Darwin: Emit deployment target that matches the SDK

Closes: #17431

15 files changed, 185 insertions, 15 deletions

diff --git a/Help/release/dev/iphone-deployment-target.rst b/Help/release/dev/iphone-deployment-target.rst
new file mode 100644
index 0000000..e586df6
--- /dev/null
+++ b/Help/release/dev/iphone-deployment-target.rst
@@ -0,0 +1,11 @@
+iphone-deployment-target
+------------------------
+
+* The minimum deployment target set in the
+  :variable:`CMAKE_OSX_DEPLOYMENT_TARGET` variable used to be only
+  applied for macOS regardless of the selected SDK.  It is now properly
+  set for the target platform selected by :variable:`CMAKE_OSX_SYSROOT`.
+
+  If for example the sysroot variable specifies an iOS SDK then the
+  value in ``CMAKE_OSX_DEPLOYMENT_TARGET`` is interpreted as minium
+  iOS version.
diff --git a/Help/variable/CMAKE_OSX_DEPLOYMENT_TARGET.rst b/Help/variable/CMAKE_OSX_DEPLOYMENT_TARGET.rst
index 4fb2caa..9df5edd 100644
--- a/Help/variable/CMAKE_OSX_DEPLOYMENT_TARGET.rst
+++ b/Help/variable/CMAKE_OSX_DEPLOYMENT_TARGET.rst
@@ -1,10 +1,12 @@
 CMAKE_OSX_DEPLOYMENT_TARGET
 ---------------------------
 
-Specify the minimum version of OS X on which the target binaries are
-to be deployed.  CMake uses this value for the ``-mmacosx-version-min``
-flag and to help choose the default SDK
-(see :variable:`CMAKE_OSX_SYSROOT`).
+Specify the minimum version of the target platform (e.g. macOS or iOS)
+on which the target binaries are to be deployed.  CMake uses this
+variable value for the ``-mmacosx-version-min`` flag or their respective
+target platform equivalents.  For older Xcode versions that shipped
+multiple macOS SDKs this variable also helps to choose the SDK in case
+:variable:`CMAKE_OSX_SYSROOT` is unset.
 
 If not set explicitly the value is initialized by the
 ``MACOSX_DEPLOYMENT_TARGET`` environment variable, if set,
diff --git a/Help/variable/CMAKE_OSX_VARIABLE.txt b/Help/variable/CMAKE_OSX_VARIABLE.txt
index 385f871..5b84726 100644
--- a/Help/variable/CMAKE_OSX_VARIABLE.txt
+++ b/Help/variable/CMAKE_OSX_VARIABLE.txt
@@ -3,4 +3,7 @@ The value of this variable should be set prior to the first
 because it may influence configuration of the toolchain and flags.
 It is intended to be set locally by the user creating a build tree.
 
