Vendor import of lld trunk r304222:

https://llvm.org/svn/llvm-project/lld/trunk@304222

ELF/LinkerScript.cpp

@@ -52,11 +52,12 @@ LinkerScript *elf::Script;
 uint64_t ExprValue::getValue() const {
   if (Sec) {
     if (Sec->getOutputSection())
-      return Sec->getOffset(Val) + Sec->getOutputSection()->Addr;
+      return alignTo(Sec->getOffset(Val) + Sec->getOutputSection()->Addr,
+                     Alignment);
     error("unable to evaluate expression: input section " + Sec->Name +
           " has no output section assigned");
   }
-  return Val;
+  return alignTo(Val, Alignment);
 }
 
 uint64_t ExprValue::getSecAddr() const {
@@ -143,7 +144,7 @@ void LinkerScript::assignSymbol(SymbolAssignment *Cmd, bool InSec) {
   } else {
     Sym->Section = V.Sec;
     if (Sym->Section->Flags & SHF_ALLOC)
-      Sym->Value = V.Val;
+      Sym->Value = alignTo(V.Val, V.Alignment);
     else
       Sym->Value = V.getValue();
   }
@@ -290,6 +291,9 @@ LinkerScript::computeInputSections(const InputSectionDescription *Cmd) {
     size_t SizeBefore = Ret.size();
 
     for (InputSectionBase *Sec : InputSections) {
+      if (!isa<InputSection>(Sec))
+        continue;
+
       if (Sec->Assigned)
         continue;
 
@@ -1076,6 +1080,9 @@ template <class ELFT> void OutputSectionCommand::writeTo(uint8_t *Buf) {
     return;
   }
 
+  if (Sec->Type == SHT_NOBITS)
+    return;
+
   // Write leading padding.
   ArrayRef<InputSection *> Sections = Sec->Sections;
   uint32_t Filler = getFiller();

ELF/LinkerScript.h

@@ -41,7 +41,12 @@ struct ExprValue {
   SectionBase *Sec;
   uint64_t Val;
   bool ForceAbsolute;
+  uint64_t Alignment = 1;
 
+  ExprValue(SectionBase *Sec, bool ForceAbsolute, uint64_t Val,
+            uint64_t Alignment)
+      : Sec(Sec), Val(Val), ForceAbsolute(ForceAbsolute), Alignment(Alignment) {
+  }
   ExprValue(SectionBase *Sec, bool ForceAbsolute, uint64_t Val)
       : Sec(Sec), Val(Val), ForceAbsolute(ForceAbsolute) {}
   ExprValue(SectionBase *Sec, uint64_t Val) : ExprValue(Sec, false, Val) {}

ELF/MapFile.cpp

@@ -100,7 +100,7 @@ getSymbolStrings(ArrayRef<DefinedRegular *> Syms) {
 }
 
 template <class ELFT>
-void elf::writeMapFile(llvm::ArrayRef<BaseCommand *> Script) {
+void elf::writeMapFile(llvm::ArrayRef<OutputSectionCommand *> Script) {
   if (Config->MapFile.empty())
     return;
 
@@ -123,10 +123,7 @@ void elf::writeMapFile(llvm::ArrayRef<BaseCommand *> Script) {
      << " Align Out     In      Symbol\n";
 
   // Print out file contents.
-  for (BaseCommand *Base : Script) {
-    auto *Cmd = dyn_cast<OutputSectionCommand>(Base);
-    if (!Cmd)
-      continue;
+  for (OutputSectionCommand *Cmd : Script) {
     OutputSection *OSec = Cmd->Sec;
     writeHeader<ELFT>(OS, OSec->Addr, OSec->Size, OSec->Alignment);
     OS << OSec->Name << '\n';
@@ -147,7 +144,7 @@ void elf::writeMapFile(llvm::ArrayRef<BaseCommand *> Script) {
   }
 }
 
-template void elf::writeMapFile<ELF32LE>(ArrayRef<BaseCommand *>);
-template void elf::writeMapFile<ELF32BE>(ArrayRef<BaseCommand *>);
-template void elf::writeMapFile<ELF64LE>(ArrayRef<BaseCommand *>);
-template void elf::writeMapFile<ELF64BE>(ArrayRef<BaseCommand *>);
+template void elf::writeMapFile<ELF32LE>(ArrayRef<OutputSectionCommand *>);
+template void elf::writeMapFile<ELF32BE>(ArrayRef<OutputSectionCommand *>);
+template void elf::writeMapFile<ELF64LE>(ArrayRef<OutputSectionCommand *>);
+template void elf::writeMapFile<ELF64BE>(ArrayRef<OutputSectionCommand *>);

ELF/MapFile.h

@@ -14,8 +14,9 @@
 
 namespace lld {
 namespace elf {
-struct BaseCommand;
-template <class ELFT> void writeMapFile(llvm::ArrayRef<BaseCommand *> Script);
+struct OutputSectionCommand;
+template <class ELFT>
+void writeMapFile(llvm::ArrayRef<OutputSectionCommand *> Script);
 }
 }
 

