[ELF] Move script into Ctx. NFC

Ctx was introduced in March 2022 as a more suitable place for such
singletons.

We now use default-initialization for `LinkerScript` and should pay
attention to non-class types (e.g. `dot` is initialized by commit
503907d).

Author: MaskRay

lld/ELF/Config.h

@@ -46,6 +46,7 @@ class Defined;
 class Symbol;
 class BitcodeCompiler;
 class OutputSection;
+class LinkerScript;
 struct Partition;
 struct PhdrEntry;
 
@@ -483,6 +484,7 @@ struct DuplicateSymbol {
 
 struct Ctx {
   LinkerDriver driver;
+  LinkerScript *script;
 
   // These variables are initialized by Writer and should not be used before
   // Writer is initialized.

lld/ELF/Driver.cpp

@@ -93,6 +93,7 @@ void elf::errorOrWarn(const Twine &msg) {
 
 void Ctx::reset() {
   driver = LinkerDriver();
+  script = nullptr;
 
   bufferStart = nullptr;
   mainPart = nullptr;
@@ -160,8 +161,9 @@ bool link(ArrayRef<const char *> args, llvm::raw_ostream &stdoutOS,
                                  "--error-limit=0 to see all errors)";
 
   config = ConfigWrapper();
-  script = ScriptWrapper();
 
+  LinkerScript script;
+  elf::ctx.script = &script;
   elf::ctx.symAux.emplace_back();
 
   partitions.clear();
@@ -463,7 +465,7 @@ static void checkOptions() {
     if (config->emachine != EM_AARCH64)
       error("--execute-only is only supported on AArch64 targets");
 
-    if (config->singleRoRx && !script->hasSectionsCommand)
+    if (config->singleRoRx && !ctx.script->hasSectionsCommand)
       error("--execute-only and --no-rosegment cannot be used together");
   }
 
@@ -2456,10 +2458,10 @@ static void readSymbolPartitionSection(InputSectionBase *s) {
   // Forbid partitions from being used on incompatible targets, and forbid them
   // from being used together with various linker features that assume a single
   // set of output sections.
-  if (script->hasSectionsCommand)
+  if (ctx.script->hasSectionsCommand)
     error(toString(s->file) +
           ": partitions cannot be used with the SECTIONS command");
-  if (script->hasPhdrsCommands())
+  if (ctx.script->hasPhdrsCommands())
     error(toString(s->file) +
           ": partitions cannot be used with the PHDRS command");
   if (!config->sectionStartMap.empty())
@@ -2873,7 +2875,7 @@ template <class ELFT> void LinkerDriver::link(opt::InputArgList &args) {
   // After potential archive member extraction involving ENTRY and
   // -u/--undefined-glob, check whether PROVIDE symbols should be defined (the
   // RHS may refer to definitions in just extracted object files).
-  script->addScriptReferencedSymbolsToSymTable();
+  ctx.script->addScriptReferencedSymbolsToSymTable();
 
   // Prevent LTO from removing any definition referenced by -u.
   for (StringRef name : config->undefined)
@@ -2939,7 +2941,7 @@ template <class ELFT> void LinkerDriver::link(opt::InputArgList &args) {
   // We want to declare linker script's symbols early,
   // so that we can version them.
   // They also might be exported if referenced by DSOs.
-  script->declareSymbols();
+  ctx.script->declareSymbols();
 
   // Handle --exclude-libs. This is before scanVersionScript() due to a
   // workaround for Android ndk: for a defined versioned symbol in an archive
@@ -3158,13 +3160,13 @@ template <class ELFT> void LinkerDriver::link(opt::InputArgList &args) {
     llvm::TimeTraceScope timeScope("Assign sections");
 
     // Create output sections described by SECTIONS commands.
-    script->processSectionCommands();
+    ctx.script->processSectionCommands();
 
     // Linker scripts control how input sections are assigned to output
     // sections. Input sections that were not handled by scripts are called
     // "orphans", and they are assigned to output sections by the default rule.
     // Process that.
-    script->addOrphanSections();
+    ctx.script->addOrphanSections();
   }
 
   {
@@ -3174,9 +3176,9 @@ template <class ELFT> void LinkerDriver::link(opt::InputArgList &args) {
     // merging MergeInputSections into a single MergeSyntheticSection. From this
     // point onwards InputSectionDescription::sections should be used instead of
     // sectionBases.
-    for (SectionCommand *cmd : script->sectionCommands)
+    for (SectionCommand *cmd : ctx.script->sectionCommands)
       if (auto *osd = dyn_cast<OutputDesc>(cmd))
-        osd->osec.finalizeInputSections(&script.s);
+        osd->osec.finalizeInputSections(ctx.script);
   }
 
   // Two input sections with different output sections should not be folded.