-This variable is ignored on platforms other than OS X.
+Despite the ``OSX`` part in the variable name(s) they apply also to
+other SDKs than macOS like iOS, tvOS, or watchOS.
+
+This variable is ignored on platforms other than Apple.
diff --git a/Modules/Platform/Darwin-Clang.cmake b/Modules/Platform/Darwin-Clang.cmake
index a6661a8..f8a07ec 100644
--- a/Modules/Platform/Darwin-Clang.cmake
+++ b/Modules/Platform/Darwin-Clang.cmake
@@ -17,4 +17,19 @@ macro(__darwin_compiler_clang lang)
   if(NOT CMAKE_${lang}_COMPILER_VERSION VERSION_LESS 3.2)
     set(CMAKE_${lang}_SYSTEM_FRAMEWORK_SEARCH_FLAG "-iframework ")
   endif()
+  if(_CMAKE_OSX_SYSROOT_PATH MATCHES "/iPhoneOS")
+    set(CMAKE_${lang}_OSX_DEPLOYMENT_TARGET_FLAG "-miphoneos-version-min=")
+  elseif(_CMAKE_OSX_SYSROOT_PATH MATCHES "/iPhoneSimulator")
+    set(CMAKE_${lang}_OSX_DEPLOYMENT_TARGET_FLAG "-mios-simulator-version-min=")
+  elseif(_CMAKE_OSX_SYSROOT_PATH MATCHES "/AppleTVOS")
+    set(CMAKE_${lang}_OSX_DEPLOYMENT_TARGET_FLAG "-mtvos-version-min=")
+  elseif(_CMAKE_OSX_SYSROOT_PATH MATCHES "/AppleTVSimulator")
+    set(CMAKE_${lang}_OSX_DEPLOYMENT_TARGET_FLAG "-mtvos-simulator-version-min=")
+  elseif(_CMAKE_OSX_SYSROOT_PATH MATCHES "/WatchOS")
+    set(CMAKE_${lang}_OSX_DEPLOYMENT_TARGET_FLAG "-mwatchos-version-min=")
+  elseif(_CMAKE_OSX_SYSROOT_PATH MATCHES "/WatchSimulator")
+    set(CMAKE_${lang}_OSX_DEPLOYMENT_TARGET_FLAG "-mwatchos-simulator-version-min=")
+  else()
+    set(CMAKE_${lang}_OSX_DEPLOYMENT_TARGET_FLAG "-mmacosx-version-min=")
+  endif()
 endmacro()
diff --git a/Source/cmGlobalXCodeGenerator.cxx b/Source/cmGlobalXCodeGenerator.cxx
index f392589..5c6a846 100644
--- a/Source/cmGlobalXCodeGenerator.cxx
+++ b/Source/cmGlobalXCodeGenerator.cxx
@@ -2992,7 +2992,7 @@ bool cmGlobalXCodeGenerator::CreateXCodeObjects(
     buildSettings->AddAttribute("ARCHS", this->CreateString(archs));
   }
   if (deploymentTarget && *deploymentTarget) {
-    buildSettings->AddAttribute("MACOSX_DEPLOYMENT_TARGET",
+    buildSettings->AddAttribute(GetDeploymentPlatform(root->GetMakefile()),
                                 this->CreateString(deploymentTarget));
   }
   if (!this->GeneratorToolset.empty()) {
@@ -3627,3 +3627,24 @@ void cmGlobalXCodeGenerator::ComputeTargetObjectDirectory(
   dir += "/";
   gt->ObjectDirectory = dir;
 }
+
+std::string cmGlobalXCodeGenerator::GetDeploymentPlatform(const cmMakefile* mf)
+{
+  switch (mf->GetAppleSDKType()) {
+    case cmMakefile::AppleSDK::AppleTVOS:
+    case cmMakefile::AppleSDK::AppleTVSimulator:
+      return "TVOS_DEPLOYMENT_TARGET";
+
+    case cmMakefile::AppleSDK::IPhoneOS:
+    case cmMakefile::AppleSDK::IPhoneSimulator:
+      return "IPHONEOS_DEPLOYMENT_TARGET";
+
+    case cmMakefile::AppleSDK::WatchOS:
+    case cmMakefile::AppleSDK::WatchSimulator:
+      return "WATCHOS_DEPLOYMENT_TARGET";
+
+    case cmMakefile::AppleSDK::MacOS:
+    default:
+      return "MACOSX_DEPLOYMENT_TARGET";
+  }
+}
diff --git a/Source/cmGlobalXCodeGenerator.h b/Source/cmGlobalXCodeGenerator.h
index b758e97..2269b25 100644
--- a/Source/cmGlobalXCodeGenerator.h
+++ b/Source/cmGlobalXCodeGenerator.h
@@ -254,6 +254,8 @@ private:
                                         const std::string& configName,
                                         const cmGeneratorTarget* t) const;
 
+  static std::string GetDeploymentPlatform(const cmMakefile* mf);
+
   void ComputeArchitectures(cmMakefile* mf);
   void ComputeObjectDirArch(cmMakefile* mf);
 
diff --git a/Source/cmMakefile.cxx b/Source/cmMakefile.cxx
index c70a7ae..5d6029c 100644
--- a/Source/cmMakefile.cxx
+++ b/Source/cmMakefile.cxx
@@ -2244,25 +2244,38 @@ bool cmMakefile::PlatformIsx32() const
   return false;
 }
 
