labath created this revision.
labath added reviewers: JDevlieghere, clayborg.
Herald added subscribers: kristof.beyls, javed.absar, aprantl.
The only reason for this function's existance is so that we could pass
the correct size into the DWARFExpression constructor. However, there is
no harm in passing the entire data extractor into the DWARFExpression,
since the same code is performing the size determination as well as the
subsequent parse. So, if we get malformed input or there's a bug in the
parser, we'd compute the wrong size anyway.
Additionally, reducing the number of entry points into the location list
parsing machinery makes it easier to switch the llvm debug_loc(lists)
parsers.
While inside, I added a couple of tests for invalid location list
handling.
https://reviews.llvm.org/D66789
Files:
include/lldb/Expression/DWARFExpression.h
lit/SymbolFile/DWARF/debug_loc.s
source/Expression/DWARFExpression.cpp
source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.cpp
source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
Index: source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
===================================================================
--- source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
+++ source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
@@ -3302,17 +3302,11 @@
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();
-
- size_t loc_list_length = DWARFExpression::LocationListSize(
- die.GetCU(), debug_loc_data, debug_loc_offset);
- if (loc_list_length > 0) {
- location = DWARFExpression(module,
- DataExtractor(debug_loc_data,
- debug_loc_offset,
- loc_list_length),
- die.GetCU());
+ DataExtractor data = DebugLocData();
+ const dw_offset_t offset = form_value.Unsigned();
+ if (data.ValidOffset(offset)) {
+ data = DataExtractor(data, offset, data.GetByteSize() - offset);
+ location = DWARFExpression(module, data, die.GetCU());
assert(func_low_pc != LLDB_INVALID_ADDRESS);
location.SetLocationListSlide(
func_low_pc -
Index: source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.cpp
===================================================================
--- source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.cpp
+++ source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.cpp
@@ -343,17 +343,11 @@
*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();
-
- size_t loc_list_length = DWARFExpression::LocationListSize(
- cu, debug_loc_data, debug_loc_offset);
- if (loc_list_length > 0) {
- *frame_base = DWARFExpression(module,
- DataExtractor(debug_loc_data,
- debug_loc_offset,
- loc_list_length),
- cu);
+ DataExtractor data = dwarf.DebugLocData();
+ const dw_offset_t offset = form_value.Unsigned();
+ if (data.ValidOffset(offset)) {
+ data = DataExtractor(data, offset, data.GetByteSize() - offset);
+ *frame_base = DWARFExpression(module, data, cu);
if (lo_pc != LLDB_INVALID_ADDRESS) {
assert(lo_pc >= cu->GetBaseAddress());
frame_base->SetLocationListSlide(lo_pc -
Index: source/Expression/DWARFExpression.cpp
===================================================================
--- source/Expression/DWARFExpression.cpp
+++ source/Expression/DWARFExpression.cpp
@@ -2708,29 +2708,6 @@
return true; // Return true on success
}
-size_t DWARFExpression::LocationListSize(const DWARFUnit *dwarf_cu,
- const DataExtractor &debug_loc_data,
- lldb::offset_t offset) {
- const lldb::offset_t debug_loc_offset = offset;
- while (debug_loc_data.ValidOffset(offset)) {
- lldb::addr_t start_addr = LLDB_INVALID_ADDRESS;
- lldb::addr_t end_addr = LLDB_INVALID_ADDRESS;
- if (!AddressRangeForLocationListEntry(dwarf_cu, debug_loc_data, &offset,
- start_addr, end_addr))
- break;
-
- if (start_addr == 0 && end_addr == 0)
- break;
-
- uint16_t loc_length = debug_loc_data.GetU16(&offset);
- offset += loc_length;
- }
-
- if (offset > debug_loc_offset)
- return offset - debug_loc_offset;
- return 0;
-}
-
bool DWARFExpression::AddressRangeForLocationListEntry(
const DWARFUnit *dwarf_cu, const DataExtractor &debug_loc_data,
lldb::offset_t *offset_ptr, lldb::addr_t &low_pc, lldb::addr_t &high_pc) {
Index: lit/SymbolFile/DWARF/debug_loc.s
===================================================================
--- lit/SymbolFile/DWARF/debug_loc.s
+++ lit/SymbolFile/DWARF/debug_loc.s
@@ -1,14 +1,22 @@
+# Test debug_loc parsing, including the cases of invalid input. The exact
+# behavior in the invalid cases is not particularly important, but it should be
+# "reasonable".
