1 files changed, 163 insertions, 0 deletions
diff --git a/ELF/ScriptParser.cpp b/ELF/ScriptParser.cpp
new file mode 100644
index 000000000000..559ec1be0e39
--- /dev/null
+++ b/ELF/ScriptParser.cpp
@@ -0,0 +1,163 @@
+//===- ScriptParser.cpp ---------------------------------------------------===//
+//
+//                             The LLVM Linker
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the base parser class for linker script and dynamic
+// list.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ScriptParser.h"
+#include "Error.h"
+#include "llvm/ADT/Twine.h"
+
+using namespace llvm;
+using namespace lld;
+using namespace lld::elf;
+
+// Returns the line that the character S[Pos] is in.
+static StringRef getLine(StringRef S, size_t Pos) {
+  size_t Begin = S.rfind('\n', Pos);
+  size_t End = S.find('\n', Pos);
+  Begin = (Begin == StringRef::npos) ? 0 : Begin + 1;
+  if (End == StringRef::npos)
+    End = S.size();
+  // rtrim for DOS-style newlines.
+  return S.substr(Begin, End - Begin).rtrim();
+}
+
+void ScriptParserBase::printErrorPos() {
+  StringRef Tok = Tokens[Pos == 0 ? 0 : Pos - 1];
+  StringRef Line = getLine(Input, Tok.data() - Input.data());
+  size_t Col = Tok.data() - Line.data();
+  error(Line);
+  error(std::string(Col, ' ') + "^");
+}
+
+// We don't want to record cascading errors. Keep only the first one.
+void ScriptParserBase::setError(const Twine &Msg) {
+  if (Error)
+    return;
+  if (Input.empty() || Tokens.empty()) {
+    error(Msg);
+  } else {
+    error("line " + Twine(getPos()) + ": " + Msg);
+    printErrorPos();
+  }
+  Error = true;
+}
+
+// Split S into linker script tokens.
+std::vector<StringRef> ScriptParserBase::tokenize(StringRef S) {
+  std::vector<StringRef> Ret;
+  for (;;) {
+    S = skipSpace(S);
+    if (S.empty())
+      return Ret;
+
+    // Quoted token
+    if (S.startswith("\"")) {
+      size_t E = S.find("\"", 1);
+      if (E == StringRef::npos) {
+        error("unclosed quote");
+        return {};
+      }
+      Ret.push_back(S.substr(1, E - 1));
+      S = S.substr(E + 1);
+      continue;
+    }
+
+    // Unquoted token
+    size_t Pos = S.find_first_not_of(
+        "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
+        "0123456789_.$/\\~=+[]*?-:!<>");
+    // A character that cannot start a word (which is usually a
+    // punctuation) forms a single character token.
+    if (Pos == 0)
+      Pos = 1;
+    Ret.push_back(S.substr(0, Pos));
+    S = S.substr(Pos);
+  }
+}
+
+// Skip leading whitespace characters or comments.
+StringRef ScriptParserBase::skipSpace(StringRef S) {
+  for (;;) {
+    if (S.startswith("/*")) {
+      size_t E = S.find("*/", 2);
+      if (E == StringRef::npos) {
+        error("unclosed comment in a linker script");
+        return "";
+      }
+      S = S.substr(E + 2);
+      continue;
+    }
+    if (S.startswith("#")) {
+      size_t E = S.find('\n', 1);
+      if (E == StringRef::npos)
+        E = S.size() - 1;
+      S = S.substr(E + 1);
+      continue;
+    }
+    size_t Size = S.size();
+    S = S.ltrim();
+    if (S.size() == Size)
+      return S;
+  }
+}
+
+// An erroneous token is handled as if it were the last token before EOF.
+bool ScriptParserBase::atEOF() { return Error || Tokens.size() == Pos; }
+
+StringRef ScriptParserBase::next() {
+  if (Error)
+    return "";
+  if (atEOF()) {
+    setError("unexpected EOF");
+    return "";
+  }
+  return Tokens[Pos++];
+}
+
+StringRef ScriptParserBase::peek() {
+  StringRef Tok = next();
+  if (Error)
+    return "";
+  --Pos;
+  return Tok;
+}
+
+bool ScriptParserBase::skip(StringRef Tok) {
+  if (Error)
+    return false;
+  if (atEOF()) {
+    setError("unexpected EOF");
+    return false;
+  }
+  if (Tokens[Pos] != Tok)
+    return false;
+  ++Pos;
+  return true;
+}
+
+void ScriptParserBase::expect(StringRef Expect) {
+  if (Error)
+    return;
+  StringRef Tok = next();
+  if (Tok != Expect)
+    setError(Expect + " expected, but got " + Tok);
+}
+
+// Returns the current line number.
+size_t ScriptParserBase::getPos() {
+  if (Pos == 0)
+    return 1;
+  const char *Begin = Input.data();
+  const char *Tok = Tokens[Pos - 1].data();
+  return StringRef(Begin, Tok - Begin).count('\n') + 1;
+}