diff --git a/lldb/source/Expression/DWARFExpression.cpp b/lldb/source/Expression/DWARFExpression.cpp --- a/lldb/source/Expression/DWARFExpression.cpp +++ b/lldb/source/Expression/DWARFExpression.cpp @@ -943,6 +943,80 @@ } } // namespace +/// Helper function to move common code used to resolve a file address and turn +/// into a load address. +/// +/// \param exe_ctx Pointer to the execution context +/// \param module_sp shared_ptr contains the module if we have one +/// \param error_ptr pointer to Status object if we have one +/// \param dw_op_type C-style string used to vary the error output +/// \param file_addr the file address we are trying to resolve and turn into a +/// load address +/// \param so_addr out parameter, will be set to load addresss or section offset +/// \param check_sectionoffset bool which determines if having a section offset +/// but not a load address is considerd a success +/// \returns llvm::Optional containing the load address if resolving and getting +/// the load address succeed or an empty Optinal otherwise. If +/// check_sectionoffset is true we consider LLDB_INVALID_ADDRESS a +/// success if so_addr.IsSectionOffset() is true. +static llvm::Optional +ResolveAndLoadFileAddress(ExecutionContext *exe_ctx, lldb::ModuleSP module_sp, + Status *error_ptr, const char *dw_op_type, + lldb::addr_t file_addr, Address &so_addr, + bool check_sectionoffset = false) { + if (!module_sp) { + if (error_ptr) + error_ptr->SetErrorStringWithFormat( + "need module to resolve file address for %s", dw_op_type); + return {}; + } + + if (!module_sp->ResolveFileAddress(file_addr, so_addr)) { + if (error_ptr) + error_ptr->SetErrorString("failed to resolve file address in module"); + return {}; + } + + addr_t load_addr = so_addr.GetLoadAddress(exe_ctx->GetTargetPtr()); + + if (load_addr == LLDB_INVALID_ADDRESS && + (check_sectionoffset && !so_addr.IsSectionOffset())) { + if (error_ptr) + error_ptr->SetErrorString("failed to resolve load address"); + return {}; + } + + return load_addr; +} + +/// Helper function to move common code used to load sized data from a uint8_t +/// buffer. +/// +/// \param addr_bytes uint8_t buffer containg raw data +/// \param size_addr_bytes how large is the underlying raw data +/// \param byte_order what is the byter order of the underlyig data +/// \param size How much of the underlying data we want to use +/// \return The underlying data converted into a Scalar +static Scalar DerefSizeExtractDataHelper(uint8_t *addr_bytes, + size_t size_addr_bytes, + ByteOrder byte_order, size_t size) { + DataExtractor addr_data(addr_bytes, size_addr_bytes, byte_order, size); + + lldb::offset_t addr_data_offset = 0; + switch (size) { + case 1: + return addr_data.GetU8(&addr_data_offset); + case 2: + return addr_data.GetU16(&addr_data_offset); + case 4: + return addr_data.GetU32(&addr_data_offset); + case 8: + return addr_data.GetU64(&addr_data_offset); + default: + return addr_data.GetAddress(&addr_data_offset); + } +} + bool DWARFExpression::Evaluate( ExecutionContext *exe_ctx, RegisterContext *reg_ctx, lldb::ModuleSP module_sp, const DataExtractor &opcodes, @@ -1025,6 +1099,7 @@ if (frame) stack.back().ConvertToLoadAddress(module_sp.get(), frame->CalculateTarget().get()); + break; // The