Vendor import of lld trunk r291274:vendor/lld/lld-trunk-r291274

https://llvm.org/svn/llvm-project/lld/trunk@291274

14 files changed, 145 insertions, 125 deletions

diff --git a/ELF/Driver.cpp b/ELF/Driver.cpp
index a11dbc7cc47f..6afbe62e5ec7 100644
--- a/ELF/Driver.cpp
+++ b/ELF/Driver.cpp
@@ -25,6 +25,7 @@
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Path.h"
 #include "llvm/Support/TargetSelect.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cstdlib>
@@ -182,8 +183,8 @@ Optional<MemoryBufferRef> LinkerDriver::readFile(StringRef Path) {
   MemoryBufferRef MBRef = MB->getMemBufferRef();
   make<std::unique_ptr<MemoryBuffer>>(std::move(MB)); // take MB ownership
 
-  if (Cpio)
-    Cpio->append(relativeToRoot(Path), MBRef.getBuffer());
+  if (Tar)
+    Tar->append(relativeToRoot(Path), MBRef.getBuffer());
 
   return MBRef;
 }
@@ -309,14 +310,16 @@ void LinkerDriver::main(ArrayRef<const char *> ArgsArr, bool CanExitEarly) {
   if (const char *Path = getReproduceOption(Args)) {
     // Note that --reproduce is a debug option so you can ignore it
     // if you are trying to understand the whole picture of the code.
-    ErrorOr<CpioFile *> F = CpioFile::create(Path);
-    if (F) {
-      Cpio.reset(*F);
-      Cpio->append("response.txt", createResponseFile(Args));
-      Cpio->append("version.txt", getLLDVersion() + "\n");
-    } else
-      error(F.getError(),
-            Twine("--reproduce: failed to open ") + Path + ".cpio");
+    Expected<std::unique_ptr<TarWriter>> ErrOrWriter =
+        TarWriter::create(Path, path::stem(Path));
+    if (ErrOrWriter) {
+      Tar = std::move(*ErrOrWriter);
+      Tar->append("response.txt", createResponseFile(Args));
+      Tar->append("version.txt", getLLDVersion() + "\n");
+    } else {
+      error(Twine("--reproduce: failed to open ") + Path + ": " +
+            toString(ErrOrWriter.takeError()));
+    }
   }
 
   readConfigs(Args);
@@ -423,7 +426,7 @@ static uint64_t parseSectionAddress(StringRef S, opt::Arg *Arg) {
   if (S.startswith("0x"))
     S = S.drop_front(2);
   if (S.getAsInteger(16, VA))
-    error("invalid argument: " + stringize(Arg));
+    error("invalid argument: " + toString(Arg));
   return VA;
 }
 
diff --git a/ELF/Driver.h b/ELF/Driver.h
index cba1eb164fdd..dadee5eef355 100644
--- a/ELF/Driver.h
+++ b/ELF/Driver.h
@@ -17,6 +17,7 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/StringSet.h"
 #include "llvm/Option/ArgList.h"
+#include "llvm/Support/TarWriter.h"
 #include "llvm/Support/raw_ostream.h"
 
 namespace lld {
@@ -29,7 +30,7 @@ public:
   void main(ArrayRef<const char *> Args, bool CanExitEarly);
   void addFile(StringRef Path);
   void addLibrary(StringRef Name);
-  std::unique_ptr<CpioFile> Cpio; // for reproduce
+  std::unique_ptr<llvm::TarWriter> Tar; // for reproduce
 
 private:
   std::vector<MemoryBufferRef> getArchiveMembers(MemoryBufferRef MB);
diff --git a/ELF/DriverUtils.cpp b/ELF/DriverUtils.cpp
index a81b133f674b..3a20cd76efe2 100644
--- a/ELF/DriverUtils.cpp
+++ b/ELF/DriverUtils.cpp
@@ -146,7 +146,7 @@ std::string elf::createResponseFile(const opt::InputArgList &Args) {
          << "\n";
       break;
     default:
-      OS << stringize(Arg) << "\n";
+      OS << toString(Arg) << "\n";
     }
   }
   return Data.str();
diff --git a/ELF/InputFiles.cpp b/ELF/InputFiles.cpp
index f4128c5096cb..bd9f25873c87 100644
--- a/ELF/InputFiles.cpp
+++ b/ELF/InputFiles.cpp
@@ -92,12 +92,11 @@ std::string elf::ObjectFile<ELFT>::getLineInfo(InputSectionBase<ELFT> *S,
       DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath, Info);
   if (Info.Line == 0)
     return "";
-  return convertToUnixPathSeparator(Info.FileName) + ":" +
-         std::to_string(Info.Line);
+  return Info.FileName + ":" + std::to_string(Info.Line);
 }
 
