[Lldb-commits] [lldb] [lldb] Support disassembling discontinuous functions (PR #126505)
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Mon Feb 10 04:02:39 PST 2025
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-lldb
Author: Pavel Labath (labath)
<details>
<summary>Changes</summary>
The command already supported disassembling multiple ranges, among other reasons because inline functions can be discontinuous. The main thing that was missing was being able to retrieve the function ranges from the top level function object.
The output of the command for the case where the function entry point is not its lowest address is somewhat confusing (we're showing negative offsets), but it is correct.
---
Full diff: https://github.com/llvm/llvm-project/pull/126505.diff
4 Files Affected:
- (modified) lldb/source/Commands/CommandObjectDisassemble.cpp (+47-41)
- (modified) lldb/source/Commands/CommandObjectDisassemble.h (+2-1)
- (modified) lldb/source/Symbol/SymbolContext.cpp (+2-2)
- (modified) lldb/test/Shell/Commands/command-disassemble.s (+103-9)
``````````diff
diff --git a/lldb/source/Commands/CommandObjectDisassemble.cpp b/lldb/source/Commands/CommandObjectDisassemble.cpp
index 5b131fe86dedbae..d116188966daa49 100644
--- a/lldb/source/Commands/CommandObjectDisassemble.cpp
+++ b/lldb/source/Commands/CommandObjectDisassemble.cpp
@@ -21,6 +21,7 @@
#include "lldb/Target/SectionLoadList.h"
#include "lldb/Target/StackFrame.h"
#include "lldb/Target/Target.h"
+#include <iterator>
static constexpr unsigned default_disasm_byte_size = 32;
static constexpr unsigned default_disasm_num_ins = 4;
@@ -236,19 +237,25 @@ CommandObjectDisassemble::CommandObjectDisassemble(
CommandObjectDisassemble::~CommandObjectDisassemble() = default;
-llvm::Error CommandObjectDisassemble::CheckRangeSize(const AddressRange &range,
- llvm::StringRef what) {
+llvm::Expected<std::vector<AddressRange>>
+CommandObjectDisassemble::CheckRangeSize(std::vector<AddressRange> ranges,
+ llvm::StringRef what) {
+ addr_t total_range_size = 0;
+ for (const AddressRange &r : ranges)
+ total_range_size += r.GetByteSize();
+
if (m_options.num_instructions > 0 || m_options.force ||
- range.GetByteSize() < GetDebugger().GetStopDisassemblyMaxSize())
- return llvm::Error::success();
+ total_range_size < GetDebugger().GetStopDisassemblyMaxSize())
+ return ranges;
+
StreamString msg;
msg << "Not disassembling " << what << " because it is very large ";
- range.Dump(&msg, &GetTarget(), Address::DumpStyleLoadAddress,
- Address::DumpStyleFileAddress);
+ for (const AddressRange &r: ranges)
+ r.Dump(&msg, &GetTarget(), Address::DumpStyleLoadAddress,
+ Address::DumpStyleFileAddress);
msg << ". To disassemble specify an instruction count limit, start/stop "
"addresses or use the --force option.";
- return llvm::createStringError(llvm::inconvertibleErrorCode(),
- msg.GetString());
+ return llvm::createStringError(msg.GetString());
}
llvm::Expected<std::vector<AddressRange>>
@@ -262,9 +269,11 @@ CommandObjectDisassemble::GetContainingAddressRanges() {
addr, eSymbolContextEverything, sc, resolve_tail_call_address);