DW_OP_addr_sect_offset4 is used for any location expressions in @@ -1088,26 +1163,15 @@ case Value::ValueType::FileAddress: { auto file_addr = stack.back().GetScalar().ULongLong( LLDB_INVALID_ADDRESS); - if (!module_sp) { - if (error_ptr) - error_ptr->SetErrorString( - "need module to resolve file address for DW_OP_deref"); - return false; - } + Address so_addr; - if (!module_sp->ResolveFileAddress(file_addr, so_addr)) { - if (error_ptr) - error_ptr->SetErrorString( - "failed to resolve file address in module"); - return false; - } - addr_t load_Addr = so_addr.GetLoadAddress(exe_ctx->GetTargetPtr()); - if (load_Addr == LLDB_INVALID_ADDRESS) { - if (error_ptr) - error_ptr->SetErrorString("failed to resolve load address"); + auto maybe_load_addr = ResolveAndLoadFileAddress( + exe_ctx, module_sp, error_ptr, "DW_OP_deref", file_addr, so_addr); + + if (!maybe_load_addr) return false; - } - stack.back().GetScalar() = load_Addr; + + stack.back().GetScalar() = *maybe_load_addr; // Fall through to load address promotion code below. } LLVM_FALLTHROUGH; case Value::ValueType::Scalar: @@ -1218,6 +1282,47 @@ stack.back().GetScalar() = ptr; stack.back().ClearContext(); } break; + case Value::ValueType::FileAddress: { + auto file_addr = + stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS); + Address so_addr; + auto maybe_load_addr = + ResolveAndLoadFileAddress(exe_ctx, module_sp, error_ptr, + "DW_OP_deref_size", file_addr, so_addr, + /*check_sectionoffset=*/true); + + if (!maybe_load_addr) + return false; + + addr_t load_addr = *maybe_load_addr; + + if (load_addr == LLDB_INVALID_ADDRESS && so_addr.IsSectionOffset()) { + uint8_t addr_bytes[size]; + Status error; + + if (exe_ctx->GetTargetRef().ReadMemory( + so_addr, &addr_bytes, size, error, + /*force_live_memory=*/false) == size) { + ObjectFile *objfile = module_sp->GetObjectFile(); + + stack.back().GetScalar() = DerefSizeExtractDataHelper( + addr_bytes, sizeof(addr_bytes), objfile->GetByteOrder(), size); + stack.back().ClearContext(); + break; + } else { + if (error_ptr) + error_ptr->SetErrorStringWithFormat( + "Failed to dereference pointer for for DW_OP_deref_size: " + "%s\n", + error.AsCString()); + return false; + } + } + stack.back().GetScalar() = load_addr; + // Fall through to load address promotion code below. + } + + LLVM_FALLTHROUGH; case Value::ValueType::Scalar: case Value::ValueType::LoadAddress: if (exe_ctx) { @@ -1228,26 +1333,10 @@ Status error; if (process->ReadMemory(pointer_addr, &addr_bytes, size, error) == size) { - DataExtractor addr_data(addr_bytes, sizeof(addr_bytes), - process->GetByteOrder(), size); - lldb::offset_t addr_data_offset = 0; - switch (size) { - case 1: - stack.back().GetScalar() = addr_data.GetU8(&addr_data_offset); - break; - case 2: - stack.back().GetScalar() = addr_data.GetU16(&addr_data_offset); - break; - case 4: - stack.back().GetScalar() = addr_data.GetU32(&addr_data_offset); - break; - case 8: - stack.back().GetScalar() = addr_data.GetU64(&addr_data_offset); - break; - default: - stack.back().GetScalar() = - addr_data.GetAddress(&addr_data_offset); - } + + stack.back().GetScalar() = + DerefSizeExtractDataHelper(addr_bytes, sizeof(addr_bytes), + process->GetByteOrder(), size); stack.back().ClearContext(); } else { if (error_ptr) @@ -1270,7 +1359,6 @@ } break; - case Value::ValueType::FileAddress: case Value::ValueType::Invalid: if (error_ptr) error_ptr->SetErrorString("Invalid value for DW_OP_deref_size.