DWARFExpression: Simplify class interface

Summary:
The DWARFExpression methods have a lot of arguments. This removes two of
them by removing the ability to slice the expression via two offset+size
parameters. This is a functionality that it is not always needed, and
when it is, we already have a different handy way of slicing a data
extractor which we can use instead.

Reviewers: JDevlieghere, clayborg

Subscribers: aprantl, lldb-commits

Differential Revision: https://reviews.llvm.org/D66745

llvm-svn: 370027

diff --git a/lldb/include/lldb/Expression/DWARFExpression.h b/lldb/include/lldb/Expression/DWARFExpression.h
index 21830a562800447b7f15027e57f6c63c6e5796ae..4157cf3b083a4da6597d9e2749a8d422ecbb159b 100644 (file)
--- a/lldb/include/lldb/Expression/DWARFExpression.h
+++ b/lldb/include/lldb/Expression/DWARFExpression.h
@@ -50,15 +50,8 @@ public:
   /// \param[in] data
   ///     A data extractor configured to read the DWARF location expression's
   ///     bytecode.
-  ///
-  /// \param[in] data_offset
-  ///     The offset of the location expression in the extractor.
-  ///
-  /// \param[in] data_length
-  ///     The byte length of the location expression.
   DWARFExpression(lldb::ModuleSP module, const DataExtractor &data,
-                  const DWARFUnit *dwarf_cu, lldb::offset_t data_offset,
-                  lldb::offset_t data_length);
+                  const DWARFUnit *dwarf_cu);
 
   /// Destructor
   virtual ~DWARFExpression();
@@ -211,12 +204,6 @@ public:
   ///     in the case where an expression needs to be evaluated while building
   ///     the stack frame list, this short-cut is available.
   ///
-  /// \param[in] offset
-  ///     The offset of the location expression in the data extractor.
-  ///
-  /// \param[in] length
-  ///     The length in bytes of the location expression.
-  ///
   /// \param[in] reg_set
   ///     The call-frame-info style register kind.
   ///
@@ -236,8 +223,7 @@ public:
   ///     details of the failure are provided through it.
   static bool Evaluate(ExecutionContext *exe_ctx, RegisterContext *reg_ctx,
                        lldb::ModuleSP opcode_ctx, const DataExtractor &opcodes,
-                       const DWARFUnit *dwarf_cu, const lldb::offset_t offset,
-                       const lldb::offset_t length,
+                       const DWARFUnit *dwarf_cu,
                        const lldb::RegisterKind reg_set,
                        const Value *initial_value_ptr,
                        const Value *object_address_ptr, Value &result,

diff --git a/lldb/source/Expression/DWARFExpression.cpp b/lldb/source/Expression/DWARFExpression.cpp
index 978ff7032dec92e2826c7fcb0eac65b55d70e10a..507e4fa4c7949469132b185a0ae97a50ce5d14c5 100644 (file)
--- a/lldb/source/Expression/DWARFExpression.cpp
+++ b/lldb/source/Expression/DWARFExpression.cpp
@@ -59,12 +59,9 @@ DWARFExpression::DWARFExpression()
 
 DWARFExpression::DWARFExpression(lldb::ModuleSP module_sp,
                                  const DataExtractor &data,
-                                 const DWARFUnit *dwarf_cu,
-                                 lldb::offset_t data_offset,
-                                 lldb::offset_t data_length)
-    : m_module_wp(), m_data(data, data_offset, data_length),
-      m_dwarf_cu(dwarf_cu), m_reg_kind(eRegisterKindDWARF),
-      m_loclist_slide(LLDB_INVALID_ADDRESS) {
+                                 const DWARFUnit *dwarf_cu)
+    : m_module_wp(), m_data(data), m_dwarf_cu(dwarf_cu),
+      m_reg_kind(eRegisterKindDWARF), m_loclist_slide(LLDB_INVALID_ADDRESS) {
   if (module_sp)
     m_module_wp = module_sp;
 }
@@ -1135,9 +1132,9 @@ bool DWARFExpression::Evaluate(ExecutionContext *exe_ctx,
 
         if (length > 0 && lo_pc <= pc && pc < hi_pc) {
           return DWARFExpression::Evaluate(
-              exe_ctx, reg_ctx, module_sp, m_data, m_dwarf_cu, offset, length,
-              m_reg_kind, initial_value_ptr, object_address_ptr, result,
-              error_ptr);
+              exe_ctx, reg_ctx, module_sp,
+              DataExtractor(m_data, offset, length), m_dwarf_cu, m_reg_kind,
+              initial_value_ptr, object_address_ptr, result, error_ptr);
         }
         offset += length;
       }
@@ -1148,20 +1145,19 @@ bool DWARFExpression::Evaluate(ExecutionContext *exe_ctx,
   }
 
