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ELF: Create a string table. 

For now only the sections are in it, but it already makes the output easier
to read and test.

llvm-svn: 244702
This commit is contained in:
Rafael Espindola 2015-08-12 00:00:24 +00:00
parent 4f89fdad9f
commit 6b83b90b6a
7 changed files with 168 additions and 37 deletions
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1
lld/ELF/CMakeLists.txt
View File

@ -15,6 +15,7 @@ add_llvm_library(lldELF2
LINK_COMPONENTS
Object
Option
MC
Support
)

50
lld/ELF/Writer.cpp
View File

@ -12,7 +12,9 @@
#include "Error.h"
#include "SymbolTable.h"
#include "Writer.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/MC/StringTableBuilder.h"
#include "llvm/Support/FileOutputBuffer.h"
using namespace llvm;
@ -41,6 +43,8 @@ public:
void addSectionChunk(SectionChunk<ELFT> *C);
std::vector<Chunk *> &getChunks() { return Chunks; }
void writeHeaderTo(Elf_Shdr *SHdr);
StringRef getName() { return Name; }
void setNameOffset(uintX_t Offset) { Header.sh_name = Offset; }
// Returns the size of the section in the output file.
uintX_t getSize() { return Header.sh_size; }
@ -73,6 +77,10 @@ private:
uintX_t FileSize;
uintX_t SizeOfHeaders;
uintX_t SectionHeaderOff;
uintX_t StringTableOff;
unsigned StringTableIndex;
StringTableBuilder StrTabBuilder;
unsigned NumSections;
std::vector<std::unique_ptr<Chunk>> Chunks;
};
@ -160,10 +168,26 @@ template <class ELFT> void Writer<ELFT>::assignAddresses() {
Sec->setFileOffset(FileOff);
VA += RoundUpToAlignment(Sec->getSize(), PageSize);
FileOff += RoundUpToAlignment(Sec->getSize(), 8);
StrTabBuilder.add(Sec->getName());
}
// Regular sections.
NumSections = OutputSections.size();
// First dummy section.
NumSections++;
// String table.
StrTabBuilder.add(".strtab");
StringTableIndex = NumSections;
StringTableOff = FileOff;
StrTabBuilder.finalize(StringTableBuilder::ELF);
FileOff += StrTabBuilder.data().size();
NumSections++;
// Add space for section headers.
SectionHeaderOff = FileOff;
FileOff += (OutputSections.size() + 1) * sizeof(Elf_Shdr_Impl<ELFT>);
FileOff += NumSections * sizeof(Elf_Shdr_Impl<ELFT>);
FileSize = SizeOfHeaders + RoundUpToAlignment(FileOff - SizeOfHeaders, 8);
}
@ -192,8 +216,8 @@ template <class ELFT> void Writer<ELFT>::writeHeader() {
EHdr->e_phentsize = sizeof(Elf_Phdr_Impl<ELFT>);
EHdr->e_phnum = 1;
EHdr->e_shentsize = sizeof(Elf_Shdr_Impl<ELFT>);
EHdr->e_shnum = OutputSections.size() + 1;
EHdr->e_shstrndx = 0;
EHdr->e_shnum = NumSections;
EHdr->e_shstrndx = StringTableIndex;
auto PHdrs = reinterpret_cast<Elf_Phdr_Impl<ELFT> *>(Buf + EHdr->e_phoff);
PHdrs->p_type = PT_LOAD;
@ -208,8 +232,22 @@ template <class ELFT> void Writer<ELFT>::writeHeader() {
auto SHdrs = reinterpret_cast<Elf_Shdr_Impl<ELFT> *>(Buf + EHdr->e_shoff);
// First entry is null.
++SHdrs;
for (OutputSection<ELFT> *Sec : OutputSections)
for (OutputSection<ELFT> *Sec : OutputSections) {
Sec->setNameOffset(StrTabBuilder.getOffset(Sec->getName()));
Sec->writeHeaderTo(SHdrs++);
}
// String table.
SHdrs->sh_name = StrTabBuilder.getOffset(".strtab");
SHdrs->sh_type = SHT_STRTAB;
SHdrs->sh_flags = 0;
SHdrs->sh_addr = 0;
SHdrs->sh_offset = StringTableOff;
SHdrs->sh_size = StrTabBuilder.data().size();
SHdrs->sh_link = 0;
SHdrs->sh_info = 0;
SHdrs->sh_addralign = 1;
SHdrs->sh_entsize = 0;
}
template <class ELFT> void Writer<ELFT>::openFile(StringRef Path) {
@ -225,4 +263,8 @@ template <class ELFT> void Writer<ELFT>::writeSections() {
for (Chunk *C : Sec->getChunks())
C->writeTo(Buf);
}
// String table.
StringRef Data = StrTabBuilder.data();
memcpy(Buf + StringTableOff, Data.data(), Data.size());
}