lld/ELF/ICF.cpp

@@ -577,7 +577,7 @@ template <class ELFT> void ICF<ELFT>::run() {
 
   // InputSectionDescription::sections is populated by processSectionCommands().
   // ICF may fold some input sections assigned to output sections. Remove them.
-  for (SectionCommand *cmd : script->sectionCommands)
+  for (SectionCommand *cmd : ctx.script->sectionCommands)
     if (auto *osd = dyn_cast<OutputDesc>(cmd))
       for (SectionCommand *subCmd : osd->osec.commands)
         if (auto *isd = dyn_cast<InputSectionDescription>(subCmd))

lld/ELF/LinkerScript.cpp

@@ -44,8 +44,6 @@ using namespace llvm::support::endian;
 using namespace lld;
 using namespace lld::elf;
 
-ScriptWrapper elf::script;
-
 static bool isSectionPrefix(StringRef prefix, StringRef name) {
   return name.consume_front(prefix) && (name.empty() || name[0] == '.');
 }
@@ -862,7 +860,7 @@ static OutputSection *findByName(ArrayRef<SectionCommand *> vec,
 }
 
 static OutputDesc *createSection(InputSectionBase *isec, StringRef outsecName) {
-  OutputDesc *osd = script->createOutputSection(outsecName, "<internal>");
+  OutputDesc *osd = ctx.script->createOutputSection(outsecName, "<internal>");
   osd->osec.recordSection(isec);
   return osd;
 }
@@ -1470,7 +1468,7 @@ void LinkerScript::allocateHeaders(SmallVector<PhdrEntry *, 0> &phdrs) {
 }
 
 LinkerScript::AddressState::AddressState() {
-  for (auto &mri : script->memoryRegions) {
+  for (auto &mri : ctx.script->memoryRegions) {
     MemoryRegion *mr = mri.second;
     mr->curPos = (mr->origin)().getValue();
   }

lld/ELF/LinkerScript.h

@@ -446,13 +446,6 @@ class LinkerScript final {
   llvm::DenseMap<llvm::CachedHashStringRef, SectionClassDesc *> sectionClasses;
 };
 
-struct ScriptWrapper {
-  LinkerScript s;
-  LinkerScript *operator->() { return &s; }
-};
-
-LLVM_LIBRARY_VISIBILITY extern ScriptWrapper script;
-
 } // end namespace lld::elf
 
 #endif // LLD_ELF_LINKER_SCRIPT_H

lld/ELF/MapFile.cpp

@@ -158,7 +158,7 @@ static void writeMapFile(raw_fd_ostream &os) {
      << "     Size Align Out     In      Symbol\n";
 
   OutputSection *osec = nullptr;
-  for (SectionCommand *cmd : script->sectionCommands) {
+  for (SectionCommand *cmd : ctx.script->sectionCommands) {
     if (auto *assign = dyn_cast<SymbolAssignment>(cmd)) {
       if (assign->provide && !assign->sym)
         continue;

lld/ELF/MarkLive.cpp

@@ -234,7 +234,7 @@ template <class ELFT> void MarkLive<ELFT>::run() {
   markSymbol(symtab.find(config->fini));
   for (StringRef s : config->undefined)
     markSymbol(symtab.find(s));
-  for (StringRef s : script->referencedSymbols)
+  for (StringRef s : ctx.script->referencedSymbols)
     markSymbol(symtab.find(s));
   for (auto [symName, _] : symtab.cmseSymMap) {
     markSymbol(symtab.cmseSymMap[symName].sym);
@@ -293,7 +293,7 @@ template <class ELFT> void MarkLive<ELFT>::run() {
 
     // Preserve special sections and those which are specified in linker
     // script KEEP command.
-    if (isReserved(sec) || script->shouldKeep(sec)) {
+    if (isReserved(sec) || ctx.script->shouldKeep(sec)) {
       enqueue(sec, 0);
     } else if ((!config->zStartStopGC || sec->name.starts_with("__libc_")) &&
                isValidCIdentifier(sec->name)) {

lld/ELF/Relocations.cpp

@@ -66,7 +66,7 @@ using namespace lld;
 using namespace lld::elf;
 
 static std::optional<std::string> getLinkerScriptLocation(const Symbol &sym) {
-  for (SectionCommand *cmd : script->sectionCommands)
+  for (SectionCommand *cmd : ctx.script->sectionCommands)
     if (auto *assign = dyn_cast<SymbolAssignment>(cmd))
       if (assign->sym == &sym)
         return assign->location;
@@ -2420,7 +2420,7 @@ static void scanCrossRefs(const NoCrossRefCommand &cmd, OutputSection *osec,
 // scan relocations from its input sections for prohibited cross references.
 template <class ELFT> void elf::checkNoCrossRefs() {
   for (OutputSection *osec : ctx.outputSections) {
-    for (const NoCrossRefCommand &noxref : script->noCrossRefs) {
+    for (const NoCrossRefCommand &noxref : ctx.script->noCrossRefs) {
       if (!llvm::is_contained(noxref.outputSections, osec->name) ||
           (noxref.toFirst && noxref.outputSections[0] == osec->name))
         continue;