[StaticAnalyzer] Completely unrolling specific loops with known bound option

This feature allows the analyzer to consider loops to completely unroll.
New requirements/rules (for unrolling) can be added easily via ASTMatchers.

Right now it is hidden behind a flag, the aim is to find the correct heuristic
and create a solution which results higher coverage % and more precise
analysis, thus can be enabled by default.

Right now the blocks which belong to an unrolled loop are marked by the
LoopVisitor which adds them to the ProgramState.
Then whenever we encounter a CFGBlock in the processCFGBlockEntrance which is
marked then we skip its investigating. That means, it won't be considered to
be visited more than the maximal bound for visiting since it won't be checked.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@309006 91177308-0d34-0410-b5e6-96231b3b80d8

10 files changed, 459 insertions, 2 deletions

diff --git a/include/clang/StaticAnalyzer/Core/AnalyzerOptions.h b/include/clang/StaticAnalyzer/Core/AnalyzerOptions.h
index 5dd6bdf384..66e1a746ff 100644
--- a/include/clang/StaticAnalyzer/Core/AnalyzerOptions.h
+++ b/include/clang/StaticAnalyzer/Core/AnalyzerOptions.h
@@ -275,6 +275,9 @@ private:
   /// \sa shouldWidenLoops
   Optional<bool> WidenLoops;
 
+  /// \sa shouldUnrollLoops
+  Optional<bool> UnrollLoops;
+
   /// \sa shouldDisplayNotesAsEvents
   Optional<bool> DisplayNotesAsEvents;
 
@@ -560,6 +563,10 @@ public:
   /// This is controlled by the 'widen-loops' config option.
   bool shouldWidenLoops();
 
+  /// Returns true if the analysis should try to unroll loops with known bounds.
+  /// This is controlled by the 'unroll-loops' config option.
+  bool shouldUnrollLoops();
+
   /// Returns true if the bug reporter should transparently treat extra note
   /// diagnostic pieces as event diagnostic pieces. Useful when the diagnostic
   /// consumer doesn't support the extra note pieces.
diff --git a/include/clang/StaticAnalyzer/Core/PathSensitive/LoopUnrolling.h b/include/clang/StaticAnalyzer/Core/PathSensitive/LoopUnrolling.h
new file mode 100644
index 0000000000..9bb4d72e91
--- /dev/null
+++ b/include/clang/StaticAnalyzer/Core/PathSensitive/LoopUnrolling.h
@@ -0,0 +1,34 @@
+//===--- LoopUnrolling.h - Unroll loops -------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// This header contains the declarations of functions which are used to decide
+/// which loops should be completely unrolled and mark their corresponding
+/// CFGBlocks.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_LOOPUNROLLING_H
+#define LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_LOOPUNROLLING_H
+
+#include "clang/Analysis/CFG.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/ExplodedGraph.h"
+
+namespace clang {
+namespace ento {
+ProgramStateRef markLoopAsUnrolled(const Stmt *Term, ProgramStateRef State,
+                                   const FunctionDecl *FD);
+bool isUnrolledLoopBlock(const CFGBlock *Block, ExplodedNode *Pred,
+                         AnalysisManager &AMgr);
+bool shouldCompletelyUnroll(const Stmt *LoopStmt, ASTContext &ASTCtx);
+
+} // end namespace ento
+} // end namespace clang
+
+#endif
diff --git a/lib/StaticAnalyzer/Checkers/ExprInspectionChecker.cpp b/lib/StaticAnalyzer/Checkers/ExprInspectionChecker.cpp
index 32040e7116..4a581bddd9 100644
--- a/lib/StaticAnalyzer/Checkers/ExprInspectionChecker.cpp
+++ b/lib/StaticAnalyzer/Checkers/ExprInspectionChecker.cpp
@@ -272,6 +272,7 @@ void ExprInspectionChecker::checkEndAnalysis(ExplodedGraph &G, BugReporter &BR,
 
     reportBug(llvm::to_string(NumTimesReached), BR, N);
   }
+  ReachedStats.clear();
 }
 
 void ExprInspectionChecker::analyzerCrash(const CallExpr *CE,
diff --git a/lib/StaticAnalyzer/Core/AnalyzerOptions.cpp b/lib/StaticAnalyzer/Core/AnalyzerOptions.cpp
index 6f48fcb9e2..d5d6527f4f 100644
--- a/lib/StaticAnalyzer/Core/AnalyzerOptions.cpp
+++ b/lib/StaticAnalyzer/Core/AnalyzerOptions.cpp
@@ -375,6 +375,12 @@ bool AnalyzerOptions::shouldWidenLoops() {
   return WidenLoops.getValue();
 }
 