   // Not a location list, just a single expression.
-  return DWARFExpression::Evaluate(
-      exe_ctx, reg_ctx, module_sp, m_data, m_dwarf_cu, 0, m_data.GetByteSize(),
-      m_reg_kind, initial_value_ptr, object_address_ptr, result, error_ptr);
+  return DWARFExpression::Evaluate(exe_ctx, reg_ctx, module_sp, m_data,
+                                   m_dwarf_cu, m_reg_kind, initial_value_ptr,
+                                   object_address_ptr, result, error_ptr);
 }
 
 bool DWARFExpression::Evaluate(
     ExecutionContext *exe_ctx, RegisterContext *reg_ctx,
     lldb::ModuleSP module_sp, const DataExtractor &opcodes,
-    const DWARFUnit *dwarf_cu, const lldb::offset_t opcodes_offset,
-    const lldb::offset_t opcodes_length, const lldb::RegisterKind reg_kind,
+    const DWARFUnit *dwarf_cu, const lldb::RegisterKind reg_kind,
     const Value *initial_value_ptr, const Value *object_address_ptr,
     Value &result, Status *error_ptr) {
 
-  if (opcodes_length == 0) {
+  if (opcodes.GetByteSize() == 0) {
     if (error_ptr)
       error_ptr->SetErrorString(
           "no location, value may have been optimized out");
@@ -1182,8 +1178,7 @@ bool DWARFExpression::Evaluate(
   if (initial_value_ptr)
     stack.push_back(*initial_value_ptr);
 
-  lldb::offset_t offset = opcodes_offset;
-  const lldb::offset_t end_offset = opcodes_offset + opcodes_length;
+  lldb::offset_t offset = 0;
   Value tmp;
   uint32_t reg_num;
 
@@ -1191,16 +1186,9 @@ bool DWARFExpression::Evaluate(
   uint64_t op_piece_offset = 0;
   Value pieces; // Used for DW_OP_piece
 
-  // Make sure all of the data is available in opcodes.
-  if (!opcodes.ValidOffsetForDataOfSize(opcodes_offset, opcodes_length)) {
-    if (error_ptr)
-      error_ptr->SetErrorString(
-          "invalid offset and/or length for opcodes buffer.");
-    return false;
-  }
   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
 
-  while (opcodes.ValidOffset(offset) && offset < end_offset) {
+  while (opcodes.ValidOffset(offset)) {
     const lldb::offset_t op_offset = offset;
     const uint8_t op = opcodes.GetU8(&offset);
 
@@ -1946,7 +1934,7 @@ bool DWARFExpression::Evaluate(
     case DW_OP_skip: {
       int16_t skip_offset = (int16_t)opcodes.GetU16(&offset);
       lldb::offset_t new_offset = offset + skip_offset;
-      if (new_offset >= opcodes_offset && new_offset < end_offset)
+      if (opcodes.ValidOffset(new_offset))
         offset = new_offset;
       else {
         if (error_ptr)
@@ -1975,7 +1963,7 @@ bool DWARFExpression::Evaluate(
         Scalar zero(0);
         if (tmp.ResolveValue(exe_ctx) != zero) {
           lldb::offset_t new_offset = offset + bra_offset;
-          if (new_offset >= opcodes_offset && new_offset < end_offset)
+          if (opcodes.ValidOffset(new_offset))
             offset = new_offset;
           else {
             if (error_ptr)

diff --git a/lldb/source/Plugins/Process/Utility/RegisterContextLLDB.cpp b/lldb/source/Plugins/Process/Utility/RegisterContextLLDB.cpp
index 27341267a8a67147d597c28a36f0015f16e1b1f8..0da687ad0b910966970dd6d3cfaf382c695bcfd7 100644 (file)
--- a/lldb/source/Plugins/Process/Utility/RegisterContextLLDB.cpp
+++ b/lldb/source/Plugins/Process/Utility/RegisterContextLLDB.cpp
@@ -1483,8 +1483,7 @@ RegisterContextLLDB::SavedLocationForRegister(
                             process->GetByteOrder(),
                             process->GetAddressByteSize());
     ModuleSP opcode_ctx;
-    DWARFExpression dwarfexpr(opcode_ctx, dwarfdata, nullptr, 0,
-                              unwindplan_regloc.GetDWARFExpressionLength());
+    DWARFExpression dwarfexpr(opcode_ctx, dwarfdata, nullptr);
     dwarfexpr.SetRegisterKind(unwindplan_registerkind);
     Value cfa_val = Scalar(m_cfa);
     cfa_val.SetValueType(Value::eValueTypeLoadAddress);
@@ -1837,8 +1836,7 @@ bool RegisterContextLLDB::ReadFrameAddress(
                             process->GetByteOrder(),
                             process->GetAddressByteSize());
     ModuleSP opcode_ctx;
-    DWARFExpression dwarfexpr(opcode_ctx, dwarfdata, nullptr, 0,
-                              fa.GetDWARFExpressionLength());
+    DWARFExpression dwarfexpr(opcode_ctx, dwarfdata, nullptr);
     dwarfexpr.SetRegisterKind(row_register_kind);
     Value result;
     Status error;

diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
index 8956a4f5c0f26f65024271277b544cea29116724..056cc70545e141611094837ea23a34efdd1f0876 100644 (file)
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
@@ -2532,9 +2532,11 @@ bool DWARFASTParserClang::ParseChildMembers(
                 if (DWARFExpression::Evaluate(
                         nullptr, // ExecutionContext *
                         nullptr, // RegisterContext *
-                        module_sp, debug_info_data, die.GetCU(), block_offset,
-                        block_length, eRegisterKindDWARF, &initialValue,
-                        nullptr, memberOffset, nullptr)) {
+                        module_sp,
+                        DataExtractor(debug_info_data, block_offset,
+                                      block_length),
+                        die.GetCU(), eRegisterKindDWARF, &initialValue, nullptr,
+                        memberOffset, nullptr)) {
                   member_byte_offset =
                       memberOffset.ResolveValue(nullptr).UInt();
                 }
@@ -2967,11 +2969,12 @@ bool DWARFASTParserClang::ParseChildMembers(
                 uint32_t block_length = form_value.Unsigned();
                 uint32_t block_offset =
                     form_value.BlockData() - debug_info_data.GetDataStart();
-                if (DWARFExpression::Evaluate(nullptr, nullptr, module_sp,
-                                              debug_info_data, die.GetCU(),
-                                              block_offset, block_length,
-                                              eRegisterKindDWARF, &initialValue,
-                                              nullptr, memberOffset, nullptr)) {
+                if (DWARFExpression::Evaluate(
+                        nullptr, nullptr, module_sp,
+                        DataExtractor(debug_info_data, block_offset,
+                                      block_length),
+                        die.GetCU(), eRegisterKindDWARF, &initialValue, nullptr,
+                        memberOffset, nullptr)) {
                   member_byte_offset =
                       memberOffset.ResolveValue(nullptr).UInt();
                 }

diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.cpp
index 2f55b7d40ed9ed0b05528291a075f0add6bdae34..a7349d197004a70d5c955392cb04b2350bc325b6 100644 (file)
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.cpp
@@ -340,8 +340,8 @@ bool DWARFDebugInfoEntry::GetDIENamesAndRanges(
               uint32_t block_offset =
                   form_value.BlockData() - data.GetDataStart();
               uint32_t block_length = form_value.Unsigned();
-              *frame_base = DWARFExpression(module, data, cu,
-                                            block_offset, block_length);
+              *frame_base = DWARFExpression(
+                  module, DataExtractor(data, block_offset, block_length), cu);
             } else {
               const DWARFDataExtractor &debug_loc_data = dwarf.DebugLocData();
               const dw_offset_t debug_loc_offset = form_value.Unsigned();
@@ -349,9 +349,11 @@ bool DWARFDebugInfoEntry::GetDIENamesAndRanges(
               size_t loc_list_length = DWARFExpression::LocationListSize(
                   cu, debug_loc_data, debug_loc_offset);
               if (loc_list_length > 0) {
-                *frame_base =
-                    DWARFExpression(module, debug_loc_data, cu,
-                                    debug_loc_offset, loc_list_length);
+                *frame_base = DWARFExpression(module,
+                                              DataExtractor(debug_loc_data,
+                                                            debug_loc_offset,
+                                                            loc_list_length),
+                                              cu);
                 if (lo_pc != LLDB_INVALID_ADDRESS) {
                   assert(lo_pc >= cu->GetBaseAddress());
                   frame_base->SetLocationListSlide(lo_pc -

diff --git a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
index 6b357c249ce750fa9548dd3a1908a467b0305f1a..f625e2bdedc123335c311410cf787151c65d23fb 100644 (file)
--- a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
@@ -3243,15 +3243,18 @@ VariableSP SymbolFileDWARF::ParseVariableDIE(const SymbolContext &sc,
                 uint32_t block_offset =
                     form_value.BlockData() - debug_info_data.GetDataStart();
                 uint32_t block_length = form_value.Unsigned();
-                location = DWARFExpression(module, debug_info_data, die.GetCU(),
-                                           block_offset, block_length);
+                location = DWARFExpression(
+                    module,
+                    DataExtractor(debug_info_data, block_offset, block_length),
+                    die.GetCU());
               } else if (DWARFFormValue::IsDataForm(form_value.Form())) {
                 // Retrieve the value as a data expression.
                 uint32_t data_offset = attributes.DIEOffsetAtIndex(i);
                 if (auto data_length = form_value.GetFixedSize())
-                  location =
-                      DWARFExpression(module, debug_info_data, die.GetCU(),
-                                      data_offset, *data_length);
+                  location = DWARFExpression(
+                      module,
+                      DataExtractor(debug_info_data, data_offset, *data_length),
+                      die.GetCU());
                 else {
                   const uint8_t *data_pointer = form_value.BlockData();
                   if (data_pointer) {
@@ -3267,17 +3270,21 @@ VariableSP SymbolFileDWARF::ParseVariableDIE(const SymbolContext &sc,
                 if (form_value.Form() == DW_FORM_strp) {
                   uint32_t data_offset = attributes.DIEOffsetAtIndex(i);
                   if (auto data_length = form_value.GetFixedSize())
-                    location =
-                        DWARFExpression(module, debug_info_data, die.GetCU(),
-                                        data_offset, *data_length);
+                    location = DWARFExpression(module,
+                                               DataExtractor(debug_info_data,
+                                                             data_offset,
+                                                             *data_length),
+                                               die.GetCU());
                 } else {
                   const char *str = form_value.AsCString();
                   uint32_t string_offset =
                       str - (const char *)debug_info_data.GetDataStart();
                   uint32_t string_length = strlen(str) + 1;
-                  location =
-                      DWARFExpression(module, debug_info_data, die.GetCU(),
-                                      string_offset, string_length);
+                  location = DWARFExpression(module,
+                                             DataExtractor(debug_info_data,
+                                                           string_offset,
+                                                           string_length),
+                                             die.GetCU());
                 }
               }
             }
@@ -3291,8 +3298,9 @@ VariableSP SymbolFileDWARF::ParseVariableDIE(const SymbolContext &sc,
               uint32_t block_offset =
                   form_value.BlockData() - data.GetDataStart();
               uint32_t block_length = form_value.Unsigned();
-              location = DWARFExpression(module, data, die.GetCU(),
-                                         block_offset, block_length);
+              location = DWARFExpression(
+                  module, DataExtractor(data, block_offset, block_length),
+                  die.GetCU());
             } else {
               const DWARFDataExtractor &debug_loc_data = DebugLocData();
               const dw_offset_t debug_loc_offset = form_value.Unsigned();
@@ -3300,8 +3308,11 @@ VariableSP SymbolFileDWARF::ParseVariableDIE(const SymbolContext &sc,
               size_t loc_list_length = DWARFExpression::LocationListSize(
                   die.GetCU(), debug_loc_data, debug_loc_offset);
               if (loc_list_length > 0) {
-                location = DWARFExpression(module, debug_loc_data, die.GetCU(),
-                                           debug_loc_offset, loc_list_length);
+                location = DWARFExpression(module,
+                                           DataExtractor(debug_loc_data,
+                                                         debug_loc_offset,
+                                                         loc_list_length),
+                                           die.GetCU());
                 assert(func_low_pc != LLDB_INVALID_ADDRESS);
                 location.SetLocationListSlide(
                     func_low_pc -

diff --git a/lldb/source/Plugins/SymbolFile/NativePDB/DWARFLocationExpression.cpp b/lldb/source/Plugins/SymbolFile/NativePDB/DWARFLocationExpression.cpp
index 3d8bfb0587217f3fe7ee72baf12e02b167cc673a..6aaff06cc13463fc7c896b5421baf5be5861de0e 100644 (file)
--- a/lldb/source/Plugins/SymbolFile/NativePDB/DWARFLocationExpression.cpp
+++ b/lldb/source/Plugins/SymbolFile/NativePDB/DWARFLocationExpression.cpp
@@ -122,7 +122,7 @@ static DWARFExpression MakeLocationExpressionInternal(lldb::ModuleSP module,
   DataBufferSP buffer =
       std::make_shared<DataBufferHeap>(stream.GetData(), stream.GetSize());
   DataExtractor extractor(buffer, byte_order, address_size, byte_size);
-  DWARFExpression result(module, extractor, nullptr, 0, buffer->GetByteSize());
+  DWARFExpression result(module, extractor, nullptr);
   result.SetRegisterKind(register_kind);
 
