install: Allow generator expressions in TARGETS DESTINATION (#14317)

This will allow per-config destinations for targets in EXPORT sets.
Using multiple install(TARGETS) with separate CONFIGURATIONS is
rejected as a target appearing more than once in an export set.
Now instead one can write

 install(TARGETS foo EXPORT exp DESTINATION lib/$<CONFIG>)

to get a single logical membership of the target in the export set
while still having a per-config destination.

1 files changed, 12 insertions, 2 deletions

diff --git a/Source/cmInstallTargetGenerator.cxx b/Source/cmInstallTargetGenerator.cxx
index 7ab88f1..b035bad 100644
--- a/Source/cmInstallTargetGenerator.cxx
+++ b/Source/cmInstallTargetGenerator.cxx
@@ -12,6 +12,7 @@
 #include "cmInstallTargetGenerator.h"
 
 #include "cmComputeLinkInformation.h"
+#include "cmGeneratorExpression.h"
 #include "cmGlobalGenerator.h"
 #include "cmLocalGenerator.h"
 #include "cmMakefile.h"
@@ -78,7 +79,7 @@ void cmInstallTargetGenerator::GenerateScriptForConfig(std::ostream& os,
     fromDirConfig += "/";
     }
   std::string toDir =
-    this->ConvertToAbsoluteDestination(this->Destination);
+    this->ConvertToAbsoluteDestination(this->GetDestination(config));
   toDir += "/";
 
   // Compute the list of files to install for this target.
@@ -323,7 +324,7 @@ void cmInstallTargetGenerator::GenerateScriptForConfig(std::ostream& os,
   const char* no_dir_permissions = 0;
   const char* no_rename = 0;
   bool optional = this->Optional || this->ImportLibrary;
-  this->AddInstallRule(os, this->Destination,
+  this->AddInstallRule(os, this->GetDestination(config),
                        type, filesFrom, optional,
                        this->FilePermissions.c_str(), no_dir_permissions,
                        no_rename, literal_args.c_str(),
@@ -336,6 +337,15 @@ void cmInstallTargetGenerator::GenerateScriptForConfig(std::ostream& os,
 
 //----------------------------------------------------------------------------
 std::string
+cmInstallTargetGenerator::GetDestination(std::string const& config) const
+{
+  cmGeneratorExpression ge;
+  return ge.Parse(this->Destination)
+    ->Evaluate(this->Target->GetMakefile(), config);
+}
+
+//----------------------------------------------------------------------------
+std::string
 cmInstallTargetGenerator::GetInstallFilename(const std::string& config) const
 {
   NameType nameType = this->ImportLibrary? NameImplib : NameNormal;