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[DWARF] DWARF verification error with LTO - invalid FileID #109227

Open wolfy1961 opened 6 days ago

wolfy1961 commented 6 days ago

repro.zip

On a Ubuntu 22.04 system we get the following verification error from llvm-dwarfdump --verify:

Verifying c.elf:        file format elf64-x86-64
Verifying .debug_abbrev...
Verifying .debug_info Unit Header Chain...
Verifying .debug_types Unit Header Chain...
Verifying non-dwo Units...
Verifying unit: 1 / 2, "b.cpp"
error: DIE has DW_AT_decl_file with an invalid file index 1 (valid values are [0-0])

0x00000037: DW_TAG_variable [4]   (0x00000029)
              DW_AT_name [DW_FORM_strx1]        (indexed (00000004) string = "amem")
              DW_AT_type [DW_FORM_ref4] (cu + 0x0040 => {0x00000040} "int")
              DW_AT_decl_file [DW_FORM_data1]   (0x01)
              DW_AT_decl_line [DW_FORM_data1]   (3)
              DW_AT_external [DW_FORM_flag_present]     (true)
              DW_AT_declaration [DW_FORM_flag_present]  (true)

Verifying unit: 2 / 2, "/home/test/a.cpp"
Verifying dwo Units...
Verifying .debug_line...
warning: .debug_line[0x00000043].prologue.file_names[1] is a duplicate of file_names[0]
Verifying .debug_str_offsets...
error: Aggregated error counts:
error: Invalid file index in DW_AT_decl_file occurred 1 time(s).
Errors detected.

The problem seems to be that the IR generated from translation unit "a.cpp" has 2 entries for its source file, one with absolute pathname as filename and the other with a relative pathname. The fact that the absolute pathname for the source is used on the command line is contributing. After IR linking the wrong fileindex is retained.

llvmbot commented 6 days ago

@llvm/issue-subscribers-debuginfo

Author: Wolfgang Pieb (wolfy1961)

[repro.zip](https://github.com/user-attachments/files/17052490/repro.zip) On a Ubuntu 22.04 system we get the following verification error from llvm-dwarfdump --verify: ``` Verifying c.elf: file format elf64-x86-64 Verifying .debug_abbrev... Verifying .debug_info Unit Header Chain... Verifying .debug_types Unit Header Chain... Verifying non-dwo Units... Verifying unit: 1 / 2, "b.cpp" error: DIE has DW_AT_decl_file with an invalid file index 1 (valid values are [0-0]) 0x00000037: DW_TAG_variable [4] (0x00000029) DW_AT_name [DW_FORM_strx1] (indexed (00000004) string = "amem") DW_AT_type [DW_FORM_ref4] (cu + 0x0040 => {0x00000040} "int") DW_AT_decl_file [DW_FORM_data1] (0x01) DW_AT_decl_line [DW_FORM_data1] (3) DW_AT_external [DW_FORM_flag_present] (true) DW_AT_declaration [DW_FORM_flag_present] (true) Verifying unit: 2 / 2, "/home/test/a.cpp" Verifying dwo Units... Verifying .debug_line... warning: .debug_line[0x00000043].prologue.file_names[1] is a duplicate of file_names[0] Verifying .debug_str_offsets... error: Aggregated error counts: error: Invalid file index in DW_AT_decl_file occurred 1 time(s). Errors detected. ``` The problem seems to be that the IR generated from translation unit "a.cpp" has 2 entries for its source file, one with absolute pathname as filename and the other with a relative pathname. The fact that the absolute pathname for the source is used on the command line is contributing. After IR linking the wrong fileindex is retained.