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8183548: Comma-expressions shouldn't use any temporary variable

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Uses enhanced let-expressions allowing multiple statements

Reviewed-by: vromero
This commit is contained in:
Bernard Blaser 2018-09-15 22:16:16 +02:00
parent 12bac3a02d
commit 8ef50b1dc3
2 changed files with 13 additions and 10 deletions
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4
src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Lower.java
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@ -2057,7 +2057,9 @@ public class Lower extends TreeTranslator {
// evaluate and discard the first expression, then evaluate the second.
JCExpression makeComma(final JCExpression expr1, final JCExpression expr2) {
return abstractRval(expr1, discarded -> expr2);
JCExpression res = make.LetExpr(List.of(make.Exec(expr1)), expr2);
res.type = expr2.type;
return res;
}
/**************************************************************************

19
test/langtools/tools/javac/desugar/BoxingAndSuper.java
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@ -100,7 +100,7 @@ public class BoxingAndSuper {
"p.Test.dump()java.lang.Integer\n" +
"{\n" +
" return (let /*synthetic*/ final Integer $le0 = (Integer)super.i " +
"in (let /*synthetic*/ final Integer $le1 = super.i = Integer.valueOf((int)(super.i.intValue() + 1)) " +
"in (let super.i = Integer.valueOf((int)(super.i.intValue() + 1)); " +
"in $le0));\n" +
"}\n");
//qualified super, same package:
@ -121,7 +121,7 @@ public class BoxingAndSuper {
"p.Test.Inner.dump()java.lang.Integer\n" +
"{\n" +
" return (let /*synthetic*/ final Integer $le0 = (Integer)Test.access$001(this$0) " +
"in (let /*synthetic*/ final Integer $le1 = Test.access$103(this$0, Integer.valueOf((int)(Test.access$201(this$0).intValue() + 1))) " +
"in (let Test.access$103(this$0, Integer.valueOf((int)(Test.access$201(this$0).intValue() + 1))); " +
"in $le0));\n" +
"}\n" +
"p.Test.access$001(p.Test)java.lang.Integer\n" +
@ -152,7 +152,7 @@ public class BoxingAndSuper {
"p1.Test.dump()java.lang.Integer\n" +
"{\n" +
" return (let /*synthetic*/ final Integer $le0 = (Integer)super.i " +
"in (let /*synthetic*/ final Integer $le1 = super.i = Integer.valueOf((int)(super.i.intValue() + 1)) " +
"in (let super.i = Integer.valueOf((int)(super.i.intValue() + 1)); " +
"in $le0));\n" +
"}\n");
//qualified super, different packages:
@ -173,7 +173,7 @@ public class BoxingAndSuper {
"p1.Test.Inner.dump()java.lang.Integer\n" +
"{\n" +
" return (let /*synthetic*/ final Integer $le0 = (Integer)Test.access$001(this$0) " +
"in (let /*synthetic*/ final Integer $le1 = Test.access$103(this$0, Integer.valueOf((int)(Test.access$201(this$0).intValue() + 1))) " +
"in (let Test.access$103(this$0, Integer.valueOf((int)(Test.access$201(this$0).intValue() + 1))); " +
"in $le0));\n" +
"}\n" +
"p1.Test.access$001(p1.Test)java.lang.Integer\n" +
@ -201,8 +201,8 @@ public class BoxingAndSuper {
String expected =
"Test.dump()void\n" +
"{\n" +
" (let /*synthetic*/ final Integer $le0 = i in (let /*synthetic*/ final Integer $le1 = i = Integer.valueOf((int)(i.intValue() + 1)) in $le0));\n" +
" (let /*synthetic*/ final Integer $le2 = (Integer)this.i in (let /*synthetic*/ final Integer $le3 = this.i = Integer.valueOf((int)(this.i.intValue() + 1)) in $le2));\n" +
" (let /*synthetic*/ final Integer $le0 = i in (let i = Integer.valueOf((int)(i.intValue() + 1)); in $le0));\n" +
" (let /*synthetic*/ final Integer $le1 = (Integer)this.i in (let this.i = Integer.valueOf((int)(this.i.intValue() + 1)); in $le1));\n" +
"}\n";
runTest(code, expected);
//qualified this:
@ -219,8 +219,8 @@ public class BoxingAndSuper {
"Test.Inner1.Inner2.dump()java.lang.Integer\n" +
"{\n" +
" return (let /*synthetic*/ final Integer $le0 = (Integer)this$1.this$0.i" +
" in (let /*synthetic*/ final Integer $le1 = this$1.this$0.i = " +
"Integer.valueOf((int)(this$1.this$0.i.intValue() + 1)) " +
" in (let this$1.this$0.i = " +
"Integer.valueOf((int)(this$1.this$0.i.intValue() + 1)); " +
"in $le0));\n" +
"}\n"
);
@ -329,7 +329,8 @@ public class BoxingAndSuper {
LetExpr le = (LetExpr) tree;
for (JCStatement var : le.defs) {
letExprRemap.put(((JCVariableDecl) var).name.toString(), "$le" + i++);
if (var.hasTag(Tag.VARDEF))
letExprRemap.put(((JCVariableDecl) var).name.toString(), "$le" + i++);
}
}
return super.visitOther(node, p);