Author: Pavel Labath Date: 2019-12-06T10:33:13+01:00 New Revision: f69f92344adaada1f8f3cfcd711037227432b062
URL: https://github.com/llvm/llvm-project/commit/f69f92344adaada1f8f3cfcd711037227432b062 DIFF: https://github.com/llvm/llvm-project/commit/f69f92344adaada1f8f3cfcd711037227432b062.diff LOG: [lldb/DWARF] Fix DW_AT_addr_base & DW_AT_low_pc interaction In DWARF5 DW_AT_low_pc (and DW_AT_entry_pc, and possibly others) can use DW_FORM_addrx to refer to the address indirectly. This means we need to have processed the DW_AT_addr_base attribute before we can do anything with these. Since we were processing the unit attributes serially, this created a problem in cases where the DW_AT_addr_base comes after DW_AT_low_pc -- we would end up computing the wrong unit base address, which also corrupted any values which later depended on that (for instance range lists). Clang currently always emits DW_AT_addr_base last. The fix is simple -- process DW_AT_addr_base first, regardless of its position in the attribute list. Added: lldb/test/Shell/SymbolFile/DWARF/DW_AT_low_pc-addrx.s Modified: lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp Removed: ################################################################################ diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp index 35f5c30e1778..072cbc2abc3a 100644 --- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp +++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp @@ -287,16 +287,25 @@ void DWARFUnit::AddUnitDIE(const DWARFDebugInfoEntry &cu_die) { DWARFAttributes attributes; size_t num_attributes = cu_die.GetAttributes(this, attributes); + + // Extract DW_AT_addr_base first, as other attributes may need it. + for (size_t i = 0; i < num_attributes; ++i) { + if (attributes.AttributeAtIndex(i) != DW_AT_addr_base) + continue; + DWARFFormValue form_value; + if (attributes.ExtractFormValueAtIndex(i, form_value)) { + addr_base = form_value.Unsigned(); + SetAddrBase(*addr_base); + break; + } + } + for (size_t i = 0; i < num_attributes; ++i) { dw_attr_t attr = attributes.AttributeAtIndex(i); DWARFFormValue form_value; if (!attributes.ExtractFormValueAtIndex(i, form_value)) continue; switch (attr) { - case DW_AT_addr_base: - addr_base = form_value.Unsigned(); - SetAddrBase(*addr_base); - break; case DW_AT_rnglists_base: ranges_base = form_value.Unsigned(); SetRangesBase(*ranges_base); diff --git a/lldb/test/Shell/SymbolFile/DWARF/DW_AT_low_pc-addrx.s b/lldb/test/Shell/SymbolFile/DWARF/DW_AT_low_pc-addrx.s new file mode 100644 index 000000000000..df089668cd96 --- /dev/null +++ b/lldb/test/Shell/SymbolFile/DWARF/DW_AT_low_pc-addrx.s @@ -0,0 +1,106 @@ +# REQUIRES: x86 + +# RUN: llvm-mc -triple=x86_64-pc-linux -filetype=obj %s > %t +# RUN: %lldb %t -o "image lookup -v -s lookup_rnglists" \ +# RUN: -o exit | FileCheck %s + +# CHECK-LABEL: image lookup -v -s lookup_rnglists +# CHECK: Function: id = {0x7fffffff0000002d}, name = "rnglists", range = [0x0000000000000000-0x0000000000000003) +# CHECK: Blocks: id = {0x7fffffff0000002d}, range = [0x00000000-0x00000003) +# CHECK-NEXT: id = {0x7fffffff00000043}, range = [0x00000001-0x00000002) + + .text +rnglists: + nop +.Lblock1_begin: +lookup_rnglists: + nop +.Lblock1_end: + nop +.Lrnglists_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 17 # DW_AT_low_pc + .byte 27 # DW_FORM_addrx + .byte 18 # DW_AT_high_pc + .byte 6 # DW_FORM_data4 + .byte 116 # DW_AT_rnglists_base + .byte 23 # DW_FORM_sec_offset + .byte 115 # DW_AT_addr_base + .byte 23 # DW_FORM_sec_offset + .byte 0 # EOM(1) + .byte 0 # EOM(2) + .byte 2 # Abbreviation Code + .byte 46 # DW_TAG_subprogram + .byte 1 # DW_CHILDREN_yes + .byte 17 # DW_AT_low_pc + .byte 1 # DW_FORM_addr + .byte 18 # DW_AT_high_pc + .byte 6 # DW_FORM_data4 + .byte 3 # DW_AT_name + .byte 8 # DW_FORM_string + .byte 0 # EOM(1) + .byte 0 # EOM(2) + .byte 5 # Abbreviation Code + .byte 11 # DW_TAG_lexical_block + .byte 0 # DW_CHILDREN_no + .byte 85 # DW_AT_ranges + .byte 35 # DW_FORM_rnglistx + .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 [1] 0xc:0x5f DW_TAG_compile_unit + .asciz "Hand-written DWARF" # DW_AT_producer + .byte 0 # DW_AT_low_pc + .long .Lrnglists_end-rnglists # DW_AT_high_pc + .long .Lrnglists_table_base0 # DW_AT_rnglists_base + .long .Laddr_table_base0 # DW_AT_addr_base + .byte 2 # Abbrev [2] 0x2b:0x37 DW_TAG_subprogram + .quad rnglists # DW_AT_low_pc + .long .Lrnglists_end-rnglists # DW_AT_high_pc + .asciz "rnglists" # DW_AT_name + .byte 5 # Abbrev [5] 0x52:0xf DW_TAG_lexical_block + .byte 0 # DW_AT_ranges + .byte 0 # End Of Children Mark + .byte 0 # End Of Children Mark +.Ldebug_info_end0: + + .section .debug_addr,"",@progbits + .long .Ldebug_addr_end0-.Ldebug_addr_start0 # Length of contribution +.Ldebug_addr_start0: + .short 5 # DWARF version number + .byte 8 # Address size + .byte 0 # Segment selector size +.Laddr_table_base0: + .quad rnglists +.Ldebug_addr_end0: + + .section .debug_rnglists,"",@progbits + .long .Ldebug_rnglist_table_end0-.Ldebug_rnglist_table_start0 # Length +.Ldebug_rnglist_table_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 4 # DW_RLE_offset_pair + .uleb128 .Lblock1_begin-rnglists # starting offset + .uleb128 .Lblock1_end-rnglists # ending offset + .byte 0 # DW_RLE_end_of_list +.Ldebug_rnglist_table_end0: _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
