Page MenuHomePhabricator
Differential D131290 Diff 457813 llvm/test/Object/objdump-no-sectionheaders.test

Changeset View

Standalone View

View Options

llvm/test/Object/objdump-no-sectionheaders.test

; RUN: llvm-objdump -h %p/Inputs/no-sections.elf-x86-64 \ ## This test checks llvm-objdump -h can handle ELF files without section info.
; RUN: | FileCheck %s ## Only PT_LOAD segments with the PF_X flag will be displayed as fake sections.
jhendersonUnsubmitted
Not Done
ReplyInline Actions
## This test checks llvm-objdump -h can handle ELF files without section info.
- ## Only PT_LOAD program with PF_X flag will be display corresponding fake sections.
+ ## Only PT_LOAD program with PF_X flag will display corresponding fake sections.
# RUN: yaml2obj %s -o %t
jhenderson:
namhyungAuthorUnsubmitted
Done
ReplyInline Actions

ok

namhyung: ok
jhendersonUnsubmitted
Not Done
ReplyInline Actions
## This test checks llvm-objdump -h can handle ELF files without section info.
- ## Only PT_LOAD program with PF_X flag will display corresponding fake sections.
+ ## Only PT_LOAD segments with the PF_X flag will be displayed as fake sections.
# RUN: yaml2obj %s -o %t

I misread this sentence. Here's a better improvement.

jhenderson: I misread this sentence. Here's a better improvement.
MaskRayUnsubmitted
Not Done
ReplyInline Actions

Nit: "This test " can be omitted. Use an imperative sentence.

MaskRay: Nit: "This test " can be omitted. Use an imperative sentence.
jhendersonUnsubmitted
Not Done
ReplyInline Actions

Concretely: "Check llvm-objdump -h ..."

jhenderson: Concretely: "Check llvm-objdump -h ..."
; CHECK: Sections: # RUN: yaml2obj %s -o %t
; CHECK-NEXT: Idx Name Size VMA Type # RUN: llvm-objdump -h %t | FileCheck %s
; CHECK-NEXT: 0 000006ec 0000000000400000 TEXT
; CHECK-NEXT: 1 00000000 0000000000000000 TEXT # CHECK: Sections:
; CHECK-NOT: {{.}} # CHECK-NEXT: Idx Name Size VMA Type
# CHECK-NEXT: 0 PT_LOAD#1 00000100 0000000000400000 TEXT
# CHECK-NEXT: 1 PT_LOAD#3 00000200 0000000000600400 TEXT
# CHECK-NOT: {{.}}
!ELF
FileHeader:
Class: ELFCLASS64
Data: ELFDATA2LSB
Type: ET_CORE
Machine: EM_X86_64
Sections:
- Type: SectionHeaderTable
NoHeaders: true
- Type: Fill
jhendersonUnsubmitted
Not Done
ReplyInline Actions

I think I see a potential problem here, which could explain the problem you're seeing: you haven't specified any contents or explicit offsets of any of these program headers, which may mean that even though they have addresses specified, they'll start at the same offset within the file. This might result in something bad such as only the one section appearing in the output, although I don't know the llvm-objdump code well enough to be certain.

jhenderson: I think I see a potential problem here, which could explain the problem you're seeing: you…
namhyungAuthorUnsubmitted
Done
ReplyInline Actions

Will check with contents and offsets.

namhyung: Will check with contents and offsets.
jhendersonUnsubmitted
Not Done
ReplyInline Actions

The Offset will physically impact the size of the file on disk, meaning this generated YAML file will be huge. Instead, use offset values around 0x100 - 0x200, which are significantly smaller (and adjust the addresses to line up too, I recommend) (you can't use 0 because of the ELF header and Program Header table). Also, the sizes of the individual blobs of data can be only a couple of bytes for the test purposes to be satisfied.

jhenderson: The `Offset` will physically impact the size of the file on disk, meaning this generated YAML…
Name: code1
Pattern: "cc"
Size: 0x100
Offset: 0x200
- Type: Fill
Name: data1
Pattern: "aa55"
Size: 0x100
Offset: 0x300
- Type: Fill
Name: code2
Pattern: "ff"
Size: 0x200
Offset: 0x400
ProgramHeaders:
- Type: PT_PHDR
Flags: [ PF_X ]
VAddr: 0x400000
MemSize: 0x100
- Type: PT_LOAD
Flags: [ PF_X ]
VAddr: 0x400000
MemSize: 0x100
FirstSec: code1
LastSec: code1
- Type: PT_LOAD
Flags: [ PF_R ]
VAddr: 0x500300
MemSize: 0x100
FirstSec: data1
LastSec: data1
- Type: PT_LOAD
Flags: [ PF_R, PF_X ]
VAddr: 0x600400
MemSize: 0x200
FirstSec: code2
LastSec: code2
jhendersonUnsubmitted
Not Done
ReplyInline Actions

I'd strongly support replacing the pre-canned ELF with a YAML input in this test. At the moment, I have no idea if the behaviour is correct without digging out a binary inspection tool to look at the ELF object.

Some key characteristics I think that need testing:

  1. That non-PT_LOAD segments are ignored (but still count towards the index), even if they have PF_X.
  2. That non-PF_X segments are ignored (but still count towards the index).
  3. That multiple PT_LOAD wiht PF_X segments can be displayed.

To achieve these points, I think it would be sufficient to have an ELF with the following program headers:

  1. PT_PHDR (or other PT_* type) with PF_X
  2. PT_LOAD with PF_X
  3. PT_LOAD without PF_X
  4. PT_LOAD with PF_X
jhenderson: I'd strongly support replacing the pre-canned ELF with a YAML input in this test. At the moment…
namhyungAuthorUnsubmitted
Not Done
ReplyInline Actions

Sounds good!

namhyung: Sounds good!