+bool AnalyzerOptions::shouldUnrollLoops() {
+  if (!UnrollLoops.hasValue())
+    UnrollLoops = getBooleanOption("unroll-loops", /*Default=*/false);
+  return UnrollLoops.getValue();
+}
+
 bool AnalyzerOptions::shouldDisplayNotesAsEvents() {
   if (!DisplayNotesAsEvents.hasValue())
     DisplayNotesAsEvents =
diff --git a/lib/StaticAnalyzer/Core/CMakeLists.txt b/lib/StaticAnalyzer/Core/CMakeLists.txt
index 85878f5e96..5ac4f942f3 100644
--- a/lib/StaticAnalyzer/Core/CMakeLists.txt
+++ b/lib/StaticAnalyzer/Core/CMakeLists.txt
@@ -35,6 +35,7 @@ add_clang_library(clangStaticAnalyzerCore
   ExprEngineObjC.cpp
   FunctionSummary.cpp
   HTMLDiagnostics.cpp
+  LoopUnrolling.cpp
   LoopWidening.cpp
   MemRegion.cpp
   PathDiagnostic.cpp
@@ -54,6 +55,7 @@ add_clang_library(clangStaticAnalyzerCore
 
   LINK_LIBS
   clangAST
+  clangASTMatchers
   clangAnalysis
   clangBasic
   clangLex
diff --git a/lib/StaticAnalyzer/Core/ExprEngine.cpp b/lib/StaticAnalyzer/Core/ExprEngine.cpp
index eee5400fe1..2970a6c879 100644
--- a/lib/StaticAnalyzer/Core/ExprEngine.cpp
+++ b/lib/StaticAnalyzer/Core/ExprEngine.cpp
@@ -17,6 +17,7 @@
 #include "PrettyStackTraceLocationContext.h"
 #include "clang/AST/CharUnits.h"
 #include "clang/AST/ParentMap.h"
+#include "clang/Analysis/CFGStmtMap.h"
 #include "clang/AST/StmtCXX.h"
 #include "clang/AST/StmtObjC.h"
 #include "clang/Basic/Builtins.h"
@@ -27,6 +28,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/LoopWidening.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/LoopUnrolling.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Support/SaveAndRestore.h"
 #include "llvm/Support/raw_ostream.h"
@@ -1497,6 +1499,26 @@ void ExprEngine::processCFGBlockEntrance(const BlockEdge &L,
                                          NodeBuilderWithSinks &nodeBuilder,
                                          ExplodedNode *Pred) {
   PrettyStackTraceLocationContext CrashInfo(Pred->getLocationContext());
+  // If we reach a loop which has a known bound (and meets
+  // other constraints) then consider completely unrolling it.
+  if (AMgr.options.shouldUnrollLoops()) {
+    const CFGBlock *ActualBlock = nodeBuilder.getContext().getBlock();
+    const Stmt *Term = ActualBlock->getTerminator();
+    if (Term && shouldCompletelyUnroll(Term, AMgr.getASTContext())) {
+      ProgramStateRef UnrolledState = markLoopAsUnrolled(
+              Term, Pred->getState(),
+              cast<FunctionDecl>(Pred->getStackFrame()->getDecl()));
+      if (UnrolledState != Pred->getState())
+        nodeBuilder.generateNode(UnrolledState, Pred);
+      return;
+    }
+
+    if (ActualBlock->empty())
+      return;
+
+    if (isUnrolledLoopBlock(ActualBlock, Pred, AMgr))
+      return;
+  }
 