ELF/OutputSections.cpp

@@ -117,7 +117,7 @@ template <class ELFT> static void finalizeShtGroup(OutputSection *Sec) {
   // the symbol table.
   Sec->Link = InX::SymTab->OutSec->SectionIndex;
 
-  // sh_link then contain index of an entry in symbol table section which
+  // sh_info then contain index of an entry in symbol table section which
   // provides signature of the section group.
   elf::ObjectFile<ELFT> *Obj = Sec->Sections[0]->getFile<ELFT>();
   assert(Config->Relocatable && Sec->Sections.size() == 1);

ELF/ScriptParser.cpp

@@ -859,7 +859,11 @@ Expr ScriptParser::readPrimary() {
     expect(",");
     Expr E2 = readExpr();
     expect(")");
-    return [=] { return alignTo(E().getValue(), E2().getValue()); };
+    return [=] {
+      ExprValue V = E();
+      V.Alignment = E2().getValue();
+      return V;
+    };
   }
   if (Tok == "ALIGNOF") {
     StringRef Name = readParenLiteral();

ELF/Writer.cpp

@@ -74,6 +74,7 @@ private:
   std::unique_ptr<FileOutputBuffer> Buffer;
 
   std::vector<OutputSection *> OutputSections;
+  std::vector<OutputSectionCommand *> OutputSectionCommands;
   OutputSectionFactory Factory{OutputSections};
 
   void addRelIpltSymbols();
@@ -262,6 +263,10 @@ template <class ELFT> void Writer<ELFT>::run() {
     Script->fabricateDefaultCommands();
   }
 
+  for (BaseCommand *Base : Script->Opt.Commands)
+    if (auto *Cmd = dyn_cast<OutputSectionCommand>(Base))
+      OutputSectionCommands.push_back(Cmd);
+
   // If -compressed-debug-sections is specified, we need to compress
   // .debug_* sections. Do it right now because it changes the size of
   // output sections.
@@ -311,7 +316,7 @@ template <class ELFT> void Writer<ELFT>::run() {
 
 
   // Handle -Map option.
-  writeMapFile<ELFT>(Script->Opt.Commands);
+  writeMapFile<ELFT>(OutputSectionCommands);
   if (ErrorCount)
     return;
 
@@ -1201,8 +1206,6 @@ template <class ELFT> void Writer<ELFT>::finalizeSections() {
   if (ErrorCount)
     return;
 
-  // So far we have added sections from input object files.
-  // This function adds linker-created Out::* sections.
   addPredefinedSections();
   removeUnusedSyntheticSections(OutputSections);
 
@@ -1270,8 +1273,20 @@ template <class ELFT> void Writer<ELFT>::addPredefinedSections() {
   // ARM ABI requires .ARM.exidx to be terminated by some piece of data.
   // We have the terminater synthetic section class. Add that at the end.
   auto *OS = dyn_cast_or_null<OutputSection>(findSection(".ARM.exidx"));
-  if (OS && !OS->Sections.empty() && !Config->Relocatable)
-    OS->addSection(make<ARMExidxSentinelSection>());
+  if (!OS || OS->Sections.empty() || Config->Relocatable)
+    return;
+
+  auto *Sentinel = make<ARMExidxSentinelSection>();
+  OS->addSection(Sentinel);
+  // If there are linker script commands existing at this point then add the
+  // sentinel to the last of these too.
+  if (OutputSectionCommand *C = Script->getCmd(OS)) {
+    auto ISD = std::find_if(C->Commands.rbegin(), C->Commands.rend(),
+                            [](const BaseCommand *Base) {
+                              return isa<InputSectionDescription>(Base);
+                            });
+    cast<InputSectionDescription>(*ISD)->Sections.push_back(Sentinel);
+  }
 }
 
 // The linker is expected to define SECNAME_start and SECNAME_end
@@ -1315,10 +1330,9 @@ void Writer<ELFT>::addStartStopSymbols(OutputSection *Sec) {
 
 template <class ELFT>
 OutputSectionCommand *Writer<ELFT>::findSectionCommand(StringRef Name) {
-  for (BaseCommand *Base : Script->Opt.Commands)
-    if (auto *Cmd = dyn_cast<OutputSectionCommand>(Base))
-      if (Cmd->Name == Name)
-        return Cmd;
+  for (OutputSectionCommand *Cmd : OutputSectionCommands)
+    if (Cmd->Name == Name)
+      return Cmd;
   return nullptr;
 }
 
@@ -1713,7 +1727,7 @@ template <class ELFT> void Writer<ELFT>::writeHeader() {
   EHdr->e_ehsize = sizeof(Elf_Ehdr);
   EHdr->e_phnum = Phdrs.size();
   EHdr->e_shentsize = sizeof(Elf_Shdr);
-  EHdr->e_shnum = OutputSections.size() + 1;
+  EHdr->e_shnum = OutputSectionCommands.size() + 1;
   EHdr->e_shstrndx = InX::ShStrTab->OutSec->SectionIndex;
 
   if (Config->EMachine == EM_ARM)
@@ -1745,8 +1759,8 @@ template <class ELFT> void Writer<ELFT>::writeHeader() {
 
