Don't emit uselist order for -fembed-bitcode

[steven_wu]

Summary

Embedded bitcode are embedded without serialization in their normal
flow. No uselist order need to be recorded.

Depends on D17390 and D17392

lib/Driver/Tools.cpp

if (isa<AnalyzeJobAction>(JA)) {
     } else {
       assert(JA.getType() == types::TY_PP_Asm && "Unexpected output type!");
     }
 
     // Preserve use-list order by default when emitting bitcode, so that
     // loading the bitcode up in 'opt' or 'llc' and running passes gives the
     // same result as running passes here.  For LTO, we don't need to preserve
     // the use-list order, since serialization to bitcode is part of the flow.
-    if (JA.getType() == types::TY_LLVM_BC)
+    // For embed-bitcode, bitcode is directly embedded without serialization.
+    if (JA.getType() == types::TY_LLVM_BC &&
+        !C.getDriver().embedBitcodeEnabled())
       CmdArgs.push_back("-emit-llvm-uselists");
 
     if (D.isUsingLTO())
       Args.AddLastArg(CmdArgs, options::OPT_flto, options::OPT_flto_EQ);
   }
 
   if (const Arg *A = Args.getLastArg(options::OPT_fthinlto_index_EQ)) {
     if (!types::isLLVMIR(Input.getType()))

test/Driver/embed-bitcode.c

 // RUN: %clang -ccc-print-bindings -c %s -fembed-bitcode 2>&1 | FileCheck %s
 // CHECK: clang
 // CHECK: clang
 
 // RUN: %clang %s -fembed-bitcode 2>&1 -### | FileCheck %s -check-prefix=CHECK-CC
 // CHECK-CC: -cc1
 // CHECK-CC: -emit-llvm-bc
+// CHECK-CC-NOT: -emit-llvm-uselists
 // CHECK-CC: -cc1
 // CHECK-CC: -emit-obj
 // CHECK-CC: -fembed-bitcode
 // CHECK-CC: ld
 // CHECK-CC: -bitcode_bundle
 
 // RUN: %clang -c %s -flto -fembed-bitcode 2>&1 -### | FileCheck %s -check-prefix=CHECK-LTO
 // CHECK-LTO: -cc1
 // CHECK-LTO: -emit-llvm-bc
 // CHECK-LTO-NOT: warning: argument unused during compilation: '-fembed-bitcode'
 // CHECK-LTO-NOT: -cc1
 // CHECK-LTO-NOT: -fembed-bitcode
 
 // RUN: %clang -c %s -fembed-bitcode-marker 2>&1 -### | FileCheck %s -check-prefix=CHECK-MARKER
 // CHECK-MARKER: -cc1
 // CHECK-MARKER: -emit-obj
 // CHECK-MARKER: -fembed-bitcode-marker
 // CHECK-MARKER-NOT: -cc1
 
+// Check clang complains about ios version min if it is used to generate link command.
+// RUN: %clang -target armv7-apple-darwin -miphoneos-version-min=6.0 %s -fembed-bitcode -### 2>&1 | \
+// RUN:   FileCheck %s -check-prefix=CHECK-PLATFORM-SUPPORTED
+// RUN: %clang -target armv7-apple-darwin -miphoneos-version-min=5.0 %s -fembed-bitcode -### 2>&1 | \
+// RUN:   FileCheck %s -check-prefix=CHECK-PLATFORM-UNSUPPORTED
+// RUN: %clang -target armv7-apple-darwin -miphoneos-version-min=5.0 -c %s -fembed-bitcode -### 2>&1 | \
+// RUN:   FileCheck %s -check-prefix=CHECK-PLATFORM-SUPPORTED
+// CHECK-PLATFORM-SUPPORTED-NOT: -fembed-bitcode is not supported on versions of iOS prior to 6.0
+// CHECK-PLATFORM-UNSUPPORTED: -fembed-bitcode is not supported on versions of iOS prior to 6.0
+