shafik updated this revision to Diff 414663.
shafik marked 12 inline comments as done.
shafik added a comment.
Addressing comment
- Adding documentation
- Moving some more error handling into helper
- Cleaning up the calling side
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D121408/new/
https://reviews.llvm.org/D121408
Files:
lldb/source/Expression/DWARFExpression.cpp
lldb/test/Shell/SymbolFile/DWARF/x86/DW_OP_deref_size_static_var.s
Index: lldb/test/Shell/SymbolFile/DWARF/x86/DW_OP_deref_size_static_var.s
===================================================================
--- lldb/test/Shell/SymbolFile/DWARF/x86/DW_OP_deref_size_static_var.s
+++ lldb/test/Shell/SymbolFile/DWARF/x86/DW_OP_deref_size_static_var.s
@@ -3,7 +3,7 @@
# CHECK: (lldb) target variable ug
# CHECK: (U) ug = {
-# CHECK: raw = 0
+# CHECK: raw = 0
# CHECK: = (a = 0, b = 0, c = 0, d = 0, e = 0, f = 0)
# CHECK: }
@@ -48,7 +48,7 @@
# 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
+# test
.zerofill __DATA,__bss,_ug.0,1,2 ## @ug.0
.zerofill __DATA,__bss,__type_anchor,4,2 ## @_type_anchor
@@ -199,7 +199,7 @@
.long 105 ## DW_AT_name
.long 129 ## DW_AT_LLVM_sysroot
.long 185 ## DW_AT_APPLE_sdk
- .long 0
+ .long 0
.long 200 ## DW_AT_comp_dir
## DW_AT_APPLE_optimized
.byte 2 ## Abbrev [2] 0x26:0x15 DW_TAG_variable
Index: lldb/source/Expression/DWARFExpression.cpp
===================================================================
--- lldb/source/Expression/DWARFExpression.cpp
+++ lldb/source/Expression/DWARFExpression.cpp
@@ -944,6 +944,80 @@
}
} // 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<lldb::addr_t>
+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,
@@ -1026,6 +1100,7 @@
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
@@ -1089,26 +1164,15 @@
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:
@@ -1219,6 +1283,47 @@
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) {
@@ -1229,26 +1334,10 @@
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)
@@ -1271,7 +1360,7 @@
}
break;
- case Value::ValueType::FileAddress:
+ // case Value::ValueType::FileAddress:
case Value::ValueType::Invalid:
if (error_ptr)
error_ptr->SetErrorString("Invalid value for DW_OP_deref_size.\n");
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