intel/llvm
1
0
Fork 0
mirror of https://github.com/intel/llvm.git synced 2026-01-16 05:32:28 +08:00
Code Issues Packages Projects Releases Wiki Activity

Delay the relocation scan.

Browse Source 
We have to scan the relaxations after every symbol is defined.

This fixes pr25218.

llvm-svn: 250702
This commit is contained in:
Rafael Espindola
2015-10-19 15:21:42 +00:00
parent bd715d4702
commit 334c3e11e6
3 changed files with 48 additions and 41 deletions
Download Patch File Download Diff File Expand all files Collapse all files

40
lld/ELF/Writer.cpp
View File

@@ -396,22 +396,6 @@ template <class ELFT> void Writer<ELFT>::createSections() {
Map[{Out<ELFT>::Bss->getName(), Out<ELFT>::Bss->getType(),
Out<ELFT>::Bss->getFlags()}] = Out<ELFT>::Bss;
// Declare linker generated symbols.
// This must be done before the relocation scan to make sure we can correctly
// decide if a dynamic relocation is needed or not.
// FIXME: Make this more declarative.
for (StringRef Name :
{"__preinit_array_start", "__preinit_array_end", "__init_array_start",
"__init_array_end", "__fini_array_start", "__fini_array_end"})
Symtab.addIgnoredSym(Name);
// __tls_get_addr is defined by the dynamic linker for dynamic ELFs. For
// static linking the linker is required to optimize away any references to
// __tls_get_addr, so it's not defined anywhere. Create a hidden definition
// to avoid the undefined symbol error.
if (!isOutputDynamic())
Symtab.addIgnoredSym("__tls_get_addr");
std::vector<OutputSectionBase<ELFT> *> RegularSections;
for (const std::unique_ptr<ObjectFile<ELFT>> &F : Symtab.getObjectFiles()) {
@@ -430,13 +414,9 @@ template <class ELFT> void Writer<ELFT>::createSections() {
RegularSections.push_back(Sec);
}
Sec->addSection(C);
scanRelocs(*C);
}
}
for (OutputSectionBase<ELFT> *Sec : RegularSections)
addStartStopSymbols(Sec);
Out<ELFT>::Dynamic->PreInitArraySec =
Map.lookup({".preinit_array", SHT_PREINIT_ARRAY, SHF_WRITE | SHF_ALLOC});
Out<ELFT>::Dynamic->InitArraySec =
@@ -449,6 +429,9 @@ template <class ELFT> void Writer<ELFT>::createSections() {
if (OS) {
Symtab.addSyntheticSym(Start, *OS, 0);
Symtab.addSyntheticSym(End, *OS, OS->getSize());
} else {
Symtab.addIgnoredSym(Start);
Symtab.addIgnoredSym(End);
}
};
@@ -459,6 +442,23 @@ template <class ELFT> void Writer<ELFT>::createSections() {
AddStartEnd("__fini_array_start", "__fini_array_end",
Out<ELFT>::Dynamic->FiniArraySec);
for (OutputSectionBase<ELFT> *Sec : RegularSections)
addStartStopSymbols(Sec);
// __tls_get_addr is defined by the dynamic linker for dynamic ELFs. For
// static linking the linker is required to optimize away any references to
// __tls_get_addr, so it's not defined anywhere. Create a hidden definition
// to avoid the undefined symbol error.
if (!isOutputDynamic())
Symtab.addIgnoredSym("__tls_get_addr");
// Scan relocations. This must be done after every symbol is declared so that
// we can correctly decide if a dynamic relocation is needed.
for (const std::unique_ptr<ObjectFile<ELFT>> &F : Symtab.getObjectFiles())
for (InputSection<ELFT> *S : F->getSections())
if (S && S != &InputSection<ELFT>::Discarded)
scanRelocs(*S);
// FIXME: Try to avoid the extra walk over all global symbols.
std::vector<DefinedCommon<ELFT> *> CommonSymbols;
for (auto &P : Symtab.getSymbols()) {

