[Analyzer] Quick Fix for exponential execution time when simpilifying complex additive expressions

Patch https://reviews.llvm.org/rC329780 not only rearranges comparisons but
also binary expressions. This latter behavior is not protected by the analyzer
option. Hower, since no complexity threshold is enforced to the symbols this
may result in exponential execution time if the expressions are too complex:
https://bugs.llvm.org/show_bug.cgi?id=38208. For a quick fix we extended the
analyzer option to also cover the additive cases.

This is only a temporary fix, the final solution should be enforcing the
complexity threshold to the symbols.

Differential Revision: https://reviews.llvm.org/D49536

llvm-svn: 337678

7 files changed, 94 insertions, 28 deletions

diff --git a/clang/include/clang/StaticAnalyzer/Core/AnalyzerOptions.h b/clang/include/clang/StaticAnalyzer/Core/AnalyzerOptions.h
index aa59d6ff538..9d292cfddb0 100644
--- a/clang/include/clang/StaticAnalyzer/Core/AnalyzerOptions.h
+++ b/clang/include/clang/StaticAnalyzer/Core/AnalyzerOptions.h
@@ -318,8 +318,8 @@ private:
   /// \sa shouldDisplayNotesAsEvents
   Optional<bool> DisplayNotesAsEvents;
 
-  /// \sa shouldAggressivelySimplifyRelationalComparison
-  Optional<bool> AggressiveRelationalComparisonSimplification;
+  /// \sa shouldAggressivelySimplifyBinaryOperation
+  Optional<bool> AggressiveBinaryOperationSimplification;
 
   /// \sa getCTUDir
   Optional<StringRef> CTUDir;
@@ -690,19 +690,19 @@ public:
   /// to false when unset.
   bool shouldDisplayNotesAsEvents();
 
-  /// Returns true if SValBuilder should rearrange comparisons of symbolic
-  /// expressions which consist of a sum of a symbol and a concrete integer
-  /// into the format where symbols are on the left-hand side and the integer
-  /// is on the right. This is only done if both symbols and both concrete
-  /// integers are signed, greater than or equal to the quarter of the minimum
-  /// value of the type and less than or equal to the quarter of the maximum
-  /// value of that type.
-  ///
-  /// A + n <REL> B + m becomes A - B <REL> m - n, where A and B symbolic,
-  /// n and m are integers. <REL> is any of '==', '!=', '<', '<=', '>' or '>='.
-  /// The rearrangement also happens with '-' instead of '+' on either or both
-  /// side and also if any or both integers are missing.
-  bool shouldAggressivelySimplifyRelationalComparison();
+  /// Returns true if SValBuilder should rearrange comparisons and additive
+  /// operations of symbolic expressions which consist of a sum of a symbol and
+  /// a concrete integer into the format where symbols are on the left-hand
+  /// side and the integer is on the right. This is only done if both symbols
+  /// and both concrete integers are signed, greater than or equal to the
+  /// quarter of the minimum value of the type and less than or equal to the
+  /// quarter of the maximum value of that type.
+  ///
+  /// A + n <OP> B + m becomes A - B <OP> m - n, where A and B symbolic,
+  /// n and m are integers. <OP> is any of '==', '!=', '<', '<=', '>', '>=',
+  /// '+' or '-'. The rearrangement also happens with '-' instead of '+' on
+  // either or both side and also if any or both integers are missing.
+  bool shouldAggressivelySimplifyBinaryOperation();
 
   /// Returns the directory containing the CTU related files.
   StringRef getCTUDir();
diff --git a/clang/lib/StaticAnalyzer/Core/AnalyzerOptions.cpp b/clang/lib/StaticAnalyzer/Core/AnalyzerOptions.cpp
index eac07e659dc..9b2dc32e060 100644
--- a/clang/lib/StaticAnalyzer/Core/AnalyzerOptions.cpp
+++ b/clang/lib/StaticAnalyzer/Core/AnalyzerOptions.cpp
@@ -463,12 +463,12 @@ bool AnalyzerOptions::shouldDisplayNotesAsEvents() {
   return DisplayNotesAsEvents.getValue();
 }
 
-bool AnalyzerOptions::shouldAggressivelySimplifyRelationalComparison() {
-  if (!AggressiveRelationalComparisonSimplification.hasValue())
-    AggressiveRelationalComparisonSimplification =
-      getBooleanOption("aggressive-relational-comparison-simplification",
+bool AnalyzerOptions::shouldAggressivelySimplifyBinaryOperation() {
+  if (!AggressiveBinaryOperationSimplification.hasValue())
+    AggressiveBinaryOperationSimplification =
+      getBooleanOption("aggressive-binary-operation-simplification",
                        /*Default=*/false);
-  return AggressiveRelationalComparisonSimplification.getValue();
+  return AggressiveBinaryOperationSimplification.getValue();
 }
 
