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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 16:51:28 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 16:51:28 +0000
commit940b4d1848e8c70ab7642901a68594e8016caffc (patch)
treeeb72f344ee6c3d9b80a7ecc079ea79e9fba8676d /compilerplugins/clang/unusedvariablecheck.cxx
parentInitial commit. (diff)
downloadlibreoffice-940b4d1848e8c70ab7642901a68594e8016caffc.tar.xz
libreoffice-940b4d1848e8c70ab7642901a68594e8016caffc.zip
Adding upstream version 1:7.0.4.upstream/1%7.0.4upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--compilerplugins/clang/unusedvariablecheck.cxx97
1 files changed, 97 insertions, 0 deletions
diff --git a/compilerplugins/clang/unusedvariablecheck.cxx b/compilerplugins/clang/unusedvariablecheck.cxx
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+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * Based on LLVM/Clang.
+ *
+ * This file is distributed under the University of Illinois Open Source
+ * License. See LICENSE.TXT for details.
+ *
+ */
+
+#ifndef LO_CLANG_SHARED_PLUGINS
+
+#include <config_global.h>
+
+#include "compat.hxx"
+#include "check.hxx"
+#include "unusedvariablecheck.hxx"
+
+namespace loplugin
+{
+
+/*
+This is a compile check.
+
+Check for unused classes where the compiler cannot decide (e.g. because of
+non-trivial or extern ctors) if a variable is unused if only its ctor/dtor
+are called and nothing else. For example std::vector is a class where
+the ctor may call further functions, but an unused std::string variable
+does nothing. On the other hand, std::lock_guard instances are used
+for their dtors and so are not unused even if not otherwise accessed.
+
+Classes which are safe to be warned about need to be marked using
+SAL_WARN_UNUSED (see e.g. OUString). For external classes such as std::vector
+that cannot be edited there is a manual list below.
+*/
+
+UnusedVariableCheck::UnusedVariableCheck( const InstantiationData& data )
+ : FilteringPlugin( data )
+ {
+ }
+
+void UnusedVariableCheck::run()
+ {
+ TraverseDecl( compiler.getASTContext().getTranslationUnitDecl());
+ }
+
+bool UnusedVariableCheck::VisitVarDecl( const VarDecl* var )
+ {
+ if( ignoreLocation( var ))
+ return true;
+ if( var->isReferenced() || var->isUsed())
+ return true;
+ if( var->isDefinedOutsideFunctionOrMethod())
+ return true;
+
+ auto type = var->getType();
+ bool check = loplugin::isExtraWarnUnusedType(type);
+
+ // this chunk of logic generates false+, which is why we don't leave it on
+/*
+ if (!check && type->isRecordType())
+ {
+ auto recordDecl
+ = dyn_cast_or_null<CXXRecordDecl>(type->getAs<RecordType>()->getDecl());
+ if (recordDecl && recordDecl->hasDefinition() && recordDecl->hasTrivialDestructor())
+ check = true;
+ }
+*/
+ if(check)
+ {
+ if( const ParmVarDecl* param = dyn_cast< ParmVarDecl >( var ))
+ {
+ if( !param->getDeclName())
+ return true; // unnamed parameter -> unused
+ // If this declaration does not have a body, then the parameter is indeed not used,
+ // so ignore.
+ if( const FunctionDecl* func = dyn_cast_or_null< FunctionDecl >( param->getParentFunctionOrMethod()))
+ if( !func->doesThisDeclarationHaveABody())
+ return true;
+ report( DiagnosticsEngine::Warning, "unused parameter %0",
+ var->getLocation()) << var->getDeclName();
+ }
+ else
+ report( DiagnosticsEngine::Warning, "unused variable %0",
+ var->getLocation()) << var->getDeclName();
+ }
+ return true;
+ }
+
+static Plugin::Registration< UnusedVariableCheck > unusedvariablecheck( "unusedvariablecheck" );
+
+} // namespace
+
+#endif // LO_CLANG_SHARED_PLUGINS
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */