[libcxxabi] r207467 - Use return address register from CIE. Move DwarfInstructions::lastRestoreReg() to Register::lastDwarfRegNum().

Nick Kledzik kledzik at apple.com
Mon Apr 28 16:43:22 PDT 2014


Author: kledzik
Date: Mon Apr 28 18:43:21 2014
New Revision: 207467

URL: http://llvm.org/viewvc/llvm-project?rev=207467&view=rev
Log:
Use return address register from CIE.  Move DwarfInstructions::lastRestoreReg() to Register::lastDwarfRegNum().

Modified:
    libcxxabi/trunk/src/Unwind/DwarfInstructions.hpp
    libcxxabi/trunk/src/Unwind/DwarfParser.hpp
    libcxxabi/trunk/src/Unwind/Registers.hpp

Modified: libcxxabi/trunk/src/Unwind/DwarfInstructions.hpp
URL: http://llvm.org/viewvc/llvm-project/libcxxabi/trunk/src/Unwind/DwarfInstructions.hpp?rev=207467&r1=207466&r2=207467&view=diff
==============================================================================
--- libcxxabi/trunk/src/Unwind/DwarfInstructions.hpp (original)
+++ libcxxabi/trunk/src/Unwind/DwarfInstructions.hpp Mon Apr 28 18:43:21 2014
@@ -74,21 +74,6 @@ private:
     assert(0 && "getCFA(): unknown location");
     __builtin_unreachable();
   }
-    // x86 specific variants
-  static int lastRestoreReg(const Registers_x86 &);
-  static bool isReturnAddressRegister(int regNum, const Registers_x86 &);
-
-  // x86_64 specific variants
-  static int lastRestoreReg(const Registers_x86_64 &);
-  static bool isReturnAddressRegister(int regNum, const Registers_x86_64 &);
-
-  // ppc specific variants
-  static int lastRestoreReg(const Registers_ppc &);
-  static bool isReturnAddressRegister(int regNum, const Registers_ppc &);
-
-  // arm64 specific variants
-  static bool isReturnAddressRegister(int regNum, const Registers_arm64 &);
-  static int lastRestoreReg(const Registers_arm64 &);
 };
 
 
@@ -176,17 +161,21 @@ int DwarfInstructions<A, R>::stepWithDwa
     PrologInfo prolog;
     if (CFI_Parser<A>::parseFDEInstructions(addressSpace, fdeInfo, cieInfo, pc,
                                                                      &prolog)) {
-      R newRegisters = registers;
-
       // get pointer to cfa (architecture specific)
       pint_t cfa = getCFA(addressSpace, prolog, registers);
 
-      // restore registers that dwarf says were saved
+       // restore registers that dwarf says were saved
+      R newRegisters = registers;
       pint_t returnAddress = 0;
-      for (int i = 0; i <= lastRestoreReg(newRegisters); ++i) {
-        if (prolog.savedRegisters[i].location !=
-            CFI_Parser<A>::kRegisterUnused) {
-          if (registers.validFloatRegister(i))
+      const int lastReg = R::lastDwarfRegNum();
+      assert((int)CFI_Parser<A>::kMaxRegisterNumber > lastReg
+                                                && "register range too large");
+      assert(lastReg <= (int)cieInfo.returnAddressRegister
+                 && "register range does not contain return address register");
+      for (int i = 0; i <= lastReg; ++i) {
+         if (prolog.savedRegisters[i].location !=
+             CFI_Parser<A>::kRegisterUnused) {
+           if (registers.validFloatRegister(i))
             newRegisters.setFloatRegister(
                 i, getSavedFloatRegister(addressSpace, registers, cfa,
                                          prolog.savedRegisters[i]));
@@ -194,7 +183,7 @@ int DwarfInstructions<A, R>::stepWithDwa
             newRegisters.setVectorRegister(
                 i, getSavedVectorRegister(addressSpace, registers, cfa,
                                           prolog.savedRegisters[i]));
-          else if (isReturnAddressRegister(i, registers))
+          else if (i == (int)cieInfo.returnAddressRegister)
             returnAddress = getSavedRegister(addressSpace, registers, cfa,
                                              prolog.savedRegisters[i]);
           else if (registers.validRegister(i))
@@ -763,73 +752,6 @@ DwarfInstructions<A, R>::evaluateExpress
   return *sp;
 }
 
