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-rw-r--r--build/clang-plugin/TemporaryLifetimeBoundChecker.cpp91
1 files changed, 91 insertions, 0 deletions
diff --git a/build/clang-plugin/TemporaryLifetimeBoundChecker.cpp b/build/clang-plugin/TemporaryLifetimeBoundChecker.cpp
new file mode 100644
index 0000000000..dc66f62b0d
--- /dev/null
+++ b/build/clang-plugin/TemporaryLifetimeBoundChecker.cpp
@@ -0,0 +1,91 @@
+/* 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 "TemporaryLifetimeBoundChecker.h"
+#include "CustomMatchers.h"
+#include "clang/Lex/Lexer.h"
+
+void TemporaryLifetimeBoundChecker::registerMatchers(MatchFinder *AstMatcher) {
+ // Look for a call to a MOZ_LIFETIME_BOUND member function
+ auto isTemporaryLifetimeBoundCall =
+ cxxMemberCallExpr(
+ onImplicitObjectArgument(anyOf(has(cxxTemporaryObjectExpr()),
+ has(materializeTemporaryExpr()))),
+ callee(functionDecl(isMozTemporaryLifetimeBound())))
+ .bind("call");
+
+ // XXX This definitely does not catch everything relevant. In particular, the
+ // matching on conditionalOperator would need to be recursive. But it's a
+ // start.
+ auto hasTemporaryLifetimeBoundCall =
+ anyOf(isTemporaryLifetimeBoundCall,
+ conditionalOperator(
+ anyOf(hasFalseExpression(isTemporaryLifetimeBoundCall),
+ hasTrueExpression(isTemporaryLifetimeBoundCall))));
+
+ AstMatcher->addMatcher(
+ returnStmt(hasReturnValue(
+ allOf(exprWithCleanups().bind("expr-with-cleanups"),
+ ignoringParenCasts(hasTemporaryLifetimeBoundCall))))
+ .bind("return-stmt"),
+ this);
+
+ AstMatcher->addMatcher(
+ varDecl(hasType(references(cxxRecordDecl())),
+ hasInitializer(
+ allOf(exprWithCleanups(),
+ ignoringParenCasts(hasTemporaryLifetimeBoundCall))))
+ .bind("var-decl"),
+ this);
+}
+
+void TemporaryLifetimeBoundChecker::check(
+ const MatchFinder::MatchResult &Result) {
+ const auto *Call = Result.Nodes.getNodeAs<CXXMemberCallExpr>("call");
+ const auto *ReturnStatement =
+ Result.Nodes.getNodeAs<ReturnStmt>("return-stmt");
+ const auto *ReferenceVarDecl = Result.Nodes.getNodeAs<VarDecl>("var-decl");
+
+ const char ErrorReturn[] =
+ "cannot return result of lifetime-bound function %0 on "
+ "temporary of type %1";
+
+ const char ErrorBindToReference[] =
+ "cannot bind result of lifetime-bound function %0 on "
+ "temporary of type %1 to reference, does not extend lifetime";
+
+ const char NoteCalledFunction[] = "member function declared here";
+
+ // We are either a return statement...
+ if (ReturnStatement) {
+ const auto *ExprWithCleanups =
+ Result.Nodes.getNodeAs<Expr>("expr-with-cleanups");
+ if (!ExprWithCleanups->isLValue()) {
+ return;
+ }
+
+ const auto Range = ReturnStatement->getSourceRange();
+
+ diag(Range.getBegin(), ErrorReturn, DiagnosticIDs::Error)
+ << Range << Call->getMethodDecl()
+ << Call->getImplicitObjectArgument()
+ ->getType()
+ .withoutLocalFastQualifiers();
+ }
+
+ // ... or a variable declaration that declare a reference
+ if (ReferenceVarDecl) {
+ const auto Range = ReferenceVarDecl->getSourceRange();
+
+ diag(Range.getBegin(), ErrorBindToReference, DiagnosticIDs::Error)
+ << Range << Call->getMethodDecl()
+ << Call->getImplicitObjectArgument()
+ ->getType()
+ .withoutLocalFastQualifiers();
+ }
+
+ const auto *MethodDecl = Call->getMethodDecl();
+ diag(MethodDecl->getCanonicalDecl()->getLocation(), NoteCalledFunction,
+ DiagnosticIDs::Note);
+}