Author: LU Hongyi Date: 2023-05-05T06:45:07-04:00 New Revision: 16c2872d7b09eee67dd0c7ef6b5dd3c3724d3cfc
URL: https://github.com/llvm/llvm-project/commit/16c2872d7b09eee67dd0c7ef6b5dd3c3724d3cfc DIFF: https://github.com/llvm/llvm-project/commit/16c2872d7b09eee67dd0c7ef6b5dd3c3724d3cfc.diff LOG: Reland "[lldb][DWARFExpression] Fix DW_OP_div to use signed division" This patch resolves an issue where a value is incorrectly displayed if it is represented by DW_OP_div. This issue is caused by lldb evaluating operands of DW_OP_div as unsigned and performed unintended unsigned division. This issue is resolved by creating two temporary signed scalar and performing signed division. (Addresses GH#61727) Differential Revision: https://reviews.llvm.org/D147370 Added: lldb/test/Shell/SymbolFile/DWARF/x86/DW_OP_div-with-signed.s Modified: lldb/source/Expression/DWARFExpression.cpp Removed: ################################################################################ diff --git a/lldb/source/Expression/DWARFExpression.cpp b/lldb/source/Expression/DWARFExpression.cpp index f2ca6534c2fc1..9232282d81353 100644 --- a/lldb/source/Expression/DWARFExpression.cpp +++ b/lldb/source/Expression/DWARFExpression.cpp @@ -1436,8 +1436,12 @@ bool DWARFExpression::Evaluate( return false; } else { stack.pop_back(); - stack.back() = - stack.back().ResolveValue(exe_ctx) / tmp.ResolveValue(exe_ctx); + Scalar divisor, dividend; + divisor = tmp.ResolveValue(exe_ctx); + dividend = stack.back().ResolveValue(exe_ctx); + divisor.MakeSigned(); + dividend.MakeSigned(); + stack.back() = dividend / divisor; if (!stack.back().ResolveValue(exe_ctx).IsValid()) { if (error_ptr) error_ptr->SetErrorString("Divide failed."); diff --git a/lldb/test/Shell/SymbolFile/DWARF/x86/DW_OP_div-with-signed.s b/lldb/test/Shell/SymbolFile/DWARF/x86/DW_OP_div-with-signed.s new file mode 100644 index 0000000000000..dd1a842864754 --- /dev/null +++ b/lldb/test/Shell/SymbolFile/DWARF/x86/DW_OP_div-with-signed.s @@ -0,0 +1,232 @@ + # Test handling of values represented via DW_OP_div + # RUN: %clang -c --target=x86_64-pc-linux -o %t %s + # RUN: %lldb %t -o "expression -T -- g" -o "exit" | FileCheck %s + + # Failing case was: + # (int) $0 = 0 + # CHECK: (int) $0 = 2 + # + # This file is crafted by hand on the basis of a very simple C program. + + # The original (NOT THIS FILE) error-triggering code is: + # #include "stdint.h" + # static volatile uint64_t g = 0; + # static const int32_t f() + # { + # uint32_t i; + # for (i = 0; (i != 10); i++) + # ++g; + # return 0; + # + # } + # + # int main() + # { + # f(); + # return 0; + # + # } + # When the above code is compiled by Clang 15.0.7 with -O1, it generates desired DW_OP_div for testing. + # Due to cross-platform issue, this case is hand-crafted for testing. + + .text + .file "DW_OP_div-with-signed.c" + .file 0 "DW_OP_div-with-signed.c" # Dummy file + .globl main # -- Begin function main + .p2align 4, 0x90 + .type main,@function +main: # @main +.Lfunc_begin0: + .loc 0 4 0 # DW_OP_div-with-signed.c:4:0 + .cfi_startproc +# %bb.0: + .loc 0 5 5 prologue_end # DW_OP_div-with-signed.c:5:5 + xorl %eax, %eax + retq +.Ltmp0: +.Lfunc_end0: + .size main, .Lfunc_end0-main + .cfi_endproc + # -- End function + .type g,@object # @g + .data + .globl g + .p2align 2, 0x0 +g: + .long 3735928559 # 0xdeadbeef + .size g, 4 + + .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 37 # DW_FORM_strx1 + .byte 19 # DW_AT_language + .byte 5 # DW_FORM_data2 + .byte 3 # DW_AT_name + .byte 37 # DW_FORM_strx1 + .byte 114 # DW_AT_str_offsets_base + .byte 23 # DW_FORM_sec_offset + .byte 16 # DW_AT_stmt_list + .byte 23 # DW_FORM_sec_offset + .byte 27 # DW_AT_comp_dir + .byte 37 # DW_FORM_strx1 + .byte 17 # DW_AT_low_pc + .byte 27 # DW_FORM_addrx + .byte 18 # DW_AT_high_pc + .byte 6 # DW_FORM_data4 + .