 // Returns "(internal)", "foo.a(bar.o)" or "baz.o".
-std::string elf::toString(const InputFile *F) {
+std::string lld::toString(const InputFile *F) {
   if (!F)
     return "(internal)";
   if (!F->ArchiveName.empty())
@@ -525,9 +524,9 @@ ArchiveFile::getMember(const Archive::Symbol *Sym) {
             "could not get the buffer for the member defining symbol " +
                 Sym->getName());
 
-  if (C.getParent()->isThin() && Driver->Cpio)
-    Driver->Cpio->append(relativeToRoot(check(C.getFullName())),
-                         Ret.getBuffer());
+  if (C.getParent()->isThin() && Driver->Tar)
+    Driver->Tar->append(relativeToRoot(check(C.getFullName())),
+                        Ret.getBuffer());
   if (C.getParent()->isThin())
     return {Ret, 0};
   return {Ret, C.getChildOffset()};
diff --git a/ELF/InputFiles.h b/ELF/InputFiles.h
index aba1d71379b0..8b188348199f 100644
--- a/ELF/InputFiles.h
+++ b/ELF/InputFiles.h
@@ -36,10 +36,16 @@ class InputFile;
 
 namespace lld {
 namespace elf {
+class InputFile;
+}
+
+// Returns "(internal)", "foo.a(bar.o)" or "baz.o".
+std::string toString(const elf::InputFile *F);
+
+namespace elf {
 
 using llvm::object::Archive;
 
-class InputFile;
 class Lazy;
 class SymbolBody;
 
@@ -84,9 +90,6 @@ private:
   const Kind FileKind;
 };
 
-// Returns "(internal)", "foo.a(bar.o)" or "baz.o".
-std::string toString(const InputFile *F);
-
 template <typename ELFT> class ELFFileBase : public InputFile {
 public:
   typedef typename ELFT::Shdr Elf_Shdr;
diff --git a/ELF/InputSection.cpp b/ELF/InputSection.cpp
index 805e51dab507..e87d92aa207c 100644
--- a/ELF/InputSection.cpp
+++ b/ELF/InputSection.cpp
@@ -34,7 +34,7 @@ using namespace lld::elf;
 
 // Returns a string to construct an error message.
 template <class ELFT>
-std::string elf::toString(const InputSectionBase<ELFT> *Sec) {
+std::string lld::toString(const InputSectionBase<ELFT> *Sec) {
   return (Sec->getFile()->getName() + ":(" + Sec->Name + ")").str();
 }
 
@@ -844,7 +844,7 @@ template class elf::MergeInputSection<ELF32BE>;
 template class elf::MergeInputSection<ELF64LE>;
 template class elf::MergeInputSection<ELF64BE>;
 
-template std::string elf::toString(const InputSectionBase<ELF32LE> *);
-template std::string elf::toString(const InputSectionBase<ELF32BE> *);
-template std::string elf::toString(const InputSectionBase<ELF64LE> *);
-template std::string elf::toString(const InputSectionBase<ELF64BE> *);
+template std::string lld::toString(const InputSectionBase<ELF32LE> *);
+template std::string lld::toString(const InputSectionBase<ELF32BE> *);
+template std::string lld::toString(const InputSectionBase<ELF64LE> *);
+template std::string lld::toString(const InputSectionBase<ELF64BE> *);
diff --git a/ELF/InputSection.h b/ELF/InputSection.h
index adbc1e1e3829..fc7a7fb60973 100644
--- a/ELF/InputSection.h
+++ b/ELF/InputSection.h
@@ -318,10 +318,9 @@ private:
 };
 
 template <class ELFT> InputSection<ELFT> InputSection<ELFT>::Discarded;
-
-template <class ELFT> std::string toString(const InputSectionBase<ELFT> *);
-
 } // namespace elf
+
+template <class ELFT> std::string toString(const elf::InputSectionBase<ELFT> *);
 } // namespace lld
 
 #endif
diff --git a/ELF/LinkerScript.cpp b/ELF/LinkerScript.cpp
index 5057b57a4a54..ccc1059949db 100644
--- a/ELF/LinkerScript.cpp
+++ b/ELF/LinkerScript.cpp
@@ -264,42 +264,12 @@ LinkerScript<ELFT>::createInputSectionList(OutputSectionCommand &OutCmd) {
 }
 
 template <class ELFT>
-static SectionKey<ELFT::Is64Bits> createKey(InputSectionBase<ELFT> *C,
-                                            StringRef OutsecName) {
-  // When using linker script the merge rules are different.
-  // Unfortunately, linker scripts are name based. This means that expressions
-  // like *(.foo*) can refer to multiple input sections that would normally be
-  // placed in different output sections. We cannot put them in different
-  // output sections or we would produce wrong results for
-  // start = .; *(.foo.*) end = .; *(.bar)
-  // and a mapping of .foo1 and .bar1 to one section and .foo2 and .bar2 to
-  // another. The problem is that there is no way to layout those output
-  // sections such that the .foo sections are the only thing between the
-  // start and end symbols.
-
-  // An extra annoyance is that we cannot simply disable merging of the contents
-  // of SHF_MERGE sections, but our implementation requires one output section
-  // per "kind" (string or not, which size/aligment).
-  // Fortunately, creating symbols in the middle of a merge section is not
-  // supported by bfd or gold, so we can just create multiple section in that
-  // case.
-  typedef typename ELFT::uint uintX_t;
-  uintX_t Flags = C->Flags & (SHF_MERGE | SHF_STRINGS);
-
-  uintX_t Alignment = 0;
-  if (isa<MergeInputSection<ELFT>>(C))
-    Alignment = std::max<uintX_t>(C->Alignment, C->Entsize);
-
-  return SectionKey<ELFT::Is64Bits>{OutsecName, /*Type*/ 0, Flags, Alignment};
-}
-
-template <class ELFT>
 void LinkerScript<ELFT>::addSection(OutputSectionFactory<ELFT> &Factory,
                                     InputSectionBase<ELFT> *Sec,
                                     StringRef Name) {
   OutputSectionBase *OutSec;
   bool IsNew;
-  std::tie(OutSec, IsNew) = Factory.create(createKey(Sec, Name), Sec);
+  std::tie(OutSec, IsNew) = Factory.create(Sec, Name);
   if (IsNew)
     OutputSections->push_back(OutSec);
   OutSec->addSection(Sec);
diff --git a/ELF/OutputSections.cpp b/ELF/OutputSections.cpp
index bf7f9c29a29a..a9d951dcc745 100644
--- a/ELF/OutputSections.cpp
+++ b/ELF/OutputSections.cpp
@@ -534,41 +534,111 @@ static typename ELFT::uint getOutFlags(InputSectionBase<ELFT> *S) {
   return S->Flags & ~SHF_GROUP & ~SHF_COMPRESSED;
 }
 
