From c1d35c578da44103120ecaf08142f0037d601bdc Mon Sep 17 00:00:00 2001
From: Louis Dionne <ldionne@apple.com>
Date: Wed, 10 Apr 2019 17:12:06 +0000
Subject: [libc++abi] Create a macro for the 32 bit guard setting on ARM
 platforms

Summary:
The goal is to use a descriptive name for this feature, instead of just
using __arm__.

Reviewers: EricWF

Subscribers: javed.absar, kristof.beyls, christof, jkorous, dexonsmith, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D60520

git-svn-id: https://llvm.org/svn/llvm-project/libcxxabi/trunk@358106 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit 1dc2c61c2a77bf864c7c627af72f1130a3e318ec)

Bug: http://b/189279320
Test: treehugger
Change-Id: I0360c4a2cd4f9f6e90dd176c4fa37fdfb817832b
---
 include/__cxxabi_config.h |  4 ++++
 include/cxxabi.h          |  2 +-
 src/cxa_guard.cpp         | 20 ++++++++++----------
 3 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/include/__cxxabi_config.h b/include/__cxxabi_config.h
index 46f5914..1f60167 100644
--- a/include/__cxxabi_config.h
+++ b/include/__cxxabi_config.h
@@ -70,4 +70,8 @@
 #define _LIBCXXABI_NO_CFI
 #endif
 
+#if defined(__arm__)
+#  define _LIBCXXABI_GUARD_ABI_ARM
+#endif
+
 #endif // ____CXXABI_CONFIG_H
diff --git a/include/cxxabi.h b/include/cxxabi.h
index c6724ad..2926081 100644
--- a/include/cxxabi.h
+++ b/include/cxxabi.h
@@ -78,7 +78,7 @@ extern _LIBCXXABI_FUNC_VIS _LIBCXXABI_NORETURN void __cxa_pure_virtual(void);
 extern _LIBCXXABI_FUNC_VIS _LIBCXXABI_NORETURN void __cxa_deleted_virtual(void);
 
 // 3.3.2 One-time Construction API
-#ifdef __arm__
+#if defined(_LIBCXXABI_GUARD_ABI_ARM)
 extern _LIBCXXABI_FUNC_VIS int __cxa_guard_acquire(uint32_t *);
 extern _LIBCXXABI_FUNC_VIS void __cxa_guard_release(uint32_t *);
 extern _LIBCXXABI_FUNC_VIS void __cxa_guard_abort(uint32_t *);
diff --git a/src/cxa_guard.cpp b/src/cxa_guard.cpp
index 8803415..9ae9e70 100644
--- a/src/cxa_guard.cpp
+++ b/src/cxa_guard.cpp
@@ -36,7 +36,7 @@ enum InitializationResult {
   INIT_NOT_COMPLETE,
 };
 
-#ifdef __arm__
+#if defined(_LIBCXXABI_GUARD_ABI_ARM)
 // A 32-bit, 4-byte-aligned static data value. The least significant 2 bits must
 // be statically initialized to 0.
 typedef uint32_t guard_type;
@@ -45,7 +45,7 @@ typedef uint64_t guard_type;
 #endif
 
 #if !defined(_LIBCXXABI_HAS_NO_THREADS) && defined(__APPLE__) &&               \
-    !defined(__arm__)
+    !defined(_LIBCXXABI_GUARD_ABI_ARM)
 // This is a special-case pthread dependency for Mac. We can't pull this
 // out into libcxx's threading API (__threading_support) because not all
 // supported Mac environments provide this function (in pthread.h). To
@@ -240,7 +240,7 @@ GuardValue GuardValue::ZERO() { return GuardValue(0); }
 
 GuardValue GuardValue::INIT_COMPLETE() {
   guard_type value = {0};
-#ifdef __arm__
+#if defined(_LIBCXXABI_GUARD_ABI_ARM)
   value |= 1;
 #else
   char* init_bit = (char*)&value;
@@ -254,7 +254,7 @@ GuardValue GuardValue::INIT_PENDING() {
 }
 
 bool GuardValue::is_initialization_complete() const {
-#ifdef __arm__
+#if defined(_LIBCXXABI_GUARD_ABI_ARM)
   return value & 1;
 #else
   const char* init_bit = (const char*)&value;
@@ -272,31 +272,31 @@ lock_type GuardValue::get_lock_value() const {
 
 // Create a guard object with the lock set to the specified value.
 guard_type GuardValue::guard_value_from_lock(lock_type l) {
-#if defined(__APPLE__) && !defined(__arm__)
+#if defined(__APPLE__) && !defined(_LIBCXXABI_GUARD_ABI_ARM)
 #if __LITTLE_ENDIAN__
   return static_cast<guard_type>(l) << 32;
 #else
   return static_cast<guard_type>(l);
 #endif
-#else  // defined(__APPLE__) && !defined(__arm__)
+#else  // defined(__APPLE__) && !defined(_LIBCXXABI_GUARD_ABI_ARM)
   guard_type f = {0};
   memcpy(static_cast<char*>(static_cast<void*>(&f)) + 1, &l, sizeof(lock_type));
   return f;
-#endif // defined(__APPLE__) && !defined(__arm__)
+#endif // defined(__APPLE__) && !defined(_LIBCXXABI_GUARD_ABI_ARM)
 }
 
 lock_type GuardValue::lock_value_from_guard(guard_type g) {
-#if defined(__APPLE__) && !defined(__arm__)
+#if defined(__APPLE__) && !defined(_LIBCXXABI_GUARD_ABI_ARM)
 #if __LITTLE_ENDIAN__
   return static_cast<lock_type>(g >> 32);
 #else
   return static_cast<lock_type>(g);
 #endif
-#else  // defined(__APPLE__) && !defined(__arm__)
+#else  // defined(__APPLE__) && !defined(_LIBCXXABI_GUARD_ABI_ARM)
   uint8_t guard_bytes[sizeof(guard_type)];
   memcpy(&guard_bytes, &g, sizeof(guard_type));
   return guard_bytes[1] != 0;
-#endif // defined(__APPLE__) && !defined(__arm__)
+#endif // defined(__APPLE__) && !defined(_LIBCXXABI_GUARD_ABI_ARM)
 }
 
 }  // __cxxabiv1
-- 
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