From 43b8acdfd7a801e1556c978f3aa956dc498c9aa2 Mon Sep 17 00:00:00 2001 From: Alexander Shaposhnikov Date: Tue, 20 Mar 2018 18:20:42 +0000 Subject: [llvm-objcopy] Implement support for section groups This diff adds support for SHT_GROUP sections to llvm-objcopy. Some sections are interrelated and comprise a group. For example, a definition of an inline function might require, in addition to the section containing its instructions, a read-only data section containing literals referenced inside the function. A section of the type SHT_GROUP contains the indices of the group members, therefore, it needs to be updated whenever the indices change. Similarly, the fields sh_link, sh_info should be recalculated as well. Test plan: make check-all Differential revision: https://reviews.llvm.org/D43996 llvm-svn: 328012 --- llvm/test/tools/llvm-objcopy/Inputs/groups.o | Bin 0 -> 5368 bytes llvm/test/tools/llvm-objcopy/group-unchanged.test | 56 +++++++++++++++++++++ llvm/test/tools/llvm-objcopy/group.test | 56 +++++++++++++++++++++ llvm/test/tools/llvm-objcopy/strip-dwo-groups.test | 40 +++++++++++++++ 4 files changed, 152 insertions(+) create mode 100644 llvm/test/tools/llvm-objcopy/Inputs/groups.o create mode 100644 llvm/test/tools/llvm-objcopy/group-unchanged.test create mode 100644 llvm/test/tools/llvm-objcopy/group.test create mode 100644 llvm/test/tools/llvm-objcopy/strip-dwo-groups.test (limited to 'llvm/test') diff --git a/llvm/test/tools/llvm-objcopy/Inputs/groups.o b/llvm/test/tools/llvm-objcopy/Inputs/groups.o new file mode 100644 index 00000000000..e92b98046a3 Binary files /dev/null and b/llvm/test/tools/llvm-objcopy/Inputs/groups.o differ diff --git a/llvm/test/tools/llvm-objcopy/group-unchanged.test b/llvm/test/tools/llvm-objcopy/group-unchanged.test new file mode 100644 index 00000000000..9e86172bad5 --- /dev/null +++ b/llvm/test/tools/llvm-objcopy/group-unchanged.test @@ -0,0 +1,56 @@ +# RUN: yaml2obj %s > %t +# RUN: llvm-objcopy -remove-section=.text.bar %t %t2 +# RUN: llvm-readobj -elf-section-groups %t2 | FileCheck %s + +# In this test the section .text.bar is getting removed, since this section +# goes after all the sections comprising a group, the content of the +# section .group doesn't change. + +# CHECK: Name: .group +# CHECK-NEXT: Index: 1 +# CHECK-NEXT: Link: 3 +# CHECK-NEXT: Info: 2 +# CHECK-NEXT: Type: COMDAT (0x1) +# CHECK-NEXT: Signature: foo +# CHECK: .text.foo (2) + +--- !ELF +FileHeader: + Class: ELFCLASS64 + Data: ELFDATA2LSB + Type: ET_REL + Machine: EM_X86_64 +Sections: + - Name: .group + Type: SHT_GROUP + Link: .symtab + AddressAlign: 0x0000000000000004 + Info: foo + Members: + - SectionOrType: GRP_COMDAT + - SectionOrType: .text.foo + - Name: .text.foo + Type: SHT_PROGBITS + Flags: [ SHF_ALLOC, SHF_EXECINSTR, SHF_GROUP ] + AddressAlign: 0x0000000000000010 + - Name: .text.bar + Type: SHT_PROGBITS + Flags: [ SHF_ALLOC, SHF_EXECINSTR ] + AddressAlign: 0x0000000000000010 +Symbols: + Local: + - Name: .text.foo + Type: STT_SECTION + Section: .text.foo + - Name: .text.bar + Type: STT_SECTION + Section: .text.bar + Weak: + - Name: foo + Type: STT_FUNC + Section: .text.foo + Size: 