   return result;
@@ -247,6 +247,6 @@ DWARFExpression lldb_private::npdb::MakeConstantLocationExpression(
               .take_front(size);
   buffer->CopyData(bytes.data(), size);
   DataExtractor extractor(buffer, lldb::eByteOrderLittle, address_size);
-  DWARFExpression result(nullptr, extractor, nullptr, 0, size);
+  DWARFExpression result(nullptr, extractor, nullptr);
   return result;
 }

diff --git a/lldb/source/Plugins/SymbolFile/PDB/PDBLocationToDWARFExpression.cpp b/lldb/source/Plugins/SymbolFile/PDB/PDBLocationToDWARFExpression.cpp
index 1c17bf6563b36d146de6380ed92d9513c66eb853..42bf1b34c956e9b1cec80be805c7bdad76229fd8 100644 (file)
--- a/lldb/source/Plugins/SymbolFile/PDB/PDBLocationToDWARFExpression.cpp
+++ b/lldb/source/Plugins/SymbolFile/PDB/PDBLocationToDWARFExpression.cpp
@@ -174,7 +174,7 @@ DWARFExpression ConvertPDBLocationToDWARFExpression(
   DataBufferSP buffer =
       std::make_shared<DataBufferHeap>(stream.GetData(), stream.GetSize());
   DataExtractor extractor(buffer, byte_order, address_size, byte_size);
-  DWARFExpression result(module, extractor, nullptr, 0, buffer->GetByteSize());
+  DWARFExpression result(module, extractor, nullptr);
   result.SetRegisterKind(register_kind);
 
   return result;

diff --git a/lldb/source/Target/RegisterContext.cpp b/lldb/source/Target/RegisterContext.cpp
index c960260f30c8850a08f1a6e39a114c8b2f06e0ae..f29cf435d028dc5fdec7055a2c88acae36fb0d25 100644 (file)
--- a/lldb/source/Target/RegisterContext.cpp
+++ b/lldb/source/Target/RegisterContext.cpp
@@ -82,14 +82,12 @@ RegisterContext::UpdateDynamicRegisterSize(const lldb_private::ArchSpec &arch,
   DataExtractor dwarf_data(dwarf_opcode_ptr, dwarf_opcode_len,
                            arch.GetByteOrder(), addr_size);
   ModuleSP opcode_ctx;
-  DWARFExpression dwarf_expr(opcode_ctx, dwarf_data, nullptr, 0,
-                             dwarf_opcode_len);
+  DWARFExpression dwarf_expr(opcode_ctx, dwarf_data, nullptr);
   Value result;
   Status error;
-  const lldb::offset_t offset = 0;
   if (dwarf_expr.Evaluate(&exe_ctx, this, opcode_ctx, dwarf_data, nullptr,
-                          offset, dwarf_opcode_len, eRegisterKindDWARF, nullptr,
-                          nullptr, result, &error)) {
+                          eRegisterKindDWARF, nullptr, nullptr, result,
+                          &error)) {
     expr_result = result.GetScalar().SInt(-1);
     switch (expr_result) {
     case 0:

diff --git a/lldb/unittests/Expression/DWARFExpressionTest.cpp b/lldb/unittests/Expression/DWARFExpressionTest.cpp
index 6ce7ce89fd7bb2cdb4db7a85b5b1389dcea14e0a..5c474eb13d85dadc6a30772465a647683ac198fb 100644 (file)
--- a/lldb/unittests/Expression/DWARFExpressionTest.cpp
+++ b/lldb/unittests/Expression/DWARFExpressionTest.cpp
@@ -24,8 +24,8 @@ static llvm::Expected<Scalar> Evaluate(llvm::ArrayRef<uint8_t> expr) {
   Status status;
   if (!DWARFExpression::Evaluate(
           /*exe_ctx*/ nullptr, /*reg_ctx*/ nullptr, /*opcode_ctx*/ nullptr,
-          extractor, /*dwarf_cu*/ nullptr, /*offset*/ 0, expr.size(),
-          lldb::eRegisterKindLLDB, /*initial_value_ptr*/ nullptr,
+          extractor, /*dwarf_cu*/ nullptr, lldb::eRegisterKindLLDB,
+          /*initial_value_ptr*/ nullptr,
           /*object_address_ptr*/ nullptr, result, &status))
     return status.ToError();