install(CODE|SCRIPT): Support $<INSTALL_PREFIX> genex

Fixes: #24534

Help/manual/cmake-generator-expressions.7.rst

@@ -1734,8 +1734,10 @@ Export And Install Expressions
 
   Content of the install prefix when the target is exported via
   :command:`install(EXPORT)`, or when evaluated in the
-  :prop_tgt:`INSTALL_NAME_DIR` property or the ``INSTALL_NAME_DIR`` argument of
-  :command:`install(RUNTIME_DEPENDENCY_SET)`, and empty otherwise.
+  :prop_tgt:`INSTALL_NAME_DIR` property, the ``INSTALL_NAME_DIR`` argument of
+  :command:`install(RUNTIME_DEPENDENCY_SET)`, the code argument of
+  :command:`install(CODE)`, or the file argument of :command:`install(SCRIPT)`,
+  and empty otherwise.
 
 Multi-level Expression Evaluation
 ---------------------------------

Help/release/dev/install-prefix-genex-install-code-script.rst

@@ -0,0 +1,5 @@
+install-prefix-genex-install-code-script
+----------------------------------------
+
+* The :command:`install(CODE)` and :command:`install(SCRIPT)` commands
+  now support the :genex:`$<INSTALL_PREFIX>` generator expression.

Source/cmInstallCommand.cxx

@@ -359,13 +359,15 @@ bool HandleScriptMode(std::vector<std::string> const& args,
     } else if (doing_script) {
       doing_script = false;
       std::string script = arg;
-      if (!cmSystemTools::FileIsFullPath(script)) {
-        script =
-          cmStrCat(helper.Makefile->GetCurrentSourceDirectory(), '/', arg);
-      }
-      if (cmSystemTools::FileIsDirectory(script)) {
-        status.SetError("given a directory as value of SCRIPT argument.");
-        return false;
+      if (!cmHasLiteralPrefix(script, "$<INSTALL_PREFIX>")) {
+        if (!cmSystemTools::FileIsFullPath(script)) {
+          script =
+            cmStrCat(helper.Makefile->GetCurrentSourceDirectory(), '/', arg);
+        }
+        if (cmSystemTools::FileIsDirectory(script)) {
+          status.SetError("given a directory as value of SCRIPT argument.");
+          return false;
+        }
       }
       helper.Makefile->AddInstallGenerator(
         cm::make_unique<cmInstallScriptGenerator>(

Source/cmInstallScriptGenerator.cxx

@@ -56,12 +56,12 @@ bool cmInstallScriptGenerator::Compute(cmLocalGenerator* lg)
 std::string cmInstallScriptGenerator::GetScript(
   std::string const& config) const
 {
-  std::string script;
+  std::string script = this->Script;
   if (this->AllowGenex && this->ActionsPerConfig) {
-    script = cmGeneratorExpression::Evaluate(this->Script,
-                                             this->LocalGenerator, config);
-  } else {
-    script = this->Script;
+    cmGeneratorExpression::ReplaceInstallPrefix(script,
+                                                "${CMAKE_INSTALL_PREFIX}");
+    script =
+      cmGeneratorExpression::Evaluate(script, this->LocalGenerator, config);
   }
   return script;
 }

Tests/RunCMake/install/RunCMakeTest.cmake

@@ -166,7 +166,6 @@ unset(RunCMake_TEST_OPTIONS)
 
 run_install_test(Deprecated)
 run_install_test(PRE_POST_INSTALL_SCRIPT)
-run_install_test(SCRIPT)
 run_install_test(TARGETS-CONFIGURATIONS)
 run_install_test(DIRECTORY-PATTERN)
 run_install_test(TARGETS-Parts)
@@ -174,6 +173,10 @@ run_install_test(FILES-PERMISSIONS)
 run_install_test(TARGETS-RPATH)
 run_install_test(InstallRequiredSystemLibraries)
 
+set(RunCMake_TEST_OPTIONS "-DCMAKE_POLICY_DEFAULT_CMP0087:STRING=NEW")
+run_install_test(SCRIPT)
+unset(RunCMake_TEST_OPTIONS)
+
 if(UNIX)
   run_install_test(DIRECTORY-symlink-clobber)
 endif()

Tests/RunCMake/install/SCRIPT-all-check.cmake

@@ -1 +1 @@
-check_installed([[^empty1.txt;empty2.txt$]])
+check_installed([[^empty1.txt;empty2.txt;empty3.cmake;empty3.txt;empty4.cmake;empty4.txt$]])

Tests/RunCMake/install/SCRIPT.cmake

@@ -1,4 +1,10 @@
+install(
+  FILES ${CMAKE_CURRENT_SOURCE_DIR}/empty3.cmake ${CMAKE_CURRENT_SOURCE_DIR}/empty4.cmake
+  DESTINATION .
+  )
 install(
   SCRIPT "${CMAKE_CURRENT_SOURCE_DIR}/install_script.cmake"
   CODE "write_empty_file(empty2.txt)"
+  SCRIPT "$<INSTALL_PREFIX>/empty3.cmake"
+  CODE [[include($<INSTALL_PREFIX>/empty4.cmake)]]
   )

Tests/RunCMake/install/empty3.cmake

@@ -0,0 +1 @@
+write_empty_file(empty3.txt)

Tests/RunCMake/install/empty4.cmake

@@ -0,0 +1 @@
+write_empty_file(empty4.txt)