 StringRef AnalyzerOptions::getCTUDir() {
diff --git a/clang/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp b/clang/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp
index 7163e380e6c..beae0dfae28 100644
--- a/clang/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp
+++ b/clang/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp
@@ -456,14 +456,17 @@ static Optional<NonLoc> tryRearrange(ProgramStateRef State,
   auto &Opts =
     StateMgr.getOwningEngine()->getAnalysisManager().getAnalyzerOptions();
 
+  // FIXME: After putting complexity threshold to the symbols we can always
+  //        rearrange additive operations but rearrange comparisons only if
+  //        option is set.
+  if(!Opts.shouldAggressivelySimplifyBinaryOperation())
+    return None;
+
   SymbolRef LSym = Lhs.getAsSymbol();
   if (!LSym)
     return None;
 
-  // Always rearrange additive operations but rearrange comparisons only if
-  // option is set.
-  if (BinaryOperator::isComparisonOp(Op) &&
-      Opts.shouldAggressivelySimplifyRelationalComparison()) {
+  if (BinaryOperator::isComparisonOp(Op)) {
     SingleTy = LSym->getType();
     if (ResultTy != SVB.getConditionType())
       return None;
diff --git a/clang/test/Analysis/constraint_manager_negate_difference.c b/clang/test/Analysis/constraint_manager_negate_difference.c
index 6856f48bb04..2236c1693b9 100644
--- a/clang/test/Analysis/constraint_manager_negate_difference.c
+++ b/clang/test/Analysis/constraint_manager_negate_difference.c
@@ -1,4 +1,4 @@
-// RUN: %clang_analyze_cc1 -analyzer-checker=debug.ExprInspection,core.builtin -analyzer-config aggressive-relational-comparison-simplification=true -verify %s
+// RUN: %clang_analyze_cc1 -analyzer-checker=debug.ExprInspection,core.builtin -analyzer-config aggressive-binary-operation-simplification=true -verify %s
 
 void clang_analyzer_eval(int);
 
diff --git a/clang/test/Analysis/iterator-range.cpp b/clang/test/Analysis/iterator-range.cpp
index 45d9f194d4c..8a4ba29b0cd 100644
--- a/clang/test/Analysis/iterator-range.cpp
+++ b/clang/test/Analysis/iterator-range.cpp
@@ -1,5 +1,5 @@
-// RUN: %clang_analyze_cc1 -std=c++11 -analyzer-checker=core,cplusplus,alpha.cplusplus.IteratorRange -analyzer-eagerly-assume -analyzer-config aggressive-relational-comparison-simplification=true -analyzer-config c++-container-inlining=false %s -verify
-// RUN: %clang_analyze_cc1 -std=c++11 -analyzer-checker=core,cplusplus,alpha.cplusplus.IteratorRange -analyzer-eagerly-assume -analyzer-config aggressive-relational-comparison-simplification=true -analyzer-config c++-container-inlining=true -DINLINE=1 %s -verify
+// RUN: %clang_analyze_cc1 -std=c++11 -analyzer-checker=core,cplusplus,alpha.cplusplus.IteratorRange -analyzer-eagerly-assume -analyzer-config aggressive-binary-operation-simplification=true -analyzer-config c++-container-inlining=false %s -verify
+// RUN: %clang_analyze_cc1 -std=c++11 -analyzer-checker=core,cplusplus,alpha.cplusplus.IteratorRange -analyzer-eagerly-assume -analyzer-config aggressive-binary-operation-simplification=true -analyzer-config c++-container-inlining=true -DINLINE=1 %s -verify
 
 #include "Inputs/system-header-simulator-cxx.h"
 
