D-Scanner/src/analysis/unused.d

403 lines
9.5 KiB
D

// Copyright Brian Schott (Hackerpilot) 2014.
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
module analysis.unused;
import std.d.ast;
import std.d.lexer;
import analysis.base;
import std.container;
import std.regex : Regex, regex, matchAll;
/**
* Checks for unused variables.
*/
class UnusedVariableCheck : BaseAnalyzer
{
alias visit = BaseAnalyzer.visit;
/**
* Params:
* fileName = the name of the file being analyzed
*/
this(string fileName)
{
super(fileName);
re = regex("[\\p{Alphabetic}_][\\w_]*");
}
override void visit(const Module mod)
{
pushScope();
mod.accept(this);
popScope();
}
override void visit(const Declaration declaration)
{
if (!isOverride) foreach (attribute; declaration.attributes)
isOverride = isOverride || (attribute.attribute == tok!"override");
declaration.accept(this);
isOverride = false;
}
override void visit(const FunctionDeclaration functionDec)
{
pushScope();
if (functionDec.functionBody !is null)
{
immutable bool ias = inAggregateScope;
inAggregateScope = false;
if (!isOverride)
functionDec.parameters.accept(this);
functionDec.functionBody.accept(this);
inAggregateScope = ias;
}
popScope();
}
mixin PartsUseVariables!AliasInitializer;
mixin PartsUseVariables!ArgumentList;
mixin PartsUseVariables!AssertExpression;
mixin PartsUseVariables!ClassDeclaration;
mixin PartsUseVariables!FunctionBody;
mixin PartsUseVariables!FunctionCallExpression;
mixin PartsUseVariables!FunctionDeclaration;
mixin PartsUseVariables!IndexExpression;
mixin PartsUseVariables!Initializer;
mixin PartsUseVariables!InterfaceDeclaration;
mixin PartsUseVariables!NewExpression;
mixin PartsUseVariables!SliceExpression;
mixin PartsUseVariables!StaticIfCondition;
mixin PartsUseVariables!StructDeclaration;
mixin PartsUseVariables!TemplateArgumentList;
mixin PartsUseVariables!ThrowStatement;
override void visit(const SwitchStatement switchStatement)
{
if (switchStatement.expression !is null)
{
interestDepth++;
switchStatement.expression.accept(this);
interestDepth--;
}
switchStatement.accept(this);
}
override void visit(const WhileStatement whileStatement)
{
interestDepth++;
whileStatement.expression.accept(this);
interestDepth--;
whileStatement.declarationOrStatement.accept(this);
}
override void visit(const DoStatement doStatement)
{
interestDepth++;
doStatement.expression.accept(this);
interestDepth--;
doStatement.statementNoCaseNoDefault.accept(this);
}
override void visit(const ForStatement forStatement)
{
if (forStatement.initialization !is null)
forStatement.initialization.accept(this);
if (forStatement.test !is null)
{
interestDepth++;
forStatement.test.accept(this);
interestDepth--;
}
if (forStatement.increment !is null)
{
interestDepth++;
forStatement.increment.accept(this);
interestDepth--;
}
forStatement.declarationOrStatement.accept(this);
}
override void visit(const IfStatement ifStatement)
{
if (ifStatement.expression !is null)
{
interestDepth++;
ifStatement.expression.accept(this);
interestDepth--;
}
ifStatement.thenStatement.accept(this);
if (ifStatement.elseStatement !is null)
ifStatement.elseStatement.accept(this);
}
override void visit(const ForeachStatement foreachStatement)
{
if (foreachStatement.low !is null)
{
interestDepth++;
foreachStatement.low.accept(this);
interestDepth--;
}
if (foreachStatement.high !is null)
{
interestDepth++;
foreachStatement.high.accept(this);
interestDepth--;
}
foreachStatement.accept(this);
}
override void visit(const AssignExpression assignExp)
{
assignExp.ternaryExpression.accept(this);
if (assignExp.assignExpression !is null)
{
interestDepth++;
assignExp.assignExpression.accept(this);
interestDepth--;
}
}
override void visit(const TemplateDeclaration templateDeclaration)
{
auto inAgg = inAggregateScope;
inAggregateScope = true;
templateDeclaration.accept(this);
inAggregateScope = inAgg;
}
override void visit(const IdentifierOrTemplateChain chain)
{
if (interestDepth > 0 && chain.identifiersOrTemplateInstances[0].identifier != tok!"")
variableUsed(chain.identifiersOrTemplateInstances[0].identifier.text);
chain.accept(this);
}
override void visit(const TemplateSingleArgument single)
{
if (single.token != tok!"")
variableUsed(single.token.text);
}
override void visit(const UnaryExpression unary)
{
if (unary.prefix == tok!"*")
interestDepth++;
unary.accept(this);
if (unary.prefix == tok!"*")
interestDepth--;
}
override void visit(const MixinExpression mix)
{
interestDepth++;
mixinDepth++;
mix.accept(this);
mixinDepth--;
interestDepth--;
}
override void visit(const PrimaryExpression primary)
{
if (interestDepth > 0)
{
if (primary.identifierOrTemplateInstance !is null
&& primary.identifierOrTemplateInstance.identifier != tok!"")
