commit 850898d26e7d759034af7958d02e758b7b5fd49d
author Daniel Kiss <daniel.kiss@arm.com> Fri Sep 18 11:37:54 2020 +0200
committer Daniel Kiss <daniel.kiss@arm.com> Fri Sep 18 11:37:54 2020 +0200
tree d17d4740df4f5487d385bd56762dc4a84a682e95
parent 0cff857754ee5faf6c55c6cafaf0e90b4361061b

Revert "[libunwind] Support for leaf function unwinding."

This reverts commit 23bef7ee9923b1262326981960397e8cd95d6923.

Cr-Mirrored-From: https://chromium.googlesource.com/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 5831adb8c38f3fd1b17ff52984c514fc32e893f6

src/DwarfInstructions.hpp

diff --git a/src/DwarfInstructions.hpp b/src/DwarfInstructions.hpp
index c39cabe..ee98f53 100644
--- a/src/DwarfInstructions.hpp
+++ b/src/DwarfInstructions.hpp
@@ -93,8 +93,7 @@
 
   case CFI_Parser<A>::kRegisterInRegister:
     return registers.getRegister((int)savedReg.value);
-  case CFI_Parser<A>::kRegisterUndefined:
-    return 0;
+
   case CFI_Parser<A>::kRegisterUnused:
   case CFI_Parser<A>::kRegisterOffsetFromCFA:
     // FIX ME
@@ -118,7 +117,6 @@
 
   case CFI_Parser<A>::kRegisterIsExpression:
   case CFI_Parser<A>::kRegisterUnused:
-  case CFI_Parser<A>::kRegisterUndefined:
   case CFI_Parser<A>::kRegisterOffsetFromCFA:
   case CFI_Parser<A>::kRegisterInRegister:
     // FIX ME
@@ -142,7 +140,6 @@
 
   case CFI_Parser<A>::kRegisterIsExpression:
   case CFI_Parser<A>::kRegisterUnused:
-  case CFI_Parser<A>::kRegisterUndefined:
   case CFI_Parser<A>::kRegisterOffsetFromCFA:
   case CFI_Parser<A>::kRegisterInRegister:
     // FIX ME
@@ -193,10 +190,6 @@
                                     prolog.savedRegisters[i]));
           else
             return UNW_EBADREG;
-        } else if (i == (int)cieInfo.returnAddressRegister) {
-            // Leaf function keeps the return address in register and there is no
-            // explicit intructions how to restore it.
-            returnAddress = registers.getRegister(cieInfo.returnAddressRegister);
         }
       }
 

src/DwarfParser.hpp

diff --git a/src/DwarfParser.hpp b/src/DwarfParser.hpp
index 86c0522..fb943ed 100644
--- a/src/DwarfParser.hpp
+++ b/src/DwarfParser.hpp
@@ -69,7 +69,6 @@
   };
   enum RegisterSavedWhere {
     kRegisterUnused,
-    kRegisterUndefined,
     kRegisterInCFA,
     kRegisterOffsetFromCFA,
     kRegisterInRegister,
@@ -506,7 +505,7 @@
                 "malformed DW_CFA_undefined DWARF unwind, reg too big");
         return false;
       }
-      results->setRegisterLocation(reg, kRegisterUndefined, initialState);
+      results->setRegisterLocation(reg, kRegisterUnused, initialState);
       _LIBUNWIND_TRACE_DWARF("DW_CFA_undefined(reg=%" PRIu64 ")\n", reg);
       break;
     case DW_CFA_same_value: