• aroben@apple.com's avatar
    Ensure no intermediate WTF::Strings are created when concatenating with string literals · 6b68717e
    aroben@apple.com authored
    Fixes <http://webkit.org/b/63330> Concatenating string literals and WTF::Strings using
    operator+ is suboptimal
    
    Reviewed by Darin Adler.
    
    Source/JavaScriptCore:
    
    * wtf/text/StringConcatenate.h:
    (WTF::StringTypeAdapter<String>::writeTo): Added a macro that can be used for testing how
    many WTF::Strings get copied while evaluating an operator+ expression.
    
    * wtf/text/StringOperators.h:
    (WTF::operator+): Changed the overload that takes a StringAppend to take it on the left-hand
    side, since operator+ is left-associative. Having the StringAppend on the right-hand side
    was causing us to make intermediate WTF::Strings when evaluating expressions that contained
    multiple calls to operator+. Added some more overloads for that take a left-hand side of
    const char* to resolve overload ambiguity for certain expressions. Added overloads that take
    a left-hand side of const UChar* (matching the const char* overloads) so that wide string
    literals don't first have to be converted to a WTF::String in operator+ expressions.
    
    Source/WebKit2:
    
    Export some symbols needed by TestWebKitAPI
    
    * win/WebKit2.def:
    
    Tools:
    
    Test that no intermediate WTF::Strings are created when concatenating with string literals
    
    * TestWebKitAPI/Tests/WTF/StringOperators.cpp: Added.
    (TestWebKitAPI::TEST): Test that a bunch of different string concatenation expressions don't
    create any intermediate WTF::Strings while they're being evaluated.
    
    * TestWebKitAPI/TestWebKitAPI.xcodeproj/project.pbxproj:
    * TestWebKitAPI/win/TestWebKitAPI.vcproj:
    Added new file.
    
    git-svn-id: http://svn.webkit.org/repository/webkit/trunk@90813 268f45cc-cd09-0410-ab3c-d52691b4dbfc
    6b68717e
WebKit2.def 5.88 KB