Неиспользуемая локальная переменная

docs/diagnostics/UnusedLocalVariable.md

@@ -0,0 +1,28 @@
+# Неиспользуемая локальная переменная (UnusedLocalVariable)
+
+| Тип | Поддерживаются<br/>языки | Важность | Включена<br/>по умолчанию | Время на<br/>исправление (мин) | Тэги |
+| :-: | :-: | :-: | :-: | :-: | :-: |
+| `Дефект кода` | `BSL`<br/>`OS` | `Важный` | `Да` | `1` | `brainoverload`<br/>`badpractice` |
+
+<!-- Блоки выше заполняются автоматически, не трогать -->
+## Описание диагностики
+Программные модули не должны иметь неиспользуемых переменных.
+
+Если локальная переменная объявлена, но не используется, это мертвый код, который следует удалить.
+Это улучшит удобство обслуживания, поскольку разработчики не будут удивляться, для чего используется переменная.
+
+## Сниппеты
+
+<!-- Блоки ниже заполняются автоматически, не трогать -->
+### Экранирование кода
+
+```bsl
+// BSLLS:UnusedLocalVariable-off
+// BSLLS:UnusedLocalVariable-on
+```
+
+### Параметр конфигурационного файла
+
+```json
+"UnusedLocalVariable": false
+```

docs/diagnostics/index.md

@@ -8,9 +8,9 @@
 
 ## Список реализованных диагностик
 
-Общее количество: **111**
+Общее количество: **112**
 
-* Дефект кода: **70**
+* Дефект кода: **71**
 * Уязвимость: **3**
 * Ошибка: **34**
 * Потенциальная уязвимость: **4**
@@ -112,6 +112,7 @@
 | [UnreachableCode](UnreachableCode.md) | Недостижимый код | Да | Незначительный | Ошибка | `design`<br/>`suspicious` |
 | [UnsafeSafeModeMethodCall](UnsafeSafeModeMethodCall.md) | Небезопасное использование функции БезопасныйРежим() | Да | Блокирующий | Ошибка | `deprecated`<br/>`error` |
 | [UnusedLocalMethod](UnusedLocalMethod.md) | Неиспользуемый локальный метод | Да | Важный | Дефект кода | `standard`<br/>`suspicious` |
+| [UnusedLocalVariable](UnusedLocalVariable.md) | Неиспользуемая локальная переменная | Да | Важный | Дефект кода | `brainoverload`<br/>`badpractice` |
 | [UnusedParameters](UnusedParameters.md) | Неиспользуемый параметр | Да | Важный | Дефект кода | `design` |
 | [UseLessForEach](UseLessForEach.md) | Бесполезный перебор коллекции | Да | Критичный | Ошибка | `clumsy` |
 | [UsingCancelParameter](UsingCancelParameter.md) | Работа с параметром "Отказ" | Да | Важный | Дефект кода | `standard`<br/>`badpractice` |

docs/en/diagnostics/UnusedLocalVariable.md

@@ -0,0 +1,28 @@
+# Unused local variable (UnusedLocalVariable)
+
+| Type | Scope | Severity | Activated<br/>by default | Minutes<br/>to fix | Tags |
+| :-: | :-: | :-: | :-: | :-: | :-: |
+| `Code smell` | `BSL`<br/>`OS` | `Major` | `Yes` | `1` | `brainoverload`<br/>`badpractice` |
+
+<!-- Блоки выше заполняются автоматически, не трогать -->
+## Description
+Unused local variables should be removed
+
+If a local variable is declared but not used, it is dead code and should be removed.
+Doing so will improve maintainability because developers will not wonder what the variable is used for.
+
+## Snippets
+
+<!-- Блоки ниже заполняются автоматически, не трогать -->
+### Diagnostic ignorance in code
+
+```bsl
+// BSLLS:UnusedLocalVariable-off
+// BSLLS:UnusedLocalVariable-on
+```
+
+### Parameter for config
+
+```json
+"UnusedLocalVariable": false
+```

docs/en/diagnostics/index.md

@@ -8,10 +8,10 @@ To escape individual sections of code or files from triggering diagnostics, you
 
