Bug 1393230 - Part 3: Convert the xpcom string classes to be template…

…d on char type. r=njn, r=fitzgen, r=sfink This removes the double-include macro hackery that we use to define two separate string types (nsAString and nsACString) in favor of a templated solution. Annotations for Valgrind and the JS hazard analysis are updated as well as the rust binding generations for string code. --HG-- extra : rebase_source : 63ab2c4620cfcd4b764d42d654c82f30f984d016 extra : source : 9115364cd4aa078c49bba7911069f8178e55166f
dothq · Aug 14, 2017 · 030b39d · 030b39d
1 parent 0617c21
commit 030b39d
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Showing 42 changed files with 1,910 additions and 1,469 deletions.
diff --git a/build/valgrind/cross-architecture.sup b/build/valgrind/cross-architecture.sup
@@ -15,7 +15,7 @@
    PR_SetEnv requires its argument to be leaked, but does not appear on stacks. (See bug 793549.)
    Memcheck:Leak
    ...
-   fun:_ZL13SaveWordToEnvPKcRK10nsACString
+   fun:_ZL13SaveWordToEnvPKcRK12nsTSubstringIcE
    ...
 }
 {

diff --git a/js/src/devtools/rootAnalysis/analyzeHeapWrites.js b/js/src/devtools/rootAnalysis/analyzeHeapWrites.js
@@ -445,17 +445,17 @@ function ignoreContents(entry)
             /nsTArray_base.*?::EnsureCapacity/,
             /nsTArray_base.*?::ShiftData/,
             /AutoTArray.*?::Init/,
-            /nsAC?String::SetCapacity/,
-            /nsAC?String::SetLength/,
-            /nsAC?String::Assign/,
-            /nsAC?String::Append/,
-            /nsAC?String::Replace/,
-            /nsAC?String::Trim/,
-            /nsAC?String::Truncate/,
-            /nsAString::StripTaggedASCII/,
-            /nsAC?String::operator=/,
-            /nsAutoString::nsAutoString/,
-            /nsFixedCString::nsFixedCString/,
+            /nsTSubstring<T>::SetCapacity/,
+            /nsTSubstring<T>::SetLength/,
+            /nsTSubstring<T>::Assign/,
+            /nsTSubstring<T>::Append/,
+            /nsTSubstring<T>::Replace/,
+            /nsTSubstring<T>::Trim/,
+            /nsTSubstring<T>::Truncate/,
+            /nsTSubstring<T>::StripTaggedASCII/,
+            /nsTSubstring<T>::operator=/,
+            /nsTAutoStringN<T, N>::nsTAutoStringN/,
+            /nsTFixedString<T>::nsTFixedString/,
 
             // Similar for some other data structures
             /nsCOMArray_base::SetCapacity/,

diff --git a/layout/style/ServoBindings.toml b/layout/style/ServoBindings.toml
@@ -343,7 +343,8 @@ mapped-generic-types = [
     { generic = false, gecko = "ServoStyleContextStrong", servo = "::gecko_bindings::sugar::ownership::Strong<::properties::ComputedValues>" },
 ]
 fixups = [
-    { pat = "root::nsString", rep = "::nsstring::nsStringRepr" },
+    { pat = "\\broot::nsString\\b", rep = "::nsstring::nsStringRepr" },
+    { pat = "\\broot::nsTString<u16>", rep = "::nsstring::nsStringRepr" },
 ]
 