30
lld/test/elf2/basic.s
View File

@ -25,15 +25,15 @@ _start:
# CHECK-NEXT: Version: 1
# CHECK-NEXT: Entry: 0x401000
# CHECK-NEXT: ProgramHeaderOffset: 0x40
# CHECK-NEXT: SectionHeaderOffset: 0x1010
# CHECK-NEXT: SectionHeaderOffset: 0x102A
# CHECK-NEXT: Flags [ (0x0)
# CHECK-NEXT: ]
# CHECK-NEXT: HeaderSize: 64
# CHECK-NEXT: ProgramHeaderEntrySize: 56
# CHECK-NEXT: ProgramHeaderCount: 1
# CHECK-NEXT: SectionHeaderEntrySize: 64
# CHECK-NEXT: SectionHeaderCount: 4
# CHECK-NEXT: StringTableSectionIndex: 0
# CHECK-NEXT: SectionHeaderCount: 5
# CHECK-NEXT: StringTableSectionIndex: 4
# CHECK-NEXT: }
# CHECK-NEXT: Sections [
# CHECK-NEXT: Section {
@ -52,7 +52,7 @@ _start:
# CHECK-NEXT: }
# CHECK-NEXT: Section {
# CHECK-NEXT: Index: 1
# CHECK-NEXT: Name: (0)
# CHECK-NEXT: Name: .text
# CHECK-NEXT: Type: SHT_PROGBITS (0x1)
# CHECK-NEXT: Flags [ (0x6)
# CHECK-NEXT: SHF_ALLOC (0x2)
@ -68,7 +68,7 @@ _start:
# CHECK-NEXT: }
# CHECK-NEXT: Section {
# CHECK-NEXT: Index: 2
# CHECK-NEXT: Name: (0)
# CHECK-NEXT: Name: .data
# CHECK-NEXT: Type: SHT_PROGBITS (0x1)
# CHECK-NEXT: Flags [ (0x3)
# CHECK-NEXT: SHF_ALLOC (0x2)
@ -84,7 +84,7 @@ _start:
# CHECK-NEXT: }
# CHECK-NEXT: Section {
# CHECK-NEXT: Index: 3
# CHECK-NEXT: Name: (0)
# CHECK-NEXT: Name: .bss
# CHECK-NEXT: Type: SHT_NOBITS (0x8)
# CHECK-NEXT: Flags [ (0x3)
# CHECK-NEXT: SHF_ALLOC (0x2)
@ -98,6 +98,20 @@ _start:
# CHECK-NEXT: AddressAlignment: 0
# CHECK-NEXT: EntrySize: 0
# CHECK-NEXT: }
# CHECK-NEXT: Section {
# CHECK-NEXT: Index: 4
# CHECK-NEXT: Name: .strtab (12)
# CHECK-NEXT: Type: SHT_STRTAB (0x3)
# CHECK-NEXT: Flags [ (0x0)
# CHECK-NEXT: ]
# CHECK-NEXT: Address: 0x0
# CHECK-NEXT: Offset: 0x1010
# CHECK-NEXT: Size: 26
# CHECK-NEXT: Link: 0
# CHECK-NEXT: Info: 0
# CHECK-NEXT: AddressAlignment: 1
# CHECK-NEXT: EntrySize: 0
# CHECK-NEXT: }
# CHECK-NEXT: ]
# CHECK-NEXT: ProgramHeaders [
# CHECK-NEXT: ProgramHeader {
@ -105,8 +119,8 @@ _start:
# CHECK-NEXT: Offset: 0x0
# CHECK-NEXT: VirtualAddress: 0x400000
# CHECK-NEXT: PhysicalAddress: 0x400000
# CHECK-NEXT: FileSize: 4368
# CHECK-NEXT: MemSize: 4368
# CHECK-NEXT: FileSize: 4464
# CHECK-NEXT: MemSize: 4464
# CHECK-NEXT: Flags [ (0x5)
# CHECK-NEXT: PF_R (0x4)
# CHECK-NEXT: PF_X (0x1)