if (sc.function || sc.symbol) {
AddressRange range;
- sc.GetAddressRange(eSymbolContextFunction | eSymbolContextSymbol, 0,
- false, range);
- ranges.push_back(range);
+ for (uint32_t idx = 0;
+ sc.GetAddressRange(eSymbolContextFunction | eSymbolContextSymbol,
+ idx, false, range);
+ ++idx)
+ ranges.push_back(range);
}
};
@@ -292,9 +301,7 @@ CommandObjectDisassemble::GetContainingAddressRanges() {
m_options.symbol_containing_addr);
}
- if (llvm::Error err = CheckRangeSize(ranges[0], "the function"))
- return std::move(err);
- return ranges;
+ return CheckRangeSize(std::move(ranges), "the function");
}
llvm::Expected<std::vector<AddressRange>>
@@ -304,29 +311,24 @@ CommandObjectDisassemble::GetCurrentFunctionRanges() {
if (!frame) {
if (process) {
return llvm::createStringError(
- llvm::inconvertibleErrorCode(),
- "Cannot disassemble around the current "
- "function without the process being stopped.\n");
- } else {
- return llvm::createStringError(llvm::inconvertibleErrorCode(),
- "Cannot disassemble around the current "
- "function without a selected frame: "
- "no currently running process.\n");
+ "Cannot disassemble around the current function without the process "
+ "being stopped.\n");
}
+ return llvm::createStringError(
+ "Cannot disassemble around the current function without a selected "
+ "frame: no currently running process.\n");
}
- SymbolContext sc(
- frame->GetSymbolContext(eSymbolContextFunction | eSymbolContextSymbol));
- AddressRange range;
+ SymbolContext sc =
+ frame->GetSymbolContext(eSymbolContextFunction | eSymbolContextSymbol);
+ std::vector<AddressRange> ranges;
if (sc.function)
- range = sc.function->GetAddressRange();
- else if (sc.symbol && sc.symbol->ValueIsAddress()) {
- range = {sc.symbol->GetAddress(), sc.symbol->GetByteSize()};
- } else
- range = {frame->GetFrameCodeAddress(), default_disasm_byte_size};
-
- if (llvm::Error err = CheckRangeSize(range, "the current function"))
- return std::move(err);
- return std::vector<AddressRange>{range};
+ ranges = sc.function->GetAddressRanges();
+ else if (sc.symbol && sc.symbol->ValueIsAddress())
+ ranges.emplace_back(sc.symbol->GetAddress(), sc.symbol->GetByteSize());
+ else
+ ranges.emplace_back(frame->GetFrameCodeAddress(), default_disasm_byte_size);
+
+ return CheckRangeSize(std::move(ranges), "the current function");
}
llvm::Expected<std::vector<AddressRange>>
@@ -372,19 +374,23 @@ CommandObjectDisassemble::GetNameRanges(CommandReturnObject &result) {
std::vector<AddressRange> ranges;
llvm::Error range_errs = llvm::Error::success();
- AddressRange range;
const uint32_t scope =
eSymbolContextBlock | eSymbolContextFunction | eSymbolContextSymbol;
const bool use_inline_block_range = true;
for (SymbolContext sc : sc_list.SymbolContexts()) {
+ std::vector<AddressRange> fn_ranges;
+ AddressRange range;
for (uint32_t range_idx = 0;
sc.GetAddressRange(scope, range_idx, use_inline_block_range, range);
- ++range_idx) {
- if (llvm::Error err = CheckRangeSize(range, "a range"))
- range_errs = joinErrors(std::move(range_errs), std::move(err));
- else
- ranges.push_back(range);
