Bug 1386103 (part 1, attempt 3) - Specify nsAuto[C]String storage siz…

…e via template parameter. r=dbaron.
Brli · Aug 9, 2017 · 57ccb9e · 57ccb9e
1 parent 1029a41
commit 57ccb9e
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Showing 8 changed files with 37 additions and 29 deletions.
diff --git a/dom/indexedDB/ProfilerHelpers.h b/dom/indexedDB/ProfilerHelpers.h
@@ -61,7 +61,7 @@ class MOZ_STACK_CLASS LoggingIdString final
   LoggingIdString(const nsID& aID)
   {
     static_assert(NSID_LENGTH > 1, "NSID_LENGTH is set incorrectly!");
-    static_assert(NSID_LENGTH <= kDefaultStorageSize,
+    static_assert(NSID_LENGTH <= kStorageSize,
                   "nID string won't fit in our storage!");
     MOZ_ASSERT(Capacity() > NSID_LENGTH);
 

diff --git a/security/manager/ssl/nsNSSCertificate.h b/security/manager/ssl/nsNSSCertificate.h
@@ -20,7 +20,6 @@
 
 namespace mozilla { namespace pkix { class DERArray; } }
 
-class nsAutoString;
 class nsINSSComponent;
 class nsIASN1Sequence;
 

diff --git a/storage/mozStorageSQLFunctions.cpp b/storage/mozStorageSQLFunctions.cpp
@@ -165,8 +165,8 @@ levenshteinDistance(const nsAString &aStringS,
     // we be able to see the current row and the previous one.
 
     // Allocate memory for two rows.
-    AutoTArray<int, nsAutoString::kDefaultStorageSize> row1;
-    AutoTArray<int, nsAutoString::kDefaultStorageSize> row2;
+    AutoTArray<int, nsAutoString::kStorageSize> row1;
+    AutoTArray<int, nsAutoString::kStorageSize> row2;
 
     // Declare the raw pointers that will actually be used to access the memory.
     int *prevRow = row1.AppendElements(sLen + 1);

diff --git a/xpcom/string/nsStringFwd.h b/xpcom/string/nsStringFwd.h
@@ -24,11 +24,14 @@ class nsCStringRepr;
 } // namespace detail
 } // namespace mozilla
 
+static const size_t AutoStringDefaultStorageSize = 64;
+
 // Double-byte (char16_t) string types.
 class nsAString;
 class nsSubstringTuple;
 class nsString;
-class nsAutoString;
+template<size_t N> class nsAutoStringN;
+using nsAutoString = nsAutoStringN<AutoStringDefaultStorageSize>;
 class nsDependentString;
 class nsDependentSubstring;
 class nsPromiseFlatString;
@@ -39,7 +42,8 @@ class nsDefaultStringComparator;
 class nsACString;
 class nsCSubstringTuple;
 class nsCString;
-class nsAutoCString;
+template<size_t N> class nsAutoCStringN;
+using nsAutoCString = nsAutoCStringN<AutoStringDefaultStorageSize>;
 class nsDependentCString;
 class nsDependentCSubstring;
 class nsPromiseFlatCString;

diff --git a/xpcom/string/nsTString.h b/xpcom/string/nsTString.h
@@ -560,63 +560,65 @@ class nsTFixedString_CharT : public nsTString_CharT
  * it contains is significantly smaller or any larger than 64 characters.
  *
  * NAMES:
- *   nsAutoString for wide characters
- *   nsAutoCString for narrow characters
+ *   nsAutoStringN / nsAutoString for wide characters
+ *   nsAutoCStringN / nsAutoCString for narrow characters
  */
-class MOZ_NON_MEMMOVABLE nsTAutoString_CharT : public nsTFixedString_CharT
+template<size_t N>
+class MOZ_NON_MEMMOVABLE nsTAutoStringN_CharT : public nsTFixedString_CharT
 {
 public:
 
-  typedef nsTAutoString_CharT self_type;
+  typedef nsTAutoStringN_CharT<N> self_type;
 
 public:
 
