[lld] r302107 - Fix accounting of tbss.
Rafael Espindola via llvm-commits
llvm-commits at lists.llvm.org
Wed May 3 20:00:27 PDT 2017
Author: rafael
Date: Wed May 3 22:00:27 2017
New Revision: 302107
URL: http://llvm.org/viewvc/llvm-project?rev=302107&view=rev
Log:
Fix accounting of tbss.
We were correctly computing the size contribution of a .tbss input
section (it is none), but we were incorrectly considering the
alignment of the output section: it was advancing Dot instead of
ThreadBssOffset.
As far as I can tell this was always wrong in our linkerscript
implementation, but that became more visible now that the code is
shared with the non linker script case.
Modified:
lld/trunk/ELF/LinkerScript.cpp
lld/trunk/ELF/LinkerScript.h
lld/trunk/test/ELF/tls-offset.s
Modified: lld/trunk/ELF/LinkerScript.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/LinkerScript.cpp?rev=302107&r1=302106&r2=302107&view=diff
==============================================================================
--- lld/trunk/ELF/LinkerScript.cpp (original)
+++ lld/trunk/ELF/LinkerScript.cpp Wed May 3 22:00:27 2017
@@ -495,17 +495,22 @@ void LinkerScript::addOrphanSections(Out
}
}
-static bool isTbss(OutputSection *Sec) {
- return (Sec->Flags & SHF_TLS) && Sec->Type == SHT_NOBITS;
+uint64_t LinkerScript::advance(uint64_t Size, unsigned Align) {
+ bool IsTbss = (CurOutSec->Flags & SHF_TLS) && CurOutSec->Type == SHT_NOBITS;
+ uint64_t Start = IsTbss ? Dot + ThreadBssOffset : Dot;
+ Start = alignTo(Start, Align);
+ uint64_t End = Start + Size;
+
+ if (IsTbss)
+ ThreadBssOffset = End - Dot;
+ else
+ Dot = End;
+ return End;
}
void LinkerScript::output(InputSection *S) {
- bool IsTbss = isTbss(CurOutSec);
-
- uint64_t Pos = IsTbss ? Dot + ThreadBssOffset : Dot;
- Pos = alignTo(Pos, S->Alignment);
- S->OutSecOff = Pos - CurOutSec->Addr;
- Pos += S->getSize();
+ uint64_t Pos = advance(S->getSize(), S->Alignment);
+ S->OutSecOff = Pos - S->getSize() - CurOutSec->Addr;
// Update output section size after adding each section. This is so that
// SIZEOF works correctly in the case below:
@@ -524,11 +529,6 @@ void LinkerScript::output(InputSection *
" bytes");
}
}
-
- if (IsTbss)
- ThreadBssOffset = Pos - Dot;
- else
- Dot = Pos;
}
void LinkerScript::switchTo(OutputSection *Sec) {
@@ -536,9 +536,7 @@ void LinkerScript::switchTo(OutputSectio
return;
CurOutSec = Sec;
-
- Dot = alignTo(Dot, CurOutSec->Alignment);
- CurOutSec->Addr = isTbss(CurOutSec) ? Dot + ThreadBssOffset : Dot;
+ CurOutSec->Addr = advance(0, CurOutSec->Alignment);
// If neither AT nor AT> is specified for an allocatable section, the linker
// will set the LMA such that the difference between VMA and LMA for the
Modified: lld/trunk/ELF/LinkerScript.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/LinkerScript.h?rev=302107&r1=302106&r2=302107&view=diff
==============================================================================
--- lld/trunk/ELF/LinkerScript.h (original)
+++ lld/trunk/ELF/LinkerScript.h Wed May 3 22:00:27 2017
@@ -228,6 +228,7 @@ protected:
MemoryRegion *findMemoryRegion(OutputSectionCommand *Cmd);
void switchTo(OutputSection *Sec);
+ uint64_t advance(uint64_t Size, unsigned Align);
void output(InputSection *Sec);
void process(BaseCommand &Base);
Modified: lld/trunk/test/ELF/tls-offset.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/tls-offset.s?rev=302107&r1=302106&r2=302107&view=diff
==============================================================================
--- lld/trunk/test/ELF/tls-offset.s (original)
+++ lld/trunk/test/ELF/tls-offset.s Wed May 3 22:00:27 2017
@@ -10,7 +10,7 @@
// RUN: .tbss : { *(.tbss) } \
// RUN: .data.rel.ro : { *(.data.rel.ro) } \
// RUN: }" > %t.script
- // RUN: ld.lld -T %t.script %t -o %tout2
+// RUN: ld.lld -T %t.script %t -o %tout2
// RUN: echo SCRIPT
// RUN: llvm-readobj -s %tout2 | FileCheck %s
.global _start
@@ -61,6 +61,6 @@ _start:
// CHECK-NEXT: SHF_ALLOC
// CHECK-NEXT: SHF_WRITE
// CHECK-NEXT: ]
-// CHECK-NEXT: Address: 0x202010
-// CHECK-NEXT: Offset: 0x2010
+// CHECK-NEXT: Address: 0x202004
+// CHECK-NEXT: Offset: 0x2004
// CHECK-NEXT: Size: 4
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