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[java] UnnecessaryLocalBeforeReturn checks usages

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- We now check symbol table usages to detect violations.
 - We drop the consecutive lines requirement.
 - Resolves #240
This commit is contained in:
Juan Martín Sotuyo Dodero
2017-02-08 12:01:59 -03:00
committed by Andreas Dangel
parent e3abbcbdd5
commit 4137df4309
2 changed files with 41 additions and 45 deletions
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54
pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/design/UnnecessaryLocalBeforeReturnRule.java
View File

@ -6,9 +6,6 @@ package net.sourceforge.pmd.lang.java.rule.design;
import java.util.List;
import java.util.Map;
import net.sourceforge.pmd.lang.ast.Node;
import net.sourceforge.pmd.lang.java.ast.ASTAssertStatement;
import net.sourceforge.pmd.lang.java.ast.ASTBlockStatement;
import net.sourceforge.pmd.lang.java.ast.ASTExpression;
import net.sourceforge.pmd.lang.java.ast.ASTMethodDeclaration;
import net.sourceforge.pmd.lang.java.ast.ASTName;
@ -43,26 +40,20 @@ public class UnnecessaryLocalBeforeReturnRule extends AbstractJavaRule {
return data;
}
Map<VariableNameDeclaration, List<NameOccurrence>> vars = name.getScope().getDeclarations(VariableNameDeclaration.class);
for (Map.Entry<VariableNameDeclaration, List<NameOccurrence>> entry: vars.entrySet()) {
VariableNameDeclaration key = entry.getKey();
Map<VariableNameDeclaration, List<NameOccurrence>> vars = name.getScope()
.getDeclarations(VariableNameDeclaration.class);
for (Map.Entry<VariableNameDeclaration, List<NameOccurrence>> entry : vars.entrySet()) {
List<NameOccurrence> usages = entry.getValue();
// skip, if there is an assert between declaration and return
if (hasAssertStatement(key, rtn)) {
continue;
}
if (usages.size() == 1) { // If there is more than 1 usage, then it's not only returned
NameOccurrence occ = usages.get(0);
for (NameOccurrence occ: usages) {
if (occ.getLocation().equals(name)) {
// only check declarations that occur one line earlier
if (key.getNode().getBeginLine() == name.getBeginLine() - 1) {
String var = name.getImage();
if (var.indexOf('.') != -1) {
var = var.substring(0, var.indexOf('.'));
}
addViolation(data, rtn, var);
String var = name.getImage();
if (var.indexOf('.') != -1) {
var = var.substring(0, var.indexOf('.'));
}
addViolation(data, rtn, var);
}
}
}
@ -85,31 +76,4 @@ public class UnnecessaryLocalBeforeReturnRule extends AbstractJavaRule {
}
return false;
}
/**
* Checks whether there is an assert statement between the variable declaration
* and the return statement, that uses the variable.
* @param variableDeclaration
* @param rtn
* @return
*/
private boolean hasAssertStatement(VariableNameDeclaration variableDeclaration, ASTReturnStatement rtn) {
ASTBlockStatement blockStatement = variableDeclaration.getAccessNodeParent().getFirstParentOfType(ASTBlockStatement.class);
int startIndex = blockStatement.jjtGetChildIndex() + 1;
int endIndex = rtn.getFirstParentOfType(ASTBlockStatement.class).jjtGetChildIndex();
Node block = blockStatement.jjtGetParent();
for (int i = startIndex; i < endIndex; i++) {
List<ASTAssertStatement> asserts = block.jjtGetChild(i).findDescendantsOfType(ASTAssertStatement.class);
for (ASTAssertStatement assertStatement : asserts) {
List<ASTName> names = assertStatement.findDescendantsOfType(ASTName.class);
for (ASTName n : names) {
if (n.hasImageEqualTo(variableDeclaration.getName())) {
return true;
}
}
}
}
return false;
}
}

32
pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/design/xml/UnnecessaryLocalBeforeReturn.xml
View File

@ -91,6 +91,38 @@ public class Foo {
return i;
}
}
}
]]></code>
</test-code>
<test-code>
<description>Detect violation even if not on consecutive lines</description>
<expected-problems>1</expected-problems>
<code><![CDATA[
public class Foo {
public int bar() {
int res = 2;
doSomething();
return res;
}
public void doSomething() { }
}
]]></code>
</test-code>
<test-code>
<description>No violations on multiple uses of the variable</description>
<expected-problems>0</expected-problems>
<code><![CDATA[
public class Foo {
public int bar() {
int res = 2;
doSomething(res);
return res;
}
public void doSomething(int x) { }
}
]]></code>
</test-code>