1 files changed, 88 insertions, 0 deletions
diff --git a/contrib/llvm/lib/MC/StringTableBuilder.cpp b/contrib/llvm/lib/MC/StringTableBuilder.cpp
new file mode 100644
index 0000000..9de9363
--- /dev/null
+++ b/contrib/llvm/lib/MC/StringTableBuilder.cpp
@@ -0,0 +1,88 @@
+//===-- StringTableBuilder.cpp - String table building utility ------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/MC/StringTableBuilder.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/Support/COFF.h"
+#include "llvm/Support/Endian.h"
+
+using namespace llvm;
+
+static bool compareBySuffix(StringRef a, StringRef b) {
+  size_t sizeA = a.size();
+  size_t sizeB = b.size();
+  size_t len = std::min(sizeA, sizeB);
+  for (size_t i = 0; i < len; ++i) {
+    char ca = a[sizeA - i - 1];
+    char cb = b[sizeB - i - 1];
+    if (ca != cb)
+      return ca > cb;
+  }
+  return sizeA > sizeB;
+}
+
+void StringTableBuilder::finalize(Kind kind) {
+  SmallVector<StringRef, 8> Strings;
+  Strings.reserve(StringIndexMap.size());
+
+  for (auto i = StringIndexMap.begin(), e = StringIndexMap.end(); i != e; ++i)
+    Strings.push_back(i->getKey());
+
+  std::sort(Strings.begin(), Strings.end(), compareBySuffix);
+
+  switch (kind) {
+  case ELF:
+  case MachO:
+    // Start the table with a NUL byte.
+    StringTable += '\x00';
+    break;
+  case WinCOFF:
+    // Make room to write the table size later.
+    StringTable.append(4, '\x00');
+    break;
+  }
+
+  StringRef Previous;
+  for (StringRef s : Strings) {
+    if (kind == WinCOFF)
+      assert(s.size() > COFF::NameSize && "Short string in COFF string table!");
+
+    if (Previous.endswith(s)) {
+      StringIndexMap[s] = StringTable.size() - 1 - s.size();
+      continue;
+    }
+
+    StringIndexMap[s] = StringTable.size();
+    StringTable += s;
+    StringTable += '\x00';
+    Previous = s;
+  }
+
+  switch (kind) {
+  case ELF:
+    break;
+  case MachO:
+    // Pad to multiple of 4.
+    while (StringTable.size() % 4)
+      StringTable += '\x00';
+    break;
+  case WinCOFF:
+    // Write the table size in the first word.
+    assert(StringTable.size() <= std::numeric_limits<uint32_t>::max());
+    uint32_t size = static_cast<uint32_t>(StringTable.size());
+    support::endian::write<uint32_t, support::little, support::unaligned>(
+        StringTable.data(), size);
+    break;
+  }
+}
+
+void StringTableBuilder::clear() {
+  StringTable.clear();
+  StringIndexMap.clear();
+}