[analyzer] Document that pointer arithmetic is not represented by SymExprs.

Add assertions to verify that.

llvm-svn: 340990

2 files changed, 7 insertions, 2 deletions

diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h
index a82559238df..264f011c3cb 100644
--- a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h
+++ b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h
@@ -763,7 +763,9 @@ class SymbolicRegion : public SubRegion {
 
   SymbolicRegion(const SymbolRef s, const MemSpaceRegion *sreg)
       : SubRegion(sreg, SymbolicRegionKind), sym(s) {
-    assert(s);
+    // Because pointer arithmetic is represented by ElementRegion layers,
+    // the base symbol here should not contain any arithmetic.
+    assert(s && isa<SymbolData>(s));
     assert(s->getType()->isAnyPointerType() ||
            s->getType()->isReferenceType() ||
            s->getType()->isBlockPointerType());
diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h
index 07455196260..888ebc214fd 100644
--- a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h
+++ b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h
@@ -309,7 +309,10 @@ protected:
   BinarySymExpr(Kind k, BinaryOperator::Opcode op, QualType t)
       : SymExpr(k), Op(op), T(t) {
     assert(classof(this));
-    assert(isValidTypeForSymbol(t));
+    // Binary expressions are results of arithmetic. Pointer arithmetic is not
+    // handled by binary expressions, but it is instead handled by applying
+    // sub-regions to regions.
+    assert(isValidTypeForSymbol(t) && !Loc::isLocType(t));
   }
 
 public: