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-rw-r--r--compilerplugins/clang/externvar.cxx104
-rw-r--r--compilerplugins/clang/test/externvar.cxx61
-rw-r--r--compilerplugins/clang/test/externvar.hxx27
-rw-r--r--solenv/CompilerTest_compilerplugins_clang.mk1
4 files changed, 193 insertions, 0 deletions
diff --git a/compilerplugins/clang/externvar.cxx b/compilerplugins/clang/externvar.cxx
new file mode 100644
index 000000000000..9569a3de37d2
--- /dev/null
+++ b/compilerplugins/clang/externvar.cxx
@@ -0,0 +1,104 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include "check.hxx"
+#include "plugin.hxx"
+
+// Find variable declarations at namespace scope that need not have external
+// linkage.
+
+namespace {
+
+// It looks like Clang wrongly implements DR 4
+// (<http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#4>) and treats
+// a variable declared in an 'extern "..." {...}'-style linkage-specification as
+// if it contained the 'extern' specifier:
+bool hasExternalLinkage(VarDecl const * decl) {
+ if (decl->getLinkageAndVisibility().getLinkage() != ExternalLinkage) {
+ return false;
+ }
+ for (auto ctx = decl->getLexicalDeclContext();
+ ctx->getDeclKind() != Decl::TranslationUnit;
+ ctx = ctx->getLexicalParent())
+ {
+ if (auto ls = dyn_cast<LinkageSpecDecl>(ctx)) {
+ if (!ls->hasBraces()) {
+ return true;
+ }
+ if (auto prev = decl->getPreviousDecl()) {
+ return hasExternalLinkage(prev);
+ }
+ return !decl->isInAnonymousNamespace();
+ }
+ }
+ return true;
+}
+
+class ExternVar: public RecursiveASTVisitor<ExternVar>, public loplugin::Plugin
+{
+public:
+ explicit ExternVar(InstantiationData const & data): Plugin(data) {}
+
+ void run() override
+ { TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()); }
+
+ bool VisitVarDecl(VarDecl const * decl) {
+ if (ignoreLocation(decl)) {
+ return true;
+ }
+ if (decl->isStaticDataMember()) {
+ return true;
+ }
+ if (!(decl->isFirstDecl()
+ && compiler.getSourceManager().isInMainFile(decl->getLocation())
+ && hasExternalLinkage(decl)))
+ {
+ return true;
+ }
+ auto def = decl->getDefinition();
+ if (def == nullptr) {
+ // Code like
+ //
+ // namespace { extern int v; }
+ // int f() { return sizeof(v); }
+ //
+ // is already handled by Clang itself with an error "variable 'v' is
+ // not needed and will not be emitted"
+ return true;
+ }
+ report(
+ DiagnosticsEngine::Warning,
+ "variable with external linkage not declared in an include file",
+ def->getLocation())
+ << def->getSourceRange();
+ report(
+ DiagnosticsEngine::Note,
+ ("should either have internal linkage or be declared in an include"
+ " file"),
+ def->getLocation())
+ << def->getSourceRange();
+ for (auto prev = def;;) {
+ prev = prev->getPreviousDecl();
+ if (prev == nullptr) {
+ break;
+ }
+ report(
+ DiagnosticsEngine::Note, "previously declared here",
+ prev->getLocation())
+ << prev->getSourceRange();
+ }
+ return true;
+ }
+};
+
+loplugin::Plugin::Registration<ExternVar> X("externvar");
+
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */
diff --git a/compilerplugins/clang/test/externvar.cxx b/compilerplugins/clang/test/externvar.cxx
new file mode 100644
index 000000000000..51f743fbba83
--- /dev/null
+++ b/compilerplugins/clang/test/externvar.cxx
@@ -0,0 +1,61 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <externvar.hxx>
+
+int v1;
+int v2; // expected-error {{variable with external linkage not declared in an include file [loplugin:externvar]}} expected-note {{should either have internal linkage or be declared in an include file [loplugin:externvar]}}
+static int v3;
+int const v4 = 0;
+
+extern int v5; // expected-note {{previously declared here [loplugin:externvar]}}
+int v5; // expected-error {{variable with external linkage not declared in an include file [loplugin:externvar]}} expected-note {{should either have internal linkage or be declared in an include file [loplugin:externvar]}}
+
+extern "C" int v6; // expected-note {{previously declared here [loplugin:externvar]}}
+int v6; // expected-error {{variable with external linkage not declared in an include file [loplugin:externvar]}} expected-note {{should either have internal linkage or be declared in an include file [loplugin:externvar]}}
+extern "C" { int v7; } // expected-error {{variable with external linkage not declared in an include file [loplugin:externvar]}} expected-note {{should either have internal linkage or be declared in an include file [loplugin:externvar]}}
+
+namespace {
+
+int u1;
+static int u2;
+extern "C" int u3; // expected-note {{previously declared here [loplugin:externvar]}}
+int u3; // expected-error {{variable with external linkage not declared in an include file [loplugin:externvar]}} expected-note {{should either have internal linkage or be declared in an include file [loplugin:externvar]}}
+extern "C" { int u4; }
+
+}
+
+namespace N {
+
+int v1;
+int v2; // expected-error {{variable with external linkage not declared in an include file [loplugin:externvar]}} expected-note {{should either have internal linkage or be declared in an include file [loplugin:externvar]}}
+static int v3;
+
+}
+
+struct S {
+ static int f() {
+ static int s = 0;
+ return s;
+ }
+
+ static int m;
+};
+
+int S::m = 0;
+
+int f(int a) {
+ static int s = 0;
+ ++s;
+ int b = a + s + v1 + v2 + v3 + v4 + v5 + v6 + v7 + u1 + u2 + u3 + u4 + N::v1
+ + N::v2 + N::v3 + S::f();
+ return b;
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */
diff --git a/compilerplugins/clang/test/externvar.hxx b/compilerplugins/clang/test/externvar.hxx
new file mode 100644
index 000000000000..225f1ee59fd0
--- /dev/null
+++ b/compilerplugins/clang/test/externvar.hxx
@@ -0,0 +1,27 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#ifndef INClUDED_COMPILERPLUGINS_CLANG_TEST_EXTERNVAR_HXX
+#define INClUDED_COMPILERPLUGINS_CLANG_TEST_EXTERNVAR_HXX
+
+extern int v1;
+
+namespace N {
+
+extern int v1;
+
+}
+
+struct S;
+
+int f(int a);
+
+#endif
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */
diff --git a/solenv/CompilerTest_compilerplugins_clang.mk b/solenv/CompilerTest_compilerplugins_clang.mk
index a4c0a15e6b8e..4934ae28ea6e 100644
--- a/solenv/CompilerTest_compilerplugins_clang.mk
+++ b/solenv/CompilerTest_compilerplugins_clang.mk
@@ -11,6 +11,7 @@ $(eval $(call gb_CompilerTest_CompilerTest,compilerplugins_clang))
$(eval $(call gb_CompilerTest_add_exception_objects,compilerplugins_clang, \
compilerplugins/clang/test/datamembershadow \
+ compilerplugins/clang/test/externvar \
compilerplugins/clang/test/finalprotected \
compilerplugins/clang/test/passstuffbyref \
compilerplugins/clang/test/oslendian-1 \
generated by cgit (git 2.34.1) at 2024-12-28 04:10:28 +0000