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

Fixes: #24534

2 files changed, 14 insertions, 12 deletions

diff --git a/Source/cmInstallCommand.cxx b/Source/cmInstallCommand.cxx
index 82adca8..56c8b26 100644
--- a/Source/cmInstallCommand.cxx
+++ b/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, "$<INSTALL_PREFIX>")) {
+        if (!cmSystemTools::FileIsFullPath(script)) {
+          script =
+            cmStrCat(helper.Makefile->GetCurrentSourceDirectory(), '/', arg);
+        }
+        if (cmSystemTools::FileIsDirectory(script)) {
+          status.SetError("given a directory as value of SCRIPT argument.");
+          return false;
+        }
       }
       helper.Makefile->AddInstallGenerator(
         cm::make_unique<cmInstallScriptGenerator>(
diff --git a/Source/cmInstallScriptGenerator.cxx b/Source/cmInstallScriptGenerator.cxx
index a5625fe..af531f2 100644
--- a/Source/cmInstallScriptGenerator.cxx
+++ b/Source/cmInstallScriptGenerator.cxx
@@ -56,12 +56,12 @@ bool cmInstallScriptGenerator::Compute(cmLocalGenerator* lg)
 std::string cmInstallScriptGenerator::GetScript(
   std::string const& config) const
 {
-  std::string script;
+  std::string script = this->Script;
   if (this->AllowGenex && this->ActionsPerConfig) {
-    script = cmGeneratorExpression::Evaluate(this->Script,
-                                             this->LocalGenerator, config);
-  } else {
-    script = this->Script;
+    cmGeneratorExpression::ReplaceInstallPrefix(script,
+                                                "${CMAKE_INSTALL_PREFIX}");
+    script =
+      cmGeneratorExpression::Evaluate(script, this->LocalGenerator, config);
   }
   return script;
 }