- }
+ ++range_idx)
+ fn_ranges.push_back(std::move(range));
+
+ if (llvm::Expected<std::vector<AddressRange>> checked_ranges =
+ CheckRangeSize(std::move(fn_ranges), "a function"))
+ llvm::move(*checked_ranges, std::back_inserter(ranges));
+ else
+ range_errs =
+ joinErrors(std::move(range_errs), checked_ranges.takeError());
}
if (ranges.empty()) {
if (range_errs)
diff --git a/lldb/source/Commands/CommandObjectDisassemble.h b/lldb/source/Commands/CommandObjectDisassemble.h
index f9cba1e5ae9cb6c..4fbcd72d1c0425e 100644
--- a/lldb/source/Commands/CommandObjectDisassemble.h
+++ b/lldb/source/Commands/CommandObjectDisassemble.h
@@ -100,7 +100,8 @@ class CommandObjectDisassemble : public CommandObjectParsed {
llvm::Expected<std::vector<AddressRange>> GetPCRanges();
llvm::Expected<std::vector<AddressRange>> GetStartEndAddressRanges();
- llvm::Error CheckRangeSize(const AddressRange &range, llvm::StringRef what);
+ llvm::Expected<std::vector<AddressRange>>
+ CheckRangeSize(std::vector<AddressRange> ranges, llvm::StringRef what);
CommandOptions m_options;
};
diff --git a/lldb/source/Symbol/SymbolContext.cpp b/lldb/source/Symbol/SymbolContext.cpp
index 19f4f91e29d2598..4725df52ff5592c 100644
--- a/lldb/source/Symbol/SymbolContext.cpp
+++ b/lldb/source/Symbol/SymbolContext.cpp
@@ -351,8 +351,8 @@ bool SymbolContext::GetAddressRange(uint32_t scope, uint32_t range_idx,
}
if ((scope & eSymbolContextFunction) && (function != nullptr)) {
- if (range_idx == 0) {
- range = function->GetAddressRange();
+ if (range_idx < function->GetAddressRanges().size()) {
+ range = function->GetAddressRanges()[range_idx];
return true;
}
}
diff --git a/lldb/test/Shell/Commands/command-disassemble.s b/lldb/test/Shell/Commands/command-disassemble.s
index 1625f80468eb17f..951d96cefd4b9d5 100644
--- a/lldb/test/Shell/Commands/command-disassemble.s
+++ b/lldb/test/Shell/Commands/command-disassemble.s
@@ -82,20 +82,25 @@
# CHECK-NEXT: (lldb) disassemble --name case2
# CHECK-NEXT: command-disassemble.s.tmp`n1::case2:
# CHECK-NEXT: command-disassemble.s.tmp[0x2044] <+0>: int $0x32
-# CHECK-NEXT: warning: Not disassembling a range because it is very large [0x0000000000002046-0x0000000000004046). To disassemble specify an instruction count limit, start/stop addresses or use the --force option.
+# 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 range because it is very large [0x0000000000004046-0x0000000000006046). To disassemble specify an instruction count limit, start/stop addresses or use the --force option.
-# CHECK-NEXT: Not disassembling a range because it is very large [0x0000000000006046-0x0000000000008046). 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)[0x0000000000009046-0x000000000000a046). 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:
+# CHECK-NEXT: command-disassemble.s.tmp[0x6046] <-12288>: int $0x2a
+# CHECK-NEXT: command-disassemble.s.tmp[0x6048] <-12286>: int $0x2a
+# 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-EMPTY:
