From 3d2b5b7b87857b0cc4c322cfc145c46c42fe2bbf Mon Sep 17 00:00:00 2001
From: Shoaib Meenai <smeenai@fb.com>
Date: Mon, 23 May 2022 22:11:34 -0700
Subject: [PATCH] [libunwind] Factor out sigreturn check condition. NFC

Create a macro for this instead of duplicating the architecture checks
everywhere. (It's a little redundant to use it when we're checking for a
specific architecture, but I'm also applying it there for consistency.)

Reviewed By: rprichard, MaskRay, #libunwind

Differential Revision: https://reviews.llvm.org/D126342
---
 libunwind/src/UnwindCursor.hpp | 35 ++++++++++++++++++++++-------------
 1 file changed, 22 insertions(+), 13 deletions(-)

diff --git a/libunwind/src/UnwindCursor.hpp b/libunwind/src/UnwindCursor.hpp
index 7e56eff..01f0c40 100644
--- a/libunwind/src/UnwindCursor.hpp
+++ b/libunwind/src/UnwindCursor.hpp
@@ -30,6 +30,11 @@
 #include <sys/pseg.h>
 #endif
 
+#if defined(_LIBUNWIND_TARGET_LINUX) &&                                        \
+    (defined(_LIBUNWIND_TARGET_AARCH64) || defined(_LIBUNWIND_TARGET_S390X))
+#define _LIBUNWIND_CHECK_LINUX_SIGRETURN 1
+#endif
+
 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
 // Provide a definition for the DISPATCHER_CONTEXT struct for old (Win7 and
 // earlier) SDKs.
@@ -953,7 +958,7 @@ private:
   }
 #endif
 
-#if defined(_LIBUNWIND_TARGET_LINUX) && (defined(_LIBUNWIND_TARGET_AARCH64) || defined(_LIBUNWIND_TARGET_S390X))
+#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
   bool setInfoForSigReturn() {
     R dummy;
     return setInfoForSigReturn(dummy);
@@ -962,14 +967,14 @@ private:
     R dummy;
     return stepThroughSigReturn(dummy);
   }
-  #if defined(_LIBUNWIND_TARGET_AARCH64)
+#if defined(_LIBUNWIND_TARGET_AARCH64)
   bool setInfoForSigReturn(Registers_arm64 &);
   int stepThroughSigReturn(Registers_arm64 &);
-  #endif
-  #if defined(_LIBUNWIND_TARGET_S390X)
+#endif
+#if defined(_LIBUNWIND_TARGET_S390X)
   bool setInfoForSigReturn(Registers_s390x &);
   int stepThroughSigReturn(Registers_s390x &);
-  #endif
+#endif
   template <typename Registers> bool setInfoForSigReturn(Registers &) {
     return false;
   }
@@ -1264,7 +1269,7 @@ private:
   unw_proc_info_t  _info;
   bool             _unwindInfoMissing;
   bool             _isSignalFrame;
-#if defined(_LIBUNWIND_TARGET_LINUX) && (defined(_LIBUNWIND_TARGET_AARCH64) || defined(_LIBUNWIND_TARGET_S390X))
+#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
   bool             _isSigReturn = false;
 #endif
 };
@@ -2471,7 +2476,7 @@ int UnwindCursor<A, R>::stepWithTBTable(pint_t pc, tbtable *TBTable,
 
 template <typename A, typename R>
 void UnwindCursor<A, R>::setInfoBasedOnIPRegister(bool isReturnAddress) {
-#if defined(_LIBUNWIND_TARGET_LINUX) && (defined(_LIBUNWIND_TARGET_AARCH64) || defined(_LIBUNWIND_TARGET_S390X))
+#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
   _isSigReturn = false;
 #endif
 
@@ -2586,7 +2591,7 @@ void UnwindCursor<A, R>::setInfoBasedOnIPRegister(bool isReturnAddress) {
   }
 #endif // #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
 
-#if defined(_LIBUNWIND_TARGET_LINUX) && (defined(_LIBUNWIND_TARGET_AARCH64) || defined(_LIBUNWIND_TARGET_S390X))
+#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
   if (setInfoForSigReturn())
     return;
 #endif
@@ -2595,7 +2600,8 @@ void UnwindCursor<A, R>::setInfoBasedOnIPRegister(bool isReturnAddress) {
   _unwindInfoMissing = true;
 }
 
-#if defined(_LIBUNWIND_TARGET_LINUX) && defined(_LIBUNWIND_TARGET_AARCH64)
+#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&                               \
+    defined(_LIBUNWIND_TARGET_AARCH64)
 template <typename A, typename R>
 bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_arm64 &) {
   // Look for the sigreturn trampoline. The trampoline's body is two
@@ -2657,9 +2663,11 @@ int UnwindCursor<A, R>::stepThroughSigReturn(Registers_arm64 &) {
   _isSignalFrame = true;
   return UNW_STEP_SUCCESS;
 }
-#endif // defined(_LIBUNWIND_TARGET_LINUX) && defined(_LIBUNWIND_TARGET_AARCH64)
+#endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&
+       // defined(_LIBUNWIND_TARGET_AARCH64)
 
-#if defined(_LIBUNWIND_TARGET_LINUX) && defined(_LIBUNWIND_TARGET_S390X)
+#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&                               \
+    defined(_LIBUNWIND_TARGET_S390X)
 template <typename A, typename R>
 bool UnwindCursor<A, R>::setInfoForSigReturn(Registers_s390x &) {
   // Look for the sigreturn trampoline. The trampoline's body is a
@@ -2755,7 +2763,8 @@ int UnwindCursor<A, R>::stepThroughSigReturn(Registers_s390x &) {
 
   return UNW_STEP_SUCCESS;
 }
-#endif // defined(_LIBUNWIND_TARGET_LINUX) && defined(_LIBUNWIND_TARGET_S390X)
+#endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&
+       // defined(_LIBUNWIND_TARGET_S390X)
 
 template <typename A, typename R>
 int UnwindCursor<A, R>::step() {
@@ -2765,7 +2774,7 @@ int UnwindCursor<A, R>::step() {
 
   // Use unwinding info to modify register set as if function returned.
   int result;
-#if defined(_LIBUNWIND_TARGET_LINUX) && (defined(_LIBUNWIND_TARGET_AARCH64) || defined(_LIBUNWIND_TARGET_S390X))
+#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN)
   if (_isSigReturn) {
     result = this->stepThroughSigReturn();
   } else
-- 
2.7.4