   // Write the section header table. Note that the first table entry is null.
   auto *SHdrs = reinterpret_cast<Elf_Shdr *>(Buf + EHdr->e_shoff);
-  for (OutputSection *Sec : OutputSections)
-    Sec->writeHeaderTo<ELFT>(++SHdrs);
+  for (OutputSectionCommand *Cmd : OutputSectionCommands)
+    Cmd->Sec->writeHeaderTo<ELFT>(++SHdrs);
 }
 
 // Open a result file.
@@ -1769,10 +1783,7 @@ template <class ELFT> void Writer<ELFT>::openFile() {
 
 template <class ELFT> void Writer<ELFT>::writeSectionsBinary() {
   uint8_t *Buf = Buffer->getBufferStart();
-  for (BaseCommand *Base : Script->Opt.Commands) {
-    auto *Cmd = dyn_cast<OutputSectionCommand>(Base);
-    if (!Cmd)
-      continue;
+  for (OutputSectionCommand *Cmd : OutputSectionCommands) {
     OutputSection *Sec = Cmd->Sec;
     if (Sec->Flags & SHF_ALLOC)
       Cmd->writeTo<ELFT>(Buf + Sec->Offset);
@@ -1799,19 +1810,13 @@ template <class ELFT> void Writer<ELFT>::writeSections() {
   // In -r or -emit-relocs mode, write the relocation sections first as in
   // ELf_Rel targets we might find out that we need to modify the relocated
   // section while doing it.
-  for (BaseCommand *Base : Script->Opt.Commands) {
-    auto *Cmd = dyn_cast<OutputSectionCommand>(Base);
-    if (!Cmd)
-      continue;
+  for (OutputSectionCommand *Cmd : OutputSectionCommands) {
     OutputSection *Sec = Cmd->Sec;
     if (Sec->Type == SHT_REL || Sec->Type == SHT_RELA)
       Cmd->writeTo<ELFT>(Buf + Sec->Offset);
   }
 
-  for (BaseCommand *Base : Script->Opt.Commands) {
-    auto *Cmd = dyn_cast<OutputSectionCommand>(Base);
-    if (!Cmd)
-      continue;
+  for (OutputSectionCommand *Cmd : OutputSectionCommands) {
     OutputSection *Sec = Cmd->Sec;
     if (Sec != Out::Opd && Sec != EhFrameHdr && Sec->Type != SHT_REL &&
         Sec->Type != SHT_RELA)

test/ELF/linkerscript/align.s

@@ -64,7 +64,7 @@
 # SYMBOLS-NEXT: 0000000000010000         *ABS*           00000000 __code_base__
 # SYMBOLS-NEXT: 0000000000001000         *ABS*           00000000 VAR
 # SYMBOLS-NEXT: 0000000000011000         .bbb            00000000 __start_bbb
-# SYMBOLS-NEXT: 0000000000012000         *ABS*           00000000 __end_bbb
+# SYMBOLS-NEXT: 0000000000012000         .bbb            00000000 __end_bbb
 
 .global _start
 _start:

test/ELF/linkerscript/bss-fill.s

@@ -0,0 +1,7 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
+# RUN: echo "SECTIONS { .bss : { . += 0x10000; *(.bss) } =0xFF };" > %t.script
+# RUN: ld.lld -o %t --script %t.script %t.o
+
+.section .bss,"",@nobits
+.short 0

test/ELF/linkerscript/merge-sections.s

@@ -31,6 +31,16 @@
 # 0x19E = begin + sizeof(.foo) = 0x190 + 0xE
 # CHECK-NEXT: Value: 0x19E
 
+# Check that we don't crash with --gc-sections
+# RUN: ld.lld --gc-sections -o %t2 --script %t.script %t -shared
+# RUN: llvm-readobj -s -t %t2 | FileCheck %s --check-prefix=GC
+
+# GC:        Name: .foo
+# GC-NEXT:   Type: SHT_PROGBITS
+# GC-NEXT:   Flags [
+# GC-NEXT:     SHF_ALLOC
+# GC-NEXT:   ]
+
 .section        .foo.1a,"aMS",@progbits,1
 .asciz "foo"
 

test/ELF/linkerscript/symbol-reserved.s

@@ -11,6 +11,12 @@
 
 # SHARED: 0000000000000005 .dynsym 00000000 .hidden newsym
 
+# RUN: echo "PROVIDE_HIDDEN(newsym = ALIGN(__ehdr_start, CONSTANT(MAXPAGESIZE)) + 5);" > %t.script
+# RUN: ld.lld -o %t1 %t.script %t
+# RUN: llvm-objdump -t %t1 | FileCheck --check-prefix=ALIGNED %s
+
+# ALIGNED: 0000000000200005 .text 00000000 .hidden newsym
+
 .global _start
 _start:
   lea newsym(%rip),%rax