[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, 59 insertions, 0 deletions

diff --git a/clang/lib/StaticAnalyzer/Core/MemRegion.cpp b/clang/lib/StaticAnalyzer/Core/MemRegion.cpp
index 083f6c01bc2..b7b6f42b291 100644
--- a/clang/lib/StaticAnalyzer/Core/MemRegion.cpp
+++ b/clang/lib/StaticAnalyzer/Core/MemRegion.cpp
@@ -632,6 +632,65 @@ void CXXBaseObjectRegion::printPrettyAsExpr(raw_ostream &os) const {
   superRegion->printPrettyAsExpr(os);
 }
 
+std::string MemRegion::getDescriptiveName(bool UseQuotes) const {
+  std::string VariableName;
+  std::string ArrayIndices;
+  const MemRegion *R = this;
+  SmallString<50> buf;
+  llvm::raw_svector_ostream os(buf);
+
+  // Obtain array indices to add them to the variable name.
+  const ElementRegion *ER = nullptr;
+  while ((ER = R->getAs<ElementRegion>())) {
+    // Index is a ConcreteInt.
+    if (auto CI = ER->getIndex().getAs<nonloc::ConcreteInt>()) {
+      llvm::SmallString<2> Idx;
+      CI->getValue().toString(Idx);
+      ArrayIndices = (llvm::Twine("[") + Idx.str() + "]" + ArrayIndices).str();
+    }
+    // If not a ConcreteInt, try to obtain the variable
+    // name by calling 'getDescriptiveName' recursively.
+    else {
+      std::string Idx = ER->getDescriptiveName(false);
+      if (!Idx.empty()) {
+        ArrayIndices = (llvm::Twine("[") + Idx + "]" + ArrayIndices).str();
+      }
+    }
+    R = ER->getSuperRegion();
+  }
+
+  // Get variable name.
+  if (R && R->canPrintPrettyAsExpr()) {
+    R->printPrettyAsExpr(os);
+    if (UseQuotes) {
+      return (llvm::Twine("'") + os.str() + ArrayIndices + "'").str();
+    } else {
+      return (llvm::Twine(os.str()) + ArrayIndices).str();
+    }
+  }
+
+  return VariableName;
+}
+
+SourceRange MemRegion::sourceRange() const {
+  const VarRegion *const VR = dyn_cast<VarRegion>(this->getBaseRegion());
+  const FieldRegion *const FR = dyn_cast<FieldRegion>(this);
+
+  // Check for more specific regions first.
+  // FieldRegion
+  if (FR) {
+    return FR->getDecl()->getSourceRange();
+  }
+  // VarRegion
+  else if (VR) {
+    return VR->getDecl()->getSourceRange();
+  }
+  // Return invalid source range (can be checked by client).
+  else {
+    return SourceRange{};
+  }
+}
+
 //===----------------------------------------------------------------------===//
 // MemRegionManager methods.
 //===----------------------------------------------------------------------===//