-bool cmMakefile::PlatformIsAppleEmbedded() const
+cmMakefile::AppleSDK cmMakefile::GetAppleSDKType() const
 {
   std::string sdkRoot;
   sdkRoot = this->GetSafeDefinition("CMAKE_OSX_SYSROOT");
   sdkRoot = cmSystemTools::LowerCase(sdkRoot);
 
-  const std::string embedded[] = {
-    "appletvos",       "appletvsimulator", "iphoneos",
-    "iphonesimulator", "watchos",          "watchsimulator",
+  struct
+  {
+    std::string name;
+    AppleSDK sdk;
+  } const sdkDatabase[]{
+    { "appletvos", AppleSDK::AppleTVOS },
+    { "appletvsimulator", AppleSDK::AppleTVSimulator },
+    { "iphoneos", AppleSDK::IPhoneOS },
+    { "iphonesimulator", AppleSDK::IPhoneSimulator },
+    { "watchos", AppleSDK::WatchOS },
+    { "watchsimulator", AppleSDK::WatchSimulator },
   };
 
-  for (std::string const& i : embedded) {
-    if (sdkRoot.find(i) == 0 ||
-        sdkRoot.find(std::string("/") + i) != std::string::npos) {
-      return true;
+  for (auto entry : sdkDatabase) {
+    if (sdkRoot.find(entry.name) == 0 ||
+        sdkRoot.find(std::string("/") + entry.name) != std::string::npos) {
+      return entry.sdk;
     }
   }
 
-  return false;
+  return AppleSDK::MacOS;
+}
+
+bool cmMakefile::PlatformIsAppleEmbedded() const
+{
+  return GetAppleSDKType() != AppleSDK::MacOS;
 }
 
 const char* cmMakefile::GetSONameFlag(const std::string& language) const
diff --git a/Source/cmMakefile.h b/Source/cmMakefile.h
index e1ec8ed..40e8148 100644
--- a/Source/cmMakefile.h
+++ b/Source/cmMakefile.h
@@ -439,6 +439,21 @@ public:
   /** Return whether the target platform is x32.  */
   bool PlatformIsx32() const;
 
+  /** Apple SDK Type */
+  enum class AppleSDK
+  {
+    MacOS,
+    IPhoneOS,
+    IPhoneSimulator,
+    AppleTVOS,
+    AppleTVSimulator,
+    WatchOS,
+    WatchSimulator,
+  };
+
+  /** What SDK type points CMAKE_OSX_SYSROOT to? */
+  AppleSDK GetAppleSDKType() const;
+
   /** Return whether the target platform is Apple iOS.  */
   bool PlatformIsAppleEmbedded() const;
 
