Xcode: Pass compile definitions to Swift

correct Xcode generator Swift definitions
original code was defining GCC_PREPROCESSOR_DEFINITIONS which is valid only for C languages
add definitions to SWIFT_ACTIVE_COMPILATION_CONDITIONS when Swift language is used in the target
add test in SwiftOnly
for old Xcode (<8.0), append defines to cflags so it ends up in OTHER_SWIFT_FLAGS

Fixes: #23637

1 files changed, 12 insertions, 0 deletions

diff --git a/Source/cmGlobalXCodeGenerator.cxx b/Source/cmGlobalXCodeGenerator.cxx
index 5738799..456f5bc 100644
--- a/Source/cmGlobalXCodeGenerator.cxx
+++ b/Source/cmGlobalXCodeGenerator.cxx
@@ -2423,6 +2423,18 @@ void cmGlobalXCodeGenerator::CreateBuildSettings(cmGeneratorTarget* gtgt,
   this->AppendDefines(ppDefs, targetDefines);
   buildSettings->AddAttribute("GCC_PREPROCESSOR_DEFINITIONS",
                               ppDefs.CreateList());
+  if (languages.count("Swift")) {
+    if (this->XcodeVersion < 80) {
+      std::string defineString;
+      std::set<std::string> defines(targetDefines.begin(),
+                                    targetDefines.end());
+      this->CurrentLocalGenerator->JoinDefines(defines, defineString, "Swift");
+      cflags["Swift"] += " " + defineString;
+    } else {
+      buildSettings->AddAttribute("SWIFT_ACTIVE_COMPILATION_CONDITIONS",
+                                  ppDefs.CreateList());
+    }
+  }
 
   std::string extraLinkOptionsVar;
   std::string extraLinkOptions;