30
lld/test/elf2/basic32.s
View File

@ -25,15 +25,15 @@ _start:
# CHECK-NEXT: Version: 1
# CHECK-NEXT: Entry: 0x401000
# CHECK-NEXT: ProgramHeaderOffset: 0x34
# CHECK-NEXT: SectionHeaderOffset: 0x1010
# CHECK-NEXT: SectionHeaderOffset: 0x102A
# CHECK-NEXT: Flags [ (0x0)
# CHECK-NEXT: ]
# CHECK-NEXT: HeaderSize: 52
# CHECK-NEXT: ProgramHeaderEntrySize: 32
# CHECK-NEXT: ProgramHeaderCount: 1
# CHECK-NEXT: SectionHeaderEntrySize: 40
# CHECK-NEXT: SectionHeaderCount: 4
# CHECK-NEXT: StringTableSectionIndex: 0
# CHECK-NEXT: SectionHeaderCount: 5
# CHECK-NEXT: StringTableSectionIndex: 4
# CHECK-NEXT: }
# CHECK-NEXT: Sections [
# CHECK-NEXT: Section {
@ -52,7 +52,7 @@ _start:
# CHECK-NEXT: }
# CHECK-NEXT: Section {
# CHECK-NEXT: Index: 1
# CHECK-NEXT: Name: (0)
# CHECK-NEXT: Name: .text
# CHECK-NEXT: Type: SHT_PROGBITS (0x1)
# CHECK-NEXT: Flags [ (0x6)
# CHECK-NEXT: SHF_ALLOC (0x2)
@ -68,7 +68,7 @@ _start:
# CHECK-NEXT: }
# CHECK-NEXT: Section {
# CHECK-NEXT: Index: 2
# CHECK-NEXT: Name: (0)
# CHECK-NEXT: Name: .data
# CHECK-NEXT: Type: SHT_PROGBITS (0x1)
# CHECK-NEXT: Flags [ (0x3)
# CHECK-NEXT: SHF_ALLOC (0x2)
@ -84,7 +84,7 @@ _start:
# CHECK-NEXT: }
# CHECK-NEXT: Section {
# CHECK-NEXT: Index: 3
# CHECK-NEXT: Name: (0)
# CHECK-NEXT: Name: .bss
# CHECK-NEXT: Type: SHT_NOBITS (0x8)
# CHECK-NEXT: Flags [ (0x3)
# CHECK-NEXT: SHF_ALLOC (0x2)
@ -98,6 +98,20 @@ _start:
# CHECK-NEXT: AddressAlignment: 0
# CHECK-NEXT: EntrySize: 0
# CHECK-NEXT: }
# CHECK-NEXT: Section {
# CHECK-NEXT: Index: 4
# CHECK-NEXT: Name: .strtab
# CHECK-NEXT: Type: SHT_STRTAB (0x3)
# CHECK-NEXT: Flags [ (0x0)
# CHECK-NEXT: ]
# CHECK-NEXT: Address: 0x0
# CHECK-NEXT: Offset: 0x1010
# CHECK-NEXT: Size: 26
# CHECK-NEXT: Link: 0
# CHECK-NEXT: Info: 0
# CHECK-NEXT: AddressAlignment: 1
# CHECK-NEXT: EntrySize: 0
# CHECK-NEXT: }
# CHECK-NEXT: ]
# CHECK-NEXT: ProgramHeaders [
# CHECK-NEXT: ProgramHeader {
@ -105,8 +119,8 @@ _start:
# CHECK-NEXT: Offset: 0x0
# CHECK-NEXT: VirtualAddress: 0x400000
# CHECK-NEXT: PhysicalAddress: 0x400000
# CHECK-NEXT: FileSize: 4272
# CHECK-NEXT: MemSize: 4272
# CHECK-NEXT: FileSize: 4344
# CHECK-NEXT: MemSize: 4344
# CHECK-NEXT: Flags [ (0x5)
# CHECK-NEXT: PF_R (0x4)
# CHECK-NEXT: PF_X (0x1)

