From: Xing Xue <xingxue@outlook.com>
Date: Thu, 10 Jun 2021 14:45:50 +0000 (-0400)
Subject:     [libc++abi] NFC: adding a new parameter base to functions for calculating address... 
X-Git-Tag: llvmorg-14-init~4340
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=7f0244afa828e0ef725a3f951304577090495713;p=platform%2Fupstream%2Fllvm.git

[libc++abi] NFC: adding a new parameter base to functions for calculating addresses with relative encodings

    Summary:
    This NFC patch adds a new parameter base to functions invoked by scan_eh_tab() for calculating the address of the encoding with a relative value. base defaults to 0. This is in preparation for the AIX implementation which uses the DW_EH_PE_datarel encoding.

    Reviewed by: MaskRay, sfertile, compnerd, libc++abi

    Differential Revision: https://reviews.llvm.org/D101545
---

diff --git a/libcxxabi/src/cxa_personality.cpp b/libcxxabi/src/cxa_personality.cpp
index cc0208c..1a656f2 100644
--- a/libcxxabi/src/cxa_personality.cpp
+++ b/libcxxabi/src/cxa_personality.cpp
@@ -241,10 +241,11 @@ readSLEB128(const uint8_t** data)
 /// @link http://dwarfstd.org/Dwarf3.pdf @unlink
 /// @param data reference variable holding memory pointer to decode from
 /// @param encoding dwarf encoding type
+/// @param base for adding relative offset, default to 0
 /// @returns decoded value
 static
 uintptr_t
-readEncodedPointer(const uint8_t** data, uint8_t encoding)
+readEncodedPointer(const uint8_t** data, uint8_t encoding, uintptr_t base = 0)
 {
     uintptr_t result = 0;
     if (encoding == DW_EH_PE_omit)
@@ -348,7 +349,7 @@ static const void* read_target2_value(const void* ptr)
 static const __shim_type_info*
 get_shim_type_info(uint64_t ttypeIndex, const uint8_t* classInfo,
                    uint8_t ttypeEncoding, bool native_exception,
-                   _Unwind_Exception* unwind_exception)
+                   _Unwind_Exception* unwind_exception, uintptr_t base = 0)
 {
     if (classInfo == 0)
     {
@@ -371,7 +372,7 @@ static
 const __shim_type_info*
 get_shim_type_info(uint64_t ttypeIndex, const uint8_t* classInfo,
                    uint8_t ttypeEncoding, bool native_exception,
-                   _Unwind_Exception* unwind_exception)
+                   _Unwind_Exception* unwind_exception, uintptr_t base = 0)
 {
     if (classInfo == 0)
     {
@@ -400,7 +401,8 @@ get_shim_type_info(uint64_t ttypeIndex, const uint8_t* classInfo,
         call_terminate(native_exception, unwind_exception);
     }
     classInfo -= ttypeIndex;
-    return (const __shim_type_info*)readEncodedPointer(&classInfo, ttypeEncoding);
+    return (const __shim_type_info*)readEncodedPointer(&classInfo,
+                                                       ttypeEncoding, base);
 }
 #endif // !defined(_LIBCXXABI_ARM_EHABI)
 
@@ -418,7 +420,8 @@ static
 bool
 exception_spec_can_catch(int64_t specIndex, const uint8_t* classInfo,
                          uint8_t ttypeEncoding, const __shim_type_info* excpType,
-                         void* adjustedPtr, _Unwind_Exception* unwind_exception)
+                         void* adjustedPtr, _Unwind_Exception* unwind_exception,
+                         uintptr_t base = 0)
 {
     if (classInfo == 0)
     {
@@ -463,7 +466,8 @@ static
 bool
 exception_spec_can_catch(int64_t specIndex, const uint8_t* classInfo,
                          uint8_t ttypeEncoding, const __shim_type_info* excpType,
-                         void* adjustedPtr, _Unwind_Exception* unwind_exception)
+                         void* adjustedPtr, _Unwind_Exception* unwind_exception,
+                         uintptr_t base = 0)
 {
     if (classInfo == 0)
     {
@@ -485,7 +489,8 @@ exception_spec_can_catch(int64_t specIndex, const uint8_t* classInfo,
                                                                classInfo,
                                                                ttypeEncoding,
                                                                true,
-                                                               unwind_exception);
+                                                               unwind_exception,
+                                                               base);
         void* tempPtr = adjustedPtr;
         if (catchType->can_catch(excpType, tempPtr))
             return false;
@@ -610,6 +615,7 @@ static void scan_eh_tab(scan_results &results, _Unwind_Action actions,
         return;
     }
     results.languageSpecificData = lsda;
+    uintptr_t base = 0;
     // Get the current instruction pointer and offset it before next
     // instruction in the current frame which threw the exception.
     uintptr_t ip = _Unwind_GetIP(context) - 1;
@@ -711,7 +717,8 @@ static void scan_eh_tab(scan_results &results, _Unwind_Action actions,
                     const __shim_type_info* catchType =
                         get_shim_type_info(static_cast<uint64_t>(ttypeIndex),
                                            classInfo, ttypeEncoding,
-                                           native_exception, unwind_exception);
+                                           native_exception, unwind_exception,
+                                           base);
                     if (catchType == 0)
                     {
                         // Found catch (...) catches everything, including
@@ -772,7 +779,8 @@ static void scan_eh_tab(scan_results &results, _Unwind_Action actions,
                         }
                         if (exception_spec_can_catch(ttypeIndex, classInfo,
                                                      ttypeEncoding, excpType,
-                                                     adjustedPtr, unwind_exception))
+                                                     adjustedPtr,
+                                                     unwind_exception, base))
                         {
                             // Native exception caught by exception
                             // specification.
@@ -1114,6 +1122,8 @@ __cxa_call_unexpected(void* arg)
     __cxa_exception* old_exception_header = 0;
     int64_t ttypeIndex;
     const uint8_t* lsda;
+    uintptr_t base = 0;
+
     if (native_old_exception)
     {
         old_exception_header = (__cxa_exception*)(unwind_exception+1) - 1;
@@ -1181,7 +1191,8 @@ __cxa_call_unexpected(void* arg)
                         ((__cxa_dependent_exception*)new_exception_header)->primaryException :
                         new_exception_header + 1;
                 if (!exception_spec_can_catch(ttypeIndex, classInfo, ttypeEncoding,
-                                              excpType, adjustedPtr, unwind_exception))
+                                              excpType, adjustedPtr,
+                                              unwind_exception, base))
                 {
                     // We need to __cxa_end_catch, but for the old exception,
                     //   not the new one.  This is a little tricky ...
@@ -1210,7 +1221,8 @@ __cxa_call_unexpected(void* arg)
             std::bad_exception be;
             adjustedPtr = &be;
             if (!exception_spec_can_catch(ttypeIndex, classInfo, ttypeEncoding,
-                                          excpType, adjustedPtr, unwind_exception))
+                                          excpType, adjustedPtr,
+                                          unwind_exception, base))
             {
                 // We need to __cxa_end_catch for both the old exception and the
                 //   new exception.  Technically we should do it in that order.