Darwin: Use the GOT to reference ___stack_chk_guard.

e018cbf changed the default behaviour for Darwin, and this breaks some
existing software.

rdar://110350601

Author: aemerson

llvm/lib/CodeGen/TargetLoweringBase.cpp

@@ -2001,7 +2001,8 @@ void TargetLoweringBase::insertSSPDeclarations(Module &M) const {
     // FreeBSD has "__stack_chk_guard" defined externally on libc.so
     if (M.getDirectAccessExternalData() &&
         !TM.getTargetTriple().isWindowsGNUEnvironment() &&
-        !TM.getTargetTriple().isOSFreeBSD())
+        !TM.getTargetTriple().isOSFreeBSD() &&
+        !TM.getTargetTriple().isOSDarwin())
       GV->setDSOLocal(true);
   }
 }

llvm/lib/Target/X86/X86ISelLowering.cpp

@@ -3082,7 +3082,8 @@ Value *X86TargetLowering::getIRStackGuard(IRBuilderBase &IRB) const {
           GV = new GlobalVariable(*M, Ty, false, GlobalValue::ExternalLinkage,
                                   nullptr, GuardSymb, nullptr,
                                   GlobalValue::NotThreadLocal, AddressSpace);
-          GV->setDSOLocal(M->getDirectAccessExternalData());
+          if (!Subtarget.isTargetDarwin())
+            GV->setDSOLocal(M->getDirectAccessExternalData());
         }
         return GV;
       }

llvm/test/CodeGen/AArch64/stack-protector-darwin-got.ll

@@ -0,0 +1,69 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 2
+; RUN: llc -mtriple=aarch64-apple-darwin < %s -o - | FileCheck %s
+
+@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
+
+; Check we use the GOT to reference ___stack_chk_guard on Darwin
+
+define void @test(ptr %a) #0 {
+; CHECK-LABEL: test:
+; CHECK:       ; %bb.0: ; %entry
+; CHECK-NEXT:    sub sp, sp, #80
+; CHECK-NEXT:    .cfi_def_cfa_offset 80
+; CHECK-NEXT:    stp x20, x19, [sp, #48] ; 16-byte Folded Spill
+; CHECK-NEXT:    stp x29, x30, [sp, #64] ; 16-byte Folded Spill
+; CHECK-NEXT:    .cfi_offset w30, -8
+; CHECK-NEXT:    .cfi_offset w29, -16
+; CHECK-NEXT:    .cfi_offset w19, -24
+; CHECK-NEXT:    .cfi_offset w20, -32
+; CHECK-NEXT:  Lloh0:
+; CHECK-NEXT:    adrp x8, ___stack_chk_guard@GOTPAGE
+; CHECK-NEXT:    mov x1, x0
+; CHECK-NEXT:    add x19, sp, #16
+; CHECK-NEXT:  Lloh1:
+; CHECK-NEXT:    ldr x8, [x8, ___stack_chk_guard@GOTPAGEOFF]
+; CHECK-NEXT:  Lloh2:
+; CHECK-NEXT:    ldr x8, [x8]
+; CHECK-NEXT:    str x8, [sp, #40]
+; CHECK-NEXT:    str x0, [sp, #8]
+; CHECK-NEXT:    add x0, sp, #16
+; CHECK-NEXT:    bl _strcpy
+; CHECK-NEXT:  Lloh3:
+; CHECK-NEXT:    adrp x0, l_.str@PAGE
+; CHECK-NEXT:  Lloh4:
+; CHECK-NEXT:    add x0, x0, l_.str@PAGEOFF
+; CHECK-NEXT:    str x19, [sp]
+; CHECK-NEXT:    bl _printf
+; CHECK-NEXT:  Lloh5:
+; CHECK-NEXT:    adrp x8, ___stack_chk_guard@GOTPAGE
+; CHECK-NEXT:  Lloh6:
+; CHECK-NEXT:    ldr x8, [x8, ___stack_chk_guard@GOTPAGEOFF]
+; CHECK-NEXT:    ldr x9, [sp, #40]
+; CHECK-NEXT:  Lloh7:
+; CHECK-NEXT:    ldr x8, [x8]
+; CHECK-NEXT:    cmp x8, x9
+; CHECK-NEXT:    b.ne LBB0_2
+; CHECK-NEXT:  ; %bb.1: ; %entry
+; CHECK-NEXT:    ldp x29, x30, [sp, #64] ; 16-byte Folded Reload
+; CHECK-NEXT:    ldp x20, x19, [sp, #48] ; 16-byte Folded Reload
+; CHECK-NEXT:    add sp, sp, #80
+; CHECK-NEXT:    ret
+; CHECK-NEXT:  LBB0_2: ; %entry
+; CHECK-NEXT:    bl ___stack_chk_fail
+; CHECK-NEXT:    .loh AdrpLdrGotLdr Lloh5, Lloh6, Lloh7
+; CHECK-NEXT:    .loh AdrpAdd Lloh3, Lloh4
+; CHECK-NEXT:    .loh AdrpLdrGotLdr Lloh0, Lloh1, Lloh2
+entry:
+  %a.addr = alloca ptr, align 8
+  %buf = alloca [16 x i8], align 16
+  store ptr %a, ptr %a.addr, align 8
+  %0 = load ptr, ptr %a.addr, align 8
+  %call = call ptr @strcpy(ptr %buf, ptr %0)
+  %call2 = call i32 (ptr, ...) @printf(ptr @.str, ptr %buf)
+  ret void
+}
+
+declare ptr @strcpy(ptr, ptr)
+declare i32 @printf(ptr, ...)
+
+attributes #0 = { ssp }