 [bindings]
@@ -541,6 +542,8 @@ servo-borrow-types = [
     "RawGeckoStyleChildrenIterator",
 ]
 fixups = [
+    # Remap the templated string type to the helper type
+    { pat = "\\bnsTString<u16>", rep = "nsString" },
     # hack for gecko-owned string
-    { pat = "<nsString", rep = "<nsStringRepr" },
+    { pat = "\\b<nsString\\b", rep = "<nsStringRepr" },
 ]
diff --git a/xpcom/string/moz.build b/xpcom/string/moz.build
@@ -19,6 +19,7 @@ EXPORTS += [
     'nsReadableUtils.h',
     'nsString.h',
     'nsStringBuffer.h',
+    'nsStringFlags.h',
     'nsStringFwd.h',
     'nsStringIterator.h',
     'nsSubstring.h',
@@ -29,12 +30,10 @@ EXPORTS += [
     'nsTLiteralString.h',
     'nsTPromiseFlatString.h',
     'nsTString.h',
+    'nsTStringRepr.h',
     'nsTSubstring.h',
     'nsTSubstringTuple.h',
     'nsUTF8Utils.h',
-    'string-template-def-char.h',
-    'string-template-def-unichar.h',
-    'string-template-undef.h',
 ]
 
 UNIFIED_SOURCES += [
@@ -49,6 +48,7 @@ UNIFIED_SOURCES += [
     'nsSubstring.cpp',
     'nsSubstringTuple.cpp',
     'nsTextFormatter.cpp',
+    'precompiled_templates.cpp',
 ]
 
 # Are we targeting x86 or x86-64?  If so, compile the SSE2 functions for

diff --git a/xpcom/string/nsAString.h b/xpcom/string/nsAString.h
@@ -17,79 +17,9 @@
 
 #define kNotFound -1
 
-namespace mozilla {
-namespace detail {
-// NOTE: these flags are declared public _only_ for convenience inside
-// the string implementation.  And they are outside of the string
-// class so that the type is the same for both narrow and wide
-// strings.
-
-// bits for mDataFlags
-enum class StringDataFlags : uint16_t
-{
-  // Some terminology:
-  //
-  //   "dependent buffer"    A dependent buffer is one that the string class
-  //                         does not own.  The string class relies on some
-  //                         external code to ensure the lifetime of the
-  //                         dependent buffer.
-  //
-  //   "shared buffer"       A shared buffer is one that the string class
-  //                         allocates.  When it allocates a shared string
-  //                         buffer, it allocates some additional space at
-  //                         the beginning of the buffer for additional
-  //                         fields, including a reference count and a
-  //                         buffer length.  See nsStringHeader.
-  //
-  //   "adopted buffer"      An adopted buffer is a raw string buffer
-  //                         allocated on the heap (using moz_xmalloc)
-  //                         of which the string class subsumes ownership.
-  //
-  // Some comments about the string data flags:
-  //
-  //   SHARED, OWNED, and FIXED are all mutually exlusive.  They
-  //   indicate the allocation type of mData.  If none of these flags
-  //   are set, then the string buffer is dependent.
-  //
-  //   SHARED, OWNED, or FIXED imply TERMINATED.  This is because
-  //   the string classes always allocate null-terminated buffers, and
-  //   non-terminated substrings are always dependent.
-  //
-  //   VOIDED implies TERMINATED, and moreover it implies that mData
-  //   points to char_traits::sEmptyBuffer.  Therefore, VOIDED is
-  //   mutually exclusive with SHARED, OWNED, and FIXED.
-
-  TERMINATED   = 1 << 0,  // IsTerminated returns true
-  VOIDED       = 1 << 1,  // IsVoid returns true
-  SHARED       = 1 << 2,  // mData points to a heap-allocated, shared buffer
-  OWNED        = 1 << 3,  // mData points to a heap-allocated, raw buffer
-  FIXED        = 1 << 4,  // mData points to a fixed-size writable, dependent buffer
-  LITERAL      = 1 << 5   // mData points to a string literal; DataFlags::TERMINATED will also be set
-};
-
-// bits for mClassFlags
-enum class StringClassFlags : uint16_t
-{
-  FIXED           = 1 << 0, // |this| is of type nsTFixedString
-  NULL_TERMINATED = 1 << 1  // |this| requires its buffer is null-terminated
-};
-
-MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(StringDataFlags)
-MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(StringClassFlags)
-
-} // namespace detail
-} // namespace mozilla
-
-// declare nsAString
-#include "string-template-def-unichar.h"
+#include "nsStringFlags.h"
+#include "nsTStringRepr.h"
 #include "nsTSubstring.h"
-#include "string-template-undef.h"
-
-// declare nsACString
-#include "string-template-def-char.h"
-#include "nsTSubstring.h"
-#include "string-template-undef.h"
-
 