   // If this block is terminated by a loop and it has already been visited the
   // maximum number of times, widen the loop.
diff --git a/lib/StaticAnalyzer/Core/LoopUnrolling.cpp b/lib/StaticAnalyzer/Core/LoopUnrolling.cpp
new file mode 100644
index 0000000000..a88e0622f1
--- /dev/null
+++ b/lib/StaticAnalyzer/Core/LoopUnrolling.cpp
@@ -0,0 +1,207 @@
+//===--- LoopUnrolling.cpp - Unroll loops -----------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// This file contains functions which are used to decide if a loop worth to be
+/// unrolled. Moreover contains function which mark the CFGBlocks which belongs
+/// to the unrolled loop and store them in ProgramState.
+///
+//===----------------------------------------------------------------------===//
+
+#include "clang/Analysis/CFGStmtMap.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/AST/ParentMap.h"
+#include "clang/AST/StmtVisitor.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/LoopUnrolling.h"
+#include "llvm/ADT/Statistic.h"
+
+using namespace clang;
+using namespace ento;
+using namespace clang::ast_matchers;
+
+#define DEBUG_TYPE "LoopUnrolling"
+
+STATISTIC(NumTimesLoopUnrolled,
+          "The # of times a loop has got completely unrolled");
+
+REGISTER_MAP_WITH_PROGRAMSTATE(UnrolledLoops, const Stmt *,
+                               const FunctionDecl *)
+
+namespace clang {
+namespace ento {
+
+static bool isLoopStmt(const Stmt *S) {
+  return S && (isa<ForStmt>(S) || isa<WhileStmt>(S) || isa<DoStmt>(S));
+}
+
+static internal::Matcher<Stmt> simpleCondition(StringRef BindName) {
+  return binaryOperator(
+      anyOf(hasOperatorName("<"), hasOperatorName(">"), hasOperatorName("<="),
+            hasOperatorName(">="), hasOperatorName("!=")),
+      hasEitherOperand(ignoringParenImpCasts(
+          declRefExpr(to(varDecl(hasType(isInteger())).bind(BindName))))),
+      hasEitherOperand(ignoringParenImpCasts(integerLiteral())));
+}
+
+static internal::Matcher<Stmt> changeIntBoundNode(StringRef NodeName) {
+  return anyOf(hasDescendant(unaryOperator(
+                   anyOf(hasOperatorName("--"), hasOperatorName("++")),
+                   hasUnaryOperand(ignoringParenImpCasts(
+                       declRefExpr(to(varDecl(equalsBoundNode(NodeName)))))))),
+               hasDescendant(binaryOperator(
+                   anyOf(hasOperatorName("="), hasOperatorName("+="),
+                         hasOperatorName("/="), hasOperatorName("*="),
+                         hasOperatorName("-=")),
+                   hasLHS(ignoringParenImpCasts(
+                       declRefExpr(to(varDecl(equalsBoundNode(NodeName)))))))));
+}
+
+static internal::Matcher<Stmt> callByRef(StringRef NodeName) {
+  return hasDescendant(callExpr(forEachArgumentWithParam(
+      declRefExpr(to(varDecl(equalsBoundNode(NodeName)))),
+      parmVarDecl(hasType(references(qualType(unless(isConstQualified()))))))));
+}
+
+static internal::Matcher<Stmt> assignedToRef(StringRef NodeName) {
+  return hasDescendant(varDecl(
+      allOf(hasType(referenceType()),
+            hasInitializer(
+                anyOf(initListExpr(has(
+                          declRefExpr(to(varDecl(equalsBoundNode(NodeName)))))),
+                      declRefExpr(to(varDecl(equalsBoundNode(NodeName)))))))));
+}
+
+static internal::Matcher<Stmt> getAddrTo(StringRef NodeName) {
+  return hasDescendant(unaryOperator(
