njames93 updated this revision to Diff 235384. njames93 edited the summary of this revision. njames93 added a comment.
Think all the test cases are working, but they look like they could do with a clean up from someone who may know the clang-tidy-checks system better than myself CHANGES SINCE LAST ACTION https://reviews.llvm.org/D71846/new/ https://reviews.llvm.org/D71846 Files: clang-tools-extra/clang-tidy/readability/ElseAfterReturnCheck.cpp clang-tools-extra/test/clang-tidy/checkers/readability-else-after-return.cpp clang/docs/LibASTMatchersReference.html clang/include/clang/ASTMatchers/ASTMatchers.h clang/lib/ASTMatchers/Dynamic/Registry.cpp clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp
Index: clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp =================================================================== --- clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp +++ clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp @@ -1071,6 +1071,35 @@ LanguageMode::Cxx17OrLater)); } +TEST(hasInitStatement, MatchesSelectionInitializers) { + EXPECT_TRUE(matches("void baz() { if (int i = 1; i > 0) {} }", + ifStmt(hasInitStatement(anything())), + LanguageMode::Cxx17OrLater)); + EXPECT_TRUE(notMatches("void baz() { if (int i = 1) {} }", + ifStmt(hasInitStatement(anything())))); + EXPECT_TRUE(notMatches("void baz() { if (1 > 0) {} }", + ifStmt(hasInitStatement(anything())))); + EXPECT_TRUE(matches( + "void baz(int i) { switch (int j = i; j) { default: break; } }", + switchStmt(hasInitStatement(anything())), LanguageMode::Cxx17OrLater)); + EXPECT_TRUE(notMatches("void baz(int i) { switch (i) { default: break; } }", + switchStmt(hasInitStatement(anything())))); +} + +TEST(hasInitStatement, MatchesRangeForInitializers) { + EXPECT_TRUE(matches("void baz() {" + "int items[] = {};" + "for (auto &arr = items; auto &item : arr) {}" + "}", + cxxForRangeStmt(hasInitStatement(anything())), + LanguageMode::Cxx2aOrLater)); + EXPECT_TRUE(notMatches("void baz() {" + "int items[] = {};" + "for (auto &item : items) {}" + "}", + cxxForRangeStmt(hasInitStatement(anything())))); +} + TEST(TemplateArgumentCountIs, Matches) { EXPECT_TRUE( matches("template<typename T> struct C {}; C<int> c;", Index: clang/lib/ASTMatchers/Dynamic/Registry.cpp =================================================================== --- clang/lib/ASTMatchers/Dynamic/Registry.cpp +++ clang/lib/ASTMatchers/Dynamic/Registry.cpp @@ -279,6 +279,7 @@ REGISTER_MATCHER(hasIndex); REGISTER_MATCHER(hasInit); REGISTER_MATCHER(hasInitializer); + REGISTER_MATCHER(hasInitStatement); REGISTER_MATCHER(hasKeywordSelector); REGISTER_MATCHER(hasLHS); REGISTER_MATCHER(hasLocalQualifiers); Index: clang/include/clang/ASTMatchers/ASTMatchers.h =================================================================== --- clang/include/clang/ASTMatchers/ASTMatchers.h +++ clang/include/clang/ASTMatchers/ASTMatchers.h @@ -4297,6 +4297,35 @@ return Node.isConstexpr(); } +/// Matches selection statements with initializer. +/// +/// Given: +/// \code +/// void foo() { +/// if (int i = foobar(); i > 0) {} +/// switch (int i = foobar(); i) {} +/// for (auto& a = get_range(); auto& x : a) {} +/// } +/// void bar() { +/// if (foobar() > 0) {} +/// switch (foobar()) {} +/// for (auto& x : get_range()) {} +/// } +/// \endcode +/// ifStmt(hasInitStatement(anything())) +/// matches the if statement in foo but not in bar. +/// switchStmt(hasInitStatement(anything())) +/// matches the switch statement in foo but not in