 /**
  * ASCII case-insensitive comparator.  (for Unicode case-insensitive

diff --git a/xpcom/string/nsDependentString.cpp b/xpcom/string/nsDependentString.cpp
@@ -7,12 +7,4 @@
 #include "nsDependentString.h"
 #include "nsAlgorithm.h"
 
-// define nsDependentString
-#include "string-template-def-unichar.h"
 #include "nsTDependentString.cpp"
-#include "string-template-undef.h"
-
-// define nsDependentCString
-#include "string-template-def-char.h"
-#include "nsTDependentString.cpp"
-#include "string-template-undef.h"
diff --git a/xpcom/string/nsDependentString.h b/xpcom/string/nsDependentString.h
@@ -10,14 +10,7 @@
 #include "nsString.h"
 #include "nsDebug.h"
 
-// declare nsDependentString
-#include "string-template-def-unichar.h"
 #include "nsTDependentString.h"
-#include "string-template-undef.h"
 
-// declare nsDependentCString
-#include "string-template-def-char.h"
-#include "nsTDependentString.h"
-#include "string-template-undef.h"
 
 #endif /* !defined(nsDependentString_h___) */
diff --git a/xpcom/string/nsDependentSubstring.cpp b/xpcom/string/nsDependentSubstring.cpp
@@ -7,12 +7,4 @@
 #include "nsDependentSubstring.h"
 #include "nsAlgorithm.h"
 
-// define nsDependentSubstring
-#include "string-template-def-unichar.h"
 #include "nsTDependentSubstring.cpp"
-#include "string-template-undef.h"
-
-// define nsDependentCSubstring
-#include "string-template-def-char.h"
-#include "nsTDependentSubstring.cpp"
-#include "string-template-undef.h"
diff --git a/xpcom/string/nsDependentSubstring.h b/xpcom/string/nsDependentSubstring.h
@@ -8,15 +8,6 @@
 #define nsDependentSubstring_h___
 
 #include "nsSubstring.h"
-
-// declare nsDependentSubstring
-#include "string-template-def-unichar.h"
-#include "nsTDependentSubstring.h"
-#include "string-template-undef.h"
-
-// declare nsDependentCSubstring
-#include "string-template-def-char.h"
 #include "nsTDependentSubstring.h"
-#include "string-template-undef.h"
 
 #endif /* !defined(nsDependentSubstring_h___) */
diff --git a/xpcom/string/nsLiteralString.h b/xpcom/string/nsLiteralString.h
@@ -10,15 +10,7 @@
 #include "nscore.h"
 #include "nsString.h"
 
-// declare nsLiteralString
-#include "string-template-def-unichar.h"
 #include "nsTLiteralString.h"
-#include "string-template-undef.h"
-
-// declare nsLiteralCString
-#include "string-template-def-char.h"
-#include "nsTLiteralString.h"
-#include "string-template-undef.h"
 
 #include "mozilla/Char16.h"
 

diff --git a/xpcom/string/nsPromiseFlatString.cpp b/xpcom/string/nsPromiseFlatString.cpp
@@ -6,12 +6,4 @@
 
 #include "nsPromiseFlatString.h"
 
-// define nsPromiseFlatString
-#include "string-template-def-unichar.h"
 #include "nsTPromiseFlatString.cpp"
-#include "string-template-undef.h"
-
-// define nsPromiseFlatCString
-#include "string-template-def-char.h"
-#include "nsTPromiseFlatString.cpp"
-#include "string-template-undef.h"
diff --git a/xpcom/string/nsPromiseFlatString.h b/xpcom/string/nsPromiseFlatString.h
@@ -9,14 +9,6 @@
 
 #include "nsString.h"
 