+namespace llvm {
+template <> struct DenseMapInfo<lld::elf::SectionKey> {
+  static lld::elf::SectionKey getEmptyKey();
+  static lld::elf::SectionKey getTombstoneKey();
+  static unsigned getHashValue(const lld::elf::SectionKey &Val);
+  static bool isEqual(const lld::elf::SectionKey &LHS,
+                      const lld::elf::SectionKey &RHS);
+};
+}
+
 template <class ELFT>
-static SectionKey<ELFT::Is64Bits> createKey(InputSectionBase<ELFT> *C,
-                                            StringRef OutsecName) {
+static SectionKey createKey(InputSectionBase<ELFT> *C, StringRef OutsecName) {
+  //  The ELF spec just says
+  // ----------------------------------------------------------------
+  // In the first phase, input sections that match in name, type and
+  // attribute flags should be concatenated into single sections.
+  // ----------------------------------------------------------------
+  //
+  // However, it is clear that at least some flags have to be ignored for
+  // section merging. At the very least SHF_GROUP and SHF_COMPRESSED have to be
+  // ignored. We should not have two output .text sections just because one was
+  // in a group and another was not for example.
+  //
+  // It also seems that that wording was a late addition and didn't get the
+  // necessary scrutiny.
+  //
+  // Merging sections with different flags is expected by some users. One
+  // reason is that if one file has
+  //
+  // int *const bar __attribute__((section(".foo"))) = (int *)0;
+  //
+  // gcc with -fPIC will produce a read only .foo section. But if another
+  // file has
+  //
+  // int zed;
+  // int *const bar __attribute__((section(".foo"))) = (int *)&zed;
+  //
+  // gcc with -fPIC will produce a read write section.
+  //
+  // Last but not least, when using linker script the merge rules are forced by
+  // the script. Unfortunately, linker scripts are name based. This means that
+  // expressions like *(.foo*) can refer to multiple input sections with
+  // different flags. We cannot put them in different output sections or we
+  // would produce wrong results for
+  //
+  // start = .; *(.foo.*) end = .; *(.bar)
+  //
+  // and a mapping of .foo1 and .bar1 to one section and .foo2 and .bar2 to
+  // another. The problem is that there is no way to layout those output
+  // sections such that the .foo sections are the only thing between the start
+  // and end symbols.
+  //
+  // Given the above issues, we instead merge sections by name and error on
+  // incompatible types and flags.
+  //
+  // The exception being SHF_MERGE, where we create different output sections
+  // for each alignment. This makes each output section simple. In case of
+  // relocatable object generation we do not try to perform merging and treat
+  // SHF_MERGE sections as regular ones, but also create different output
+  // sections for them to allow merging at final linking stage.
+  //
+  // Fortunately, creating symbols in the middle of a merge section is not
+  // supported by bfd or gold, so the SHF_MERGE exception should not cause
+  // problems with most linker scripts.
+
   typedef typename ELFT::uint uintX_t;
-  uintX_t Flags = getOutFlags(C);
+  uintX_t Flags = C->Flags & (SHF_MERGE | SHF_STRINGS);
 
-  // For SHF_MERGE we create different output sections for each alignment.
-  // This makes each output section simple and keeps a single level mapping from
-  // input to output.
-  // In case of relocatable object generation we do not try to perform merging
-  // and treat SHF_MERGE sections as regular ones, but also create different
-  // output sections for them to allow merging at final linking stage.
   uintX_t Alignment = 0;
   if (isa<MergeInputSection<ELFT>>(C) ||
       (Config->Relocatable && (C->Flags & SHF_MERGE)))
     Alignment = std::max<uintX_t>(C->Alignment, C->Entsize);
 
-  return SectionKey<ELFT::Is64Bits>{OutsecName, C->Type, Flags, Alignment};
+  return SectionKey{OutsecName, Flags, Alignment};
 }
 
+template <class ELFT> OutputSectionFactory<ELFT>::OutputSectionFactory() {}
+
+template <class ELFT> OutputSectionFactory<ELFT>::~OutputSectionFactory() {}
+
 template <class ELFT>
 std::pair<OutputSectionBase *, bool>
 OutputSectionFactory<ELFT>::create(InputSectionBase<ELFT> *C,
                                    StringRef OutsecName) {
-  SectionKey<ELFT::Is64Bits> Key = createKey(C, OutsecName);
+  SectionKey Key = createKey(C, OutsecName);
   return create(Key, C);
 }
 
+static uint64_t getIncompatibleFlags(uint64_t Flags) {
+  return Flags & (SHF_ALLOC | SHF_TLS);
+}
+
 template <class ELFT>
 std::pair<OutputSectionBase *, bool>
-OutputSectionFactory<ELFT>::create(const SectionKey<ELFT::Is64Bits> &Key,
+OutputSectionFactory<ELFT>::create(const SectionKey &Key,
                                    InputSectionBase<ELFT> *C) {
   uintX_t Flags = getOutFlags(C);
   OutputSectionBase *&Sec = Map[Key];
   if (Sec) {
+    if (getIncompatibleFlags(Sec->Flags) != getIncompatibleFlags(C->Flags))
+      error("Section has flags incompatible with others with the same name " +
+            toString(C));
+    if (Sec->Type != C->Type)
+      error("Section has different type from others with the same name " +
+            toString(C));
     Sec->Flags |= Flags;
     return {Sec, false};
   }
@@ -588,36 +658,22 @@ OutputSectionFactory<ELFT>::create(const SectionKey<ELFT::Is64Bits> &Key,
   return {Sec, true};
 }
 