# CHECK-NEXT: command-disassemble.s.tmp`n1::case3:
# CHECK-NEXT: command-disassemble.s.tmp[0x4046] <+0>: int $0x2a
# CHECK-NEXT: command-disassemble.s.tmp[0x4048] <+2>: int $0x2a
# CHECK-NEXT: command-disassemble.s.tmp[0x404a] <+4>: int $0x2a
-# CHECK-EMPTY:
-# CHECK-NEXT: command-disassemble.s.tmp`n2::case3:
-# CHECK-NEXT: command-disassemble.s.tmp[0x6046] <+0>: int $0x2a
-# CHECK-NEXT: command-disassemble.s.tmp[0x6048] <+2>: int $0x2a
-# CHECK-NEXT: command-disassemble.s.tmp[0x604a] <+4>: int $0x2a
# CHECK-EMPTY:
@@ -158,8 +163,97 @@ _ZN2n15case3Ev:
.rept 0x1000
int $42
.endr
+ .size _ZN2n15case3Ev, .-_ZN2n15case3Ev
-_ZN2n25case3Ev:
+.L_ZN2n25case3Ev.__part.1:
+ .rept 0x800
+ int $42
+ .endr
+.L_ZN2n25case3Ev.__part.1_end:
+
+.Lpadding:
.rept 0x1000
int $42
.endr
+
+_ZN2n25case3Ev:
+ .rept 0x800
+ int $42
+ .endr
+.L_ZN2n25case3Ev_end:
+
+ .section .debug_abbrev,"", at progbits
+ .byte 1 # Abbreviation Code
+ .byte 17 # DW_TAG_compile_unit
+ .byte 1 # DW_CHILDREN_yes
+ .byte 37 # DW_AT_producer
+ .byte 8 # DW_FORM_string
+ .byte 19 # DW_AT_language
+ .byte 5 # DW_FORM_data2
+ .byte 17 # DW_AT_low_pc
+ .byte 1 # DW_FORM_addr
+ .byte 85 # DW_AT_ranges
+ .byte 23 # DW_FORM_sec_offset
+ .byte 0 # EOM(1)
+ .byte 0 # EOM(2)
+ .byte 2 # Abbreviation Code
+ .byte 57 # DW_TAG_namespace
+ .byte 1 # DW_CHILDREN_yes
+ .byte 3 # DW_AT_name
+ .byte 8 # DW_FORM_string
+ .byte 0 # EOM(1)
+ .byte 0 # EOM(2)
+ .byte 3 # Abbreviation Code
+ .byte 46 # DW_TAG_subprogram
+ .byte 0 # DW_CHILDREN_no
+ .byte 85 # DW_AT_ranges
+ .byte 23 # DW_FORM_sec_offset
+ .byte 3 # DW_AT_name
+ .byte 8 # DW_FORM_string
+ .byte 110 # DW_AT_linkage_name
+ .byte 8 # DW_FORM_string
+ .byte 0 # EOM(1)
+ .byte 0 # EOM(2)
+ .byte 0 # EOM(3)
+
+ .section .debug_info,"", at progbits
+.Lcu_begin0:
+ .long .Ldebug_info_end0-.Ldebug_info_start0 # Length of Unit
+.Ldebug_info_start0:
+ .short 5 # DWARF version number
+ .byte 1 # DWARF Unit Type
+ .byte 8 # Address Size (in bytes)
+ .long .debug_abbrev # Offset Into Abbrev. Section
+ .byte 1 # Abbrev DW_TAG_compile_unit
+ .asciz "Hand-written DWARF" # DW_AT_producer
+ .short 29 # DW_AT_language
+ .quad 0 # DW_AT_low_pc
+ .long .Ldebug_ranges0 # DW_AT_ranges
+ .byte 2 # Abbrev DW_TAG_namespace
+ .asciz "n2" # DW_AT_name
+ .byte 3 # Abbrev DW_TAG_subprogram
+ .long .Ldebug_ranges0 # DW_AT_ranges
+ .asciz "case3" # DW_AT_name
+ .asciz "_ZN2n25case3Ev" # DW_AT_linkage_name
+ .byte 0 # End Of Children Mark
+ .byte 0 # End Of Children Mark
+.Ldebug_info_end0:
+
+ .section .debug_rnglists,"", at progbits
+ .long .Ldebug_list_header_end0-.Ldebug_list_header_start0 # Length
+.Ldebug_list_header_start0:
+ .short 5 # Version
+ .byte 8 # Address size
+ .byte 0 # Segment selector size
+ .long 2 # Offset entry count
+.Lrnglists_table_base0:
+ .long .Ldebug_ranges0-.Lrnglists_table_base0
+.Ldebug_ranges0:
+ .byte 6 # DW_RLE_start_end
+ .quad _ZN2n25case3Ev
+ .quad .L_ZN2n25case3Ev_end
+ .byte 6 # DW_RLE_start_end
+ .quad .L_ZN2n25case3Ev.__part.1
+ .quad .L_ZN2n25case3Ev.__part.1_end
+ .byte 0 # DW_RLE_end_of_list
+.Ldebug_list_header_end0:
``````````
</details>
https://github.com/llvm/llvm-project/pull/126505
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