30
lld/test/elf2/basic32be.s
View File

@ -25,15 +25,15 @@ _start:
# CHECK-NEXT: Version: 1
# CHECK-NEXT: Entry: 0x401000
# CHECK-NEXT: ProgramHeaderOffset: 0x34
# CHECK-NEXT: SectionHeaderOffset: 0x1010
# CHECK-NEXT: SectionHeaderOffset: 0x102A
# CHECK-NEXT: Flags [ (0x0)
# CHECK-NEXT: ]
# CHECK-NEXT: HeaderSize: 52
# CHECK-NEXT: ProgramHeaderEntrySize: 32
# CHECK-NEXT: ProgramHeaderCount: 1
# CHECK-NEXT: SectionHeaderEntrySize: 40
# CHECK-NEXT: SectionHeaderCount: 4
# CHECK-NEXT: StringTableSectionIndex: 0
# CHECK-NEXT: SectionHeaderCount: 5
# CHECK-NEXT: StringTableSectionIndex: 4
# CHECK-NEXT: }
# CHECK-NEXT: Sections [
# CHECK-NEXT: Section {
@ -52,7 +52,7 @@ _start:
# CHECK-NEXT: }
# CHECK-NEXT: Section {
# CHECK-NEXT: Index: 1
# CHECK-NEXT: Name: (0)
# CHECK-NEXT: Name: .text
# CHECK-NEXT: Type: SHT_PROGBITS (0x1)
# CHECK-NEXT: Flags [ (0x6)
# CHECK-NEXT: SHF_ALLOC (0x2)
@ -68,7 +68,7 @@ _start:
# CHECK-NEXT: }
# CHECK-NEXT: Section {
# CHECK-NEXT: Index: 2
# CHECK-NEXT: Name: (0)
# CHECK-NEXT: Name: .data
# CHECK-NEXT: Type: SHT_PROGBITS (0x1)
# CHECK-NEXT: Flags [ (0x3)
# CHECK-NEXT: SHF_ALLOC (0x2)
@ -84,7 +84,7 @@ _start:
# CHECK-NEXT: }
# CHECK-NEXT: Section {
# CHECK-NEXT: Index: 3
# CHECK-NEXT: Name: (0)
# CHECK-NEXT: Name: .bss
# CHECK-NEXT: Type: SHT_NOBITS (0x8)
# CHECK-NEXT: Flags [ (0x3)
# CHECK-NEXT: SHF_ALLOC (0x2)
@ -98,6 +98,20 @@ _start:
# CHECK-NEXT: AddressAlignment: 0
# CHECK-NEXT: EntrySize: 0
# CHECK-NEXT: }
# CHECK-NEXT: Section {
# CHECK-NEXT: Index: 4
# CHECK-NEXT: Name: .strtab
# CHECK-NEXT: Type: SHT_STRTAB (0x3)
# CHECK-NEXT: Flags [ (0x0)
# CHECK-NEXT: ]
# CHECK-NEXT: Address: 0x0
# CHECK-NEXT: Offset: 0x1010
# CHECK-NEXT: Size: 26
# CHECK-NEXT: Link: 0
# CHECK-NEXT: Info: 0
# CHECK-NEXT: AddressAlignment: 1
# CHECK-NEXT: EntrySize: 0
# CHECK-NEXT: }
# CHECK-NEXT: ]
# CHECK-NEXT: ProgramHeaders [
# CHECK-NEXT: ProgramHeader {
@ -105,8 +119,8 @@ _start:
# CHECK-NEXT: Offset: 0x0
# CHECK-NEXT: VirtualAddress: 0x400000
# CHECK-NEXT: PhysicalAddress: 0x400000
# CHECK-NEXT: FileSize: 4272
# CHECK-NEXT: MemSize: 4272
# CHECK-NEXT: FileSize: 4344
# CHECK-NEXT: MemSize: 4344
# CHECK-NEXT: Flags [ (0x5)
# CHECK-NEXT: PF_R (0x4)
# CHECK-NEXT: PF_X (0x1)