-// declare nsPromiseFlatString
-#include "string-template-def-unichar.h"
 #include "nsTPromiseFlatString.h"
-#include "string-template-undef.h"
-
-// declare nsPromiseFlatCString
-#include "string-template-def-char.h"
-#include "nsTPromiseFlatString.h"
-#include "string-template-undef.h"
 
 #endif /* !defined(nsPromiseFlatString_h___) */
diff --git a/xpcom/string/nsString.cpp b/xpcom/string/nsString.cpp
@@ -6,12 +6,4 @@
 
 #include "nsString.h"
 
-// define nsString
-#include "string-template-def-unichar.h"
 #include "nsTString.cpp"
-#include "string-template-undef.h"
-
-// define nsCString
-#include "string-template-def-char.h"
-#include "nsTString.cpp"
-#include "string-template-undef.h"
diff --git a/xpcom/string/nsString.h b/xpcom/string/nsString.h
@@ -9,6 +9,8 @@
 
 #include "mozilla/Attributes.h"
 
+#include "nsStringFwd.h"
+
 #include "nsSubstring.h"
 #include "nsDependentSubstring.h"
 #include "nsReadableUtils.h"
@@ -27,16 +29,7 @@
 #define kAutoDetect     (100)
 #endif
 
-
-// declare nsString, et. al.
-#include "string-template-def-unichar.h"
-#include "nsTString.h"
-#include "string-template-undef.h"
-
-// declare nsCString, et. al.
-#include "string-template-def-char.h"
 #include "nsTString.h"
-#include "string-template-undef.h"
 
 static_assert(sizeof(char16_t) == 2, "size of char16_t must be 2");
 static_assert(sizeof(nsString::char_type) == 2,
@@ -46,6 +39,14 @@ static_assert(nsString::char_type(-1) > nsString::char_type(0),
 static_assert(sizeof(nsCString::char_type) == 1,
               "size of nsCString::char_type must be 1");
 
+static_assert(sizeof(nsTLiteralString<char>) == sizeof(nsTString<char>),
+              "nsLiteralCString can masquerade as nsCString, "
+              "so they must have identical layout");
+
+static_assert(sizeof(nsTLiteralString<char16_t>) == sizeof(nsTString<char16_t>),
+              "nsTLiteralString can masquerade as nsString, "
+              "so they must have identical layout");
+
 
 /**
  * A helper class that converts a UTF-16 string to ASCII in a lossy manner
@@ -60,7 +61,7 @@ class NS_LossyConvertUTF16toASCII : public nsAutoCString
 
   NS_LossyConvertUTF16toASCII(const char16ptr_t aString, uint32_t aLength)
   {
-    LossyAppendUTF16toASCII(Substring(aString, aLength), *this);
+    LossyAppendUTF16toASCII(Substring(static_cast<const char16_t*>(aString), aLength), *this);
   }
 
   explicit NS_LossyConvertUTF16toASCII(const nsAString& aString)
@@ -111,7 +112,7 @@ class NS_ConvertUTF16toUTF8 : public nsAutoCString
 
   NS_ConvertUTF16toUTF8(const char16ptr_t aString, uint32_t aLength)
   {
-    AppendUTF16toUTF8(Substring(aString, aLength), *this);
+    AppendUTF16toUTF8(Substring(static_cast<const char16_t*>(aString), aLength), *this);
   }
 
   explicit NS_ConvertUTF16toUTF8(const nsAString& aString)

diff --git a/xpcom/string/nsStringComparator.cpp b/xpcom/string/nsStringComparator.cpp
@@ -8,16 +8,7 @@
 #include "nsAString.h"
 #include "plstr.h"
 
-
-// define nsStringComparator
-#include "string-template-def-unichar.h"
-#include "nsTStringComparator.cpp"
-#include "string-template-undef.h"
-
-// define nsCStringComparator
-#include "string-template-def-char.h"
 #include "nsTStringComparator.cpp"
-#include "string-template-undef.h"
 
 
 int