0x0000000000000000 + - Name: bar + Type: STT_FUNC + Section: .text.bar + Size: 0x0000000000000000 diff --git a/llvm/test/tools/llvm-objcopy/group.test b/llvm/test/tools/llvm-objcopy/group.test new file mode 100644 index 00000000000..4023f1228f0 --- /dev/null +++ b/llvm/test/tools/llvm-objcopy/group.test @@ -0,0 +1,56 @@ +# RUN: yaml2obj %s > %t +# RUN: llvm-objcopy -remove-section=.text.bar %t %t2 +# RUN: llvm-readobj -elf-section-groups %t2 | FileCheck %s + +# In this test the section .text.bar is getting removed, as a result, +# the indices of the sections which go after .text.bar will change, +# thus the fields Link, Info and the content of .group should be updated. + +# CHECK: Name: .group +# CHECK-NEXT: Index: 1 +# CHECK-NEXT: Link: 3 +# CHECK-NEXT: Info: 2 +# CHECK-NEXT: Type: COMDAT (0x1) +# CHECK-NEXT: Signature: foo +# CHECK: .text.foo (2) + +--- !ELF +FileHeader: + Class: ELFCLASS64 + Data: ELFDATA2LSB + Type: ET_REL + Machine: EM_X86_64 +Sections: + - Name: .group + Type: SHT_GROUP + Link: .symtab + AddressAlign: 0x0000000000000004 + Info: foo + Members: + - SectionOrType: GRP_COMDAT + - SectionOrType: .text.foo + - Name: .text.bar + Type: SHT_PROGBITS + Flags: [ SHF_ALLOC, SHF_EXECINSTR ] + AddressAlign: 0x0000000000000010 + - Name: .text.foo + Type: SHT_PROGBITS + Flags: [ SHF_ALLOC, SHF_EXECINSTR, SHF_GROUP ] + AddressAlign: 0x0000000000000010 +Symbols: + Local: + - Name: .text.bar + Type: STT_SECTION + Section: .text.bar + - Name: .text.foo + Type: STT_SECTION + Section: .text.foo + Weak: + - Name: bar + Type: STT_FUNC + Section: .text.bar + Size: 0x0000000000000000 + - Name: foo + Type: STT_FUNC + Section: .text.foo + Size: 0x0000000000000000 diff --git a/llvm/test/tools/llvm-objcopy/strip-dwo-groups.test b/llvm/test/tools/llvm-objcopy/strip-dwo-groups.test new file mode 100644 index 00000000000..957bb553b72 --- /dev/null +++ b/llvm/test/tools/llvm-objcopy/strip-dwo-groups.test @@ -0,0 +1,40 @@ +# RUN: cp %p/Inputs/groups.o %t +# RUN: llvm-objcopy -strip-dwo %t +# RUN: llvm-readobj -elf-section-groups %t | FileCheck %s + +// Source code of groups.o: +// +// template +// struct S { +// static constexpr T X = T(1); +// T getX() { return X; } +// }; +// void f() { +// S A; +// S B; +// int a = A.getX(); +// int b = B.getX(); +// } +// +// clang -g -gsplit-dwarf -std=c++11 -c groups.cpp -o groups.o + +// `llvm-objcopy -strip-dwo` strips out dwo sections, as a result, the index of +// the symbol table, the indices of the symbols and the indices of the sections +// which go after the removed ones will change. Consequently, the fields +// Link, Info and the content of .group need to be updated. In the past +// `llvm-objcopy -strip-dwo` used to produce invalid binaries with +// broken .group section, this test verifies the correctness of +// Link, Info and the content of this section. + +CHECK: Name: .group (179) +CHECK-NEXT: Index: 17 +CHECK-NEXT: Link: 19 +CHECK-NEXT: Info: 14 +CHECK: .text._ZN1SIiE4getXEv (2) + +CHECK: Name: .group (179) +CHECK-NEXT: Index: 18 +CHECK-NEXT: Link: 19 +CHECK-NEXT: Info: 13 +CHECK: .text._ZN1SIdE4getXEv (4) +CHECK-NEXT: .rela.text._ZN1SIdE4getXEv (21) -- cgit v1.2.3