{
variableUsed(primary.identifierOrTemplateInstance.identifier.text);
}
if (mixinDepth > 0 && primary.primary == tok!"stringLiteral"
|| primary.primary == tok!"wstringLiteral"
|| primary.primary == tok!"dstringLiteral")
{
foreach (part; matchAll(primary.primary.text, re))
{
immutable size_t treeIndex = tree.length - 1;
auto uu = UnUsed(part.hit);
auto r = tree[treeIndex].equalRange(&uu);
if (!r.empty)
r.front.uncertain = true;
}
}
}
primary.accept(this);
}
override void visit(const ReturnStatement retStatement)
{
if (retStatement.expression !is null)
{
interestDepth++;
visit(retStatement.expression);
interestDepth--;
}
}
override void visit(const BlockStatement blockStatement)
{
immutable bool sb = inAggregateScope;
inAggregateScope = false;
if (blockStatementIntroducesScope)
pushScope();
blockStatement.accept(this);
if (blockStatementIntroducesScope)
popScope();
inAggregateScope = sb;
}
override void visit(const VariableDeclaration variableDeclaration)
{
foreach (d; variableDeclaration.declarators)
this.variableDeclared(d.name.text, d.name.line, d.name.column, false, false);
variableDeclaration.accept(this);
}
override void visit(const AutoDeclaration autoDeclaration)
{
foreach (t; autoDeclaration.identifiers)
this.variableDeclared(t.text, t.line, t.column, false, false);
autoDeclaration.accept(this);
}
override void visit(const WithStatement withStatetement)
{
interestDepth++;
withStatetement.expression.accept(this);
interestDepth--;
withStatetement.statementNoCaseNoDefault.accept(this);
}
override void visit(const Parameter parameter)
{
import std.algorithm : canFind;
import std.array : array;
if (parameter.name != tok!"")
{
immutable bool isRef = canFind(parameter.parameterAttributes, cast(IdType) tok!"ref")
|| canFind(parameter.parameterAttributes, cast(IdType) tok!"in")
|| canFind(parameter.parameterAttributes, cast(IdType) tok!"out");
variableDeclared(parameter.name.text, parameter.name.line,
parameter.name.column, true, isRef);
if (parameter.default_ !is null)
{
interestDepth++;
parameter.default_.accept(this);
interestDepth--;
}
}
}
override void visit(const StructBody structBody)
{
immutable bool sb = inAggregateScope;
inAggregateScope = true;
foreach (dec; structBody.declarations)
visit(dec);
inAggregateScope = sb;
}
override void visit(const ConditionalStatement conditionalStatement)
{
immutable bool cs = blockStatementIntroducesScope;
blockStatementIntroducesScope = false;
conditionalStatement.accept(this);
blockStatementIntroducesScope = cs;
}
override void visit(const AsmPrimaryExp primary)
{
if (primary.token != tok!"")
variableUsed(primary.token.text);
if (primary.identifierChain !is null)
variableUsed(primary.identifierChain.identifiers[0].text);
}
override void visit(const TraitsExpression)
{
// Issue #266. Ignore everything inside of __traits expressions.
}
private:
mixin template PartsUseVariables(NodeType)
{
override void visit(const NodeType node)
{
interestDepth++;
node.accept(this);
interestDepth--;
}
}
void variableDeclared(string name, size_t line, size_t column,
bool isParameter, bool isRef)
{
if (inAggregateScope)
return;
tree[$ - 1].insert(new UnUsed(name, line, column, isParameter, isRef));
}
void variableUsed(string name)
{
size_t treeIndex = tree.length - 1;
auto uu = UnUsed(name);
while (true)
{
if (tree[treeIndex].removeKey(&uu) != 0 || treeIndex == 0)
break;
treeIndex--;
}
}
void popScope()
{
foreach (uu; tree[$ - 1])
{
if (!uu.isRef && tree.length > 1)
{
immutable string certainty = uu.uncertain ? " might not be used." : " is never used.";
immutable string errorMessage = (uu.isParameter ? "Parameter " : "Variable ")
~ uu.name ~ certainty;
addErrorMessage(uu.line, uu.column,
uu.isParameter ? "dscanner.suspicious.unused_parameter"
: "dscanner.suspicious.unused_variable", errorMessage);
}
}
tree = tree[0 .. $ - 1];
}
void pushScope()
{
tree ~= new RedBlackTree!(UnUsed*, "a.name < b.name");
}
struct UnUsed
{
string name;
size_t line;
size_t column;
bool isParameter;
bool isRef;
bool uncertain;
}
RedBlackTree!(UnUsed*, "a.name < b.name")[] tree;
uint interestDepth;
uint mixinDepth;
bool isOverride;
bool inAggregateScope;
bool blockStatementIntroducesScope = true;
Regex!char re;
}