+      hasOperatorName("&"),
+      hasUnaryOperand(declRefExpr(hasDeclaration(equalsBoundNode(NodeName))))));
+}
+
+static internal::Matcher<Stmt> hasSuspiciousStmt(StringRef NodeName) {
+  return anyOf(hasDescendant(gotoStmt()), hasDescendant(switchStmt()),
+               // Escaping and not known mutation of the loop counter is handled
+               // by exclusion of assigning and address-of operators and
+               // pass-by-ref function calls on the loop counter from the body.
+               changeIntBoundNode(NodeName), callByRef(NodeName),
+               getAddrTo(NodeName), assignedToRef(NodeName));
+}
+
+static internal::Matcher<Stmt> forLoopMatcher() {
+  return forStmt(
+             hasCondition(simpleCondition("initVarName")),
+             // Initialization should match the form: 'int i = 6' or 'i = 42'.
+             hasLoopInit(
+                 anyOf(declStmt(hasSingleDecl(
+                           varDecl(allOf(hasInitializer(integerLiteral()),
+                                         equalsBoundNode("initVarName"))))),
+                       binaryOperator(hasLHS(declRefExpr(to(varDecl(
+                                          equalsBoundNode("initVarName"))))),
+                                      hasRHS(integerLiteral())))),
+             // Incrementation should be a simple increment or decrement
+             // operator call.
+             hasIncrement(unaryOperator(
+                 anyOf(hasOperatorName("++"), hasOperatorName("--")),
+                 hasUnaryOperand(declRefExpr(
+                     to(varDecl(allOf(equalsBoundNode("initVarName"),
+                                      hasType(isInteger())))))))),
+             unless(hasBody(hasSuspiciousStmt("initVarName")))).bind("forLoop");
+}
+
+bool shouldCompletelyUnroll(const Stmt *LoopStmt, ASTContext &ASTCtx) {
+
+  if (!isLoopStmt(LoopStmt))
+    return false;
+
+  // TODO: Match the cases where the bound is not a concrete literal but an
+  // integer with known value
+
+  auto Matches = match(forLoopMatcher(), *LoopStmt, ASTCtx);
+  return !Matches.empty();
+}
+
+namespace {
+class LoopBlockVisitor : public ConstStmtVisitor<LoopBlockVisitor> {
+public:
+  LoopBlockVisitor(llvm::SmallPtrSet<const CFGBlock *, 8> &BS) : BlockSet(BS) {}
+
+  void VisitChildren(const Stmt *S) {
+    for (const Stmt *Child : S->children())
+      if (Child)
+        Visit(Child);
+  }
+
+  void VisitStmt(const Stmt *S) {
+    // In case of nested loops we only unroll the inner loop if it's marked too.
+    if (!S || (isLoopStmt(S) && S != LoopStmt))
+      return;
+    BlockSet.insert(StmtToBlockMap->getBlock(S));
+    VisitChildren(S);
+  }
+
+  void setBlocksOfLoop(const Stmt *Loop, const CFGStmtMap *M) {
+    BlockSet.clear();
+    StmtToBlockMap = M;
+    LoopStmt = Loop;
+    Visit(LoopStmt);
+  }
+
+private:
+  llvm::SmallPtrSet<const CFGBlock *, 8> &BlockSet;
+  const CFGStmtMap *StmtToBlockMap;
+  const Stmt *LoopStmt;
+};
+}
+// TODO: refactor this function using LoopExit CFG element - once we have the
+// information when the simulation reaches the end of the loop we can cleanup
+// the state
+bool isUnrolledLoopBlock(const CFGBlock *Block, ExplodedNode *Pred,
+                         AnalysisManager &AMgr) {
+  const Stmt *Term = Block->getTerminator();
+  auto State = Pred->getState();
+  // In case of nested loops in an inlined function should not be unrolled only