-template <bool Is64Bits>
-typename lld::elf::SectionKey<Is64Bits>
-DenseMapInfo<lld::elf::SectionKey<Is64Bits>>::getEmptyKey() {
-  return SectionKey<Is64Bits>{DenseMapInfo<StringRef>::getEmptyKey(), 0, 0, 0};
+SectionKey DenseMapInfo<SectionKey>::getEmptyKey() {
+  return SectionKey{DenseMapInfo<StringRef>::getEmptyKey(), 0, 0};
 }
 
-template <bool Is64Bits>
-typename lld::elf::SectionKey<Is64Bits>
-DenseMapInfo<lld::elf::SectionKey<Is64Bits>>::getTombstoneKey() {
-  return SectionKey<Is64Bits>{DenseMapInfo<StringRef>::getTombstoneKey(), 0, 0,
-                              0};
+SectionKey DenseMapInfo<SectionKey>::getTombstoneKey() {
+  return SectionKey{DenseMapInfo<StringRef>::getTombstoneKey(), 0, 0};
 }
 
-template <bool Is64Bits>
-unsigned
-DenseMapInfo<lld::elf::SectionKey<Is64Bits>>::getHashValue(const Key &Val) {
-  return hash_combine(Val.Name, Val.Type, Val.Flags, Val.Alignment);
+unsigned DenseMapInfo<SectionKey>::getHashValue(const SectionKey &Val) {
+  return hash_combine(Val.Name, Val.Flags, Val.Alignment);
 }
 
-template <bool Is64Bits>
-bool DenseMapInfo<lld::elf::SectionKey<Is64Bits>>::isEqual(const Key &LHS,
-                                                           const Key &RHS) {
+bool DenseMapInfo<SectionKey>::isEqual(const SectionKey &LHS,
+                                       const SectionKey &RHS) {
   return DenseMapInfo<StringRef>::isEqual(LHS.Name, RHS.Name) &&
-         LHS.Type == RHS.Type && LHS.Flags == RHS.Flags &&
-         LHS.Alignment == RHS.Alignment;
-}
-
-namespace llvm {
-template struct DenseMapInfo<SectionKey<true>>;
-template struct DenseMapInfo<SectionKey<false>>;
+         LHS.Flags == RHS.Flags && LHS.Alignment == RHS.Alignment;
 }
 
 namespace lld {
diff --git a/ELF/OutputSections.h b/ELF/OutputSections.h
index 978b1f8191ef..45e1a232e2a9 100644
--- a/ELF/OutputSections.h
+++ b/ELF/OutputSections.h
@@ -217,12 +217,10 @@ template <class ELFT> struct Out {
   static OutputSectionBase *FiniArray;
 };
 
-template <bool Is64Bits> struct SectionKey {
-  typedef typename std::conditional<Is64Bits, uint64_t, uint32_t>::type uintX_t;
+struct SectionKey {
   StringRef Name;
-  uint32_t Type;
-  uintX_t Flags;
-  uintX_t Alignment;
+  uint64_t Flags;
+  uint64_t Alignment;
 };
 
 // This class knows how to create an output section for a given
@@ -232,16 +230,17 @@ template <bool Is64Bits> struct SectionKey {
 template <class ELFT> class OutputSectionFactory {
   typedef typename ELFT::Shdr Elf_Shdr;
   typedef typename ELFT::uint uintX_t;
-  typedef typename elf::SectionKey<ELFT::Is64Bits> Key;
 
