JDK-6906748 : Project Coin: Minor strings in switch cleanup
  • Type: Bug
  • Component: tools
  • Sub-Component: javac
  • Affected Version: 7
  • Priority: P4
  • Status: Closed
  • Resolution: Fixed
  • OS: generic
  • CPU: generic
  • Submitted: 2009-12-03
  • Updated: 2021-03-03
  • Resolved: 2011-07-25
The Version table provides details related to the release that this issue/RFE will be addressed.

Unresolved : Release in which this issue/RFE will be addressed.
Resolved: Release in which this issue/RFE has been resolved.
Fixed : Release in which this issue/RFE has been fixed. The release containing this fix may be available for download as an Early Access Release or a General Availability Release.

To download the current JDK release, click here.
JDK 7
7 b78Fixed
Related Reports
Relates :  
JDK-6827009 - Project Coin: Strings in Switch
Relates :  
JDK-8261606 - Surprising behavior of step over in String switch
Description
Neal made some suggestions for code cleanups and doc clarifications in the strings in switch implementation.
Comments
PUBLIC COMMENTS See http://hg.openjdk.java.net/jdk7/tl/langtools/rev/121e0ebf1658
03-12-2009
SUGGESTED FIX # HG changeset patch # User darcy # Date 1259877833 28800 # Node ID 121e0ebf16587ff8a3ae30d36bdb41d2099bad8a # Parent b1508b6affd8c44518320070169aea2bcdef2390 6906748: Project Coin: Minor strings in switch cleanup Reviewed-by: jjg --- a/src/share/classes/com/sun/tools/javac/code/Source.java Mon Nov 23 19:58:05 2009 -0800 +++ b/src/share/classes/com/sun/tools/javac/code/Source.java Thu Dec 03 14:03:53 2009 -0800 @@ -110,9 +110,6 @@ public enum Source { } /** Allow encoding errors, giving only warnings. */ - public boolean allowStringsInSwitch() { - return compareTo(JDK1_7) >= 0; - } public boolean allowEncodingErrors() { return compareTo(JDK1_6) < 0; } @@ -168,6 +165,9 @@ public enum Source { public boolean allowUnderscoresInLiterals() { return compareTo(JDK1_7) >= 0; } + public boolean allowStringsInSwitch() { + return compareTo(JDK1_7) >= 0; + } public static SourceVersion toSourceVersion(Source source) { switch(source) { case JDK1_2: --- a/src/share/classes/com/sun/tools/javac/comp/Lower.java Mon Nov 23 19:58:05 2009 -0800 +++ b/src/share/classes/com/sun/tools/javac/comp/Lower.java Thu Dec 03 14:03:53 2009 -0800 @@ -3117,7 +3117,6 @@ public class Lower extends TreeTranslato tree.cases = translateCases(tree.cases); if (enumSwitch) { result = visitEnumSwitch(tree); - patchTargets(result, tree, result); } else if (stringSwitch) { result = visitStringSwitch(tree); } else { @@ -3146,7 +3145,9 @@ public class Lower extends TreeTranslato cases.append(c); } } - return make.Switch(selector, cases.toList()); + JCSwitch enumSwitch = make.Switch(selector, cases.toList()); + patchTargets(enumSwitch, tree, enumSwitch); + return enumSwitch; } public JCTree visitStringSwitch(JCSwitch tree) { @@ -3187,7 +3188,14 @@ public class Lower extends TreeTranslato * of String is the same in the compilation environment as * in the environment the code will run in. The string * hashing algorithm in the SE JDK has been unchanged - * since at least JDK 1.2. + * since at least JDK 1.2. Since the algorithm has been + * specified since that release as well, it is very + * unlikely to be changed in the future. + * + * Different hashing algorithms, such as the length of the + * strings or a perfect hashing algorithm over the + * particular set of case labels, could potentially be + * used instead of String.hashCode. */ ListBuffer<JCStatement> stmtList = new ListBuffer<JCStatement>();
03-12-2009
EVALUATION A fine idea.
03-12-2009