ELF2: Create LinkerScript.cpp and move code from DriverUtils to there.
llvm-svn: 248920
diff --git a/lld/ELF/LinkerScript.cpp b/lld/ELF/LinkerScript.cpp
new file mode 100644
index 0000000..746af74
--- /dev/null
+++ b/lld/ELF/LinkerScript.cpp
@@ -0,0 +1,156 @@
+//===- LinkerScript.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 parser/evaluator of the linker script.
+// It does not construct an AST but consume linker script directives directly.
+// Results are written to Symtab or Config object.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Config.h"
+#include "Driver.h"
+#include "SymbolTable.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/MemoryBuffer.h"
+
+using namespace llvm;
+using namespace lld;
+using namespace lld::elf2;
+
+namespace {
+class LinkerScript {
+public:
+ LinkerScript(SymbolTable *T, StringRef S) : Symtab(T), Tokens(tokenize(S)) {}
+ void run();
+
+private:
+ static std::vector<StringRef> tokenize(StringRef S);
+ static StringRef skipSpace(StringRef S);
+ StringRef next();
+ bool atEOF() { return Tokens.size() == Pos; }
+ void expect(StringRef Expect);
+
+ void readAsNeeded();
+ void readGroup();
+ void readOutputFormat();
+
+ SymbolTable *Symtab;
+ std::vector<StringRef> Tokens;
+ size_t Pos = 0;
+};
+}
+
+void LinkerScript::run() {
+ while (!atEOF()) {
+ StringRef Tok = next();
+ if (Tok == "GROUP") {
+ readGroup();
+ } else if (Tok == "OUTPUT_FORMAT") {
+ readOutputFormat();
+ } else {
+ error("unknown directive: " + Tok);
+ }
+ }
+}
+
+// Split S into linker script tokens.
+std::vector<StringRef> LinkerScript::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");
+ Ret.push_back(S.substr(1, E));
+ 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 /**/-style comments.
+StringRef LinkerScript::skipSpace(StringRef S) {
+ for (;;) {
+ if (S.startswith("/*")) {
+ size_t E = S.find("*/", 2);
+ if (E == StringRef::npos)
+ error("unclosed comment in a linker script");
+ S = S.substr(E + 2);
+ continue;
+ }
+ size_t Size = S.size();
+ S = S.ltrim();
+ if (S.size() == Size)
+ return S;
+ }
+}
+
+StringRef LinkerScript::next() {
+ if (Pos == Tokens.size())
+ error("unexpected EOF");
+ return Tokens[Pos++];
+}
+
+void LinkerScript::expect(StringRef Expect) {
+ StringRef Tok = next();
+ if (Tok != Expect)
+ error(Expect + " expected, but got " + Tok);
+}
+
+void LinkerScript::readAsNeeded() {
+ expect("(");
+ for (;;) {
+ StringRef Tok = next();
+ if (Tok == ")")
+ return;
+ Symtab->addFile(createFile(openFile(Tok)));
+ }
+}
+
+void LinkerScript::readGroup() {
+ expect("(");
+ for (;;) {
+ StringRef Tok = next();
+ if (Tok == ")")
+ return;
+ if (Tok == "AS_NEEDED") {
+ readAsNeeded();
+ continue;
+ }
+ Symtab->addFile(createFile(openFile(Tok)));
+ }
+}
+
+void LinkerScript::readOutputFormat() {
+ // Error checking only for now.
+ expect("(");
+ next();
+ expect(")");
+}
+
+// Entry point. The other functions or classes are private to this file.
+void lld::elf2::readLinkerScript(SymbolTable *Symtab, MemoryBufferRef MB) {
+ LinkerScript(Symtab, MB.getBuffer()).run();
+}