jankratochvil created this revision.
jankratochvil added reviewers: dblaikie, davide.
jankratochvil added a project: LLDB.
Herald added a reviewer: jdoerfert.
Herald added a subscriber: sstefan1.
jankratochvil retitled this revision from "Fix SLEB128 decoding" to "[lldb] Fix
SLEB128 decoding".
davide added reviewers: clayborg, labath.
davide added a comment.
Greg & Pavel might have opinions on this patch. I'm not qualified to review it.
Bug 46181 <https://bugs.llvm.org/show_bug.cgi?id=46181> shows SLEB128
`0xED9A924C00011151` decoded as `0xffffffff80011151`.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D81119
Files:
lldb/source/Utility/DataExtractor.cpp
lldb/test/Shell/SymbolFile/DWARF/dwarf-sleb128.s
Index: lldb/test/Shell/SymbolFile/DWARF/dwarf-sleb128.s
===================================================================
--- /dev/null
+++ lldb/test/Shell/SymbolFile/DWARF/dwarf-sleb128.s
@@ -0,0 +1,181 @@
+# This tests that lldb is able to process 64-bit wide negative SLEB128.
+
+# REQUIRES: lld, x86
+
+# RUN: llvm-mc -g -dwarf-version=5 -triple x86_64-unknown-linux-gnu %s -filetype=obj > %t.o
+# RUN: ld.lld -m elf_x86_64 %t.o -o %t
+# RUN: %lldb %t -o "p/x magic64" -o exit | FileCheck %s
+
+# CHECK: (const long) $0 = 0xed9a924c00011151
+
+# It is built from this source with a few #-marked patched lines:
+# static const long magic64 = 0xED9A924C00011151;
+# int main(void) { return magic64; }
+
+ .text
+ .file "lldb46181c.c"
+ .file 1 "" "lldb46181c.c"
+ .globl main # -- Begin function main
+ .p2align 4, 0x90
+ .type main,@function
+main: # @main
+.Lfunc_begin0:
+ .loc 1 2 0 # lldb46181c.c:2:0
+ .cfi_startproc
+# %bb.0:
+ .loc 1 2 18 prologue_end # lldb46181c.c:2:18
+ movl $69969, %eax # imm = 0x11151
+ retq
+.Ltmp0:
+.Lfunc_end0:
+ .size main, .Lfunc_end0-main
+ .cfi_endproc
+ # -- End function
+ .section .debug_str,"MS",@progbits,1
+.Linfo_string0:
+ .asciz "clang version 10.0.0 (Fedora 10.0.0-1.fc32)" # string offset=0
+.Linfo_string1:
+ .asciz "lldb46181c.c" # string offset=44
+.Linfo_string2:
+ .asciz "" # string offset=57
+.Linfo_string3:
+ .asciz "magic64" # string offset=74
+.Linfo_string4:
+ .asciz "long int" # string offset=82
+.Linfo_string5:
+ .asciz "main" # string offset=91
+.Linfo_string6:
+ .asciz "int" # string offset=96
+ .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 14 # DW_FORM_strp
+ .byte 19 # DW_AT_language
+ .byte 5 # DW_FORM_data2
+ .byte 3 # DW_AT_name
+ .byte 14 # DW_FORM_strp
+ .byte 16 # DW_AT_stmt_list
+ .byte 23 # DW_FORM_sec_offset
+ .byte 27 # DW_AT_comp_dir
+ .byte 14 # DW_FORM_strp
+ .byte 17 # DW_AT_low_pc
+ .byte 1 # DW_FORM_addr
+ .byte 18 # DW_AT_high_pc
+ .byte 6 # DW_FORM_data4
+ .byte 0 # EOM(1)
+ .byte 0 # EOM(2)
+ .byte 2 # Abbreviation Code
+ .byte 52 # DW_TAG_variable
+ .byte 0 # DW_CHILDREN_no
+ .byte 3 # DW_AT_name
+ .byte 14 # DW_FORM_strp
+ .byte 73 # DW_AT_type
+ .byte 19 # DW_FORM_ref4
+ .byte 58 # DW_AT_decl_file
+ .byte 11 # DW_FORM_data1
+ .byte 59 # DW_AT_decl_line
+# .byte 11 # DW_FORM_data1
+ .byte 5 # DW_FORM_data2
+ .byte 28 # DW_AT_const_value
+# .byte 15 # DW_FORM_udata
+ .byte 13 # DW_FORM_sdata
+ .byte 0 # EOM(1)
+ .byte 0 # EOM(2)
+ .byte 3 # Abbreviation Code
+ .byte 38 # DW_TAG_const_type
+ .byte 0 # DW_CHILDREN_no
+ .byte 73 # DW_AT_type