diff --git a/Tests/RunCMake/XcodeProject/DeploymentTarget.c b/Tests/RunCMake/XcodeProject/DeploymentTarget.c
new file mode 100644
index 0000000..51af046
--- /dev/null
+++ b/Tests/RunCMake/XcodeProject/DeploymentTarget.c
@@ -0,0 +1,26 @@
+#include <Availability.h>
+#include <TargetConditionals.h>
+
+#if TARGET_OS_OSX
+#if __MAC_OS_X_VERSION_MIN_REQUIRED != __MAC_10_11
+#error macOS deployment version mismatch
+#endif
+#elif TARGET_OS_IOS
+#if __IPHONE_OS_VERSION_MIN_REQUIRED != __IPHONE_9_1
+#error iOS deployment version mismatch
+#endif
+#elif TARGET_OS_WATCH
+#if __WATCH_OS_VERSION_MIN_REQUIRED != __WATCHOS_2_0
+#error watchOS deployment version mismatch
+#endif
+#elif TARGET_OS_TV
+#if __TV_OS_VERSION_MIN_REQUIRED != __TVOS_9_0
+#error tvOS deployment version mismatch
+#endif
+#else
+#error unknown OS
+#endif
+
+void foo()
+{
+}
diff --git a/Tests/RunCMake/XcodeProject/DeploymentTarget.cmake b/Tests/RunCMake/XcodeProject/DeploymentTarget.cmake
new file mode 100644
index 0000000..6281352
--- /dev/null
+++ b/Tests/RunCMake/XcodeProject/DeploymentTarget.cmake
@@ -0,0 +1,32 @@
+cmake_minimum_required(VERSION 3.10)
+project(DeploymentTarget C)
+
+# using Xcode 7.1 SDK versions for deployment targets
+
+if(SDK MATCHES iphone)
+  set(CMAKE_OSX_SYSROOT ${SDK})
+  set(CMAKE_OSX_ARCHITECTURES "armv7;x86_64")
+  set(CMAKE_OSX_DEPLOYMENT_TARGET "9.1")
+  set(CMAKE_XCODE_ATTRIBUTE_CODE_SIGNING_REQUIRED "NO")
+  set(CMAKE_XCODE_ATTRIBUTE_ENABLE_BITCODE "NO")
+elseif(SDK MATCHES watch)
+  set(CMAKE_OSX_SYSROOT ${SDK})
+  set(CMAKE_OSX_ARCHITECTURES "armv7k;i386")
+  set(CMAKE_OSX_DEPLOYMENT_TARGET "2.0")
+  set(CMAKE_XCODE_ATTRIBUTE_CODE_SIGNING_REQUIRED "NO")
+  set(CMAKE_XCODE_ATTRIBUTE_CODE_SIGN_IDENTITY "")
+  set(CMAKE_XCODE_ATTRIBUTE_ENABLE_BITCODE "YES")
+elseif(SDK MATCHES appletv)
+  set(CMAKE_OSX_SYSROOT ${SDK})
+  set(CMAKE_OSX_DEPLOYMENT_TARGET "9.0")
+  set(CMAKE_OSX_ARCHITECTURES "arm64;x86_64")
+  set(CMAKE_XCODE_ATTRIBUTE_CODE_SIGNING_REQUIRED "NO")
+  set(CMAKE_XCODE_ATTRIBUTE_CODE_SIGN_IDENTITY "")
+  set(CMAKE_XCODE_ATTRIBUTE_ENABLE_BITCODE "YES")
+else()
+  set(CMAKE_OSX_SYSROOT ${SDK})
+  set(CMAKE_OSX_DEPLOYMENT_TARGET "10.11")
+endif()
+
+add_library(myFramework STATIC DeploymentTarget.c)
+set_target_properties(myFramework PROPERTIES FRAMEWORK TRUE)
diff --git a/Tests/RunCMake/XcodeProject/RunCMakeTest.cmake b/Tests/RunCMake/XcodeProject/RunCMakeTest.cmake
index 7eb624c..1313cb5 100644
--- a/Tests/RunCMake/XcodeProject/RunCMakeTest.cmake
+++ b/Tests/RunCMake/XcodeProject/RunCMakeTest.cmake
@@ -216,3 +216,21 @@ endfunction()
 if(NOT XCODE_VERSION VERSION_LESS 7)
   XcodeSchemaGeneration()
 endif()
+
+if(XCODE_VERSION VERSION_GREATER_EQUAL 8)
+  function(deploymeny_target_test SDK)
+    set(RunCMake_TEST_BINARY_DIR ${RunCMake_BINARY_DIR}/DeploymentTarget-${SDK}-build)
+    set(RunCMake_TEST_NO_CLEAN 1)
+    set(RunCMake_TEST_OPTIONS "-DSDK=${SDK}")
+
+    file(REMOVE_RECURSE "${RunCMake_TEST_BINARY_DIR}")
+    file(MAKE_DIRECTORY "${RunCMake_TEST_BINARY_DIR}")
+
+    run_cmake(DeploymentTarget)
+    run_cmake_command(DeploymentTarget-${SDK} ${CMAKE_COMMAND} --build .)
+  endfunction()
+
+  foreach(SDK macosx iphoneos iphonesimulator appletvos appletvsimulator watchos watchsimulator)
+    deploymeny_target_test(${SDK})
+  endforeach()
+endif()
diff --git a/Tests/RunCMake/XcodeProject/XcodeBundles.cmake b/Tests/RunCMake/XcodeProject/XcodeBundles.cmake
index 0b854d8..5d19ee8 100644
--- a/Tests/RunCMake/XcodeProject/XcodeBundles.cmake
+++ b/Tests/RunCMake/XcodeProject/XcodeBundles.cmake
@@ -3,6 +3,9 @@
 cmake_minimum_required(VERSION 3.3)
 enable_language(C)
 
