r368471 - CodeGen: ensure 8-byte aligned String Swift CF ABI

[Saleem Abdulrasool via cfe-commits]

Author: compnerd
Date: Fri Aug  9 12:29:05 2019
New Revision: 368471

URL: http://llvm.org/viewvc/llvm-project?rev=368471&view=rev
Log:
CodeGen: ensure 8-byte aligned String Swift CF ABI

CFStrings should be 8-byte aligned when built for the Swift CF runtime
ABI as the atomic CF info field must be properly aligned.  This is a
problem on 32-bit platforms which would give the structure 4-byte
alignment rather than 8-byte alignment.

Modified:
    cfe/trunk/lib/CodeGen/CodeGenModule.cpp
    cfe/trunk/test/CodeGen/cf-runtime-abi.c

Modified: cfe/trunk/lib/CodeGen/CodeGenModule.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenModule.cpp?rev=368471&r1=368470&r2=368471&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenModule.cpp (original)
+++ cfe/trunk/lib/CodeGen/CodeGenModule.cpp Fri Aug  9 12:29:05 2019
@@ -4669,7 +4669,10 @@ CodeGenModule::GetAddrOfConstantCFString
   }
   Fields.addInt(LengthTy, StringLength);
 
-  CharUnits Alignment = getPointerAlign();
+  // Swift ABI requires 8-byte alignment to ensure that the _Atomic(uint64_t) is
+  // properly aligned on 32-bit platforms.
+  CharUnits Alignment =
+      IsSwiftABI ? Context.toCharUnitsFromBits(64) : getPointerAlign();
 
   // The struct.
   GV = Fields.finishAndCreateGlobal("_unnamed_cfstring_", Alignment,

Modified: cfe/trunk/test/CodeGen/cf-runtime-abi.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/cf-runtime-abi.c?rev=368471&r1=368470&r2=368471&view=diff
==============================================================================
--- cfe/trunk/test/CodeGen/cf-runtime-abi.c (original)
+++ cfe/trunk/test/CodeGen/cf-runtime-abi.c Fri Aug  9 12:29:05 2019
@@ -46,15 +46,21 @@ const __NSConstantString *s = __builtin_
 // CHECK-SWIFT-DARWIN-5_0-64: @_unnamed_cfstring_ = private global %struct.__NSConstantString_tag { i64 ptrtoint (i64* @"$s15SwiftFoundation19_NSCFConstantStringCN" to i64), i64 1, i64 1992, i8* getelementptr inbounds ([1 x i8], [1 x i8]* @.str, i32 0, i32 0), i64 0 }
 // CHECK-SWIFT-DARWIN-5_0-32: @_unnamed_cfstring_ = private global %struct.__NSConstantString_tag { i32 ptrtoint (i32* @"$s15SwiftFoundation19_NSCFConstantStringCN" to i32), i32 1, i64 1992, i8* getelementptr inbounds ([1 x i8], [1 x i8]* @.str, i32 0, i32 0), i32 0 }
 // CHECK-SWIFT-5_0-64: @_unnamed_cfstring_ = private global %struct.__NSConstantString_tag { i64 ptrtoint (i64* @"$s10Foundation19_NSCFConstantStringCN" to i64), i64 1, i64 1992, i8* getelementptr inbounds ([1 x i8], [1 x i8]* @.str, i32 0, i32 0), i64 0 }
+// CHECK-SWIFT-5_0-64-SAME: align 8
 // CHECK-SWIFT-5_0-32: @_unnamed_cfstring_ = private global %struct.__NSConstantString_tag { i32 ptrtoint (i32* @"$s10Foundation19_NSCFConstantStringCN" to i32), i32 1, i64 1992, i8* getelementptr inbounds ([1 x i8], [1 x i8]* @.str, i32 0, i32 0), i32 0 }
+// CHECK-SWIFT-5_0-32-SAME: align 8
 
 // CHECK-SWIFT-DARWIN-4_2-64: @_unnamed_cfstring_ = private global %struct.__NSConstantString_tag { i64 ptrtoint (i64* @"$S15SwiftFoundation19_NSCFConstantStringCN" to i64), i64 1, i64 1992, i8* getelementptr inbounds ([1 x i8], [1 x i8]* @.str, i32 0, i32 0), i32 0 }
 // CHECK-SWIFT-DARWIN-4_2-32: @_unnamed_cfstring_ = private global %struct.__NSConstantString_tag { i32 ptrtoint (i32* @"$S15SwiftFoundation19_NSCFConstantStringCN" to i32), i32 1, i64 1992, i8* getelementptr inbounds ([1 x i8], [1 x i8]* @.str, i32 0, i32 0), i32 0 }
 // CHECK-SWIFT-4_2-64: @_unnamed_cfstring_ = private global %struct.__NSConstantString_tag { i64 ptrtoint (i64* @"$S10Foundation19_NSCFConstantStringCN" to i64), i64 1, i64 1992, i8* getelementptr inbounds ([1 x i8], [1 x i8]* @.str, i32 0, i32 0), i32 0 }
+// CHECK-SWIFT-4_2-64-SAME: align 8
 // CHECK-SWIFT-4_2-32: @_unnamed_cfstring_ = private global %struct.__NSConstantString_tag { i32 ptrtoint (i32* @"$S10Foundation19_NSCFConstantStringCN" to i32), i32 1, i64 1992, i8* getelementptr inbounds ([1 x i8], [1 x i8]* @.str, i32 0, i32 0), i32 0 }
+// CHECK-SWIFT-4_2-32-SAME: align 8
 
 // CHECK-SWIFT-DARWIN-4_1-64: @_unnamed_cfstring_ = private global %struct.__NSConstantString_tag { i64 ptrtoint (i64* @__T015SwiftFoundation19_NSCFConstantStringCN to i64), i64 5, i64 1992, i8* getelementptr inbounds ([1 x i8], [1 x i8]* @.str, i32 0, i32 0), i32 0 }
 // CHECK-SWIFT-DARWIN-4_1-32: @_unnamed_cfstring_ = private global %struct.__NSConstantString_tag { i32 ptrtoint (i32* @__T015SwiftFoundation19_NSCFConstantStringCN to i32), i32 5, i64 1992, i8* getelementptr inbounds ([1 x i8], [1 x i8]* @.str, i32 0, i32 0), i32 0 }
 // CHECK-SWIFT-4_1-64: @_unnamed_cfstring_ = private global %struct.__NSConstantString_tag { i64 ptrtoint (i64* @__T010Foundation19_NSCFConstantStringCN to i64), i64 5, i64 1992, i8* getelementptr inbounds ([1 x i8], [1 x i8]* @.str, i32 0, i32 0), i32 0 }
+// CHECK-SWIFT-4_1-64-SAME: align 8
 // CHECK-SWIFT-4_1-32: @_unnamed_cfstring_ = private global %struct.__NSConstantString_tag { i32 ptrtoint (i32* @__T010Foundation19_NSCFConstantStringCN to i32), i32 5, i64 1992, i8* getelementptr inbounds ([1 x i8], [1 x i8]* @.str, i32 0, i32 0), i32 0 }
+// CHECK-SWIFT-4_1-32-SAME: align 8