[lld][LinkingContext] Atoms created from command line options should be available in YAML

This adds an API to the LinkingContext for flavors to add Internal files
containing atoms that need to appear in the YAML output as well, when -emit-yaml
switch is used.

Flavors can add more internal files for other options that are needed.

llvm-svn: 189718

1 files changed, 30 insertions, 6 deletions

diff --git a/lld/lib/ReaderWriter/ELF/ELFLinkingContext.cpp b/lld/lib/ReaderWriter/ELF/ELFLinkingContext.cpp
index e19a4be573b..7e013705647 100644
--- a/lld/lib/ReaderWriter/ELF/ELFLinkingContext.cpp
+++ b/lld/lib/ReaderWriter/ELF/ELFLinkingContext.cpp
@@ -9,6 +9,7 @@
 
 #include "lld/ReaderWriter/ELFLinkingContext.h"
 
+#include "File.h"
 #include "TargetHandler.h"
 #include "Targets.h"
 
@@ -22,6 +23,17 @@
 #include "llvm/Support/Path.h"
 
 namespace lld {
+
+class CommandLineUndefinedAtom : public SimpleUndefinedAtom {
+public:
+  CommandLineUndefinedAtom(const File &f, StringRef name)
+      : SimpleUndefinedAtom(f, name) {}
+
+  virtual CanBeNull canBeNull() const {
+    return CanBeNull::canBeNullAtBuildtime;
+  }
+};
+
 ELFLinkingContext::ELFLinkingContext(
     llvm::Triple triple, std::unique_ptr<TargetHandlerBase> targetHandler)
     : _outputFileType(elf::ET_EXEC), _triple(triple),
@@ -29,8 +41,7 @@ ELFLinkingContext::ELFLinkingContext(
       _isStaticExecutable(false), _outputYAML(false), _noInhibitExec(false),
       _mergeCommonStrings(false), _runLayoutPass(true),
       _useShlibUndefines(false), _dynamicLinkerArg(false),
-      _noAllowDynamicLibraries(false),
-      _outputMagic(OutputMagic::DEFAULT) {}
+      _noAllowDynamicLibraries(false), _outputMagic(OutputMagic::DEFAULT) {}
 
 bool ELFLinkingContext::is64Bits() const { return getTriple().isArch64Bit(); }
 
@@ -59,11 +70,13 @@ uint16_t ELFLinkingContext::getOutputMachine() const {
   }
 }
 
-bool ELFLinkingContext::validateImpl(raw_ostream &diagnostics) {
-  if (_outputFileType == elf::ET_EXEC && _entrySymbolName.empty()) {
-    _entrySymbolName = "_start";
-  }
+StringRef ELFLinkingContext::entrySymbolName() const {
+  if (_outputFileType == elf::ET_EXEC && _entrySymbolName.empty())
+    return "_start";
+  return _entrySymbolName;
+}
 
+bool ELFLinkingContext::validateImpl(raw_ostream &diagnostics) {
   _elfReader = createReaderELF(*this);
   _linkerScriptReader.reset(new ReaderLinkerScript(*this));
   _writer = _outputYAML ? createWriterYAML(*this) : createWriterELF(*this);
@@ -157,4 +170,15 @@ StringRef ELFLinkingContext::searchLibrary(
   return libName;
 }
 
+std::unique_ptr<File> ELFLinkingContext::createUndefinedSymbolFile() {
+  if (_initialUndefinedSymbols.empty())
+    return nullptr;
+  std::unique_ptr<SimpleFile> undefinedSymFile(
+      new SimpleFile(*this, "command line option -u"));
+  for (auto undefSymStr : _initialUndefinedSymbols)
+    undefinedSymFile->addAtom(*(new (_allocator) CommandLineUndefinedAtom(
+                                   *undefinedSymFile, undefSymStr)));
+  return std::move(undefinedSymFile);
+}
+
 } // end namespace lld