12
lld/test/elf2/pre_init_fini_array.s
View File

@@ -67,7 +67,7 @@ _start:
// CHECK-NEXT: Size: 0
// CHECK-NEXT: Binding: Local
// CHECK-NEXT: Type: None
// CHECK-NEXT: Other: 2
// CHECK-NEXT: Other: 0
// CHECK-NEXT: Section: .fini_array
// CHECK-NEXT: }
// CHECK-NEXT: Symbol {
@@ -76,7 +76,7 @@ _start:
// CHECK-NEXT: Size: 0
// CHECK-NEXT: Binding: Local
// CHECK-NEXT: Type: None
// CHECK-NEXT: Other: 2
// CHECK-NEXT: Other: 0
// CHECK-NEXT: Section: .fini_array
// CHECK-NEXT: }
// CHECK-NEXT: Symbol {
@@ -85,7 +85,7 @@ _start:
// CHECK-NEXT: Size: 0
// CHECK-NEXT: Binding: Local
// CHECK-NEXT: Type: None
// CHECK-NEXT: Other: 2
// CHECK-NEXT: Other: 0
// CHECK-NEXT: Section: .init_array
// CHECK-NEXT: }
// CHECK-NEXT: Symbol {
@@ -94,7 +94,7 @@ _start:
// CHECK-NEXT: Size: 0
// CHECK-NEXT: Binding: Local
// CHECK-NEXT: Type: None
// CHECK-NEXT: Other: 2
// CHECK-NEXT: Other: 0
// CHECK-NEXT: Section: .init_array
// CHECK-NEXT: }
// CHECK-NEXT: Symbol {
@@ -103,7 +103,7 @@ _start:
// CHECK-NEXT: Size: 0
// CHECK-NEXT: Binding: Local
// CHECK-NEXT: Type: None
// CHECK-NEXT: Other: 2
// CHECK-NEXT: Other: 0
// CHECK-NEXT: Section: .preinit_array
// CHECK-NEXT: }
// CHECK-NEXT: Symbol {
@@ -112,7 +112,7 @@ _start:
// CHECK-NEXT: Size: 0
// CHECK-NEXT: Binding: Local
// CHECK-NEXT: Type: None
// CHECK-NEXT: Other: 2
// CHECK-NEXT: Other: 0
// CHECK-NEXT: Section: .preinit_array
// CHECK-NEXT: }

37
lld/test/elf2/startstop.s
View File

@@ -1,41 +1,48 @@
// REQUIRES: x86
// RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t
// RUN: ld.lld2 %t -o %tout
// RUN: ld.lld2 %t -o %tout -shared
// RUN: llvm-objdump -d %tout | FileCheck -check-prefix=DISASM %s
// RUN: llvm-readobj -symbols %tout | FileCheck -check-prefix=SYMBOL %s
// RUN: llvm-readobj -symbols -r %tout | FileCheck -check-prefix=SYMBOL %s
// DISASM: _start:
// DISASM: 11000: e8 0a 00 00 00 callq 10
// DISASM: 11005: e8 08 00 00 00 callq 8
// DISASM: 1100a: e8 03 00 00 00 callq 3
// DISASM: 1000: {{.*}} callq 10
// DISASM: 1005: {{.*}} callq 8
// DISASM: 100a: {{.*}} callq 3
// DISASM: Disassembly of section foo:
// DISASM: __start_foo:
// DISASM: 1100f: 90 nop
// DISASM: 11010: 90 nop
// DISASM: 11011: 90 nop
// DISASM: 100f: 90 nop
// DISASM: 1010: 90 nop
// DISASM: 1011: 90 nop
// DISASM: Disassembly of section bar:
// DISASM: __start_bar:
// DISASM: 11012: 90 nop
// DISASM: 11013: 90 nop
// DISASM: 11014: 90 nop
// DISASM: 1012: 90 nop
// DISASM: 1013: 90 nop
// DISASM: 1014: 90 nop
// SYMBOL: Relocations [
// SYMBOL-NEXT: ]
// SYMBOL: Symbol {
// SYMBOL: Name: __start_bar
// SYMBOL: Value: 0x11012
// SYMBOL: Value: 0x1012
// SYMBOL: Section: bar
// SYMBOL: }
// SYMBOL-NOT: Section: __stop_bar
// SYMBOL: Symbol {
// SYMBOL: Name: __start_foo
// SYMBOL: Value: 0x1100F
// SYMBOL: Value: 0x100F
// SYMBOL: Section: foo
// SYMBOL: }
// SYMBOL: Symbol {
// SYMBOL: Name: __stop_foo
// SYMBOL: Value: 0x11012
// SYMBOL: Section: foo (0x2)
// SYMBOL: Value: 0x1012
// SYMBOL: Section: foo
// SYMBOL: }
.hidden __start_foo
.hidden __stop_foo
.hidden __start_bar
.global _start
.text
_start: