[lld] r302413 - [ELF] - Linkerscript: support combination of linkerscript and --compress-debug-sections.
George Rimar via llvm-commits
llvm-commits at lists.llvm.org
Mon May 8 03:18:13 PDT 2017
Author: grimar
Date: Mon May 8 05:18:12 2017
New Revision: 302413
URL: http://llvm.org/viewvc/llvm-project?rev=302413&view=rev
Log:
[ELF] - Linkerscript: support combination of linkerscript and --compress-debug-sections.
Previously it was impossible to use linkerscript with --compress-debug-sections
because of assert failture:
Assertion failed: isFinalized(), file C:\llvm\lib\MC\StringTableBuilder.cpp, line 64
Patch fixes the issue
Added:
lld/trunk/test/ELF/linkerscript/Inputs/compress-debug-sections.s
lld/trunk/test/ELF/linkerscript/compress-debug-sections.s
Modified:
lld/trunk/ELF/LinkerScript.cpp
lld/trunk/ELF/OutputSections.cpp
Modified: lld/trunk/ELF/LinkerScript.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/LinkerScript.cpp?rev=302413&r1=302412&r2=302413&view=diff
==============================================================================
--- lld/trunk/ELF/LinkerScript.cpp (original)
+++ lld/trunk/ELF/LinkerScript.cpp Mon May 8 05:18:12 2017
@@ -406,15 +406,8 @@ void LinkerScript::processCommands(Outpu
}
// Add input sections to an output section.
- unsigned Pos = 0;
- for (InputSectionBase *S : V) {
- // The actual offset will be computed during
- // assignAddresses. For now, use the index as a very crude
- // approximation so that it is at least easy for other code to
- // know the section order.
- cast<InputSection>(S)->OutSecOff = Pos++;
+ for (InputSectionBase *S : V)
Factory.addInputSec(S, Cmd->Name, Cmd->Sec);
- }
if (OutputSection *Sec = Cmd->Sec) {
assert(Sec->SectionIndex == INT_MAX);
Sec->SectionIndex = I;
@@ -648,6 +641,11 @@ void LinkerScript::assignOffsets(OutputS
Dot = CurMemRegion->Offset;
switchTo(Sec);
+ // We do not support custom layout for compressed debug sectons.
+ // At this point we already know their size and have compressed content.
+ if (CurOutSec->Flags & SHF_COMPRESSED)
+ return;
+
for (BaseCommand *C : Cmd->Commands)
process(*C);
}
Modified: lld/trunk/ELF/OutputSections.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/OutputSections.cpp?rev=302413&r1=302412&r2=302413&view=diff
==============================================================================
--- lld/trunk/ELF/OutputSections.cpp (original)
+++ lld/trunk/ELF/OutputSections.cpp Mon May 8 05:18:12 2017
@@ -140,12 +140,24 @@ template <class ELFT> void OutputSection
this->Info = S->OutSec->SectionIndex;
}
+static uint64_t updateOffset(uint64_t Off, InputSection *S) {
+ Off = alignTo(Off, S->Alignment);
+ S->OutSecOff = Off;
+ return Off + S->getSize();
+}
+
void OutputSection::addSection(InputSection *S) {
assert(S->Live);
Sections.push_back(S);
S->OutSec = this;
this->updateAlignment(S->Alignment);
+ // The actual offsets will be computed by assignAddresses. For now, use
+ // crude approximation so that it is at least easy for other code to know the
+ // section order. It is also used to calculate the output section size early
+ // for compressed debug sections.
+ this->Size = updateOffset(Size, S);
+
// If this section contains a table of fixed-size entries, sh_entsize
// holds the element size. Consequently, if this contains two or more
// input sections, all of them must have the same sh_entsize. However,
@@ -160,11 +172,8 @@ void OutputSection::addSection(InputSect
// and scan relocations to setup sections' offsets.
void OutputSection::assignOffsets() {
uint64_t Off = 0;
- for (InputSection *S : Sections) {
- Off = alignTo(Off, S->Alignment);
- S->OutSecOff = Off;
- Off += S->getSize();
- }
+ for (InputSection *S : Sections)
+ Off = updateOffset(Off, S);
this->Size = Off;
}
Added: lld/trunk/test/ELF/linkerscript/Inputs/compress-debug-sections.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/linkerscript/Inputs/compress-debug-sections.s?rev=302413&view=auto
==============================================================================
--- lld/trunk/test/ELF/linkerscript/Inputs/compress-debug-sections.s (added)
+++ lld/trunk/test/ELF/linkerscript/Inputs/compress-debug-sections.s Mon May 8 05:18:12 2017
@@ -0,0 +1,3 @@
+.section .debug_str
+ .asciz "CCC"
+ .asciz "DDD"
Added: lld/trunk/test/ELF/linkerscript/compress-debug-sections.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/linkerscript/compress-debug-sections.s?rev=302413&view=auto
==============================================================================
--- lld/trunk/test/ELF/linkerscript/compress-debug-sections.s (added)
+++ lld/trunk/test/ELF/linkerscript/compress-debug-sections.s Mon May 8 05:18:12 2017
@@ -0,0 +1,36 @@
+# REQUIRES: x86, zlib
+
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux \
+# RUN: %S/Inputs/compress-debug-sections.s -o %t1.o
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t2.o
+
+## .debug_str section is mergeable. LLD would combine all of them into single
+## mergeable synthetic section. We use -O0 here to disable merging, that
+## allows to check that input sections has correctly assigned offsets.
+
+# RUN: echo "SECTIONS { }" > %t.script
+# RUN: ld.lld -O0 %t1.o %t2.o %t.script -o %t1 --compress-debug-sections=zlib
+# RUN: llvm-dwarfdump %t1 | FileCheck %s
+# RUN: llvm-readobj -s %t1 | FileCheck %s --check-prefix=ZLIBFLAGS
+
+# RUN: echo "SECTIONS { .debug_str 0 : { *(.debug_str) } }" > %t2.script
+# RUN: ld.lld -O0 %t1.o %t2.o %t2.script -o %t2 --compress-debug-sections=zlib
+# RUN: llvm-dwarfdump %t2 | FileCheck %s
+# RUN: llvm-readobj -s %t2 | FileCheck %s --check-prefix=ZLIBFLAGS
+
+# CHECK: .debug_str contents:
+# CHECK-NEXT: CCC
+# CHECK-NEXT: DDD
+# CHECK-NEXT: AAA
+# CHECK-NEXT: BBB
+
+# ZLIBFLAGS: Section {
+# ZLIBFLAGS: Index:
+# ZLIBFLAGS: Name: .debug_str
+# ZLIBFLAGS-NEXT: Type: SHT_PROGBITS
+# ZLIBFLAGS-NEXT: Flags [
+# ZLIBFLAGS-NEXT: SHF_COMPRESSED
+
+.section .debug_str
+ .asciz "AAA"
+ .asciz "BBB"
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