For PR411:

First step in refactoring the SymbolTable is to split it into two classes,
one for a symbol table of types and one for a symbol table of Values.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25175 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 193 insertions, 0 deletions

diff --git a/lib/VMCore/TypeSymbolTable.cpp b/lib/VMCore/TypeSymbolTable.cpp
new file mode 100644
index 0000000..e2712d0
--- /dev/null
+++ b/lib/VMCore/TypeSymbolTable.cpp
@@ -0,0 +1,193 @@
+//===-- TypeSymbolTable.cpp - Implement the TypeSymbolTable class ---------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and revised by Reid
+// Spencer. It is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the TypeSymbolTable class for the VMCore library.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/TypeSymbolTable.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/ADT/StringExtras.h"
+#include <iostream>
+
+using namespace llvm;
+
+#define DEBUG_SYMBOL_TABLE 0
+#define DEBUG_ABSTYPE 0
+
+TypeSymbolTable::~TypeSymbolTable() {
+  // Drop all abstract type references in the type plane...
+  for (iterator TI = tmap.begin(), TE = tmap.end(); TI != TE; ++TI) {
+    if (TI->second->isAbstract())   // If abstract, drop the reference...
+      cast<DerivedType>(TI->second)->removeAbstractTypeUser(this);
+  }
+}
+
+std::string TypeSymbolTable::getUniqueName(const std::string &BaseName) const {
+  std::string TryName = BaseName;
+  const_iterator End = tmap.end();
+
+  // See if the name exists
+  while (tmap.find(TryName) != End)            // Loop until we find a free
+    TryName = BaseName + utostr(++LastUnique); // name in the symbol table
+  return TryName;
+}
+
+// lookup a type by name - returns null on failure
+Type* TypeSymbolTable::lookup(const std::string& Name) const {
+  const_iterator TI = tmap.find(Name);
+  if (TI != tmap.end())
+    return const_cast<Type*>(TI->second);
+  return 0;
+}
+
+// Erase a specific type from the symbol table
+bool TypeSymbolTable::erase(Type *N) {
+  for (iterator TI = tmap.begin(), TE = tmap.end(); TI != TE; ++TI) {
+    if (TI->second == N) {
+      this->erase(TI);
+      return true;
+    }
+  }
+  return false;
+}
+
+// remove - Remove a type from the symbol table...
+Type* TypeSymbolTable::erase(iterator Entry) {
+  assert(Entry != tmap.end() && "Invalid entry to remove!");
+
+  const Type* Result = Entry->second;
+
+#if DEBUG_SYMBOL_TABLE
+  dump();
+  std::cerr << " Removing Value: " << Result->getName() << "\n";
+#endif
+
+  tmap.erase(Entry);
+
+  // If we are removing an abstract type, remove the symbol table from it's use
+  // list...
+  if (Result->isAbstract()) {
+#if DEBUG_ABSTYPE
+    std::cerr << "Removing abstract type from symtab" << Result->getDescription()<<"\n";
+#endif
+    cast<DerivedType>(Result)->removeAbstractTypeUser(this);
+  }
+
+  return const_cast<Type*>(Result);
+}
+
+
+// insert - Insert a type into the symbol table with the specified name...
+void TypeSymbolTable::insert(const std::string& Name, const Type* T) {
+  assert(T && "Can't insert null type into symbol table!");
+
+  // Check to see if there is a naming conflict.  If so, rename this type!
+  std::string UniqueName = Name;
+  if (lookup(Name))
+    UniqueName = getUniqueName(Name);
+
+#if DEBUG_SYMBOL_TABLE
+  dump();
+  std::cerr << " Inserting type: " << UniqueName << ": "
+            << T->getDescription() << "\n";
+#endif
+
+  // Insert the tmap entry
+  tmap.insert(make_pair(UniqueName, T));
+
+  // If we are adding an abstract type, add the symbol table to it's use list.
+  if (T->isAbstract()) {
+    cast<DerivedType>(T)->addAbstractTypeUser(this);
+#if DEBUG_ABSTYPE
+    std::cerr << "Added abstract type to ST: " << T->getDescription() << "\n";
+#endif
+  }
+}
+
+// Strip the symbol table of its names.
+bool TypeSymbolTable::strip() {
+  bool RemovedSymbol = false;
+  for (iterator TI = tmap.begin(); TI != tmap.end(); ) {
+    erase(TI++);
+    RemovedSymbol = true;
+  }
+
+  return RemovedSymbol;
+}
+
+/// rename - Given a value with a non-empty name, remove its existing entry
+/// from the symbol table and insert a new one for Name.  This is equivalent to
+/// doing "remove(V), V->Name = Name, insert(V)", but is faster, and will not
+/// temporarily remove the symbol table plane if V is the last value in the
+/// symtab with that name (which could invalidate iterators to that plane).
+bool TypeSymbolTable::rename(Type *T, const std::string &name) {
+  for (iterator TI = tmap.begin(), TE = tmap.end(); TI != TE; ++TI) {
+    if (TI->second == T) {
+      // Remove the old entry.
+      tmap.erase(TI);
+      // Add the new entry.
+      this->insert(name,T);
+      return true;
+    }
+  }
+  return false;
+}
+
+// This function is called when one of the types in the type plane are refined
+void TypeSymbolTable::refineAbstractType(const DerivedType *OldType,
+                                         const Type *NewType) {
+
+  // Loop over all of the types in the symbol table, replacing any references
+  // to OldType with references to NewType.  Note that there may be multiple
+  // occurrences, and although we only need to remove one at a time, it's
+  // faster to remove them all in one pass.
+  //
+  for (iterator I = begin(), E = end(); I != E; ++I) {
+    if (I->second == (Type*)OldType) {  // FIXME when Types aren't const.
+#if DEBUG_ABSTYPE
+      std::cerr << "Removing type " << OldType->getDescription() << "\n";
+#endif
+      OldType->removeAbstractTypeUser(this);
+
+      I->second = (Type*)NewType;  // TODO FIXME when types aren't const
+      if (NewType->isAbstract()) {
+#if DEBUG_ABSTYPE
+        std::cerr << "Added type " << NewType->getDescription() << "\n";
+#endif
+        cast<DerivedType>(NewType)->addAbstractTypeUser(this);
+      }
+    }
+  }
+}
+
+
+// Handle situation where type becomes Concreate from Abstract
+void TypeSymbolTable::typeBecameConcrete(const DerivedType *AbsTy) {
+  // Loop over all of the types in the symbol table, dropping any abstract
+  // type user entries for AbsTy which occur because there are names for the
+  // type.
+  for (iterator TI = begin(), TE = end(); TI != TE; ++TI)
+    if (TI->second == const_cast<Type*>(static_cast<const Type*>(AbsTy)))
+      AbsTy->removeAbstractTypeUser(this);
+}
+
+static void DumpTypes(const std::pair<const std::string, const Type*>& T ) {
+  std::cerr << "  '" << T.first << "' = ";
+  T.second->dump();
+  std::cerr << "\n";
+}
+
+void TypeSymbolTable::dump() const {
+  std::cerr << "TypeSymbolPlane: ";
+  for_each(tmap.begin(), tmap.end(), DumpTypes);
+}
+
+// vim: sw=2 ai