diff --git a/clang/test/Analysis/plist-macros.cpp b/clang/test/Analysis/plist-macros.cpp
index 53f7a19c13f..4f7d3a25457 100644
--- a/clang/test/Analysis/plist-macros.cpp
+++ b/clang/test/Analysis/plist-macros.cpp
@@ -637,6 +637,69 @@ void test2(int *p) {
 // CHECK-NEXT:         <key>end</key>
 // CHECK-NEXT:          <array>
 // CHECK-NEXT:           <dict>
+// CHECK-NEXT:            <key>line</key><integer>36</integer>
+// CHECK-NEXT:            <key>col</key><integer>7</integer>
+// CHECK-NEXT:            <key>file</key><integer>0</integer>
+// CHECK-NEXT:           </dict>
+// CHECK-NEXT:           <dict>
+// CHECK-NEXT:            <key>line</key><integer>36</integer>
+// CHECK-NEXT:            <key>col</key><integer>7</integer>
+// CHECK-NEXT:            <key>file</key><integer>0</integer>
+// CHECK-NEXT:           </dict>
+// CHECK-NEXT:          </array>
+// CHECK-NEXT:        </dict>
+// CHECK-NEXT:       </array>
+// CHECK-NEXT:     </dict>
+// CHECK-NEXT:     <dict>
+// CHECK-NEXT:      <key>kind</key><string>event</string>
+// CHECK-NEXT:      <key>location</key>
+// CHECK-NEXT:      <dict>
+// CHECK-NEXT:       <key>line</key><integer>36</integer>
+// CHECK-NEXT:       <key>col</key><integer>7</integer>
+// CHECK-NEXT:       <key>file</key><integer>0</integer>
+// CHECK-NEXT:      </dict>
+// CHECK-NEXT:      <key>ranges</key>
+// CHECK-NEXT:      <array>
+// CHECK-NEXT:        <array>
+// CHECK-NEXT:         <dict>
+// CHECK-NEXT:          <key>line</key><integer>36</integer>
+// CHECK-NEXT:          <key>col</key><integer>7</integer>
+// CHECK-NEXT:          <key>file</key><integer>0</integer>
+// CHECK-NEXT:         </dict>
+// CHECK-NEXT:         <dict>
+// CHECK-NEXT:          <key>line</key><integer>36</integer>
+// CHECK-NEXT:          <key>col</key><integer>25</integer>
+// CHECK-NEXT:          <key>file</key><integer>0</integer>
+// CHECK-NEXT:         </dict>
+// CHECK-NEXT:        </array>
+// CHECK-NEXT:      </array>
+// CHECK-NEXT:      <key>depth</key><integer>0</integer>
+// CHECK-NEXT:      <key>extended_message</key>
+// CHECK-NEXT:      <string>Assuming the condition is true</string>
+// CHECK-NEXT:      <key>message</key>
+// CHECK-NEXT:      <string>Assuming the condition is true</string>
+// CHECK-NEXT:     </dict>
+// CHECK-NEXT:     <dict>
+// CHECK-NEXT:      <key>kind</key><string>control</string>
+// CHECK-NEXT:      <key>edges</key>
+// CHECK-NEXT:       <array>
+// CHECK-NEXT:        <dict>
+// CHECK-NEXT:         <key>start</key>
+// CHECK-NEXT:          <array>
+// CHECK-NEXT:           <dict>
+// CHECK-NEXT:            <key>line</key><integer>36</integer>
+// CHECK-NEXT:            <key>col</key><integer>7</integer>
+// CHECK-NEXT:            <key>file</key><integer>0</integer>
+// CHECK-NEXT:           </dict>
+// CHECK-NEXT:           <dict>
+// CHECK-NEXT:            <key>line</key><integer>36</integer>
+// CHECK-NEXT:            <key>col</key><integer>7</integer>
+// CHECK-NEXT:            <key>file</key><integer>0</integer>
+// CHECK-NEXT:           </dict>
+// CHECK-NEXT:          </array>
+// CHECK-NEXT:         <key>end</key>
+// CHECK-NEXT:          <array>
+// CHECK-NEXT:           <dict>
 // CHECK-NEXT:            <key>line</key><integer>37</integer>
 // CHECK-NEXT:            <key>col</key><integer>5</integer>
 // CHECK-NEXT:            <key>file</key><integer>0</integer>
diff --git a/clang/test/Analysis/svalbuilder-rearrange-comparisons.c b/clang/test/Analysis/svalbuilder-rearrange-comparisons.c
index 2303ce693ca..ac186120fe1 100644
--- a/clang/test/Analysis/svalbuilder-rearrange-comparisons.c
+++ b/clang/test/Analysis/svalbuilder-rearrange-comparisons.c
@@ -1,4 +1,4 @@
-// RUN: %clang_analyze_cc1 -analyzer-checker=debug.ExprInspection,core.builtin -analyzer-config aggressive-relational-comparison-simplification=true -verify %s
+// RUN: %clang_analyze_cc1 -analyzer-checker=debug.ExprInspection,core.builtin -analyzer-config aggressive-binary-operation-simplification=true -verify %s
 
 void clang_analyzer_dump(int x);
 void clang_analyzer_eval(int x);