-//
-//  x86_64 specific functions
-//
-template <typename A, typename R>
-int DwarfInstructions<A, R>::lastRestoreReg(const Registers_x86_64 &) {
-  static_assert((int)CFI_Parser<A>::kMaxRegisterNumber
-              > (int)DW_X86_64_RET_ADDR, "register number out of range");
-  return DW_X86_64_RET_ADDR;
-}
-
-template <typename A, typename R>
-bool
-DwarfInstructions<A, R>::isReturnAddressRegister(int regNum,
-                                                 const Registers_x86_64 &) {
-  return (regNum == DW_X86_64_RET_ADDR);
-}
-
-
-//
-//  x86 specific functions
-//
-template <typename A, typename R>
-int DwarfInstructions<A, R>::lastRestoreReg(const Registers_x86 &) {
-  static_assert((int)CFI_Parser<A>::kMaxRegisterNumber
-              > (int)DW_X86_RET_ADDR, "register number out of range");
-  return DW_X86_RET_ADDR;
-}
-
-template <typename A, typename R>
-bool DwarfInstructions<A, R>::isReturnAddressRegister(int regNum,
-                                                      const Registers_x86 &) {
-  return (regNum == DW_X86_RET_ADDR);
-}
-
-
-//
-//  ppc specific functions
-//
-template <typename A, typename R>
-int DwarfInstructions<A, R>::lastRestoreReg(const Registers_ppc &) {
-  static_assert((int)CFI_Parser<A>::kMaxRegisterNumber
-              > (int)UNW_PPC_SPEFSCR, "register number out of range");
-  return UNW_PPC_SPEFSCR;
-}
-
-template <typename A, typename R>
-bool DwarfInstructions<A, R>::isReturnAddressRegister(int regNum,
-                                                      const Registers_ppc &) {
-  return (regNum == UNW_PPC_LR);
-}
-
-
-//
-// arm64 specific functions
-//
-template <typename A, typename R>
-bool DwarfInstructions<A, R>::isReturnAddressRegister(int regNum,
-                                                      const Registers_arm64 &) {
-  return (regNum == UNW_ARM64_LR);
-}
-
-template <typename A, typename R>
-int DwarfInstructions<A, R>::lastRestoreReg(const Registers_arm64 &) {
-  static_assert((int)CFI_Parser<A>::kMaxRegisterNumber
-              > (int)UNW_ARM64_D31, "register number out of range");
-  return UNW_ARM64_D31;
-}
 
 
 } // namespace libunwind

Modified: libcxxabi/trunk/src/Unwind/DwarfParser.hpp
URL: http://llvm.org/viewvc/llvm-project/libcxxabi/trunk/src/Unwind/DwarfParser.hpp?rev=207467&r1=207466&r2=207467&view=diff
==============================================================================
--- libcxxabi/trunk/src/Unwind/DwarfParser.hpp (original)
+++ libcxxabi/trunk/src/Unwind/DwarfParser.hpp Mon Apr 28 18:43:21 2014
@@ -49,6 +49,7 @@ public:
     int       dataAlignFactor;
     bool      isSignalFrame;
     bool      fdesHaveAugmentationData;
+    uint8_t   returnAddressRegister;
   };
 
   /// Information about an FDE (Frame Description Entry)
@@ -295,7 +296,9 @@ const char *CFI_Parser<A>::parseCIE(A &a
   // parse data alignment factor
   cieInfo->dataAlignFactor = (int)addressSpace.getSLEB128(p, cieContentEnd);
   // parse return address register
-  addressSpace.getULEB128(p, cieContentEnd);
+  uint64_t raReg = addressSpace.getULEB128(p, cieContentEnd);
+  assert(raReg < 255 && "return address register too large");
+  cieInfo->returnAddressRegister = (uint8_t)raReg;
   // parse augmentation data based on augmentation string
   const char *result = NULL;
   if (addressSpace.get8(strStart) == 'z') {

Modified: libcxxabi/trunk/src/Unwind/Registers.hpp
URL: http://llvm.org/viewvc/llvm-project/libcxxabi/trunk/src/Unwind/Registers.hpp?rev=207467&r1=207466&r2=207467&view=diff
==============================================================================
--- libcxxabi/trunk/src/Unwind/Registers.hpp (original)
+++ libcxxabi/trunk/src/Unwind/Registers.hpp Mon Apr 28 18:43:21 2014
@@ -44,6 +44,7 @@ public:
   void        setVectorRegister(int num, v128 value);
   const char *getRegisterName(int num);
   void        jumpto();
+  static int  lastDwarfRegNum() { return 8; }
 
   uint32_t  getSP() const          { return _registers.__esp; }
   void      setSP(uint32_t value)  { _registers.__esp = value; }
@@ -231,6 +232,7 @@ public:
   void        setVectorRegister(int num, v128 value);
   const char *getRegisterName(int num);
   void        jumpto();
+  static int  lastDwarfRegNum() { return 16; }
 
   uint64_t  getSP() const          { return _registers.__rsp; }
   void      setSP(uint64_t value)  { _registers.__rsp = value; }
@@ -478,6 +480,7 @@ public:
   void        setVectorRegister(int num, v128 value);
   const char *getRegisterName(int num);
   void        jumpto();
+  static int  lastDwarfRegNum() { return 112; }
 
   uint64_t  getSP() const         { return _registers.__r1; }
   void      setSP(uint32_t value) { _registers.__r1 = value; }
@@ -1031,6 +1034,7 @@ public:
   void        setVectorRegister(int num, v128 value);
   const char *getRegisterName(int num);
   void        jumpto();
+  static int  lastDwarfRegNum() { return 95; }
 
   uint64_t  getSP() const         { return _registers.__sp; }
   void      setSP(uint64_t value) { _registers.__sp = value; }





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