+# due to lack of toolchain file it might point to running macOS version
+unset(CMAKE_OSX_DEPLOYMENT_TARGET CACHE)
+
 if(TEST_IOS)
   set(CMAKE_OSX_SYSROOT iphoneos)
   set(CMAKE_OSX_ARCHITECTURES "armv7")
diff --git a/Tests/RunCMake/XcodeProject/XcodeIOSInstallCombined.cmake b/Tests/RunCMake/XcodeProject/XcodeIOSInstallCombined.cmake
index fc830b1..d7f3920 100644
--- a/Tests/RunCMake/XcodeProject/XcodeIOSInstallCombined.cmake
+++ b/Tests/RunCMake/XcodeProject/XcodeIOSInstallCombined.cmake
@@ -2,6 +2,9 @@ cmake_minimum_required(VERSION 3.3)
 
 project(IOSInstallCombined CXX)
 
+# due to lack of toolchain file it might point to running macOS version
+unset(CMAKE_OSX_DEPLOYMENT_TARGET CACHE)
+
 set(CMAKE_OSX_SYSROOT iphoneos)
 set(CMAKE_XCODE_ATTRIBUTE_CODE_SIGNING_REQUIRED "NO")
 set(CMAKE_XCODE_ATTRIBUTE_DEBUG_INFORMATION_FORMAT "dwarf")
diff --git a/Tests/RunCMake/XcodeProject/XcodeIOSInstallCombinedPrune.cmake b/Tests/RunCMake/XcodeProject/XcodeIOSInstallCombinedPrune.cmake
index b47d3a5..28ab883 100644
--- a/Tests/RunCMake/XcodeProject/XcodeIOSInstallCombinedPrune.cmake
+++ b/Tests/RunCMake/XcodeProject/XcodeIOSInstallCombinedPrune.cmake
@@ -2,6 +2,9 @@ cmake_minimum_required(VERSION 3.3)
 
 project(XcodeIOSInstallCombinedPrune CXX)
 
+# due to lack of toolchain file it might point to running macOS version
+unset(CMAKE_OSX_DEPLOYMENT_TARGET CACHE)
+
 set(CMAKE_OSX_SYSROOT iphoneos)
 set(CMAKE_XCODE_ATTRIBUTE_CODE_SIGNING_REQUIRED "NO")
 set(CMAKE_XCODE_ATTRIBUTE_DEBUG_INFORMATION_FORMAT "dwarf")
diff --git a/Tests/RunCMake/XcodeProject/XcodeIOSInstallCombinedSingleArch.cmake b/Tests/RunCMake/XcodeProject/XcodeIOSInstallCombinedSingleArch.cmake
index 4b5e7ce..5e7961a 100644
--- a/Tests/RunCMake/XcodeProject/XcodeIOSInstallCombinedSingleArch.cmake
+++ b/Tests/RunCMake/XcodeProject/XcodeIOSInstallCombinedSingleArch.cmake
@@ -2,6 +2,9 @@ cmake_minimum_required(VERSION 3.3)
 
 project(XcodeIOSInstallCombinedSingleArch CXX)
 
+# due to lack of toolchain file it might point to running macOS version
+unset(CMAKE_OSX_DEPLOYMENT_TARGET CACHE)
+
 set(CMAKE_OSX_SYSROOT iphoneos)
 set(CMAKE_XCODE_ATTRIBUTE_CODE_SIGNING_REQUIRED "NO")
 set(CMAKE_XCODE_ATTRIBUTE_DEBUG_INFORMATION_FORMAT "dwarf")