codegenexlib,NAME>\")")
diff --git a/Tests/RunCMake/install/CMP0087-OLD-check.cmake b/Tests/RunCMake/install/CMP0087-OLD-check.cmake
new file mode 100644
index 0000000..c5984bc
--- /dev/null
+++ b/Tests/RunCMake/install/CMP0087-OLD-check.cmake
@@ -0,0 +1,8 @@
+execute_process(COMMAND ${CMAKE_COMMAND} -P ${RunCMake_TEST_BINARY_DIR}/cmake_install.cmake
+  OUTPUT_VARIABLE out ERROR_VARIABLE err)
+
+if(NOT out MATCHES "-- Install configuration: .*-- \\$<TARGET_PROPERTY:codegenexlib,NAME>")
+  string(REGEX REPLACE "\n" "\n  " out "  ${out}")
+  string(APPEND RunCMake_TEST_FAILED
+      "\"-- $<TARGET_PROPERTY:codegenexlib,NAME>\" was not found:\n${out}")
+endif()
diff --git a/Tests/RunCMake/install/CMP0087-OLD.cmake b/Tests/RunCMake/install/CMP0087-OLD.cmake
new file mode 100644
index 0000000..e7ed4ee
--- /dev/null
+++ b/Tests/RunCMake/install/CMP0087-OLD.cmake
@@ -0,0 +1,3 @@
+# Need a new directory scope, not just a new policy scope
+# to test this correctly
+add_subdirectory(CMP0087-OLD)
diff --git a/Tests/RunCMake/install/CMP0087-OLD/CMakeLists.txt b/Tests/RunCMake/install/CMP0087-OLD/CMakeLists.txt
new file mode 100644
index 0000000..b1d4e2e
--- /dev/null
+++ b/Tests/RunCMake/install/CMP0087-OLD/CMakeLists.txt
@@ -0,0 +1,6 @@
+# Note that it is the policy settings at the end of the directory
+# scope that will be used when deciding whether or not generator
+# expressions should be evaluated in the installed code.
+cmake_policy(VERSION 3.13)
+cmake_policy(SET CMP0087 OLD)
+install(CODE "message( STATUS \"$<TARGET_PROPERTY:codegenexlib,NAME>\")")
diff --git a/Tests/RunCMake/install/CMP0087-WARN-stderr.txt b/Tests/RunCMake/install/CMP0087-WARN-stderr.txt
new file mode 100644
index 0000000..75fbf2c
--- /dev/null
+++ b/Tests/RunCMake/install/CMP0087-WARN-stderr.txt
@@ -0,0 +1,5 @@
+CMake Warning (dev) in CMakeLists.txt:
+  Policy CMP0087 is not set: Install CODE|SCRIPT allow the use of generator
+  expressions.  Run "cmake --help-policy CMP0087" for policy details.  Use
+  the cmake_policy command to set the policy and suppress this warning.
+This warning is for project developers.  Use -Wno-dev to suppress it.
diff --git a/Tests/RunCMake/install/CMP0087-WARN.cmake b/Tests/RunCMake/install/CMP0087-WARN.cmake
new file mode 100644
index 0000000..3b8513d
--- /dev/null
+++ b/Tests/RunCMake/install/CMP0087-WARN.cmake
@@ -0,0 +1,2 @@
+add_library( codegenexlib INTERFACE )
+install(CODE "message( STATUS \"$<TARGET_PROPERTY:codegenexlib,NAME>\")")
diff --git a/Tests/RunCMake/install/RunCMakeTest.cmake b/Tests/RunCMake/install/RunCMakeTest.cmake
index f7e1dee..28e8ec4 100644
--- a/Tests/RunCMake/install/RunCMakeTest.cmake
+++ b/Tests/RunCMake/install/RunCMakeTest.cmake
@@ -63,6 +63,9 @@ run_cmake(EXPORT-OldIFace)
 run_cmake(CMP0062-OLD)
 run_cmake(CMP0062-NEW)
 run_cmake(CMP0062-WARN)
+run_cmake(CMP0087-OLD)
+run_cmake(CMP0087-NEW)
+run_cmake(CMP0087-WARN)
 run_cmake(TARGETS-NAMELINK_COMPONENT-bad-all)
 run_cmake(TARGETS-NAMELINK_COMPONENT-bad-exc)
 run_cmake(FILES-DESTINATION-TYPE)