bar. +/// cxxForRangeStmt(hasInitStatement(anything())) +/// matches the range for statement in foo but not in bar. +AST_POLYMORPHIC_MATCHER_P(hasInitStatement, + AST_POLYMORPHIC_SUPPORTED_TYPES(IfStmt, SwitchStmt, + CXXForRangeStmt), + internal::Matcher<Stmt>, InnerMatcher) { + const Stmt *Init = Node.getInit(); + return Init != nullptr && InnerMatcher.matches(*Init, Finder, Builder); +} + /// Matches the condition expression of an if statement, for loop, /// switch statement or conditional operator. /// Index: clang/docs/LibASTMatchersReference.html =================================================================== --- clang/docs/LibASTMatchersReference.html +++ clang/docs/LibASTMatchersReference.html @@ -3009,6 +3009,23 @@ </pre></td></tr> +<tr><td>Matcher<<a href="https://clang.llvm.org/doxygen/classclang_1_1Expr.html">Expr</a>></td><td class="name" onclick="toggle('nullPointerConstant0')"><a name="nullPointerConstant0Anchor">nullPointerConstant</a></td><td></td></tr> +<tr><td colspan="4" class="doc" id="nullPointerConstant0"><pre>Matches expressions that resolve to a null pointer constant, such as +GNU's __null, C++11's nullptr, or C's NULL macro. + +Given: + void *v1 = NULL; + void *v2 = nullptr; + void *v3 = __null; // GNU extension + char *cp = (char *)0; + int *ip = 0; + int i = 0; +expr(nullPointerConstant()) + matches the initializer for v1, v2, v3, cp, and ip. Does not match the + initializer for i. +</pre></td></tr> + + <tr><td>Matcher<<a href="https://clang.llvm.org/doxygen/classclang_1_1FieldDecl.html">FieldDecl</a>></td><td class="name" onclick="toggle('hasBitWidth0')"><a name="hasBitWidth0Anchor">hasBitWidth</a></td><td>unsigned Width</td></tr> <tr><td colspan="4" class="doc" id="hasBitWidth0"><pre>Matches non-static data members that are bit-fields of the specified bit width. @@ -3761,6 +3778,18 @@ Example matches y (matcher = parmVarDecl(hasDefaultArgument())) void x(int val) {} void y(int val = 0) {} + +Deprecated. Use hasInitializer() instead to be able to +match on the contents of the default argument. For example: + +void x(int val = 7) {} +void y(int val = 42) {} +parmVarDecl(hasInitializer(integerLiteral(equals(42)))) + matches the parameter of y + +A matcher such as + parmVarDecl(hasInitializer(anything())) +is equivalent to parmVarDecl(hasDefaultArgument()). </pre></td></tr> @@ -4479,23 +4508,6 @@ </pre></td></tr> -<tr><td>Matcher<internal::Matcher<<a href="https://clang.llvm.org/doxygen/classclang_1_1Expr.html">Expr</a>>></td><td class="name" onclick="toggle('nullPointerConstant0')"><a name="nullPointerConstant0Anchor">nullPointerConstant</a></td><td></td></tr> -<tr><td colspan="4" class="doc" id="nullPointerConstant0"><pre>Matches expressions that resolve to a null pointer constant, such as -GNU's __null, C++11's nullptr, or C's NULL macro. - -Given: - void *v1 = NULL; - void *v2 = nullptr; - void *v3 = __null; // GNU extension - char *cp = (char *)0; - int *ip = 0; - int i = 0; -expr(nullPointerConstant()) - matches the initializer for v1, v2, v3, cp, and ip. Does not match the - initializer for i. -</pre></td></tr> - - <tr><td>Matcher<internal::Matcher<<a href="https://clang.llvm.org/doxygen/classclang_1_1NamedDecl.html">NamedDecl</a>>></td><td class="name" onclick="toggle('hasAnyName0')"><a name="hasAnyName0Anchor">hasAnyName</a></td><td>StringRef, ..., StringRef</td></tr> <tr><td colspan="4" class="doc" id="hasAnyName0"><pre>Matches NamedDecl nodes that have any of the specified names. @@ -5082,6 +5094,29 @@ </pre></td></tr> +<tr><td>Matcher<<a