Шпынов Никита. Лабораторная работа №1 - ClangAST. Вариант №2

clang/compiler-course/Shpynov_N_ClangAST_var2/CMakeLists.txt

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+set(Title "ClangAST_var2")
+set(Student "Shpynov_Nikita")
+set(Group "FIIT1")
+set(TARGET_NAME "${Title}_${Student}_${Group}_ClangAST")
+
+file(GLOB_RECURSE SOURCES *.cpp *.h *.hpp)
+add_llvm_library(${TARGET_NAME} MODULE ${SOURCES} PLUGIN_TOOL clang)
+
+if(WIN32 OR CYGWIN)
+    set(LLVM_LINK_COMPONENTS Support)
+    clang_target_link_libraries(${TARGET_NAME} PRIVATE
+        clangAST
+        clangBasic
+        clangFrontend
+    )
+endif()
+
+set(CLANG_TEST_DEPS "${TARGET_NAME}" ${CLANG_TEST_DEPS} PARENT_SCOPE)

clang/compiler-course/Shpynov_N_ClangAST_var2/Shpynov_N_ClangAST.cpp

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+#include "clang/AST/ASTConsumer.h"
+#include "clang/AST/RecursiveASTVisitor.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/FrontendPluginRegistry.h"
+#include "clang/Rewrite/Core/Rewriter.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace clang;
+namespace {
+class MaybeUnusedVisitor : public RecursiveASTVisitor<MaybeUnusedVisitor> {
+private:
+  ASTContext &Context;
+  Rewriter &rewriter;
+
+public:
+  explicit MaybeUnusedVisitor(ASTContext &context, Rewriter &RW)
+      : Context(context), rewriter(RW) {}
+  bool VisitVarDecl(VarDecl *VarDec) {
+    if (VarDec->isUsed() || VarDec->hasAttr<clang::UnusedAttr>())
+      return false;
+    SourceLocation loc = VarDec->getBeginLoc();
+    if (!Rewriter::isRewritable(loc))
+      return false;
+    rewriter.InsertTextBefore(loc, "[[maybe_unused]] ");
+    return true;
+  }
+  bool VisitParmVarDecl(ParmVarDecl *ParDec) {
+    if (ParDec->isUsed() || ParDec->hasAttr<clang::UnusedAttr>())
+      return false;
+    SourceLocation loc = ParDec->getBeginLoc();
+    if (!Rewriter::isRewritable(loc))
+      return false;
+    rewriter.InsertTextBefore(loc, "[[maybe_unused]] ");
+    return true;
+  }
+};
+
+class MaybeUnusedASTConsumer : public ASTConsumer {
+private:
+  MaybeUnusedVisitor p_visitor;
+
+public:
+  explicit MaybeUnusedASTConsumer(ASTContext &context, Rewriter &R)
+      : p_visitor(context, R) {}
+
+  void HandleTranslationUnit(ASTContext &Context) override {
+    p_visitor.TraverseDecl(Context.getTranslationUnitDecl());
+  }
+};
+
+class MaybeUnusedAction : public PluginASTAction {
+private:
+  Rewriter rewriter;
+
+public:
+  std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI,
+                                                 llvm::StringRef) override {
+    rewriter.setSourceMgr(CI.getSourceManager(), CI.getLangOpts());
+    return std::make_unique<MaybeUnusedASTConsumer>(CI.getASTContext(),
+                                                    rewriter);
+  }
+
+  bool ParseArgs(const CompilerInstance &CI,
+                 const std::vector<std::string> &args) override {
+    return true;
+  }
+
+  void EndSourceFileAction() override {
+    SourceManager &SM = rewriter.getSourceMgr();
+    rewriter.getEditBuffer(SM.getMainFileID()).write(llvm::outs());
+  }
+};
+} // namespace
+
+static clang::FrontendPluginRegistry::Add<MaybeUnusedAction>
+    X("ClangAST_var2_Shpynov_Nikita_FIIT1_ClangAST",
+      "Automatically inserts [[maybe_unused]] attribute on every potentially "
+      "unused variable or parameter");

clang/test/compiler-course/Shpynov_N_ClangAST_var2_test/Shpynov_N_ClangAST_test.cpp

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+// RUN: %clang_cc1 -load %llvmshlibdir/ClangAST_var2_Shpynov_Nikita_FIIT1_ClangAST%pluginext -plugin ClangAST_var2_Shpynov_Nikita_FIIT1_ClangAST %s -fsyntax-only 2>&1 | FileCheck %s
+
+// CHECK:\[\[maybe_unused\]\] int d = 0;
+
+// CHECK:int foo(int a, int b, \[\[maybe_unused\]\] int c) {
+// CHECK-NEXT:\[\[maybe_unused\]\] double value = 0.0;
+// CHECK-NEXT: return a + b;
+
+// CHECK: \[\[maybe_unused\]\] int e = 0;
+int d = 0;
+
+int foo(int a, int b, int c) {
+    double value = 0.0;
+    return a + b;
+}
+
+int e = 0;