[cfe-commits] r164622 - in /cfe/trunk: lib/StaticAnalyzer/Core/ProgramState.cpp lib/StaticAnalyzer/Core/SymbolManager.cpp test/Analysis/traversal-path-unification.c

[Jordan Rose]

Author: jrose
Date: Tue Sep 25 14:03:06 2012
New Revision: 164622

URL: http://llvm.org/viewvc/llvm-project?rev=164622&view=rev
Log:
Reapply "[analyzer] Remove constraints on dead symbols as part of removeDeadBindings."

Previously, we'd just keep constraints around forever, which means we'd
never be able to merge paths that differed only in constraints on dead
symbols.

Because we now allow constraints on symbolic expressions, not just single
symbols, this requires changing SymExpr::symbol_iterator to include
intermediate symbol nodes in its traversal, not just the SymbolData leaf
nodes.

This depends on the previous commit to be correct. Originally applied in
r163444, reverted in r164275, now being re-applied.

Added:
    cfe/trunk/test/Analysis/traversal-path-unification.c
Modified:
    cfe/trunk/lib/StaticAnalyzer/Core/ProgramState.cpp
    cfe/trunk/lib/StaticAnalyzer/Core/SymbolManager.cpp

Modified: cfe/trunk/lib/StaticAnalyzer/Core/ProgramState.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Core/ProgramState.cpp?rev=164622&r1=164621&r2=164622&view=diff
==============================================================================
--- cfe/trunk/lib/StaticAnalyzer/Core/ProgramState.cpp (original)
+++ cfe/trunk/lib/StaticAnalyzer/Core/ProgramState.cpp Tue Sep 25 14:03:06 2012
@@ -106,8 +106,9 @@
                                                    SymReaper);
   NewState.setStore(newStore);
   SymReaper.setReapedStore(newStore);
-  
-  return getPersistentState(NewState);
+
+  ProgramStateRef Result = getPersistentState(NewState);
+  return ConstraintMgr->removeDeadBindings(Result, SymReaper);
 }
 
 ProgramStateRef ProgramState::bindCompoundLiteral(const CompoundLiteralExpr *CL,
@@ -686,7 +687,9 @@
   bool Tainted = false;
   for (SymExpr::symbol_iterator SI = Sym->symbol_begin(), SE =Sym->symbol_end();
        SI != SE; ++SI) {
-    assert(isa<SymbolData>(*SI));
+    if (!isa<SymbolData>(*SI))
+      continue;
+    
     const TaintTagType *Tag = get<TaintMap>(*SI);
     Tainted = (Tag && *Tag == Kind);
 

Modified: cfe/trunk/lib/StaticAnalyzer/Core/SymbolManager.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Core/SymbolManager.cpp?rev=164622&r1=164621&r2=164622&view=diff
==============================================================================
--- cfe/trunk/lib/StaticAnalyzer/Core/SymbolManager.cpp (original)
+++ cfe/trunk/lib/StaticAnalyzer/Core/SymbolManager.cpp Tue Sep 25 14:03:06 2012
@@ -117,21 +117,17 @@
 
 SymExpr::symbol_iterator::symbol_iterator(const SymExpr *SE) {
   itr.push_back(SE);
-  while (!isa<SymbolData>(itr.back())) expand();
 }
 
 SymExpr::symbol_iterator &SymExpr::symbol_iterator::operator++() {
   assert(!itr.empty() && "attempting to iterate on an 'end' iterator");
-  assert(isa<SymbolData>(itr.back()));
-  itr.pop_back();
-  if (!itr.empty())
-    while (!isa<SymbolData>(itr.back())) expand();
+  expand();
   return *this;
 }
 
 SymbolRef SymExpr::symbol_iterator::operator*() {
   assert(!itr.empty() && "attempting to dereference an 'end' iterator");
-  return cast<SymbolData>(itr.back());
+  return itr.back();
 }
 
 void SymExpr::symbol_iterator::expand() {

Added: cfe/trunk/test/Analysis/traversal-path-unification.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/traversal-path-unification.c?rev=164622&view=auto
==============================================================================
--- cfe/trunk/test/Analysis/traversal-path-unification.c (added)
+++ cfe/trunk/test/Analysis/traversal-path-unification.c Tue Sep 25 14:03:06 2012
@@ -0,0 +1,21 @@
+// RUN: %clang_cc1 -analyze -analyzer-checker=core,debug.DumpTraversal %s | FileCheck %s
+
+int a();
+int b();
+int c();
+
+void testRemoveDeadBindings() {
+  int i = a();
+  if (i)
+    a();
+  else
+    b();
+
+  // At this point the symbol bound to 'i' is dead.
+  // The effects of a() and b() are identical (they both invalidate globals).
+  // We should unify the two paths here and only get one end-of-path node.
+  c();
+}
+
+// CHECK: --END PATH--
+// CHECK-NOT: --END PATH--
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