r340990 - [analyzer] Document that pointer arithmetic is not represented by SymExprs.

[Artem Dergachev via cfe-commits]

Author: dergachev
Date: Wed Aug 29 15:57:52 2018
New Revision: 340990

URL: http://llvm.org/viewvc/llvm-project?rev=340990&view=rev
Log:
[analyzer] Document that pointer arithmetic is not represented by SymExprs.

Add assertions to verify that.

Modified:
    cfe/trunk/include/clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h
    cfe/trunk/include/clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h

Modified: cfe/trunk/include/clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h?rev=340990&r1=340989&r2=340990&view=diff
==============================================================================
--- cfe/trunk/include/clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h (original)
+++ cfe/trunk/include/clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h Wed Aug 29 15:57:52 2018
@@ -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());

Modified: cfe/trunk/include/clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h?rev=340990&r1=340989&r2=340990&view=diff
==============================================================================
--- cfe/trunk/include/clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h (original)
+++ cfe/trunk/include/clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h Wed Aug 29 15:57:52 2018
@@ -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: