intel/llvm
1
0
Fork 0
mirror of https://github.com/intel/llvm.git synced 2026-02-02 02:00:03 +08:00
Code Issues Packages Projects Releases Wiki Activity

[ELF] Mark linker defined symbols as .hidden when needed.

Browse Source 
I noticed that gold mark these as hidden. While at it I rewrote the test for
this feature to use yaml rather than an object file as input.

Differential Revision:	http://reviews.llvm.org/D9418
Reviewed by:	ruiu

llvm-svn: 236291
This commit is contained in:
Davide Italiano
2015-05-01 00:07:11 +00:00
parent 2127b00cd5
commit 0e4a3addf0
6 changed files with 104 additions and 15 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
lld/lib/ReaderWriter/ELF/ELFFile.cpp
View File

@@ -741,14 +741,17 @@ bool ELFFile<ELFT>::redirectReferenceUsingUndefAtom(
}
template <class ELFT>
void RuntimeFile<ELFT>::addAbsoluteAtom(StringRef symbolName) {
void RuntimeFile<ELFT>::addAbsoluteAtom(StringRef symbolName, bool isHidden) {
assert(!symbolName.empty() && "AbsoluteAtoms must have a name");
Elf_Sym *sym = new (this->_readerStorage) Elf_Sym;
sym->st_name = 0;
sym->st_value = 0;
sym->st_shndx = llvm::ELF::SHN_ABS;
sym->setBindingAndType(llvm::ELF::STB_GLOBAL, llvm::ELF::STT_OBJECT);
sym->setVisibility(llvm::ELF::STV_DEFAULT);
if (isHidden)
sym->setVisibility(llvm::ELF::STV_HIDDEN);
else
sym->setVisibility(llvm::ELF::STV_DEFAULT);
sym->st_size = 0;
ELFAbsoluteAtom<ELFT> *atom = this->createAbsoluteAtom(symbolName, sym, -1);
this->addAtom(*atom);

2
lld/lib/ReaderWriter/ELF/ELFFile.h
View File

@@ -398,7 +398,7 @@ public:
: ELFFile<ELFT>(name, ctx) {}
/// \brief add a global absolute atom
virtual void addAbsoluteAtom(StringRef symbolName);
virtual void addAbsoluteAtom(StringRef symbolName, bool isHidden = false);
/// \brief add an undefined atom
virtual void addUndefinedAtom(StringRef symbolName);

12
lld/lib/ReaderWriter/ELF/ExecutableWriter.h
View File

@@ -81,10 +81,10 @@ std::unique_ptr<RuntimeFile<ELFT>> ExecutableWriter<ELFT>::createRuntimeFile() {
file->addAbsoluteAtom("__bss_end");
file->addAbsoluteAtom("_end");
file->addAbsoluteAtom("end");
file->addAbsoluteAtom("__preinit_array_start");
file->addAbsoluteAtom("__preinit_array_end");
file->addAbsoluteAtom("__init_array_start");
file->addAbsoluteAtom("__init_array_end");
file->addAbsoluteAtom("__preinit_array_start", true);
file->addAbsoluteAtom("__preinit_array_end", true);
file->addAbsoluteAtom("__init_array_start", true);
file->addAbsoluteAtom("__init_array_end", true);
if (this->_ctx.isRelaOutputFormat()) {
file->addAbsoluteAtom("__rela_iplt_start");
file->addAbsoluteAtom("__rela_iplt_end");
@@ -92,8 +92,8 @@ std::unique_ptr<RuntimeFile<ELFT>> ExecutableWriter<ELFT>::createRuntimeFile() {
file->addAbsoluteAtom("__rel_iplt_start");
file->addAbsoluteAtom("__rel_iplt_end");
}
file->addAbsoluteAtom("__fini_array_start");
file->addAbsoluteAtom("__fini_array_end");
file->addAbsoluteAtom("__fini_array_start", true);
file->addAbsoluteAtom("__fini_array_end", true);
return file;
}

BIN
lld/test/elf/Inputs/init_array.x86-64
View File

Binary file not shown.

2
lld/test/elf/X86_64/omagic.test
View File

@@ -187,7 +187,7 @@ OMAGICSECTIONS: Address: 0x0
OMAGICSECTIONS: Offset: 0x1E8
OMAGICSECTIONS: Size: 504
OMAGICSECTIONS: Link: 13
OMAGICSECTIONS: Info: 2
OMAGICSECTIONS: Info: 8
OMAGICSECTIONS: AddressAlignment: 8
OMAGICSECTIONS: EntrySize: 24
OMAGICSECTIONS: }

96
lld/test/elf/init_array.test
View File

@@ -1,6 +1,92 @@
RUN: lld -flavor gnu -target x86_64-linux -o %t %p/Inputs/init_array.x86-64 \
RUN: -e __init_array_start
RUN: llvm-objdump -t -section-headers %t | FileCheck %s
#RUN: yaml2obj -format=elf %s -o=%t.o
#RUN: lld -flavor gnu -target x86_64-linux %t.o -o %t1 -e=main
#RUN: llvm-objdump -t -section-headers %t | FileCheck %s
CHECK: .init_array {{[0-9]+}} [[ADDR:[0-9]+]]
CHECK: [[ADDR]] g *ABS* {{[0-9]+}} __init_array_start
#CHECK: .init_array {{[0-9]+}} [[ADDR:[0-9]+]]
#CHECK: [[ADDR]] l *ABS* {{[0-9]+}} .hidden __init_array_start
---
FileHeader:
Class: ELFCLASS64
Data: ELFDATA2LSB
OSABI: ELFOSABI_FREEBSD
Type: ET_REL
Machine: EM_X86_64
Sections:
- Name: .text
Type: SHT_PROGBITS
Flags: [ SHF_ALLOC, SHF_EXECINSTR ]
AddressAlign: 0x0000000000000010
Content: 554889E5B800000000C745FC000000008B0C2500000000894DF85DC3
- Name: .rela.text
Type: SHT_RELA
Link: .symtab
AddressAlign: 0x0000000000000008
Info: .text
Relocations:
- Offset: 0x0000000000000013
Symbol: a
Type: R_X86_64_32S
- Name: .data
Type: SHT_PROGBITS
Flags: [ SHF_WRITE, SHF_ALLOC ]
AddressAlign: 0x0000000000000004
Content: '05000000'
- Name: .bss
Type: SHT_NOBITS
Flags: [ SHF_WRITE, SHF_ALLOC ]
AddressAlign: 0x0000000000000004
Content: ''
- Name: .comment
Type: SHT_PROGBITS
Flags: [ SHF_MERGE, SHF_STRINGS ]
AddressAlign: 0x0000000000000001
Content: 004672656542534420636C616E672076657273696F6E20332E342E312028746167732F52454C454153455F33342F646F74312D66696E616C203230383033322920323031343035313200
- Name: .note.GNU-stack
Type: SHT_PROGBITS
AddressAlign: 0x0000000000000001
Content: ''
- Name: .eh_frame
Type: SHT_PROGBITS
Flags: [ SHF_ALLOC ]
AddressAlign: 0x0000000000000008
Content: 1400000000000000017A5200017810011B0C0708900100001C0000001C000000000000001C00000000410E108602430D0600000000000000
- Name: .rela.eh_frame
Type: SHT_RELA
Link: .symtab
AddressAlign: 0x0000000000000008
Info: .eh_frame
Relocations:
- Offset: 0x0000000000000020
Symbol: .text
Type: R_X86_64_PC32
Symbols:
Local:
- Name: .text
Type: STT_SECTION
Section: .text
- Name: .data
Type: STT_SECTION
Section: .data
- Name: .bss
Type: STT_SECTION
Section: .bss
- Name: .comment
Type: STT_SECTION
Section: .comment
- Name: .note.GNU-stack
Type: STT_SECTION
Section: .note.GNU-stack
- Name: .eh_frame
Type: STT_SECTION
Section: .eh_frame
Global:
- Name: a
Type: STT_OBJECT
Section: .data
Size: 0x0000000000000004
- Name: main
Type: STT_FUNC
Section: .text
Size: 0x000000000000001C
...