+
# REQUIRES: x86
# RUN: llvm-mc -triple=x86_64-pc-linux -filetype=obj %s > %t
-# RUN: lldb %t -o "image lookup -v -a 0" -o "image lookup -v -a 2" -o exit \
+# RUN: %lldb %t -o "image lookup -v -a 0" -o "image lookup -v -a 2" -o exit \
# RUN: | FileCheck %s
# CHECK-LABEL: image lookup -v -a 0
-# CHECK: Variable: {{.*}}, name = "x", type = "int", location = rdi,
+# CHECK: Variable: {{.*}}, name = "x0", type = "int", location = rdi,
+# CHECK: Variable: {{.*}}, name = "x1", type = "int", location = ,
+# CHECK: Variable: {{.*}}, name = "x2", type = "int", location = ,
# CHECK-LABEL: image lookup -v -a 2
-# CHECK: Variable: {{.*}}, name = "x", type = "int", location = rax,
+# CHECK: Variable: {{.*}}, name = "x0", type = "int", location = rax,
+# CHECK: Variable: {{.*}}, name = "x1", type = "int", location = ,
+# CHECK: Variable: {{.*}}, name = "x2", type = "int", location = ,
.type f,@function
f: # @f
@@ -27,8 +35,12 @@
.asciz "f"
.Linfo_string4:
.asciz "int"
-.Linfo_string5:
- .asciz "x"
+.Lx0:
+ .asciz "x0"
+.Lx1:
+ .asciz "x1"
+.Lx2:
+ .asciz "x2"
.section .debug_loc,"",@progbits
.Ldebug_loc0:
@@ -42,6 +54,10 @@
.byte 80 # super-register DW_OP_reg0
.quad 0
.quad 0
+.Ldebug_loc2:
+ .quad .Lfunc_begin0-.Lfunc_begin0
+ .quad .Lfunc_end0-.Lfunc_begin0
+ .short 0xdead # Loc expr size
.section .debug_abbrev,"",@progbits
.byte 1 # Abbreviation Code
@@ -104,10 +120,18 @@
.quad .Lfunc_begin0 # DW_AT_low_pc
.long .Lfunc_end0-.Lfunc_begin0 # DW_AT_high_pc
.long .Linfo_string3 # DW_AT_name
- .long 83 # DW_AT_type
- .byte 3 # Abbrev [3] 0x43:0xf DW_TAG_formal_parameter
+ .long .Lint # DW_AT_type
+ .byte 3 # Abbrev [3] DW_TAG_formal_parameter
.long .Ldebug_loc0 # DW_AT_location
- .long .Linfo_string5 # DW_AT_name
+ .long .Lx0 # DW_AT_name
+ .long .Lint-.Lcu_begin0 # DW_AT_type
+ .byte 3 # Abbrev [3] DW_TAG_formal_parameter
+ .long 0xdeadbeef # DW_AT_location
+ .long .Lx1 # DW_AT_name
+ .long .Lint-.Lcu_begin0 # DW_AT_type
+ .byte 3 # Abbrev [3] DW_TAG_formal_parameter
+ .long .Ldebug_loc2 # DW_AT_location
+ .long .Lx2 # DW_AT_name
.long .Lint-.Lcu_begin0 # DW_AT_type
.byte 0 # End Of Children Mark
.Lint:
Index: include/lldb/Expression/DWARFExpression.h
===================================================================
--- include/lldb/Expression/DWARFExpression.h
+++ include/lldb/Expression/DWARFExpression.h
@@ -238,10 +238,6 @@
lldb::addr_t loclist_base_load_addr,
lldb::addr_t address, ABI *abi);
- static size_t LocationListSize(const DWARFUnit *dwarf_cu,
- const DataExtractor &debug_loc_data,
- lldb::offset_t offset);
-
static bool PrintDWARFExpression(Stream &s, const DataExtractor &data,
int address_size, int dwarf_ref_size,
bool location_expression);
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