 ## Implemented diagnostics
 
-Total: **111**
+Total: **112**
 
 * Error: **34**
-* Code smell: **70**
+* Code smell: **71**
 * Vulnerability: **3**
 * Security Hotspot: **4**
 
@@ -112,6 +112,7 @@ Total: **111**
 | [UnreachableCode](UnreachableCode.md) | Unreachable Code | Yes | Minor | Error | `design`<br/>`suspicious` |
 | [UnsafeSafeModeMethodCall](UnsafeSafeModeMethodCall.md) | Unsafe SafeMode method call | Yes | Blocker | Error | `deprecated`<br/>`error` |
 | [UnusedLocalMethod](UnusedLocalMethod.md) | Unused local method | Yes | Major | Code smell | `standard`<br/>`suspicious` |
+| [UnusedLocalVariable](UnusedLocalVariable.md) | Unused local variable | Yes | Major | Code smell | `brainoverload`<br/>`badpractice` |
 | [UnusedParameters](UnusedParameters.md) | Unused parameter | Yes | Major | Code smell | `design` |
 | [UseLessForEach](UseLessForEach.md) | Useless collection iteration | Yes | Critical | Error | `clumsy` |
 | [UsingCancelParameter](UsingCancelParameter.md) | Using parameter "Cancel" | Yes | Major | Code smell | `standard`<br/>`badpractice` |

src/main/java/com/github/_1c_syntax/bsl/languageserver/context/computer/VariableSymbolComputer.java

@@ -22,7 +22,9 @@
 package com.github._1c_syntax.bsl.languageserver.context.computer;
 
 import com.github._1c_syntax.bsl.languageserver.context.DocumentContext;
+import com.github._1c_syntax.bsl.languageserver.context.symbol.Usage;
 import com.github._1c_syntax.bsl.languageserver.context.symbol.VariableSymbol;
+import com.github._1c_syntax.bsl.languageserver.context.symbol.VariableUsage;
 import com.github._1c_syntax.bsl.languageserver.context.symbol.variable.VariableDescription;
 import com.github._1c_syntax.bsl.languageserver.context.symbol.variable.VariableKind;
 import com.github._1c_syntax.bsl.languageserver.utils.Ranges;
@@ -42,6 +44,9 @@ public class VariableSymbolComputer extends BSLParserBaseVisitor<ParseTree> impl
 
   private final DocumentContext documentContext;
   private final List<VariableSymbol> variables = new ArrayList<>();
+  private ArrayList<String> currentMethodParameters = new ArrayList<>();
+  private Range currentMethodRange;
+
 
   public VariableSymbolComputer(DocumentContext documentContext) {
     this.documentContext = documentContext;
@@ -62,6 +67,21 @@ public ParseTree visitModuleVarDeclaration(BSLParser.ModuleVarDeclarationContext
     return ctx;
   }
 
+  @Override
+  public ParseTree visitSub(BSLParser.SubContext ctx) {
+    currentMethodRange = Ranges.create(ctx);
+    ParseTree tree = super.visitSub(ctx);
+    currentMethodRange = null;
+    currentMethodParameters.clear();
+    return tree;
+  }
+
+  @Override
+  public ParseTree visitParam(BSLParser.ParamContext ctx) {
+    currentMethodParameters.add(ctx.getText());
+    return ctx;
+  }
+
   @Override
   public ParseTree visitSubVarDeclaration(BSLParser.SubVarDeclarationContext ctx) {
     var symbol = createVariableSymbol(ctx, ctx.var_name(), false, VariableKind.LOCAL);
@@ -70,6 +90,55 @@ public ParseTree visitSubVarDeclaration(BSLParser.SubVarDeclarationContext ctx)
     return ctx;
   }
 
+  @Override
+  public ParseTree visitLValue(BSLParser.LValueContext ctx) {
+    if (ctx.getChildCount() > 1) {
+      return ctx;
+    }
+
+    if (notParameter(ctx.getText()) && notRegistered(ctx.getText())) {
+      VariableSymbol symbol = VariableSymbol.builder()
+        .name(ctx.getText())
+        .range(Ranges.create(ctx))
+        .variableNameRange(Ranges.create(ctx))
+        .export(false)
+        .kind(VariableKind.LOCAL)
+        .description(createDescription(getTokenToSearchComments(ctx)))
+        .build();
+      variables.add(symbol);
+    }
+    return ctx;
+  }
+
+  @Override
+  public ParseTree visitCallStatement(BSLParser.CallStatementContext ctx) {
+    if(ctx.getStart().getType() == BSLParser.IDENTIFIER) {
+      findVariableSymbol(ctx.getStart().getText()).ifPresent(symbol -> {
+        Usage usage  = VariableUsage.builder()
+          .range(Ranges.create(ctx.getStart()))
+          .kind(Usage.Kind.OBJECT)
+          .build();
+        symbol.addUsage(usage);
+      });
+    }
+    return super.visitCallStatement(ctx);
+  }
+
+  @Override
+  public ParseTree visitComplexIdentifier(BSLParser.ComplexIdentifierContext ctx) {
+    if (ctx.getStart().getType() == BSLParser.IDENTIFIER) {
+      findVariableSymbol(ctx.getStart().getText()).ifPresent(symbol -> {
+        Usage usage  = VariableUsage.builder()
+          .range(Ranges.create(ctx.getStart()))
+          .kind(Usage.Kind.OTHER)
+          .build();
+        symbol.addUsage(usage);
+      });
+    }
+
+    return super.visitComplexIdentifier(ctx);
+  }
+
   private VariableSymbol createVariableSymbol(
     BSLParserRuleContext ctx,
     BSLParser.Var_nameContext varName,
@@ -134,4 +203,25 @@ private static Range getRangeForDescription(List<Token> tokens) {
     return Ranges.create(firstElement, lastElement);
   }
 
+  private boolean notParameter(String variableName) {
+    return !currentMethodParameters.contains(variableName);
+  }
+
+  private boolean notRegistered(String variableName) {
+    return variables.stream()
+      .filter(v -> v.getKind() == VariableKind.MODULE
+        || currentMethodRange == null
+        || Ranges.containsRange(currentMethodRange, v.getRange()))
+      .noneMatch(v -> v.getName().equals(variableName));
+  }
+
+  private Optional<VariableSymbol> findVariableSymbol(String variableName) {
+    return variables.stream()
+      .filter(v -> v.getKind() == VariableKind.MODULE
+        || currentMethodRange == null
+        || Ranges.containsRange(currentMethodRange, v.getRange()))
+      .filter(v -> v.getName().equals(variableName))
+      .findFirst();
+  }
+
 }

src/main/java/com/github/_1c_syntax/bsl/languageserver/context/symbol/Usage.java

@@ -0,0 +1,37 @@
+/*
+ * This file is a part of BSL Language Server.
+ *
+ * Copyright © 2018-2020
+ * Alexey Sosnoviy <[email protected]>, Nikita Gryzlov <[email protected]> and contributors
+ *
+ * SPDX-License-Identifier: LGPL-3.0-or-later
+ *
+ * BSL Language Server is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3.0 of the License, or (at your option) any later version.
+ *
+ * BSL Language Server is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with BSL Language Server.
+ */
+package com.github._1c_syntax.bsl.languageserver.context.symbol;
+
+import org.eclipse.lsp4j.Range;
+
+public interface Usage {
+
+  Range getRange();
+
+  Kind getKind();
+
+  enum Kind {
+    OTHER,
+    OBJECT
+  }
+
+}

src/main/java/com/github/_1c_syntax/bsl/languageserver/context/symbol/VariableSymbol.java

@@ -32,6 +32,7 @@
 import lombok.experimental.NonFinal;
 import org.eclipse.lsp4j.Range;
 
+import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 import java.util.Optional;
@@ -57,4 +58,10 @@ public class VariableSymbol implements Symbol {
   VariableKind kind;
   boolean export;
   Optional<VariableDescription> description;
+
+  ArrayList<Usage> usages = new ArrayList<>();
+
+  public void addUsage(Usage usage) {
+    usages.add(usage);
+  }
 }

src/main/java/com/github/_1c_syntax/bsl/languageserver/context/symbol/VariableUsage.java

@@ -0,0 +1,35 @@
+/*
+ * This file is a part of BSL Language Server.
+ *
+ * Copyright © 2018-2020
+ * Alexey Sosnoviy <[email protected]>, Nikita Gryzlov <[email protected]> and contributors
+ *
+ * SPDX-License-Identifier: LGPL-3.0-or-later
+ *
+ * BSL Language Server is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3.0 of the License, or (at your option) any later version.
+ *
+ * BSL Language Server is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with BSL Language Server.
+ */
+package com.github._1c_syntax.bsl.languageserver.context.symbol;
+
+import lombok.Builder;
+import lombok.Value;
+import org.eclipse.lsp4j.Range;
+
+@Value
+@Builder
+public class VariableUsage implements Usage {
+
+  Range range;
+  Kind kind;
+
+}

src/main/java/com/github/_1c_syntax/bsl/languageserver/diagnostics/UnusedLocalVariableDiagnostic.java

@@ -0,0 +1,64 @@
+/*
+ * This file is a part of BSL Language Server.
+ *
+ * Copyright © 2018-2020
+ * Alexey Sosnoviy <[email protected]>, Nikita Gryzlov <[email protected]> and contributors
+ *
+ * SPDX-License-Identifier: LGPL-3.0-or-later
+ *
+ * BSL Language Server is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3.0 of the License, or (at your option) any later version.
+ *
+ * BSL Language Server is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with BSL Language Server.
+ */
+package com.github._1c_syntax.bsl.languageserver.diagnostics;
+
+import com.github._1c_syntax.bsl.languageserver.context.symbol.VariableSymbol;
+import com.github._1c_syntax.bsl.languageserver.diagnostics.metadata.DiagnosticInfo;
+import com.github._1c_syntax.bsl.languageserver.diagnostics.metadata.DiagnosticMetadata;
+import com.github._1c_syntax.bsl.languageserver.diagnostics.metadata.DiagnosticSeverity;
+import com.github._1c_syntax.bsl.languageserver.diagnostics.metadata.DiagnosticTag;
+import com.github._1c_syntax.bsl.languageserver.diagnostics.metadata.DiagnosticType;
+import com.github._1c_syntax.mdclasses.metadata.additional.ModuleType;
+
+@DiagnosticMetadata(
+  type = DiagnosticType.CODE_SMELL,
+  severity = DiagnosticSeverity.MAJOR,
+  minutesToFix = 1,
+  tags = {
+    DiagnosticTag.BRAINOVERLOAD,
+    DiagnosticTag.BADPRACTICE
+  },
+  modules = {
+    ModuleType.CommandModule,
+    ModuleType.CommonModule,
+    ModuleType.ManagerModule,
+    ModuleType.ValueManagerModule,
+    ModuleType.SessionModule,
+  }
+)
+public class UnusedLocalVariableDiagnostic extends AbstractDiagnostic {
+
+  public UnusedLocalVariableDiagnostic(DiagnosticInfo info) {
+    super(info);
+  }
+
+  @Override
+  protected void check() {
+    documentContext
+      .getSymbolTree()
+      .getChildrenFlat(VariableSymbol.class)
+      .stream()
+      .filter(v -> v.getUsages().isEmpty())
+      .filter(v -> !v.isExport())
+      .forEach(v -> diagnosticStorage.addDiagnostic(v.getRange()));
+  }
+}

src/main/resources/com/github/_1c_syntax/bsl/languageserver/configuration/parameters-schema.json

@@ -1216,6 +1216,16 @@
             "title": "Unused local method",
             "$id": "#/definitions/UnusedLocalMethod"
         },
+        "UnusedLocalVariable": {
+            "description": "Unused local variable",
+            "default": true,
+            "type": [
+                "boolean",
+                "object"
+            ],
+            "title": "Unused local variable",
+            "$id": "#/definitions/UnusedLocalVariable"
+        },
         "UnusedParameters": {
             "description": "Unused parameter",
             "default": true,