[Driver] Allow users to silence the warning that is issued when the

deployment target is earlier than iOS 11 and the target is 32-bit.

This is a follow-up to r306922.

rdar://problem/32230613

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@309607 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit 4633b85c2c9915c7b57fb2327912a0cc59e1b077)

Conflicts:
lib/Driver/ToolChains/Darwin.cpp

apple-llvm-split-commit: e8adf5b68976d706116bb2f5fbf8e583179283fb
apple-llvm-split-dir: clang/

Author: ahatanaka

clang/include/clang/Basic/DiagnosticDriverKinds.td

@@ -135,9 +135,10 @@ def err_drv_cc_print_options_failure : Error<
     "unable to open CC_PRINT_OPTIONS file: %0">;
 def err_drv_preamble_format : Error<
     "incorrect format for -preamble-bytes=N,END">;
-def err_invalid_ios_deployment_target : Error<
+def warn_invalid_ios_deployment_target : Warning<
   "invalid iOS deployment version '%0', iOS 10 is the maximum deployment "
-  "target for 32-bit targets">;
+  "target for 32-bit targets">, InGroup<InvalidIOSDeploymentTarget>,
+  DefaultError;
 def err_drv_conflicting_deployment_targets : Error<
   "conflicting deployment targets, both '%0' and '%1' are present in environment">;
 def err_arc_unsupported_on_runtime : Error<

clang/include/clang/Basic/DiagnosticGroups.td

@@ -146,6 +146,9 @@ def GNUFlexibleArrayUnionMember : DiagGroup<"gnu-flexible-array-union-member">;
 def GNUFoldingConstant : DiagGroup<"gnu-folding-constant">;
 def FormatExtraArgs : DiagGroup<"format-extra-args">;
 def FormatZeroLength : DiagGroup<"format-zero-length">;
+
+def InvalidIOSDeploymentTarget : DiagGroup<"invalid-ios-deployment-target">;
+
 def CXX1zCompatMangling : DiagGroup<"c++1z-compat-mangling">;
 
 // Warnings for C++1y code which is not compatible with prior C++ standards.

clang/lib/Driver/ToolChains.cpp

@@ -601,7 +601,7 @@ void Darwin::AddDeploymentTarget(DerivedArgList &Args) const {
       Driver::GetReleaseVersion(iOSVersion->getValue(), Major, Minor, Micro,
                                 HadExtra) &&
       Major > 10)
-    getDriver().Diag(diag::err_invalid_ios_deployment_target)
+    getDriver().Diag(diag::warn_invalid_ios_deployment_target)
         << iOSVersion->getAsString(Args);
 
   // Add a macro to differentiate between m(iphone|tv|watch)os-version-min=X.Y and
@@ -650,7 +650,7 @@ void Darwin::AddDeploymentTarget(DerivedArgList &Args) const {
         Driver::GetReleaseVersion(iOSTarget.c_str(), Major, Minor, Micro,
                                   HadExtra) &&
         Major > 10)
-      getDriver().Diag(diag::err_invalid_ios_deployment_target)
+      getDriver().Diag(diag::warn_invalid_ios_deployment_target)
           << std::string("IPHONEOS_DEPLOYMENT_TARGET=") + iOSTarget;
 
     // If there is no command-line argument to specify the Target version and

clang/test/Driver/darwin-version.c

@@ -45,6 +45,10 @@
 // RUN: FileCheck --check-prefix=CHECK-VERSION-IOS11 %s
 // CHECK-VERSION-IOS11: arm64-apple-ios11.1.0
 
+// RUN: %clang -target armv7-apple-ios9.0 -miphoneos-version-min=11.0 -c -Wno-invalid-ios-deployment-target -### %s 2>&1 | \
+// RUN: FileCheck --check-prefix=CHECK-VERSION-IOS12 %s
+// CHECK-VERSION-IOS12: thumbv7-apple-ios11.0.0
+
 // RUN: %clang -target i686-apple-darwin8 -c %s -### 2>&1 | \
 // RUN:   FileCheck --check-prefix=CHECK-VERSION-OSX4 %s
 // RUN: %clang -target i686-apple-darwin9 -mmacosx-version-min=10.4 -c %s -### 2>&1 | \