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 52 # DW_TAG_variable + .byte 0 # DW_CHILDREN_no + .byte 3 # DW_AT_name + .byte 37 # DW_FORM_strx1 + .byte 73 # DW_AT_type + .byte 19 # DW_FORM_ref4 + .byte 63 # DW_AT_external + .byte 25 # DW_FORM_flag_present + .byte 58 # DW_AT_decl_file + .byte 11 # DW_FORM_data1 + .byte 59 # DW_AT_decl_line + .byte 11 # DW_FORM_data1 + .byte 2 # DW_AT_location + .byte 24 # DW_FORM_exprloc + .byte 0 # EOM(1) + .byte 0 # EOM(2) + .byte 3 # Abbreviation Code + .byte 36 # DW_TAG_base_type + .byte 0 # DW_CHILDREN_no + .byte 3 # DW_AT_name + .byte 37 # DW_FORM_strx1 + .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 4 # Abbreviation Code + .byte 46 # DW_TAG_subprogram + .byte 0 # DW_CHILDREN_no + .byte 17 # DW_AT_low_pc + .byte 27 # DW_FORM_addrx + .byte 18 # DW_AT_high_pc + .byte 6 # DW_FORM_data4 + .byte 64 # DW_AT_frame_base + .byte 24 # DW_FORM_exprloc + .byte 122 # DW_AT_call_all_calls + .byte 25 # DW_FORM_flag_present + .byte 3 # DW_AT_name + .byte 37 # DW_FORM_strx1 + .byte 58 # DW_AT_decl_file + .byte 11 # DW_FORM_data1 + .byte 59 # DW_AT_decl_line + .byte 11 # DW_FORM_data1 + .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 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:0x36 DW_TAG_compile_unit + .byte 0 # DW_AT_producer + .short 29 # DW_AT_language + .byte 1 # DW_AT_name + .long .Lstr_offsets_base0 # DW_AT_str_offsets_base + .long .Lline_table_start0 # DW_AT_stmt_list + .byte 2 # DW_AT_comp_dir + .byte 1 # DW_AT_low_pc + .long .Lfunc_end0-.Lfunc_begin0 # DW_AT_high_pc + .long .Laddr_table_base0 # DW_AT_addr_base + .byte 2 # Abbrev [2] 0x23:0xb DW_TAG_variable + .byte 3 # DW_AT_name + .long 60 # DW_AT_type + # DW_AT_external + .byte 0 # DW_AT_decl_file + .byte 1 # DW_AT_decl_line + .byte 16 # DW_AT_location + .byte 49 + .byte 49 + .byte 16 # DW_OP_constu + .byte 255 # 4294967295 + .byte 255 # + .byte 255 # + .byte 255 # + .byte 15 # + .byte 26 # DW_OP_and + .byte 17 # DW_OP_consts + .byte 3 # 3 + .byte 28 # DW_OP_minus + .byte 17 # DW_OP_consts + .byte 127 # -1 + .byte 27 # DW_OP_div + .byte 159 + .byte 3 # Abbrev [3] 0x2e:0x4 DW_TAG_base_type + .byte 4 # DW_AT_name + .byte 5 # DW_AT_encoding + .byte 4 # DW_AT_byte_size + .byte 4 # Abbrev [4] 0x32:0xf DW_TAG_subprogram + .byte 1 # DW_AT_low_pc + .long .Lfunc_end0-.Lfunc_begin0 # DW_AT_high_pc + .byte 1 # DW_AT_frame_base + .byte 87 + # DW_AT_call_all_calls + .byte 5 # DW_AT_name + .byte 0 # DW_AT_decl_file + .byte 3 # DW_AT_decl_line + .long 60 # DW_AT_type + # DW_AT_external + .byte 0 # End Of Children Mark +.Ldebug_info_end0: + .section .debug_str_offsets,"",@progbits + .long 28 # Length of String Offsets Set + .short 5 + .short 0 +.Lstr_offsets_base0: + .section .debug_str,"MS",@progbits,1 +.Linfo_string0: + .asciz "clang version 17.0.0 (https://github.com/llvm/llvm-project.git 1b18ab358a8e91e69a54f676c77f6a4cda8ba02d)" # string offset=0 +.Linfo_string1: + .asciz "DW_OP_div-with-signed.c" # string offset=105 +.Linfo_string2: + .asciz "" # string offset=129 +.Linfo_string3: + .asciz "g" # string offset=166 +.Linfo_string4: + .asciz "int" # string offset=168 +.Linfo_string5: + .asciz "main" # string offset=172 + .section .debug_str_offsets,"",@progbits + .long .Linfo_string0 + .long .Linfo_string1 + .long .Linfo_string2 + .long .Linfo_string3 + .long .Linfo_string4 + .long .Linfo_string5 + .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 g + .quad .Lfunc_begin0 +.Ldebug_addr_end0: + .ident "clang version 17.0.0 (https://github.com/llvm/llvm-project.git 1b18ab358a8e91e69a54f676c77f6a4cda8ba02d)" + .section ".note.GNU-stack","",@progbits + .addrsig + .section .debug_line,"",@progbits +.Lline_table_start0: _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