href="https://clang.llvm.org/doxygen/classclang_1_1CXXForRangeStmt.html">CXXForRangeStmt</a>></td><td class="name" onclick="toggle('hasInitStatement2')"><a name="hasInitStatement2Anchor">hasInitStatement</a></td><td>Matcher<<a href="https://clang.llvm.org/doxygen/classclang_1_1Stmt.html">Stmt</a>> InnerMatcher</td></tr> +<tr><td colspan="4" class="doc" id="hasInitStatement2"><pre>Matches selection statements with initializer. + +Given: + void foo() { + if (int i = foobar(); i > 0) {} + switch (int i = foobar(); i) {} + for (auto& a = get_range(); auto& x : a) {} + } + void bar() { + if (foobar() > 0) {} + switch (foobar()) {} + for (auto& x : get_range()) {} + } +ifStmt(hasInitStatement(anything())) + matches the if statement in foo but not in bar. +switchStmt(hasInitStatement(anything())) + matches the switch statement in foo but not in bar. +cxxForRangeStmt(hasInitStatement(anything())) + matches the range for statement in foo but not in bar. +</pre></td></tr> + + <tr><td>Matcher<<a href="https://clang.llvm.org/doxygen/classclang_1_1CXXForRangeStmt.html">CXXForRangeStmt</a>></td><td class="name" onclick="toggle('hasLoopVariable0')"><a name="hasLoopVariable0Anchor">hasLoopVariable</a></td><td>Matcher<<a href="https://clang.llvm.org/doxygen/classclang_1_1VarDecl.html">VarDecl</a>> InnerMatcher</td></tr> <tr><td colspan="4" class="doc" id="hasLoopVariable0"><pre>Matches the initialization statement of a for loop. @@ -6206,6 +6241,29 @@ </pre></td></tr> +<tr><td>Matcher<<a href="https://clang.llvm.org/doxygen/classclang_1_1IfStmt.html">IfStmt</a>></td><td class="name" onclick="toggle('hasInitStatement0')"><a name="hasInitStatement0Anchor">hasInitStatement</a></td><td>Matcher<<a href="https://clang.llvm.org/doxygen/classclang_1_1Stmt.html">Stmt</a>> InnerMatcher</td></tr> +<tr><td colspan="4" class="doc" id="hasInitStatement0"><pre>Matches selection statements with initializer. + +Given: + void foo() { + if (int i = foobar(); i > 0) {} + switch (int i = foobar(); i) {} + for (auto& a = get_range(); auto& x : a) {} + } + void bar() { + if (foobar() > 0) {} + switch (foobar()) {} + for (auto& x : get_range()) {} + } +ifStmt(hasInitStatement(anything())) + matches the if statement in foo but not in bar. +switchStmt(hasInitStatement(anything())) + matches the switch statement in foo but not in bar. +cxxForRangeStmt(hasInitStatement(anything())) + matches the range for statement in foo but not in bar. +</pre></td></tr> + + <tr><td>Matcher<<a href="https://clang.llvm.org/doxygen/classclang_1_1IfStmt.html">IfStmt</a>></td><td class="name" onclick="toggle('hasThen0')"><a name="hasThen0Anchor">hasThen</a></td><td>Matcher<<a href="https://clang.llvm.org/doxygen/classclang_1_1Stmt.html">Stmt</a>> InnerMatcher</td></tr> <tr><td colspan="4" class="doc" id="hasThen0"><pre>Matches the then-statement of an if statement. @@ -6943,6 +7001,29 @@ </pre></td></tr> +<tr><td>Matcher<<a href="https://clang.llvm.org/doxygen/classclang_1_1SwitchStmt.html">SwitchStmt</a>></td><td class="name" onclick="toggle('hasInitStatement1')"><a name="hasInitStatement1Anchor">hasInitStatement</a></td><td>Matcher<<a href="https://clang.llvm.org/doxygen/classclang_1_1Stmt.html">Stmt</a>> InnerMatcher</td></tr> +<tr><td colspan="4" class="doc" id="hasInitStatement1"><pre>Matches selection statements with initializer. + +Given: + void foo() { + if (int i = foobar(); i > 0) {} + switch (int i = foobar(); i) {} + for (auto& a = get_range(); auto& x : a) {} + } + void bar() { + if (foobar() > 0) {} + switch (foobar()) {} + for (auto& x : get_range()) {} + } +ifStmt(hasInitStatement(anything())) + matches the if statement in foo but not in bar. +switchStmt(hasInitStatement(anything())) + matches the switch statement in foo but not in bar. +cxxForRangeStmt(hasInitStatement(anything())) + matches the range for statement in foo but not in bar. +</pre></td></tr> + + <tr><td>Matcher<<a href="https://clang.llvm.org/doxygen/classclang_1_1TagType.html">TagType</a>></td><td class="name" onclick="toggle('hasDeclaration4')"><a name="hasDeclaration4Anchor">hasDeclaration</a></td><td>const Matcher<<a href="https://clang.llvm.org/doxygen/classclang_1_1Decl.html">Decl</a>> InnerMatcher</td></tr> <tr><td colspan="4" class="doc" id="hasDeclaration4"><pre>Matches a node if the declaration associated with that node matches the given matcher. @@ -7170,6 +7251,22 @@ </pre></td></tr> +<tr><td>Matcher<T></td><td class="name" onclick="toggle('traverse0')"><a name="traverse0Anchor">traverse</a></td><td>ast_type_traits::TraversalKind TK, const Matcher<T> InnerMatcher</td></tr> +<tr><td colspan="4" class="doc" id="traverse0"><pre>Causes all nested matchers to be matched with the specified traversal kind. + +Given + void foo() + { + int i = 3.0; + } +The matcher + traverse(ast_type_traits::TK_IgnoreImplicitCastsAndParentheses, + varDecl(hasInitializer(floatLiteral().bind("init"))) + ) +matches the variable declaration with "init" bound to the "3.0". +</pre></td></tr> + + <tr><td>Matcher<<a href="https://clang.llvm.org/doxygen/classclang_1_1TypedefNameDecl.html">TypedefNameDecl</a>></td><td class="name" onclick="toggle('hasType2')"><a name="hasType2Anchor">hasType</a></td><td>Matcher<<a href="https://clang.llvm.org/doxygen/classclang_1_1QualType.html">QualType</a>> InnerMatcher</td></tr> <tr><td colspan="4" class="doc" id="hasType2"><pre>Matches if the expression's or declaration's type matches a type matcher. Index: clang-tools-extra/test/clang-tidy/checkers/readability-else-after-return.cpp =================================================================== --- clang-tools-extra/test/clang-tidy/checkers/readability-else-after-return.cpp +++ clang-tools-extra/test/clang-tidy/checkers/readability-else-after-return.cpp @@ -1,4 +1,4 @@ -// RUN: %check_clang_tidy %s readability-else-after-return %t -- -- -fexceptions +// RUN: %check_clang_tidy %s readability-else-after-return %t -- -- -fexceptions -std=c++17 namespace std { struct string { @@ -15,15 +15,15 @@ if (a > 0) return; else // comment-0 - // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: do not use 'else' after 'return' - // CHECK-FIXES: {{^}} // comment-0 + // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: do not use 'else' after 'return' + // CHECK-FIXES: {{^}} // comment-0 return; if (a > 0) { return; } else { // comment-1 - // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: do not use 'else' after 'return' - // CHECK-FIXES: {{^}} } // comment-1 + // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: do not use 'else' after 'return' + // CHECK-FIXES: {{^}} } // comment-1 return; } @@ -60,15 +60,15 @@ if (a < 10) return; else // comment-5 - // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: do not use 'else' after 'return' - // CHECK-FIXES: {{^}} // comment-5 + // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: do not use 'else' after 'return' + // CHECK-FIXES: {{^}} // comment-5 f(0); } else { if (a > 10) return; else // comment-6 - // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: do not use 'else' after 'return' - // CHECK-FIXES: {{^}} // comment-6 + // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: do not use 'else' after 'return' + // CHECK-FIXES: {{^}} // comment-6 f(0); } } @@ -78,29 +78,29 @@ if (x) { continue; } else { // comment-7 - // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: do not use 'else' after 'continue' - // CHECK-FIXES: {{^}} } // comment-7 + // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: do not use 'else' after 'continue' + // CHECK-FIXES: {{^}} } // comment-7 x++; } if (x) { break; } else { // comment-8 - // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: do not use 'else' after 'break' - // CHECK-FIXES: {{^}} } // comment-8 + // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: do not use 'else' after 'break' + // CHECK-FIXES: {{^}} } // comment-8 x++; } if (x) { throw 42; } else { // comment-9 - // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: do not use 'else' after 'throw' - // CHECK-FIXES: {{^}} } // comment-9 + // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: do not use 'else' after 'throw' + // CHECK-FIXES: {{^}} } // comment-9 x++; } if (x) { throw my_exception("foo"); } else { // comment-10 - // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: do not use 'else' after 'throw' - // CHECK-FIXES: {{^}} } // comment-10 + // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: do not use 'else' after 'throw' + // CHECK-FIXES: {{^}} } // comment-10 x++; } } @@ -109,11 +109,68 @@ extern int *g(); extern void h(int **x); -int *decl_in_condition() { +int *declInConditionUsedInElse() { if (int *x = g()) { return x; - } else { + } else { // comment-11 + // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: do not use 'else' after 'return' + // CHECK-FIXES: {{^}} } // comment-11 h(&x); return x; } } +int *declInConditionUnusedInElse() { + if (int *x = g()) { + h(&x); + return x; + } else { // comment-12 + // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: do not use 'else' after 'return' + // CHECK-FIXES: {{^}} } // comment-12 + return nullptr; + } +} + +int *varInitAndCondition() { + if (int *X = g(); X != nullptr) { + return X; + } else { // comment-13 + // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: do not use 'else' after 'return' + // CHECK-FIXES: {{^}} } // comment-13 + h(&X); + return X; + } +} + +int *varInitAndConditionUnusedInElse() { + if (int *X = g(); X != nullptr) { + return X; + } else { // comment-14 + // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: do not use 'else' after 'return' + // CHECK-FIXES: {{^}} } // comment-14 + return nullptr; + } +} + +int *initAndCondition() { + int *X; + if (X = g(); X != nullptr) { + return X; + } else { // comment-15 + // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: do not use 'else' after 'return' + // CHECK-FIXES: {{^}} } // comment-15 + h(&X); + return X; + } +} + +int *varInitAndConditionUnusedInElseWithDecl() { + int *Y = g(); + if (int *X = g(); X != nullptr) { + return X; + } else { // comment-16 + // CHECK-FIXES-NOT{{^}} } // comment-16 + int *Y = g(); + h(&Y); + } + return Y; +} Index: clang-tools-extra/clang-tidy/readability/ElseAfterReturnCheck.cpp =================================================================== --- clang-tools-extra/clang-tidy/readability/ElseAfterReturnCheck.cpp +++ clang-tools-extra/clang-tidy/readability/ElseAfterReturnCheck.cpp @@ -23,39 +23,183 @@ breakStmt().bind("break"), expr(ignoringImplicit(cxxThrowExpr().bind("throw"))))); Finder->addMatcher( - compoundStmt(forEach( - ifStmt(unless(isConstexpr()), - // FIXME: Explore alternatives