Add a note about a potential PIC optimization.

[oota-llvm.git] / include / llvm / ADT / StringMap.h

diff --git a/include/llvm/ADT/StringMap.h b/include/llvm/ADT/StringMap.h
index dd040f927db9e10f36519f37da2d0b7ce3e96296..0a4a5d631d9c55df99e10d12b5f51eeff4348fc3 100644 (file)
--- a/include/llvm/ADT/StringMap.h
+++ b/include/llvm/ADT/StringMap.h
@@ -153,13 +153,14 @@ public:
   static StringMapEntry *Create(const char *KeyStart, const char *KeyEnd,
                                 AllocatorTy &Allocator,
                                 InitType InitVal) {
-    unsigned KeyLength = KeyEnd-KeyStart;
+    unsigned KeyLength = static_cast<unsigned>(KeyEnd-KeyStart);
 
     // Okay, the item doesn't already exist, and 'Bucket' is the bucket to fill
     // in.  Allocate a new item with space for the string at the end and a null
     // terminator.
 
-    unsigned AllocSize = sizeof(StringMapEntry)+KeyLength+1;
+    unsigned AllocSize = static_cast<unsigned>(sizeof(StringMapEntry))+
+      KeyLength+1;
     unsigned Alignment = alignof<StringMapEntry>();
 
     StringMapEntry *NewItem =
@@ -236,9 +237,9 @@ class StringMap : public StringMapImpl {
   AllocatorTy Allocator;
   typedef StringMapEntry<ValueTy> MapEntryTy;
 public:
-  StringMap() : StringMapImpl(sizeof(MapEntryTy)) {}
+  StringMap() : StringMapImpl(static_cast<unsigned>(sizeof(MapEntryTy))) {}
   explicit StringMap(unsigned InitialSize)
-    : StringMapImpl(InitialSize, sizeof(MapEntryTy)) {}
+    : StringMapImpl(InitialSize, static_cast<unsigned>(sizeof(MapEntryTy))) {}
 
   AllocatorTy &getAllocator() { return Allocator; }
   const AllocatorTy &getAllocator() const { return Allocator; }
@@ -273,7 +274,7 @@ public:
     return find(Key, Key + strlen(Key));
   }
   iterator find(const std::string &Key) {
-    const char* key_start = &Key[0];
+    const char* key_start = (Key.empty() ? NULL : &Key[0]);
     return find(key_start, key_start + Key.size());
   }
 
@@ -286,7 +287,7 @@ public:
     return find(Key, Key + strlen(Key));
   }
   const_iterator find(const std::string &Key) const {
-    const char* key_start = &Key[0];
+    const char* key_start = (Key.empty() ? NULL : &Key[0]);
     return find(key_start, key_start + Key.size());
   }
 
@@ -295,7 +296,7 @@ public:
     return entry.getValue();
   }
   ValueTy& operator[](const std::string &Key) {
-    const char* key_start = &Key[0];
+    const char* key_start = (Key.empty() ? NULL : &Key[0]);
     value_type& entry = GetOrCreateValue(key_start, key_start + Key.size());
     return entry.getValue();
   }
@@ -307,7 +308,7 @@ public:
     return count(Key, Key + strlen(Key));
   }
   size_type count(const std::string &Key) const {
-    const char* key_start = &Key[0];
+    const char* key_start = (Key.empty() ? NULL : &Key[0]);
     return count(key_start, key_start + Key.size());
   }
 
@@ -376,6 +377,20 @@ public:
     V.Destroy(Allocator);
   }
 
+  bool erase(const char *Key) {
+    iterator I = find(Key);
+    if (I == end()) return false;
+    erase(I);
+    return true;
+  }
+
+  bool erase(std::string Key) {
+    iterator I = find(Key);
+    if (I == end()) return false;
+    erase(I);
+    return true;
+  }
+
   ~StringMap() {
     for (ItemBucket *I = TheTable, *E = TheTable+NumBuckets; I != E; ++I) {
       if (I->Item && I->Item != getTombstoneVal())