 public:
+  OutputSectionFactory();
+  ~OutputSectionFactory();
   std::pair<OutputSectionBase *, bool> create(InputSectionBase<ELFT> *C,
                                               StringRef OutsecName);
-  std::pair<OutputSectionBase *, bool>
-  create(const SectionKey<ELFT::Is64Bits> &Key, InputSectionBase<ELFT> *C);
+  std::pair<OutputSectionBase *, bool> create(const SectionKey &Key,
+                                              InputSectionBase<ELFT> *C);
 
 private:
-  llvm::SmallDenseMap<Key, OutputSectionBase *> Map;
+  llvm::SmallDenseMap<SectionKey, OutputSectionBase *> Map;
 };
 
 template <class ELFT> uint64_t getHeaderSize() {
@@ -265,15 +264,5 @@ template <class ELFT> OutputSectionBase *Out<ELFT>::FiniArray;
 } // namespace elf
 } // namespace lld
 
-namespace llvm {
-template <bool Is64Bits> struct DenseMapInfo<lld::elf::SectionKey<Is64Bits>> {
-  typedef typename lld::elf::SectionKey<Is64Bits> Key;
-
-  static Key getEmptyKey();
-  static Key getTombstoneKey();
-  static unsigned getHashValue(const Key &Val);
-  static bool isEqual(const Key &LHS, const Key &RHS);
-};
-}
 
 #endif
diff --git a/ELF/Symbols.cpp b/ELF/Symbols.cpp
index f168d37bdf0a..72bcff4e0f4d 100644
--- a/ELF/Symbols.cpp
+++ b/ELF/Symbols.cpp
@@ -305,7 +305,7 @@ void elf::printTraceSymbol(Symbol *Sym) {
 }
 
 // Returns a symbol for an error message.
-std::string elf::toString(const SymbolBody &B) {
+std::string lld::toString(const SymbolBody &B) {
   if (Config->Demangle)
     if (Optional<std::string> S = demangle(B.getName()))
       return *S;
diff --git a/ELF/Symbols.h b/ELF/Symbols.h
index cbf8fa81a138..38889571679c 100644
--- a/ELF/Symbols.h
+++ b/ELF/Symbols.h
@@ -453,10 +453,9 @@ inline Symbol *SymbolBody::symbol() {
   return reinterpret_cast<Symbol *>(reinterpret_cast<char *>(this) -
                                     offsetof(Symbol, Body));
 }
-
-std::string toString(const SymbolBody &B);
-
 } // namespace elf
+
+std::string toString(const elf::SymbolBody &B);
 } // namespace lld
 
 #endif
diff --git a/ELF/Target.cpp b/ELF/Target.cpp
index d82e654b9c4c..cb2b178fa849 100644
--- a/ELF/Target.cpp
+++ b/ELF/Target.cpp
@@ -44,6 +44,10 @@ using namespace llvm::object;
 using namespace llvm::support::endian;
 using namespace llvm::ELF;
 
+std::string lld::toString(uint32_t Type) {
+  return getELFRelocationTypeName(elf::Config->EMachine, Type);
+}
+
 namespace lld {
 namespace elf {
 
@@ -52,10 +56,6 @@ TargetInfo *Target;
 static void or32le(uint8_t *P, int32_t V) { write32le(P, read32le(P) | V); }
 static void or32be(uint8_t *P, int32_t V) { write32be(P, read32be(P) | V); }
 
-std::string toString(uint32_t Type) {
-  return getELFRelocationTypeName(Config->EMachine, Type);
-}
-
 template <class ELFT> static std::string getErrorLoc(uint8_t *Loc) {
   for (InputSectionData *D : Symtab<ELFT>::X->Sections) {
     auto *IS = dyn_cast_or_null<InputSection<ELFT>>(D);
diff --git a/ELF/Target.h b/ELF/Target.h
index 156a2c023230..752f9cd5ee4e 100644
--- a/ELF/Target.h
+++ b/ELF/Target.h
@@ -104,13 +104,14 @@ public:
   virtual void relaxTlsLdToLe(uint8_t *Loc, uint32_t Type, uint64_t Val) const;
 };
 
-std::string toString(uint32_t RelType);
 uint64_t getPPC64TocBase();
 uint64_t getAArch64Page(uint64_t Expr);
 
 extern TargetInfo *Target;
 TargetInfo *createTarget();
 }
+
+std::string toString(uint32_t RelType);
 }
 
 #endif