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[lldb] Correctly resolve (discontinuous) function offsets when disassembling #126925

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Merged
merged 1 commit into from
Feb 13, 2025
Merged

[lldb] Correctly resolve (discontinuous) function offsets when disassembling #126925

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12 changes: 8 additions & 4 deletions lldb/source/Plugins/Disassembler/LLVMC/DisassemblerLLVMC.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -31,6 +31,7 @@

#include "lldb/Core/Address.h"
#include "lldb/Core/Module.h"
#include "lldb/Symbol/Function.h"
#include "lldb/Symbol/SymbolContext.h"
#include "lldb/Target/ExecutionContext.h"
#include "lldb/Target/Process.h"
Expand Down Expand Up @@ -1806,10 +1807,13 @@ const char *DisassemblerLLVMC::SymbolLookup(uint64_t value, uint64_t *type_ptr,
bool format_omitting_current_func_name = false;
if (sym_ctx.symbol || sym_ctx.function) {
AddressRange range;
if (sym_ctx.GetAddressRange(resolve_scope, 0, false, range) &&
range.GetBaseAddress().IsValid() &&
range.ContainsLoadAddress(value_so_addr, target)) {
format_omitting_current_func_name = true;
for (uint32_t idx = 0;
sym_ctx.GetAddressRange(resolve_scope, idx, false, range);
++idx) {
if (range.ContainsLoadAddress(value_so_addr, target)) {
format_omitting_current_func_name = true;
break;
}
}
}

Expand Down
14 changes: 9 additions & 5 deletions lldb/source/Symbol/SymbolContext.cpp
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Expand Up @@ -104,15 +104,19 @@ bool SymbolContext::DumpStopContext(

if (addr_t file_addr = addr.GetFileAddress();
file_addr != LLDB_INVALID_ADDRESS) {
const addr_t function_offset =
file_addr - function->GetAddress().GetFileAddress();
// Avoiding signed arithmetic due to UB in -INT_MAX.
const char sign =
file_addr >= function->GetAddress().GetFileAddress() ? '+' : '-';
addr_t offset = file_addr - function->GetAddress().GetFileAddress();
if (sign == '-')
offset = -offset;
if (!show_function_name) {
// Print +offset even if offset is 0
dumped_something = true;
s->Printf("+%" PRIu64 ">", function_offset);
} else if (function_offset) {
s->Format("{0}{1}>", sign, offset);
} else if (offset) {
dumped_something = true;
s->Printf(" + %" PRIu64, function_offset);
s->Format(" {0} {1}", sign, offset);
}
}

Expand Down
13 changes: 8 additions & 5 deletions lldb/test/Shell/Commands/command-disassemble.s
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Expand Up @@ -84,7 +84,7 @@
# CHECK-NEXT: command-disassemble.s.tmp[0x2044] <+0>: int $0x32
# CHECK-NEXT: warning: Not disassembling a function because it is very large [0x0000000000002046-0x0000000000004046). To disassemble specify an instruction count limit, start/stop addresses or use the --force option.
# CHECK-NEXT: (lldb) disassemble --name case3
# CHECK-NEXT: error: Not disassembling a function because it is very large [0x0000000000006046-0x0000000000007046)[0x0000000000009046-0x000000000000a046). To disassemble specify an instruction count limit, start/stop addresses or use the --force option.
# CHECK-NEXT: error: Not disassembling a function because it is very large [0x0000000000006046-0x0000000000007046)[0x0000000000009046-0x000000000000a050). To disassemble specify an instruction count limit, start/stop addresses or use the --force option.
# CHECK-NEXT: Not disassembling a function because it is very large [0x0000000000004046-0x0000000000006046). To disassemble specify an instruction count limit, start/stop addresses or use the --force option.
# CHECK-NEXT: (lldb) disassemble --name case3 --count 3
# CHECK-NEXT: command-disassemble.s.tmp`n2::case3:
Expand All @@ -93,9 +93,10 @@
# CHECK-NEXT: command-disassemble.s.tmp[0x604a] <-12284>: int $0x2a
# CHECK-EMPTY:
# CHECK-NEXT: command-disassemble.s.tmp`n2::case3:
# CHECK-NEXT: command-disassemble.s.tmp[0x9046] <+0>: int $0x2a
# CHECK-NEXT: command-disassemble.s.tmp[0x9048] <+2>: int $0x2a
# CHECK-NEXT: command-disassemble.s.tmp[0x904a] <+4>: int $0x2a
# CHECK-NEXT: command-disassemble.s.tmp[0x9046] <+0>: jmp 0x6046 ; <-12288>
## FIXME: This should resolve to `middle_of_case3`
# CHECK-NEXT: command-disassemble.s.tmp[0x904b] <+5>: jmp 0x7046 ; n2::case3 - 8192
# CHECK-NEXT: command-disassemble.s.tmp[0x9050] <+10>: int $0x2a
# CHECK-EMPTY:
# CHECK-NEXT: command-disassemble.s.tmp`n1::case3:
# CHECK-NEXT: command-disassemble.s.tmp[0x4046] <+0>: int $0x2a
Expand Down Expand Up @@ -171,12 +172,14 @@ _ZN2n15case3Ev:
.endr
.L_ZN2n25case3Ev.__part.1_end:

.Lpadding:
middle_of_case3:
.rept 0x1000
int $42
.endr

_ZN2n25case3Ev:
jmp .L_ZN2n25case3Ev.__part.1
jmp middle_of_case3
.rept 0x800
int $42
.endr
Expand Down