+ .byte 19 # DW_FORM_ref4
+ .byte 0 # EOM(1)
+ .byte 0 # EOM(2)
+ .byte 4 # Abbreviation Code
+ .byte 36 # DW_TAG_base_type
+ .byte 0 # DW_CHILDREN_no
+ .byte 3 # DW_AT_name
+ .byte 14 # DW_FORM_strp
+ .byte 62 # DW_AT_encoding
+ .byte 11 # DW_FORM_data1
+ .byte 11 # DW_AT_byte_size
+ .byte 11 # DW_FORM_data1
+ .byte 0 # EOM(1)
+ .byte 0 # EOM(2)
+ .byte 5 # Abbreviation Code
+ .byte 46 # DW_TAG_subprogram
+ .byte 0 # DW_CHILDREN_no
+ .byte 17 # DW_AT_low_pc
+ .byte 1 # DW_FORM_addr
+ .byte 18 # DW_AT_high_pc
+ .byte 6 # DW_FORM_data4
+ .byte 64 # DW_AT_frame_base
+ .byte 24 # DW_FORM_exprloc
+ .ascii "\227B" # DW_AT_GNU_all_call_sites
+ .byte 25 # DW_FORM_flag_present
+ .byte 3 # DW_AT_name
+ .byte 14 # DW_FORM_strp
+ .byte 58 # DW_AT_decl_file
+ .byte 11 # DW_FORM_data1
+ .byte 59 # DW_AT_decl_line
+ .byte 11 # DW_FORM_data1
+ .byte 39 # DW_AT_prototyped
+ .byte 25 # DW_FORM_flag_present
+ .byte 73 # DW_AT_type
+ .byte 19 # DW_FORM_ref4
+ .byte 63 # DW_AT_external
+ .byte 25 # DW_FORM_flag_present
+ .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 4 # DWARF version number
+ .long .debug_abbrev # Offset Into Abbrev. Section
+ .byte 8 # Address Size (in bytes)
+ .byte 1 # Abbrev [1] 0xb:0x61 DW_TAG_compile_unit
+ .long .Linfo_string0 # DW_AT_producer
+ .short 12 # DW_AT_language
+ .long .Linfo_string1 # DW_AT_name
+ .long .Lline_table_start0 # DW_AT_stmt_list
+ .long .Linfo_string2 # DW_AT_comp_dir
+ .quad .Lfunc_begin0 # DW_AT_low_pc
+ .long .Lfunc_end0-.Lfunc_begin0 # DW_AT_high_pc
+ .byte 2 # Abbrev [2] 0x2a:0x15 DW_TAG_variable
+ .long .Linfo_string3 # DW_AT_name
+ .long 63 # DW_AT_type
+ .byte 1 # DW_AT_decl_file
+# .byte 1 # DW_AT_decl_line
+ .short 1 # DW_AT_decl_line
+# .ascii "\321\242\204\200\300\311\244\315\355\001" # DW_AT_const_value
+ .ascii "\321\242\204\200\300\311\244\315m" # DW_AT_const_value - sdata
+ .byte 3 # Abbrev [3] 0x3f:0x5 DW_TAG_const_type
+ .long 68 # DW_AT_type
+ .byte 4 # Abbrev [4] 0x44:0x7 DW_TAG_base_type
+ .long .Linfo_string4 # DW_AT_name
+ .byte 5 # DW_AT_encoding
+ .byte 8 # DW_AT_byte_size
+ .byte 5 # Abbrev [5] 0x4b:0x19 DW_TAG_subprogram
+ .quad .Lfunc_begin0 # DW_AT_low_pc
+ .long .Lfunc_end0-.Lfunc_begin0 # DW_AT_high_pc
+ .byte 1 # DW_AT_frame_base
+ .byte 87
+ # DW_AT_GNU_all_call_sites
+ .long .Linfo_string5 # DW_AT_name
+ .byte 1 # DW_AT_decl_file
+ .byte 2 # DW_AT_decl_line
+ # DW_AT_prototyped
+ .long 100 # DW_AT_type
+ # DW_AT_external
+ .byte 4 # Abbrev [4] 0x64:0x7 DW_TAG_base_type
+ .long .Linfo_string6 # DW_AT_name
+ .byte 5 # DW_AT_encoding
+ .byte 4 # DW_AT_byte_size
+ .byte 0 # End Of Children Mark
+.Ldebug_info_end0:
+ .ident "clang version 10.0.0 (Fedora 10.0.0-1.fc32)"
+ .section ".note.GNU-stack","",@progbits
+ .addrsig
+ .section .debug_line,"",@progbits
+.Lline_table_start0:
Index: lldb/source/Utility/DataExtractor.cpp
===================================================================
--- lldb/source/Utility/DataExtractor.cpp
+++ lldb/source/Utility/DataExtractor.cpp
@@ -931,7 +931,7 @@
// Sign bit of byte is 2nd high order bit (0x40)
if (shift < size && (byte & 0x40))
- result |= -(1 << shift);
+ result |= -(static_cast<int64_t>(1) << shift);
*offset_ptr += bytecount;
return result;
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