[analyzer] Fix an assertation failure for invalid sourcelocation, add a new debug checker

For a rather short code snippet, if debug.ReportStmts (added in this patch) was
enabled, a bug reporter visitor crashed:

struct h {
  operator int();
};

int k() {
  return h();
}

Ultimately, this originated from PathDiagnosticLocation::createMemberLoc, as it
didn't handle the case where it's MemberExpr typed parameter returned and
invalid SourceLocation for MemberExpr::getMemberLoc. The solution was to find
any related valid SourceLocaion, and Stmt::getBeginLoc happens to be just that.

Differential Revision: https://reviews.llvm.org/D58777

llvm-svn: 356161

1 files changed, 31 insertions, 0 deletions

diff --git a/clang/lib/StaticAnalyzer/Checkers/DebugCheckers.cpp b/clang/lib/StaticAnalyzer/Checkers/DebugCheckers.cpp
index 50715f5721c..63215e6bd3b 100644
--- a/clang/lib/StaticAnalyzer/Checkers/DebugCheckers.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/DebugCheckers.cpp
@@ -266,3 +266,34 @@ void ento::registerExplodedGraphViewer(CheckerManager &mgr) {
 bool ento::shouldRegisterExplodedGraphViewer(const LangOptions &LO) {
   return true;
 }
+
+//===----------------------------------------------------------------------===//
+// Emits a report for every Stmt that the analyzer visits.
+//===----------------------------------------------------------------------===//
+
+namespace {
+
+class ReportStmts : public Checker<check::PreStmt<Stmt>> {
+  BuiltinBug BT_stmtLoc{this, "Statement"};
+
+public:
+  void checkPreStmt(const Stmt *S, CheckerContext &C) const {
+    ExplodedNode *Node = C.generateNonFatalErrorNode();
+    if (!Node)
+      return;
+
+    auto Report = llvm::make_unique<BugReport>(BT_stmtLoc, "Statement", Node);
+
+    C.emitReport(std::move(Report));
+  }
+};
+
+} // end of anonymous namespace
+
+void ento::registerReportStmts(CheckerManager &mgr) {
+  mgr.registerChecker<ReportStmts>();
+}
+
+bool ento::shouldRegisterReportStmts(const LangOptions &LO) {
+  return true;
+}