install: Allow generator expressions in FILES DESTINATION

Help/command/install.rst

@@ -192,6 +192,10 @@ The list of ``files...`` given to ``FILES`` or ``PROGRAMS`` may use
 However, if any item begins in a generator expression it must evaluate
 to a full path.
 
+The install destination given to the files install ``DESTINATION`` may
+use "generator expressions" with the syntax ``$<...>``.  See the
+:manual:`cmake-generator-expressions(7)` manual for available expressions.
+
 Installing Directories
 ^^^^^^^^^^^^^^^^^^^^^^
 

Help/release/dev/install-files-dest-genex.rst

+install-files-dest-genex
+------------------------
+
+* The :command:`install(FILES)` command ``DESTINATION`` option learned to
+  support :manual:`generator expressions <cmake-generator-expressions(7)>`.

Source/cmInstallFilesGenerator.cxx

@@ -34,6 +34,12 @@ cmInstallFilesGenerator
   Programs(programs),
   Optional(optional)
 {
+  // We need per-config actions if the destination has generator expressions.
+  if(cmGeneratorExpression::Find(Destination) != std::string::npos)
+    {
+    this->ActionsPerConfig = true;
+    }
+
   // We need per-config actions if any files have generator expressions.
   for(std::vector<std::string>::const_iterator i = files.begin();
       !this->ActionsPerConfig && i != files.end(); ++i)
@@ -56,15 +62,26 @@ void cmInstallFilesGenerator::Compute(cmLocalGenerator* lg)
   this->LocalGenerator = lg;
 }
 
+//----------------------------------------------------------------------------
+std::string
+cmInstallFilesGenerator::GetDestination(std::string const& config) const
+{
+  cmGeneratorExpression ge;
+  return ge.Parse(this->Destination)
+    ->Evaluate(this->LocalGenerator->GetMakefile(), config);
+}
+
 //----------------------------------------------------------------------------
 void cmInstallFilesGenerator::AddFilesInstallRule(
-  std::ostream& os, Indent const& indent,
+  std::ostream& os,
+  const std::string config,
+  Indent const& indent,
   std::vector<std::string> const& files)
 {
   // Write code to install the files.
   const char* no_dir_permissions = 0;
   this->AddInstallRule(os,
-                       this->Destination,
+                       this->GetDestination(config),
                        (this->Programs
                         ? cmInstallType_PROGRAMS
                         : cmInstallType_FILES),
@@ -84,7 +101,7 @@ void cmInstallFilesGenerator::GenerateScriptActions(std::ostream& os,
     }
   else
     {
-    this->AddFilesInstallRule(os, indent, this->Files);
+    this->AddFilesInstallRule(os, "", indent, this->Files);
     }
 }
 
@@ -102,5 +119,5 @@ void cmInstallFilesGenerator::GenerateScriptForConfig(std::ostream& os,
     cmSystemTools::ExpandListArgument(cge->Evaluate(
         this->LocalGenerator->GetMakefile(), config), files);
     }
-  this->AddFilesInstallRule(os, indent, files);
+  this->AddFilesInstallRule(os, config, indent, files);
 }

Source/cmInstallFilesGenerator.h

@@ -32,12 +32,16 @@ public:
 
   void Compute(cmLocalGenerator* lg);
 
+  std::string GetDestination(std::string const& config) const;
+
 protected:
   virtual void GenerateScriptActions(std::ostream& os, Indent const& indent);
   virtual void GenerateScriptForConfig(std::ostream& os,
                                        const std::string& config,
                                        Indent const& indent);
-  void AddFilesInstallRule(std::ostream& os, Indent const& indent,
+  void AddFilesInstallRule(std::ostream& os,
+                           const std::string config,
+                           Indent const& indent,
                            std::vector<std::string> const& files);
 
   cmLocalGenerator* LocalGenerator;