[analyzer] Add checker to verify the correct usage of the MPI API

This commit adds a static analysis checker to verify the correct usage of the MPI API in C
and C++. This version updates the reverted r271981 to fix a memory corruption found by the
ASan bots.

Three path-sensitive checks are included:
- Double nonblocking: Double request usage by nonblocking calls without intermediate wait
- Missing wait: Nonblocking call without matching wait.
- Unmatched wait: Waiting for a request that was never used by a nonblocking call

Examples of how to use the checker can be found at https://github.com/0ax1/MPI-Checker

A patch by Alexander Droste!

Reviewers: zaks.anna, dcoughlin

Differential Revision: http://reviews.llvm.org/D21081

llvm-svn: 272529

1 files changed, 115 insertions, 0 deletions

diff --git a/clang/lib/StaticAnalyzer/Checkers/MPI-Checker/MPIBugReporter.cpp b/clang/lib/StaticAnalyzer/Checkers/MPI-Checker/MPIBugReporter.cpp
new file mode 100644
index 00000000000..d56ea6d689d
--- /dev/null
+++ b/clang/lib/StaticAnalyzer/Checkers/MPI-Checker/MPIBugReporter.cpp
@@ -0,0 +1,115 @@
+//===-- MPIBugReporter.cpp - bug reporter -----------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// This file defines prefabricated reports which are emitted in
+/// case of MPI related bugs, detected by path-sensitive analysis.
+///
+//===----------------------------------------------------------------------===//
+
+#include "MPIBugReporter.h"
+#include "MPIChecker.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
+
+namespace clang {
+namespace ento {
+namespace mpi {
+
+void MPIBugReporter::reportDoubleNonblocking(
+    const CallEvent &MPICallEvent, const ento::mpi::Request &Req,
+    const MemRegion *const RequestRegion,
+    const ExplodedNode *const ExplNode,
+    BugReporter &BReporter) const {
+
+  std::string ErrorText;
+  ErrorText = "Double nonblocking on request " +
+              RequestRegion->getDescriptiveName() + ". ";
+
+  auto Report = llvm::make_unique<BugReport>(*DoubleNonblockingBugType,
+                                             ErrorText, ExplNode);
+
+  Report->addRange(MPICallEvent.getSourceRange());
+  SourceRange Range = RequestRegion->sourceRange();
+
+  if (Range.isValid())
+    Report->addRange(Range);
+
+  Report->addVisitor(llvm::make_unique<RequestNodeVisitor>(
+      RequestRegion, "Request is previously used by nonblocking call here. "));
+  Report->markInteresting(RequestRegion);
+
+  BReporter.emitReport(std::move(Report));
+}
+
+void MPIBugReporter::reportMissingWait(
+    const ento::mpi::Request &Req, const MemRegion *const RequestRegion,
+    const ExplodedNode *const ExplNode,
+    BugReporter &BReporter) const {
+  std::string ErrorText{"Request " + RequestRegion->getDescriptiveName() +
+                        " has no matching wait. "};
+
+  auto Report =
+      llvm::make_unique<BugReport>(*MissingWaitBugType, ErrorText, ExplNode);
+
+  SourceRange Range = RequestRegion->sourceRange();
+  if (Range.isValid())
+    Report->addRange(Range);
+  Report->addVisitor(llvm::make_unique<RequestNodeVisitor>(
+      RequestRegion, "Request is previously used by nonblocking call here. "));
+  Report->markInteresting(RequestRegion);
+
+  BReporter.emitReport(std::move(Report));
+}
+
+void MPIBugReporter::reportUnmatchedWait(
+    const CallEvent &CE, const clang::ento::MemRegion *const RequestRegion,
+    const ExplodedNode *const ExplNode,
+    BugReporter &BReporter) const {
+  std::string ErrorText{"Request " + RequestRegion->getDescriptiveName() +
+                        " has no matching nonblocking call. "};
+
+  auto Report =
+      llvm::make_unique<BugReport>(*UnmatchedWaitBugType, ErrorText, ExplNode);
+
+  Report->addRange(CE.getSourceRange());
+  SourceRange Range = RequestRegion->sourceRange();
+  if (Range.isValid())
+    Report->addRange(Range);
+
+  BReporter.emitReport(std::move(Report));
+}
+
+PathDiagnosticPiece *MPIBugReporter::RequestNodeVisitor::VisitNode(
+    const ExplodedNode *N, const ExplodedNode *PrevN, BugReporterContext &BRC,
+    BugReport &BR) {
+
+  if (IsNodeFound)
+    return nullptr;
+
+  const Request *const Req = N->getState()->get<RequestMap>(RequestRegion);
+  const Request *const PrevReq =
+      PrevN->getState()->get<RequestMap>(RequestRegion);
+
+  // Check if request was previously unused or in a different state.
+  if ((Req && !PrevReq) || (Req->CurrentState != PrevReq->CurrentState)) {
+    IsNodeFound = true;
+
+    ProgramPoint P = PrevN->getLocation();
+    PathDiagnosticLocation L =
+        PathDiagnosticLocation::create(P, BRC.getSourceManager());
+
+    return new PathDiagnosticEventPiece(L, ErrorText);
+  }
+
+  return nullptr;
+}
+
+} // end of namespace: mpi
+} // end of namespace: ento
+} // end of namespace: clang