[cfe-commits] r106972 - in /cfe/trunk: lib/Checker/SimpleConstraintManager.cpp test/Analysis/misc-ps.m

[Jordy Rose]

Author: jrose
Date: Sat Jun 26 20:20:56 2010
New Revision: 106972

URL: http://llvm.org/viewvc/llvm-project?rev=106972&view=rev
Log:
Implicitly compare symbolic expressions to zero when they're being used as constraints. Part of PR7491.

Modified:
    cfe/trunk/lib/Checker/SimpleConstraintManager.cpp
    cfe/trunk/test/Analysis/misc-ps.m

Modified: cfe/trunk/lib/Checker/SimpleConstraintManager.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Checker/SimpleConstraintManager.cpp?rev=106972&r1=106971&r2=106972&view=diff
==============================================================================
--- cfe/trunk/lib/Checker/SimpleConstraintManager.cpp (original)
+++ cfe/trunk/lib/Checker/SimpleConstraintManager.cpp Sat Jun 26 20:20:56 2010
@@ -174,9 +174,13 @@
       return state;
 
     BinaryOperator::Opcode op = SE->getOpcode();
-    // FIXME: We should implicitly compare non-comparison expressions to 0.
-    if (!BinaryOperator::isComparisonOp(op))
-      return state;
+    // Implicitly compare non-comparison expressions to 0.
+    if (!BinaryOperator::isComparisonOp(op)) {
+      QualType T = SymMgr.getType(SE);
+      const llvm::APSInt &zero = BasicVals.getValue(0, T);
+      op = (Assumption ? BinaryOperator::NE : BinaryOperator::EQ);
+      return AssumeSymRel(state, SE, op, zero);
+    }
 
     // From here on out, op is the real comparison we'll be testing.
     if (!Assumption)

Modified: cfe/trunk/test/Analysis/misc-ps.m
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/misc-ps.m?rev=106972&r1=106971&r2=106972&view=diff
==============================================================================
--- cfe/trunk/test/Analysis/misc-ps.m (original)
+++ cfe/trunk/test/Analysis/misc-ps.m Sat Jun 26 20:20:56 2010
@@ -981,3 +981,21 @@
 
 MAKE_TEST_FN() // expected-warning{{null pointer}}
 
+//===----------------------------------------------------------------------===
+// PR 7491 - Test that symbolic expressions can be used as conditions.
+//===----------------------------------------------------------------------===
+
+void pr7491 () {
+  extern int getint();
+  int a = getint()-1;
+  if (a) {
+    return;
+  }
+  if (!a) {
+    return;
+  } else {
+    // Should be unreachable
+    (void)*(char*)0; // no-warning
+  }
+}
+