+  // if the inner loop is marked.
+  if (Term && isLoopStmt(Term) && !State->contains<UnrolledLoops>(Term))
+    return false;
+
+  const CFGBlock *SearchedBlock;
+  llvm::SmallPtrSet<const CFGBlock *, 8> BlockSet;
+  LoopBlockVisitor LBV(BlockSet);
+  // Check the CFGBlocks of every marked loop.
+  for (auto &E : State->get<UnrolledLoops>()) {
+    SearchedBlock = Block;
+    const StackFrameContext *StackFrame = Pred->getStackFrame();
+    ParentMap PM(E.second->getBody());
+    CFGStmtMap *M = CFGStmtMap::Build(AMgr.getCFG(E.second), &PM);
+    LBV.setBlocksOfLoop(E.first, M);
+    // In case of an inlined function call check if any of its callSiteBlock is
+    // marked.
+    while (SearchedBlock && BlockSet.find(SearchedBlock) == BlockSet.end()) {
+      SearchedBlock = StackFrame->getCallSiteBlock();
+      StackFrame = StackFrame->getParent()->getCurrentStackFrame();
+    }
+    delete M;
+    if (SearchedBlock)
+      return true;
+  }
+  return false;
+}
+
+ProgramStateRef markLoopAsUnrolled(const Stmt *Term, ProgramStateRef State,
+                                   const FunctionDecl *FD) {
+  if (State->contains<UnrolledLoops>(Term))
+    return State;
+
+  State = State->set<UnrolledLoops>(Term, FD);
+  ++NumTimesLoopUnrolled;
+  return State;
+}
+}
+}
diff --git a/test/Analysis/analyzer-config.c b/test/Analysis/analyzer-config.c
index 0d8d34fbf6..7bed7cb5e3 100644
--- a/test/Analysis/analyzer-config.c
+++ b/test/Analysis/analyzer-config.c
@@ -27,6 +27,7 @@ void foo() {
 // CHECK-NEXT: min-cfg-size-treat-functions-as-large = 14
 // CHECK-NEXT: mode = deep
 // CHECK-NEXT: region-store-small-struct-limit = 2
+// CHECK-NEXT: unroll-loops = false
 // CHECK-NEXT: widen-loops = false
 // CHECK-NEXT: [stats]
-// CHECK-NEXT: num-entries = 17
+// CHECK-NEXT: num-entries = 18
diff --git a/test/Analysis/analyzer-config.cpp b/test/Analysis/analyzer-config.cpp
index 4166a730cf..155ee02e83 100644
--- a/test/Analysis/analyzer-config.cpp
+++ b/test/Analysis/analyzer-config.cpp
@@ -38,6 +38,7 @@ public:
 // CHECK-NEXT: min-cfg-size-treat-functions-as-large = 14
 // CHECK-NEXT: mode = deep
 // CHECK-NEXT: region-store-small-struct-limit = 2
+// CHECK-NEXT: unroll-loops = false
 // CHECK-NEXT: widen-loops = false
 // CHECK-NEXT: [stats]
-// CHECK-NEXT: num-entries = 22
+// CHECK-NEXT: num-entries = 23
diff --git a/test/Analysis/loop-unrolling.cpp b/test/Analysis/loop-unrolling.cpp
new file mode 100644
index 0000000000..9381c4c7d9
--- /dev/null
+++ b/test/Analysis/loop-unrolling.cpp
@@ -0,0 +1,176 @@
+// RUN: %clang_analyze_cc1 -analyzer-checker=core,debug.ExprInspection -analyzer-config unroll-loops=true -analyzer-stats -verify -std=c++11 %s
+
+void clang_analyzer_numTimesReached();
+
+int getNum();
+void foo(int &);
+// Testing for loops.
+int simple_unroll1() {
+  int a[9];
+  int k = 42;
+  for (int i = 0; i < 9; i++) {
+    clang_analyzer_numTimesReached(); // expected-warning {{9}}
+    a[i] = 42;
+  }
+  int b = 22 / (k - 42); // expected-warning {{Division by zero}}
+  return 0;
+}
+
+int simple_unroll2() {
+  int a[9];
+  int k = 42;
+  int i;
+  for (i = 0; i < 9; i++) {
+    clang_analyzer_numTimesReached(); // expected-warning {{9}}
+    a[i] = 42;
+  }
+  int b = 22 / (k - 42); // expected-warning {{Division by zero}}
+  return 0;
+}
+
+int simple_no_unroll1() {
+  int a[9];
+  int k = 42;