\n"); diff --git a/lldb/test/Shell/SymbolFile/DWARF/x86/DW_OP_deref_size_static_var.s b/lldb/test/Shell/SymbolFile/DWARF/x86/DW_OP_deref_size_static_var.s new file mode 100644 --- /dev/null +++ b/lldb/test/Shell/SymbolFile/DWARF/x86/DW_OP_deref_size_static_var.s @@ -0,0 +1,316 @@ +# RUN: llvm-mc -filetype=obj -o %t -triple x86_64-apple-macosx10.15.0 %s +# RUN: %lldb %t -o "target variable ug" -b | FileCheck %s + +# CHECK: (lldb) target variable ug +# CHECK: (U) ug = { +# CHECK: raw = 0 +# CHECK: = (a = 0, b = 0, c = 0, d = 0, e = 0, f = 0) +# CHECK: } + +# We are testing how DWARFExpression::Evaluate(...) in the case of +# DW_OP_deref_size deals with static variable. +# +# The address will be a ValueType::FileAddress type which we will not be able +# to turn into a load address but it is a section offset. We should be able to +# use Target::ReadMemory(...) to read the data in this case. +# Compiling at -O1 allows us to capture this case and test it. +# +# typedef union { +# unsigned raw; +# struct { +# unsigned a : 8; +# unsigned b : 8; +# unsigned c : 6; +# unsigned d : 2; +# unsigned e : 6; +# unsigned f : 2; +# }; +# } U; +# +# // This appears first in the debug info and pulls the type definition in... +# static U __attribute__((used)) _type_anchor; +# // ... then our useful variable appears last in the debug info and we can +# // tweak the assembly without needing to edit a lot of offsets by hand. +# static U ug; +# +# extern void f(U); +# +# // Omit debug info for main. +# __attribute__((nodebug)) +# int main() { +# ug.raw = 0x64A40101; +# f(ug); +# f((U)ug.raw); +# } +# +# Compiled as follows: +# +# clang -O1 -gdwarf-4 dw_op_deref_size_test.c -S -o dw_op_deref_size_test.s +# +# Hand modified .s file to remoce various section that are not needed for this +# test + +.zerofill __DATA,__bss,_ug.0,1,2 ## @ug.0 +.zerofill __DATA,__bss,__type_anchor,4,2 ## @_type_anchor + .no_dead_strip __type_anchor + .section __DWARF,__debug_abbrev,regular,debug +Lsection_abbrev: + .byte 1 ## Abbreviation Code + .byte 17 ## DW_TAG_compile_unit + .byte 1 ## DW_CHILDREN_yes + .byte 37 ## DW_AT_producer + .byte 14 ## DW_FORM_strp + .byte 19 ## DW_AT_language + .byte 5 ## DW_FORM_data2 + .byte 3 ## DW_AT_name + .byte 14 ## DW_FORM_strp + .ascii "\202|" ## DW_AT_LLVM_sysroot + .byte 14 ## DW_FORM_strp + .ascii "\357\177" ## DW_AT_APPLE_sdk + .byte 14 ## DW_FORM_strp + .byte 16 ## DW_AT_stmt_list + .byte 23 ## DW_FORM_sec_offset + .byte 27 ## DW_AT_comp_dir + .byte 14 ## DW_FORM_strp + .ascii "\341\177" ## DW_AT_APPLE_optimized + .byte 25 ## DW_FORM_flag_present + .byte 0 ## EOM(1) + .byte 0 ## EOM(2) + .byte 2 ## Abbreviation Code + .byte 52 ## DW_TAG_variable + .byte 0 ## DW_CHILDREN_no + .byte 3 ## DW_AT_name + .byte 14 ## DW_FORM_strp + .byte 73 ## DW_AT_type + .byte 19 ## DW_FORM_ref4 + .byte 58 ## DW_AT_decl_file + .byte 11 ## DW_FORM_data1 + .byte 59 ## DW_AT_decl_line + .byte 11 ## DW_FORM_data1 + .byte 2 ## DW_AT_location + .byte 24 ## DW_FORM_exprloc + .byte 0 ## EOM(1) + .byte 0 ## EOM(2) + .byte 3 ## Abbreviation Code + .byte 22 ## DW_TAG_typedef + .byte 0 ## DW_CHILDREN_no + .byte 73 ## DW_AT_type + .byte 19 ## DW_FORM_ref4 + .byte 3 ## DW_AT_name + .byte 14 ## DW_FORM_strp + .byte 58 ## DW_AT_decl_file + .byte 11 ## DW_FORM_data1 + .byte 59 ## DW_AT_decl_line + .byte 11 ## DW_FORM_data1 + .byte 0 ## EOM(1) + .byte 0 ## EOM(2) + .byte 4 ## Abbreviation Code + .byte 23 ## DW_TAG_union_type + .byte 1 ## DW_CHILDREN_yes + .byte 11 ## DW_AT_byte_size + .byte 11 ## DW_FORM_data1 + .byte 58 ## DW_AT_decl_file + .byte 11 ## DW_FORM_data1 + .byte 59 ## DW_AT_decl_line + .byte 11 ## DW_FORM_data1 + .byte 0 ## EOM(1) + .byte 0 ## EOM(2) + .byte 5 ## Abbreviation Code + .byte 13 ## DW_TAG_member + .byte 0 ## DW_CHILDREN_no + .byte 3 ## DW_AT_name + .byte 14 ## DW_FORM_strp + .byte 73 ## DW_AT_type + .byte 19 ## DW_FORM_ref4 + .byte 58 ## DW_AT_decl_file + .byte 11 ## DW_FORM_data1 + .byte 59 ## DW_AT_decl_line + .byte 11 ## DW_FORM_data1 + .byte 56 ## DW_AT_data_member_location + .byte 11 ## DW_FORM_data1 + .byte 0 ## EOM(1) + .byte 0 ## EOM(2) + .byte 6 ## Abbreviation Code + .byte 13 ## DW_TAG_member + .byte 0 ## DW_CHILDREN_no + .byte 73 ## DW_AT_type + .byte 19 ## DW_FORM_ref4 + .byte 58 ## DW_AT_decl_file + .byte 11 ## DW_FORM_data1 + .byte 59 ## DW_AT_decl_line + .byte 11 ## DW_FORM_data1 + .byte 56 ## DW_AT_data_member_location + .byte 11 ## DW_FORM_data1 + .byte 0 ## EOM(1) + .byte 0 ## EOM(2) + .byte 7 ## Abbreviation Code + .byte 19 ## DW_TAG_structure_type + .byte 1 ## DW_CHILDREN_yes + .byte 11 ## DW_AT_byte_size + .byte 11 ## DW_FORM_data1 + .byte 58 ## DW_AT_decl_file + .byte 11 ## DW_FORM_data1 + .byte 59 ## DW_AT_decl_line + .byte 11 ## DW_FORM_data1 + .byte 0 ## EOM(1) + .byte 0 ## EOM(2) + .byte 8 ## Abbreviation Code + .byte 13 ## DW_TAG_member + .byte 0 ## DW_CHILDREN_no + .byte 3 ## DW_AT_name + .byte 14 ## DW_FORM_strp + .byte 73 ## DW_AT_type + .byte 19 ## DW_FORM_ref4 + .byte 58 ## DW_AT_decl_file + .byte 11 ## DW_FORM_data1 + .byte 59 ## DW_AT_decl_line + .byte 11 ## DW_FORM_data1 + .byte 13 ## DW_AT_bit_size + .byte 11 ## DW_FORM_data1 + .byte 107 ## DW_AT_data_bit_offset + .byte 11 ## DW_FORM_data1 + .byte 0 ## EOM(1) + .byte 0 ## EOM(2) + .byte 9 ## Abbreviation Code + .byte 36 ## DW_TAG_base_type + .byte 0 ## DW_CHILDREN_no + .byte 3 ## DW_AT_name + .byte 14 ## DW_FORM_strp + .byte 62 ## DW_AT_encoding + .byte 11 ## DW_FORM_data1 + .byte 11 ## DW_AT_byte_size + .byte 11 ## DW_FORM_data1 + .byte 0 ## EOM(1) + .byte 0 ## EOM(2) + .byte 0 ## EOM(3) + .section __DWARF,__debug_info,regular,debug +Lsection_info: +Lcu_begin0: +.set Lset0, Ldebug_info_end0-Ldebug_info_start0 ## Length of Unit + .long Lset0 +Ldebug_info_start0: + .short 4 ## DWARF version number +.set Lset1, Lsection_abbrev-Lsection_abbrev ## Offset Into Abbrev. Section + .long Lset1 + .byte 8 ## Address Size (in bytes) + .byte 1 ## Abbrev [1] 0xb:0xd0 DW_TAG_compile_unit + .long 0 ## DW_AT_producer + .short 12 ## DW_AT_language + .long 105 ## DW_AT_name + .long 129 ## DW_AT_LLVM_sysroot + .long 185 ## DW_AT_APPLE_sdk + .long 0 + .long 200 ## DW_AT_comp_dir + ## DW_AT_APPLE_optimized + .byte 2 ## Abbrev [2] 0x26:0x15 DW_TAG_variable + .long 219 ## DW_AT_name + .long 59 ## DW_AT_type + .byte 1 ## DW_AT_decl_file + .byte 14 ## DW_AT_decl_line + .byte 9 ## DW_AT_location + .byte 3 + .quad __type_anchor + .byte 3 ## Abbrev [3] 0x3b:0xb DW_TAG_typedef + .long 70 ## DW_AT_type + .long 232 ## DW_AT_name + .byte 1 ## DW_AT_decl_file + .byte 11 ## DW_AT_decl_line + .byte 4 ## Abbrev [4] 0x46:0x6c DW_TAG_union_type + .byte 4 ## DW_AT_byte_size + .byte 1 ## DW_AT_decl_file + .byte 1 ## DW_AT_decl_line + .byte 5 ## Abbrev [5] 0x4a:0xc DW_TAG_member + .long 234 ## DW_AT_name + .long 178 ## DW_AT_type + .byte 1 ## DW_AT_decl_file + .byte 2 ## DW_AT_decl_line + .byte 0 ## DW_AT_data_member_location + .byte 6 ## Abbrev [6] 0x56:0x8 DW_TAG_member + .long 94 ## DW_AT_type + .byte 1 ## DW_AT_decl_file + .byte 3 ## DW_AT_decl_line + .byte 0 ## DW_AT_data_member_location + .byte 7 ## Abbrev [7] 0x5e:0x53 DW_TAG_structure_type + .byte 4 ## DW_AT_byte_size + .byte 1 ## DW_AT_decl_file + .byte 3 ## DW_AT_decl_line + .byte 8 ## Abbrev [8] 0x62:0xd DW_TAG_member + .long 251 ## DW_AT_name + .long 178 ## DW_AT_type + .byte 1 ## DW_AT_decl_file + .byte 4 ## DW_AT_decl_line + .byte 8 ## DW_AT_bit_size + .byte 0 ## DW_AT_data_bit_offset + .byte 8 ## Abbrev [8] 0x6f:0xd DW_TAG_member + .long 253 ## DW_AT_name + .long 178 ## DW_AT_type + .byte 1 ## DW_AT_decl_file + .byte 5 ## DW_AT_decl_line + .byte 8 ## DW_AT_bit_size + .byte 8 ## DW_AT_data_bit_offset + .byte 8 ## Abbrev [8] 0x7c:0xd DW_TAG_member + .long 255 ## DW_AT_name + .long 178 ## DW_AT_type + .byte 1 ## DW_AT_decl_file + .byte 6 ## DW_AT_decl_line + .byte 6 ## DW_AT_bit_size + .byte 16 ## DW_AT_data_bit_offset + .byte 8 ## Abbrev [8] 0x89:0xd DW_TAG_member + .long 257 ## DW_AT_name + .long 178 ## DW_AT_type + .byte 1 ## DW_AT_decl_file + .byte 7 ## DW_AT_decl_line + .byte 2 ## DW_AT_bit_size + .byte 22 ## DW_AT_data_bit_offset + .byte 8 ## Abbrev [8] 0x96:0xd DW_TAG_member + .long 259 ## DW_AT_name + .long 178 ## DW_AT_type + .byte 1 ## DW_AT_decl_file + .byte 8 ## DW_AT_decl_line + .byte 6 ## DW_AT_bit_size + .byte 24 ## DW_AT_data_bit_offset + .byte 8 ## Abbrev [8] 0xa3:0xd DW_TAG_member + .long 261 ## DW_AT_name + .long 178 ## DW_AT_type + .byte 1 ## DW_AT_decl_file + .byte 9 ## DW_AT_decl_line + .byte 2 ## DW_AT_bit_size + .byte 30 ## DW_AT_data_bit_offset + .byte 0 ## End Of Children Mark + .byte 0 ## End Of Children Mark + .byte 9 ## Abbrev [9] 0xb2:0x7 DW_TAG_base_type + .long 238 ## DW_AT_name + .byte 7 ## DW_AT_encoding + .byte 4 ## DW_AT_byte_size + .byte 2 ## Abbrev [2] 0xb9:0x21 DW_TAG_variable + .long 263 ## DW_AT_name + .long 59 ## DW_AT_type + .byte 1 ## DW_AT_decl_file + .byte 17 ## DW_AT_decl_line + .byte 21 ## DW_AT_location + .byte 3 + .quad _ug.0 + .byte 148 + .byte 1 + .byte 16 + .ascii "\201\202\220\245\006" + .byte 30 + .byte 48 + .byte 34 + .byte 159 + .byte 0 ## End Of Children Mark +Ldebug_info_end0: + .section __DWARF,__debug_str,regular,debug +Linfo_string: + .zero 219 + .asciz "_type_anchor" ## string offset=219 + .asciz "U" ## string offset=232 + .asciz "raw" ## string offset=234 + .asciz "unsigned int" ## string offset=238 + .asciz "a" ## string offset=251 + .asciz "b" ## string offset=253 + .asciz "c" ## string offset=255 + .asciz "d" ## string offset=257 + .asciz "e" ## string offset=259 + .asciz "f" ## string offset=261 + .asciz "ug" ## string offset=263