[llvm] 3fe7f1d - [yaml2obj] - Make .symtab to be not mandatory section for SHT_REL[A] section.
Georgii Rymar via llvm-commits
llvm-commits at lists.llvm.org
Tue Oct 29 01:49:33 PDT 2019
Author: Georgii Rymar
Date: 2019-10-29T11:43:12+03:00
New Revision: 3fe7f1dcf44ced0648fd0aef2b33056bbee37881
URL: https://github.com/llvm/llvm-project/commit/3fe7f1dcf44ced0648fd0aef2b33056bbee37881
DIFF: https://github.com/llvm/llvm-project/commit/3fe7f1dcf44ced0648fd0aef2b33056bbee37881.diff
LOG: [yaml2obj] - Make .symtab to be not mandatory section for SHT_REL[A] section.
Before this change .symtab section was required for SHT_REL[A] section
declarations. yaml2obj automatically defined it in case when YAML document
did not have it.
With this change it is now possible to produce an object that
has a relocation section, but has no symbol table.
It simplifies the code and also it is inline with how we handle Link fields
for another special sections.
Differential revision: https://reviews.llvm.org/D69260
Added:
Modified:
llvm/lib/ObjectYAML/ELFEmitter.cpp
llvm/test/Object/invalid.test
llvm/test/Object/objdump-sectionheaders.test
llvm/test/tools/llvm-objcopy/ELF/no-symbol-relocation.test
llvm/test/tools/llvm-readobj/all.test
llvm/test/tools/llvm-readobj/elf-reloc-negative-addend-no-sym.test
llvm/test/tools/obj2yaml/elf-ppc64-relocations.yaml
llvm/test/tools/obj2yaml/no-symbol-reloc.test
llvm/test/tools/obj2yaml/relocation-unsupported-machine.yaml
Removed:
################################################################################
diff --git a/llvm/lib/ObjectYAML/ELFEmitter.cpp b/llvm/lib/ObjectYAML/ELFEmitter.cpp
index 6a4e00c62857..64b5cd4df5bf 100644
--- a/llvm/lib/ObjectYAML/ELFEmitter.cpp
+++ b/llvm/lib/ObjectYAML/ELFEmitter.cpp
@@ -205,17 +205,10 @@ template <class ELFT>
ELFState<ELFT>::ELFState(ELFYAML::Object &D, yaml::ErrorHandler EH)
: Doc(D), ErrHandler(EH) {
StringSet<> DocSections;
- for (std::unique_ptr<ELFYAML::Section> &D : Doc.Sections) {
+ for (std::unique_ptr<ELFYAML::Section> &D : Doc.Sections)
if (!D->Name.empty())
DocSections.insert(D->Name);
- // Some sections wants to link to .symtab by default.
- // That means we want to create the symbol table for them.
- if (D->Type == llvm::ELF::SHT_REL || D->Type == llvm::ELF::SHT_RELA)
- if (!Doc.Symbols && D->Link.empty())
- Doc.Symbols.emplace();
- }
-
// Insert SHT_NULL section implicitly when it is not defined in YAML.
if (Doc.Sections.empty() || Doc.Sections.front()->Type != ELF::SHT_NULL)
Doc.Sections.insert(
@@ -742,8 +735,9 @@ void ELFState<ELFT>::writeSectionContent(
SHeader.sh_size = SHeader.sh_entsize * Section.Relocations.size();
// For relocation section set link to .symtab by default.
- if (Section.Link.empty())
- SHeader.sh_link = SN2I.get(".symtab");
+ unsigned Link = 0;
+ if (Section.Link.empty() && SN2I.lookup(".symtab", Link))
+ SHeader.sh_link = Link;
if (!Section.RelocatableSec.empty())
SHeader.sh_info = toSectionIndex(Section.RelocatableSec, Section.Name);
diff --git a/llvm/test/Object/invalid.test b/llvm/test/Object/invalid.test
index 396776c5f919..2c95eea74f24 100644
--- a/llvm/test/Object/invalid.test
+++ b/llvm/test/Object/invalid.test
@@ -333,6 +333,7 @@ Sections:
- Offset: 0x0
Type: R_X86_64_64
Symbol: 0xFFFFFF
+Symbols: []
## Check llvm-readobj does not crash on a truncated ELF.
diff --git a/llvm/test/Object/objdump-sectionheaders.test b/llvm/test/Object/objdump-sectionheaders.test
index fba4fa799805..aab3f54d7dbf 100644
--- a/llvm/test/Object/objdump-sectionheaders.test
+++ b/llvm/test/Object/objdump-sectionheaders.test
@@ -39,3 +39,4 @@ Sections:
Address: 0x0000000000000038
Info: .text
Relocations:
+Symbols: []
diff --git a/llvm/test/tools/llvm-objcopy/ELF/no-symbol-relocation.test b/llvm/test/tools/llvm-objcopy/ELF/no-symbol-relocation.test
index 4b13dda6484b..91040170d739 100644
--- a/llvm/test/tools/llvm-objcopy/ELF/no-symbol-relocation.test
+++ b/llvm/test/tools/llvm-objcopy/ELF/no-symbol-relocation.test
@@ -21,6 +21,8 @@ Sections:
Relocations:
- Offset: 0x1000
Type: R_X86_64_RELATIVE
+## TODO: llvm-objcopy crashes without the following line.
+Symbols: []
# CHECK: Relocations [
# CHECK-NEXT: Section (2) .rel.text {
diff --git a/llvm/test/tools/llvm-readobj/all.test b/llvm/test/tools/llvm-readobj/all.test
index 944ad0384001..5edda0af1f9c 100644
--- a/llvm/test/tools/llvm-readobj/all.test
+++ b/llvm/test/tools/llvm-readobj/all.test
@@ -110,3 +110,4 @@ ProgramHeaders:
- Type: PT_NOTE
Sections:
- Section: .note.gnu.build-id
+Symbols: []
diff --git a/llvm/test/tools/llvm-readobj/elf-reloc-negative-addend-no-sym.test b/llvm/test/tools/llvm-readobj/elf-reloc-negative-addend-no-sym.test
index 86ec658f19a8..3a318d52175f 100644
--- a/llvm/test/tools/llvm-readobj/elf-reloc-negative-addend-no-sym.test
+++ b/llvm/test/tools/llvm-readobj/elf-reloc-negative-addend-no-sym.test
@@ -29,7 +29,6 @@ Sections:
Size: 0x10
- Name: .rela.text
Type: SHT_RELA
- Link: .symtab
Info: .text
Relocations:
- Offset: 0
diff --git a/llvm/test/tools/obj2yaml/elf-ppc64-relocations.yaml b/llvm/test/tools/obj2yaml/elf-ppc64-relocations.yaml
index 68be4276fc2f..d80d9290cc81 100644
--- a/llvm/test/tools/obj2yaml/elf-ppc64-relocations.yaml
+++ b/llvm/test/tools/obj2yaml/elf-ppc64-relocations.yaml
@@ -12,7 +12,6 @@
# CHECK-NEXT: Sections:
# CHECK-NEXT: - Name: .rela.text
# CHECK-NEXT: Type: SHT_RELA
-# CHECK-NEXT: Link: .symtab
# CHECK-NEXT: EntSize: 0x0000000000000018
# CHECK-NEXT: Relocations:
# CHECK-NEXT: - Offset: 0x0000000000000000
diff --git a/llvm/test/tools/obj2yaml/no-symbol-reloc.test b/llvm/test/tools/obj2yaml/no-symbol-reloc.test
index 09299968885a..56d8c1ae101b 100644
--- a/llvm/test/tools/obj2yaml/no-symbol-reloc.test
+++ b/llvm/test/tools/obj2yaml/no-symbol-reloc.test
@@ -16,7 +16,6 @@
# CHECK-NEXT: Flags: [ SHF_ALLOC, SHF_EXECINSTR ]
# CHECK-NEXT: - Name: .rela.text
# CHECK-NEXT: Type: SHT_RELA
-# CHECK-NEXT: Link: .symtab
# CHECK-NEXT: EntSize: 0x0000000000000018
# CHECK-NEXT: Info: .text
# CHECK-NEXT: Relocations:
@@ -24,7 +23,6 @@
# CHECK-NEXT: Type: R_X86_64_NONE
# CHECK-NEXT: - Offset: 0x0000000000000004
# CHECK-NEXT: Type: R_X86_64_NONE
-# CHECK-NEXT: Symbols: []
# CHECK-NEXT: ...
--- !ELF
diff --git a/llvm/test/tools/obj2yaml/relocation-unsupported-machine.yaml b/llvm/test/tools/obj2yaml/relocation-unsupported-machine.yaml
index 54dd2e7b9284..84e5c13b53d6 100644
--- a/llvm/test/tools/obj2yaml/relocation-unsupported-machine.yaml
+++ b/llvm/test/tools/obj2yaml/relocation-unsupported-machine.yaml
@@ -12,7 +12,6 @@
# CHECK-NEXT: Sections:
# CHECK-NEXT: - Name: .rela.text
# CHECK-NEXT: Type: SHT_RELA
-# CHECK-NEXT: Link: .symtab
# CHECK-NEXT: EntSize: 0x0000000000000018
# CHECK-NEXT: Relocations:
# CHECK-NEXT: - Offset: 0x0000000000000001
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