+  for (int i = 0; i < 9; i++) {
+    clang_analyzer_numTimesReached(); // expected-warning {{4}}
+    a[i] = 42;
+    foo(i);
+  }
+  int b = 22 / (k - 42); // expected-warning {{Division by zero}}
+  return 0;
+}
+
+int simple_no_unroll2() {
+  int a[9];
+  int k = 42;
+  int i;
+  for (i = 0; i < 9; i++) {
+    clang_analyzer_numTimesReached(); // expected-warning {{4}}
+    a[i] = 42;
+    i += getNum();
+  }
+  int b = 22 / (k - 42); // expected-warning {{Division by zero}}
+  return 0;
+}
+
+int simple_no_unroll3() {
+  int a[9];
+  int k = 42;
+  int i;
+  for (i = 0; i < 9; i++) {
+    clang_analyzer_numTimesReached(); // expected-warning {{4}}
+    a[i] = 42;
+    (void)&i;
+  }
+  int b = 22 / (k - 42); // no-warning
+  return 0;
+}
+
+int simple_no_unroll4() {
+  int a[9];
+  int k = 42;
+  int i;
+  for (i = 0; i < 9; i++) {
+    clang_analyzer_numTimesReached(); // expected-warning {{4}}
+    a[i] = 42;
+    int &j = i;
+  }
+  int b = 22 / (k - 42); // no-warning
+  return 0;
+}
+
+int simple_no_unroll5() {
+  int a[9];
+  int k = 42;
+  int i;
+  for (i = 0; i < 9; i++) {
+    clang_analyzer_numTimesReached(); // expected-warning {{4}}
+    a[i] = 42;
+    int &j{i};
+  }
+  int b = 22 / (k - 42); // no-warning
+  return 0;
+}
+
+int nested_outer_unrolled() {
+  int a[9];
+  int k = 42;
+  int j = 0;
+  for (int i = 0; i < 9; i++) {
+    clang_analyzer_numTimesReached(); // expected-warning {{16}}
+    for (j = 0; j < getNum(); ++j) {
+      clang_analyzer_numTimesReached(); // expected-warning {{15}}
+      a[j] = 22;
+    }
+    a[i] = 42;
+  }
+  int b = 22 / (k - 42); // no-warning
+  return 0;
+}
+
+int nested_inner_unrolled() {
+  int a[9];
+  int k = 42;
+  int j = 0;
+  for (int i = 0; i < getNum(); i++) {
+    clang_analyzer_numTimesReached(); // expected-warning {{4}}
+    for (j = 0; j < 8; ++j) {
+      clang_analyzer_numTimesReached(); // expected-warning {{32}}
+      a[j] = 22;
+    }
+    a[i] = 42;
+  }
+  int b = 22 / (k - 42); // expected-warning {{Division by zero}}
+  return 0;
+}
+
+int nested_both_unrolled() {
+  int a[9];
+  int k = 42;
+  int j = 0;
+  for (int i = 0; i < 7; i++) {
+    clang_analyzer_numTimesReached(); // expected-warning {{7}}
+    for (j = 0; j < 6; ++j) {
+      clang_analyzer_numTimesReached(); // expected-warning {{42}}
+      a[j] = 22;
+    }
+    a[i] = 42;
+  }
+  int b = 22 / (k - 42); // expected-warning {{Division by zero}}
+  return 0;
+}
+
+int simple_known_bound_loop() {
+  for (int i = 2; i < 12; i++) {
+    // This function is inlined in nested_inlined_unroll1()
+    clang_analyzer_numTimesReached(); // expected-warning {{90}}
+  }
+  return 0;
+}
+
+int simple_unknown_bound_loop() {
+  for (int i = 2; i < getNum(); i++) {
+    clang_analyzer_numTimesReached(); // expected-warning {{10}}
+  }
+  return 0;
+}
+
+int nested_inlined_unroll1() {
+  int k;
+  for (int i = 0; i < 9; i++) {
+    clang_analyzer_numTimesReached(); // expected-warning {{9}}
+    k = simple_known_bound_loop();    // no reevaluation without inlining
+  }
+  int a = 22 / k; // expected-warning {{Division by zero}}
+  return 0;
+}
+
+int nested_inlined_no_unroll1() {
+  int k;
+  for (int i = 0; i < 9; i++) {
+    clang_analyzer_numTimesReached(); // expected-warning {{26}}
+    k = simple_unknown_bound_loop();  // reevaluation without inlining
+  }
+  int a = 22 / k; // no-warning
+  return 0;
+}