   /**
    * constructors
    */
 
-  nsTAutoString_CharT()
-    : fixed_string_type(mStorage, kDefaultStorageSize, 0)
+  nsTAutoStringN_CharT()
+    : fixed_string_type(mStorage, N, 0)
   {
   }
 
   explicit
-  nsTAutoString_CharT(char_type aChar)
-    : fixed_string_type(mStorage, kDefaultStorageSize, 0)
+  nsTAutoStringN_CharT(char_type aChar)
+    : fixed_string_type(mStorage, N, 0)
   {
     Assign(aChar);
   }
 
   explicit
-  nsTAutoString_CharT(const char_type* aData, size_type aLength = size_type(-1))
-    : fixed_string_type(mStorage, kDefaultStorageSize, 0)
+  nsTAutoStringN_CharT(const char_type* aData,
+                       size_type aLength = size_type(-1))
+    : fixed_string_type(mStorage, N, 0)
   {
     Assign(aData, aLength);
   }
 
 #if defined(CharT_is_PRUnichar) && defined(MOZ_USE_CHAR16_WRAPPER)
   explicit
-  nsTAutoString_CharT(char16ptr_t aData, size_type aLength = size_type(-1))
-    : nsTAutoString_CharT(static_cast<const char16_t*>(aData), aLength)
+  nsTAutoStringN_CharT(char16ptr_t aData, size_type aLength = size_type(-1))
+    : nsTAutoStringN_CharT(static_cast<const char16_t*>(aData), aLength)
   {
   }
 #endif
 
-  nsTAutoString_CharT(const self_type& aStr)
-    : fixed_string_type(mStorage, kDefaultStorageSize, 0)
+  nsTAutoStringN_CharT(const self_type& aStr)
+    : fixed_string_type(mStorage, N, 0)
   {
     Assign(aStr);
   }
 
   explicit
-  nsTAutoString_CharT(const substring_type& aStr)
-    : fixed_string_type(mStorage, kDefaultStorageSize, 0)
+  nsTAutoStringN_CharT(const substring_type& aStr)
+    : fixed_string_type(mStorage, N, 0)
   {
     Assign(aStr);
   }
 
-  MOZ_IMPLICIT nsTAutoString_CharT(const substring_tuple_type& aTuple)
-    : fixed_string_type(mStorage, kDefaultStorageSize, 0)
+  MOZ_IMPLICIT nsTAutoStringN_CharT(const substring_tuple_type& aTuple)
+    : fixed_string_type(mStorage, N, 0)
   {
     Assign(aTuple);
   }
@@ -655,16 +657,16 @@ class MOZ_NON_MEMMOVABLE nsTAutoString_CharT : public nsTFixedString_CharT
     return *this;
   }
 
-  enum
-  {
-    kDefaultStorageSize = 64
-  };
+  static const size_t kStorageSize = N;
 
 private:
 
-  char_type mStorage[kDefaultStorageSize];
+  char_type mStorage[N];
 };
 
+// We define this typedef instead of providing a default value for N so that so
+// there is a default typename that doesn't require angle brackets.
+using nsTAutoString_CharT = nsTAutoStringN_CharT<AutoStringDefaultStorageSize>;
 
 //
 // nsAutoString stores pointers into itself which are invalidated when an

diff --git a/xpcom/string/string-template-def-char.h b/xpcom/string/string-template-def-char.h
@@ -11,6 +11,7 @@
 #define nsTString_CharT                     nsCString
 #define nsTStringRepr_CharT                 nsCStringRepr
 #define nsTFixedString_CharT                nsFixedCString
+#define nsTAutoStringN_CharT                nsAutoCStringN
 #define nsTAutoString_CharT                 nsAutoCString
 #define nsTSubstring_CharT                  nsACString
 #define PrintfAppend_CharT                  PrintfAppend_nsACString

diff --git a/xpcom/string/string-template-def-unichar.h b/xpcom/string/string-template-def-unichar.h
@@ -11,6 +11,7 @@
 #define nsTString_CharT                     nsString
 #define nsTStringRepr_CharT                 nsStringRepr
 #define nsTFixedString_CharT                nsFixedString
+#define nsTAutoStringN_CharT                nsAutoStringN
 #define nsTAutoString_CharT                 nsAutoString
 #define nsTSubstring_CharT                  nsAString
 #define PrintfAppend_CharT                  PrintfAppend_nsAString

diff --git a/xpcom/string/string-template-undef.h b/xpcom/string/string-template-undef.h
@@ -12,6 +12,7 @@
 #undef nsTString_CharT
 #undef nsTStringRepr_CharT
 #undef nsTFixedString_CharT
+#undef nsTAutoStringN_CharT
 #undef nsTAutoString_CharT
 #undef nsTSubstring_CharT
 #undef PrintfAppend_CharT