https://github.com/labath created
https://github.com/llvm/llvm-project/pull/137955
Continuing the theme from #116777 and #124931, this patch ensures we compute
the correct address when a functions is spread across multiple sections. Due to
this, it's not sufficient to adjust the offset in the section+offset pair
(Address::Slide). We must actually slide the file offset and then recompute the
section using the result.
>From 9a6a3130942ac3ff90dc3e2eb83748700bf136ae Mon Sep 17 00:00:00 2001
From: Pavel Labath <pa...@labath.sk>
Date: Tue, 29 Apr 2025 16:27:11 +0200
Subject: [PATCH] [lldb] Fix block address resolution for functions in multiple
sections
Continuing the theme from #116777 and #124931, this patch ensures we
compute the correct address when a functions is spread across multiple
sections. Due to this, it's not sufficient to adjust the offset in the
section+offset pair (Address::Slide). We must actually slide the file
offset and then recompute the section using the result.
---
lldb/source/Symbol/Block.cpp | 39 +++----
.../Commands/command-disassemble-sections.s | 102 ++++++++++++++++++
2 files changed, 123 insertions(+), 18 deletions(-)
create mode 100644 lldb/test/Shell/Commands/command-disassemble-sections.s
diff --git a/lldb/source/Symbol/Block.cpp b/lldb/source/Symbol/Block.cpp
index 9d01293ea64e0..b630b148a90c9 100644
--- a/lldb/source/Symbol/Block.cpp
+++ b/lldb/source/Symbol/Block.cpp
@@ -283,39 +283,42 @@ uint32_t Block::GetRangeIndexContainingAddress(const
Address &addr) {
return m_ranges.FindEntryIndexThatContains(file_addr - func_file_addr);
}
+static AddressRange ToAddressRange(const Address &func_addr,
+ const Block::Range &range) {
+ assert(func_addr.GetModule());
+ return AddressRange(func_addr.GetFileAddress() + range.base, range.size,
+ func_addr.GetModule()->GetSectionList());
+}
+
bool Block::GetRangeAtIndex(uint32_t range_idx, AddressRange &range) {
if (range_idx >= m_ranges.GetSize())
return false;
- Function &function = GetFunction();
- const Range &vm_range = m_ranges.GetEntryRef(range_idx);
- range.GetBaseAddress() = function.GetAddress();
- range.GetBaseAddress().Slide(vm_range.GetRangeBase());
- range.SetByteSize(vm_range.GetByteSize());
+ Address addr = GetFunction().GetAddress();
+ if (!addr.GetModule())
+ return false;
+
+ range = ToAddressRange(addr, m_ranges.GetEntryRef(range_idx));
return true;
}
AddressRanges Block::GetRanges() {
+ Address addr = GetFunction().GetAddress();
+ if (!addr.GetModule())
+ return {};
+
AddressRanges ranges;
- Function &function = GetFunction();
- for (size_t i = 0, e = m_ranges.GetSize(); i < e; ++i) {
- ranges.emplace_back();
- auto &range = ranges.back();
- const Range &vm_range = m_ranges.GetEntryRef(i);
- range.GetBaseAddress() = function.GetAddress();
- range.GetBaseAddress().Slide(vm_range.GetRangeBase());
- range.SetByteSize(vm_range.GetByteSize());
- }
+ for (size_t i = 0, e = m_ranges.GetSize(); i < e; ++i)
+ ranges.push_back(ToAddressRange(addr, m_ranges.GetEntryRef(i)));
return ranges;
}
bool Block::GetStartAddress(Address &addr) {
- if (m_ranges.IsEmpty())
+ Address func_addr = GetFunction().GetAddress();
+ if (!func_addr.GetModule() || m_ranges.IsEmpty())
return false;
- Function &function = GetFunction();
- addr = function.GetAddress();
- addr.Slide(m_ranges.GetEntryRef(0).GetRangeBase());
+ addr = ToAddressRange(func_addr, m_ranges.GetEntryRef(0)).GetBaseAddress();
return true;
}
diff --git a/lldb/test/Shell/Commands/command-disassemble-sections.s
b/lldb/test/Shell/Commands/command-disassemble-sections.s
new file mode 100644
index 0000000000000..d7ade39241b22
--- /dev/null
+++ b/lldb/test/Shell/Commands/command-disassemble-sections.s
@@ -0,0 +1,102 @@
+# REQUIRES: x86, lld
+
+# RUN: split-file %s %t
+# RUN: llvm-mc -filetype=obj -triple x86_64-pc-linux %t/file.s -o %t/file.o
+# RUN: ld.lld %t/file.o -o %t/file.out -T %t/file.lds
+# RUN: %lldb %t/file.out -o "disassemble --name func1" -o exit | FileCheck %s
+
+# CHECK: (lldb) disassemble --name func1
+# CHECK: file.out`func1:
+# CHECK-NEXT: file.out[0x0] <+0>: int $0x2a
+# CHECK: file.out`func1:
+# CHECK-NEXT: file.out[0x1000] <+4096>: int $0x2f
+
+
+#--- file.lds
+PHDRS {
+ text1 PT_LOAD;
+ text2 PT_LOAD;
+}
+SECTIONS {
+ . = 0;
+ .text.part1 : { *(.text.part1) } :text1
+ .text.part2 : { *(.text.part2) } :text2
+}
+
+#--- file.s
+ .section .text.part1,"ax",@progbits
+ .p2align 12
+func1:
+ int $42
+.Lfunc1_end:
+
+ .section .text.part2,"ax",@progbits
+ .p2align 12
+func1.__part.1:
+ int $47
+.Lfunc1.__part.1_end:
+
+
+
+ .section .debug_abbrev,"",@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 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 0 # EOM(1)
+ .byte 0 # EOM(2)
+ .byte 0 # EOM(3)
+
+ .section .debug_info,"",@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_subprogram
+ .long .Ldebug_ranges0 # DW_AT_ranges
+ .asciz "func1" # DW_AT_name
+ .byte 0 # End Of Children Mark
+.Ldebug_info_end0:
+
+ .section .debug_rnglists,"",@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 1 # Offset entry count
+.Lrnglists_table_base0:
+ .long .Ldebug_ranges0-.Lrnglists_table_base0
+.Ldebug_ranges0:
+ .byte 6 # DW_RLE_start_end
+ .quad func1
+ .quad .Lfunc1_end
+ .byte 6 # DW_RLE_start_end
+ .quad func1.__part.1
+ .quad .Lfunc1.__part.1_end
+ .byte 0 # DW_RLE_end_of_list
+.Ldebug_list_header_end0:
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