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[ELF] - Linkerscript: implemented ALIGN modificatior of output sections. 

Output section description can contain ALIGN modificator:
https://sourceware.org/binutils/docs/ld/Output-Section-Description.html#Output-Section-Description

Patch implements it.

Differential revision: https://reviews.llvm.org/D22674

llvm-svn: 276780
This commit is contained in:
George Rimar 2016-07-26 18:06:29 +00:00
parent cb42ea0b4f
commit 630c617912
3 changed files with 34 additions and 0 deletions
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13
lld/ELF/LinkerScript.cpp
View File

@ -226,6 +226,9 @@ void LinkerScript<ELFT>::assignAddresses(
if (Cmd->AddrExpr) if (Cmd->AddrExpr)
Dot = Cmd->AddrExpr(Dot); Dot = Cmd->AddrExpr(Dot);
if (Cmd->AlignExpr)
Sec->updateAlignment(Cmd->AlignExpr(Dot));
if ((Sec->getFlags() & SHF_TLS) && Sec->getType() == SHT_NOBITS) { if ((Sec->getFlags() & SHF_TLS) && Sec->getType() == SHT_NOBITS) {
uintX_t TVA = Dot + ThreadBssOffset; uintX_t TVA = Dot + ThreadBssOffset;
TVA = alignTo(TVA, Sec->getAlignment()); TVA = alignTo(TVA, Sec->getAlignment());
@ -433,6 +436,7 @@ private:
std::vector<StringRef> readOutputSectionPhdrs(); std::vector<StringRef> readOutputSectionPhdrs();
unsigned readPhdrType(); unsigned readPhdrType();
void readProvide(bool Hidden); void readProvide(bool Hidden);
void readAlign(OutputSectionCommand *Cmd);
Expr readExpr(); Expr readExpr();
Expr readExpr1(Expr Lhs, int MinPrec); Expr readExpr1(Expr Lhs, int MinPrec);
@ -671,6 +675,12 @@ void ScriptParser::readKeep(OutputSectionCommand *Cmd) {
expect(")"); expect(")");
} }
void ScriptParser::readAlign(OutputSectionCommand *Cmd) {
expect("(");
Cmd->AlignExpr = readExpr();
expect(")");
}
void ScriptParser::readOutputSectionDescription(StringRef OutSec) { void ScriptParser::readOutputSectionDescription(StringRef OutSec) {
OutputSectionCommand *Cmd = new OutputSectionCommand(OutSec); OutputSectionCommand *Cmd = new OutputSectionCommand(OutSec);
Opt.Commands.emplace_back(Cmd); Opt.Commands.emplace_back(Cmd);
@ -682,6 +692,9 @@ void ScriptParser::readOutputSectionDescription(StringRef OutSec) {
expect(":"); expect(":");
if (skip("ALIGN"))
readAlign(Cmd);
// Parse constraints. // Parse constraints.
if (skip("ONLY_IF_RO")) if (skip("ONLY_IF_RO"))
Cmd->Constraint = ConstraintKind::ReadOnly; Cmd->Constraint = ConstraintKind::ReadOnly;

1
lld/ELF/LinkerScript.h
View File

@ -73,6 +73,7 @@ struct OutputSectionCommand : BaseCommand {
static bool classof(const BaseCommand *C); static bool classof(const BaseCommand *C);
StringRef Name; StringRef Name;
Expr AddrExpr; Expr AddrExpr;
Expr AlignExpr;
std::vector<std::unique_ptr<BaseCommand>> Commands; std::vector<std::unique_ptr<BaseCommand>> Commands;
std::vector<StringRef> Phdrs; std::vector<StringRef> Phdrs;
std::vector<uint8_t> Filler; std::vector<uint8_t> Filler;

20
lld/test/ELF/linkerscript/linkerscript-align.s
View File

@ -1,6 +1,7 @@
# REQUIRES: x86 # REQUIRES: x86
# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t
## Check that ALIGN command workable using location counter
# RUN: echo "SECTIONS { \ # RUN: echo "SECTIONS { \
# RUN: . = 0x10000; \ # RUN: . = 0x10000; \
# RUN: .aaa : \ # RUN: .aaa : \
@ -27,6 +28,25 @@
# CHECK-NEXT: 2 .bbb 00000008 0000000000011000 DATA # CHECK-NEXT: 2 .bbb 00000008 0000000000011000 DATA
# CHECK-NEXT: 3 .ccc 00000008 0000000000014000 DATA # CHECK-NEXT: 3 .ccc 00000008 0000000000014000 DATA
## Check output sections ALIGN modificator
# RUN: echo "SECTIONS { \
# RUN: . = 0x10000; \
# RUN: .aaa : \
# RUN: { \
# RUN: *(.aaa) \
# RUN: } \
# RUN: .bbb : ALIGN(4096) \
# RUN: { \
# RUN: *(.bbb) \
# RUN: } \
# RUN: .ccc : ALIGN(4096 * 4) \
# RUN: { \
# RUN: *(.ccc) \
# RUN: } \
# RUN: }" > %t2.script
# RUN: ld.lld -o %t2 --script %t2.script %t
# RUN: llvm-objdump -section-headers %t1 | FileCheck %s
.global _start .global _start
_start: _start:
nop nop