for the - // `if (T x = ...) {... return; } else { <use x> }` - // pattern: - // * warn, but don't fix; - // * fix by pulling out the variable declaration out of - // the condition. - unless(hasConditionVariableStatement(anything())), - hasThen(stmt(anyOf(InterruptsControlFlow, - compoundStmt(has(InterruptsControlFlow))))), - hasElse(stmt().bind("else"))) - .bind("if"))), + compoundStmt( + forEach(ifStmt(unless(isConstexpr()), + hasThen(stmt( + anyOf(InterruptsControlFlow, + compoundStmt(has(InterruptsControlFlow))))), + hasElse(stmt().bind("else"))) + .bind("if"))) + .bind("cs"), this); } +const DeclRefExpr *findUsage(const Stmt *Node, int64_t DeclIdentifier) { + if (const auto *DeclRef = dyn_cast_or_null<DeclRefExpr>(Node)) { + if (DeclRef->getDecl()->getID() == DeclIdentifier) { + return DeclRef; + } + } else { + for (const auto &ChildNode : Node->children()) { + if (auto Result = findUsage(ChildNode, DeclIdentifier)) { + return Result; + } + } + } + return nullptr; +} + +const DeclRefExpr * +findUsageRange(const Stmt *Node, + const llvm::iterator_range<int64_t *> &DeclIdentifiers) { + if (const auto *DeclRef = dyn_cast_or_null<DeclRefExpr>(Node)) { + if (llvm::is_contained(DeclIdentifiers, DeclRef->getDecl()->getID())) { + return DeclRef; + } + } else { + for (const auto &ChildNode : Node->children()) { + if (auto Result = findUsageRange(ChildNode, DeclIdentifiers)) { + return Result; + } + } + } + return nullptr; +} + +const DeclRefExpr *checkInitDeclUsageInElse(const IfStmt *If) { + auto InitDeclStmt = dyn_cast_or_null<DeclStmt>(If->getInit()); + if (!InitDeclStmt) + return nullptr; + if (InitDeclStmt->isSingleDecl()) { + auto InitDecl = InitDeclStmt->getSingleDecl(); + assert(isa<VarDecl>(InitDecl) && "SingleDecl must be a VarDecl"); + return findUsage(If->getElse(), InitDecl->getID()); + } + llvm::SmallVector<int64_t, 4> DeclIdentifiers; + for (const auto &Decl : InitDeclStmt->decls()) { + assert(isa<VarDecl>(Decl) && "Init Decls must be a VarDecl"); + DeclIdentifiers.push_back(Decl->getID()); + } + return findUsageRange(If->getElse(), DeclIdentifiers); +} + +const DeclRefExpr *checkConditionVarUsageInElse(const IfStmt *If) { + auto CondVar = If->getConditionVariable(); + return CondVar != nullptr ? findUsage(If->getElse(), CondVar->getID()) + : nullptr; +} + +bool containsDeclInScope(const Stmt *Node) { + if (isa<DeclStmt>(Node)) { + return true; + } + if (auto Compound = dyn_cast<CompoundStmt>(Node)) { + return llvm::any_of(Compound->body(), [](const Stmt *SubNode) { + return isa<DeclStmt>(SubNode); + }); + } + return false; +} + +void removeElseAndBrackets(DiagnosticBuilder &Diag, ASTContext &Context, + const Stmt *Else, SourceLocation ElseLoc) { + auto Remap = [&](SourceLocation Loc) { + return Context.getSourceManager().getExpansionLoc(Loc); + }; + auto TokLen = [&](SourceLocation Loc) { + return Lexer::MeasureTokenLength(Loc, Context.getSourceManager(), + Context.getLangOpts()); + }; + + if (auto CS = dyn_cast<CompoundStmt>(Else)) { + Diag << tooling::fixit::createRemoval(ElseLoc); + const auto LBrace = CS->getLBracLoc(); + const auto RBrace = CS->getRBracLoc(); + const auto RangeStart = Remap(LBrace).getLocWithOffset(TokLen(LBrace)); + const auto RangeEnd = Remap(RBrace).getLocWithOffset(-1); + + const auto Repl = Lexer::getSourceText( + CharSourceRange::getTokenRange(RangeStart, RangeEnd), + Context.getSourceManager(), Context.getLangOpts()); + Diag << tooling::fixit::createReplacement(CS->getSourceRange(), Repl); + } else { + const auto ElseExpandedLoc = Remap(ElseLoc); + const auto EndLoc = Remap(Else->getEndLoc()); + + const auto Repl = Lexer::getSourceText( + CharSourceRange::getTokenRange( + ElseExpandedLoc.getLocWithOffset(TokLen(ElseLoc)), EndLoc), + Context.getSourceManager(), Context.getLangOpts()); + Diag << tooling::fixit::createReplacement( + SourceRange(ElseExpandedLoc, EndLoc), Repl); + } +} + void ElseAfterReturnCheck::check(const MatchFinder::MatchResult &Result) { - const auto *If = Result.Nodes.getNodeAs<IfStmt>("if"); + const auto If = Result.Nodes.getNodeAs<IfStmt>("if"); + const auto Else = Result.Nodes.getNodeAs<Stmt>("else"); + const auto OuterScope = Result.Nodes.getNodeAs<CompoundStmt>("cs"); + const bool IsLastInScope = OuterScope->body_back() == If; + + if (!IsLastInScope && containsDeclInScope(Else)) { + // { + // ... + // if (a) { return } + // else { int b = 0; } cant remove the else as b will leak its scope + // ... + // } + return; + } + SourceLocation ElseLoc = If->getElseLoc(); - std::string ControlFlowInterruptor; - for (const auto *BindingName : {"return", "continue", "break", "throw"}) - if (Result.Nodes.getNodeAs<Stmt>(BindingName)) - ControlFlowInterruptor = BindingName; + llvm::StringRef ControlFlowInterruptor = [&]() -> llvm::StringRef { + for (llvm::StringRef BindingName : {"return", "continue", "break", "throw"}) + if (Result.Nodes.getNodeAs<Stmt>(BindingName)) + return BindingName; + return {}; + }(); + if (checkInitDeclUsageInElse(If) != nullptr || + checkConditionVarUsageInElse(If) != nullptr) { + if (IsLastInScope) { + // If the if statement is the last statement its enclosing statements + // scope, we can pull the decl out of the if statement. + DiagnosticBuilder Diag = diag(ElseLoc, "do not use 'else' after '%0'", + clang::DiagnosticIDs::Level::Remark) + << ControlFlowInterruptor; + if (If->hasInitStorage()) { + Diag << tooling::fixit::createReplacement( + SourceRange(If->getIfLoc()), + (tooling::fixit::getText(*If->getInit(), *Result.Context) + + llvm::StringRef("\n") + + tooling::fixit::getText(If->getIfLoc(), *Result.Context)) + .str()) + << tooling::fixit::createRemoval(If->getInit()->getSourceRange()); + removeElseAndBrackets(Diag, *Result.Context, Else, ElseLoc); + } else { // condition variable + auto VDeclStmt = If->getConditionVariableDeclStmt(); + auto VDecl = If->getConditionVariable(); + auto Repl = (tooling::fixit::getText(*VDeclStmt, *Result.Context) + + llvm::StringRef(";\n") + + tooling::fixit::getText(If->getIfLoc(), *Result.Context)) + .str(); + Diag << tooling::fixit::createReplacement(SourceRange(If->getIfLoc()), + Repl) + << tooling::fixit::createReplacement(VDeclStmt->getSourceRange(), + VDecl->getName()); + removeElseAndBrackets(Diag, *Result.Context, Else, ElseLoc); + } + } else { + // warn, but don't attempt an autofix + diag(ElseLoc, "do not use 'else' after '%0'", + clang::DiagnosticIDs::Level::Remark) + << ControlFlowInterruptor; + } + return; + } DiagnosticBuilder Diag = diag(ElseLoc, "do not use 'else' after '%0'") << ControlFlowInterruptor; - Diag << tooling::fixit::createRemoval(ElseLoc); - - // FIXME: Removing the braces isn't always safe. Do a more careful analysis. - // FIXME: Change clang-format to correctly un-indent the code. - if (const auto *CS = Result.Nodes.getNodeAs<CompoundStmt>("else")) - Diag << tooling::fixit::createRemoval(CS->getLBracLoc()) - << tooling::fixit::createRemoval(CS->getRBracLoc()); + removeElseAndBrackets(Diag, *Result.Context, Else, ElseLoc); } } // namespace readability
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