32
lld/test/elf2/basic64be.s
View File

@ -30,15 +30,15 @@ _start:
# CHECK-NEXT: Version: 1
# CHECK-NEXT: Entry: 0x401000
# CHECK-NEXT: ProgramHeaderOffset: 0x40
# CHECK-NEXT: SectionHeaderOffset: 0x1028
# CHECK-NEXT: SectionHeaderOffset: 0x1047
# CHECK-NEXT: Flags [ (0x0)
# CHECK-NEXT: ]
# CHECK-NEXT: HeaderSize: 64
# CHECK-NEXT: ProgramHeaderEntrySize: 56
# CHECK-NEXT: ProgramHeaderCount: 1
# CHECK-NEXT: SectionHeaderEntrySize: 64
# CHECK-NEXT: SectionHeaderCount: 5
# CHECK-NEXT: StringTableSectionIndex: 0
# CHECK-NEXT: SectionHeaderCount: 6
# CHECK-NEXT: StringTableSectionIndex: 5
# CHECK-NEXT: }
# CHECK-NEXT: Sections [
# CHECK-NEXT: Section {
@ -57,7 +57,7 @@ _start:
# CHECK-NEXT: }
# CHECK-NEXT: Section {
# CHECK-NEXT: Index: 1
# CHECK-NEXT: Name: (0)
# CHECK-NEXT: Name: .text
# CHECK-NEXT: Type: SHT_PROGBITS (0x1)
# CHECK-NEXT: Flags [ (0x6)
# CHECK-NEXT: SHF_ALLOC (0x2)
@ -73,7 +73,7 @@ _start:
# CHECK-NEXT: }
# CHECK-NEXT: Section {
# CHECK-NEXT: Index: 2
# CHECK-NEXT: Name: (0)
# CHECK-NEXT: Name: .data
# CHECK-NEXT: Type: SHT_PROGBITS (0x1)
# CHECK-NEXT: Flags [ (0x3)
# CHECK-NEXT: SHF_ALLOC (0x2)
@ -89,7 +89,7 @@ _start:
# CHECK-NEXT: }
# CHECK-NEXT: Section {
# CHECK-NEXT: Index: 3
# CHECK-NEXT: Name: (0)
# CHECK-NEXT: Name: .bss
# CHECK-NEXT: Type: SHT_NOBITS (0x8)
# CHECK-NEXT: Flags [ (0x3)
# CHECK-NEXT: SHF_ALLOC (0x2)
@ -105,7 +105,7 @@ _start:
# CHECK-NEXT: }
# CHECK-NEXT: Section {
# CHECK-NEXT: Index: 4
# CHECK-NEXT: Name: (0)
# CHECK-NEXT: Name: .opd
# CHECK-NEXT: Type: SHT_PROGBITS (0x1)
# CHECK-NEXT: Flags [ (0x3)
# CHECK-NEXT: SHF_ALLOC (0x2)
@ -119,6 +119,20 @@ _start:
# CHECK-NEXT: AddressAlignment: 0
# CHECK-NEXT: EntrySize: 0
# CHECK-NEXT: }
# CHECK-NEXT: Section {
# CHECK-NEXT: Index: 5
# CHECK-NEXT: Name: .strtab
# CHECK-NEXT: Type: SHT_STRTAB (0x3)
# CHECK-NEXT: Flags [ (0x0)
# CHECK-NEXT: ]
# CHECK-NEXT: Address: 0x0
# CHECK-NEXT: Offset: 0x1028
# CHECK-NEXT: Size: 31
# CHECK-NEXT: Link: 0
# CHECK-NEXT: Info: 0
# CHECK-NEXT: AddressAlignment: 1
# CHECK-NEXT: EntrySize: 0
# CHECK-NEXT: }
# CHECK-NEXT: ]
# CHECK-NEXT: ProgramHeaders [
# CHECK-NEXT: ProgramHeader {
@ -126,8 +140,8 @@ _start:
# CHECK-NEXT: Offset: 0x0
# CHECK-NEXT: VirtualAddress: 0x400000
# CHECK-NEXT: PhysicalAddress: 0x400000
# CHECK-NEXT: FileSize: 4456
# CHECK-NEXT: MemSize: 4456
# CHECK-NEXT: FileSize: 4552
# CHECK-NEXT: MemSize: 4552
# CHECK-NEXT: Flags [ (0x5)
# CHECK-NEXT: PF_R (0x4)
# CHECK-NEXT: PF_X (0x1)

32
lld/test/elf2/string-table.s Normal file
View File

@ -0,0 +1,32 @@
// RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t
// RUN: lld -flavor gnu2 %t -o %t2
// RUN: llvm-readobj -sections -section-data %t2 | FileCheck %s
// REQUIRES: x86
.global _start
_start:
.section bar, "a"
.section foobar, "a"
// Test that the sting "bar" is merged into "foobar"
// CHECK: Section {
// CHECK: Index: 6
// CHECK-NEXT: Name: .strtab
// CHECK-NEXT: Type: SHT_STRTAB (0x3)
// CHECK-NEXT: Flags [ (0x0)
// CHECK-NEXT: ]
// CHECK-NEXT: Address: 0x0
// CHECK-NEXT: Offset:
// CHECK-NEXT: Size: 33
// CHECK-NEXT: Link: 0
// CHECK-NEXT: Info: 0
// CHECK-NEXT: AddressAlignment: 1
// CHECK-NEXT: EntrySize: 0
// CHECK-NEXT: SectionData (
// CHECK-NEXT: 0000: 002E7465 7874002E 62737300 666F6F62 |..text..bss.foob|
// CHECK-NEXT: 0010: 6172002E 73747274 6162002E 64617461 |ar..strtab..data|
// CHECK-NEXT: 0020: 00 |.|
// CHECK-NEXT: )
// CHECK-NEXT: }