if (const llvm::APSInt *Constant = state->getSymVal(RSym)) {
// The symbol evaluates to a constant.
const llvm::APSInt *rhs_I;
- if (BinaryOperator::isRelationalOp(op))
+ if (BinaryOperator::isComparisonOp(op))
rhs_I = &BasicVals.Convert(lhsInt.getValue(), *Constant);
else
rhs_I = &BasicVals.Convert(resultTy, *Constant);
// The conversion type is usually the result type, but not in the case
// of relational expressions.
QualType conversionType = resultTy;
- if (BinaryOperator::isRelationalOp(op))
+ if (BinaryOperator::isComparisonOp(op))
conversionType = lhsType;
// Does the symbol simplify to a constant? If so, "fold" the constant
free(b);
return; // no-warning
}
+
+
+// PR12206/12510 - When SimpleSValBuilder figures out that a symbol is fully
+// constrained, it should cast the value to the result type in a binary
+// operation...unless the binary operation is a comparison, in which case the
+// two arguments should be the same type, but won't match the result type.
+//
+// This is easier to trigger in C++ mode, where the comparison result type is
+// 'bool' and is thus differently sized from int on pretty much every system.
+//
+// This is not directly related to additive folding, but we use SValBuilder's
+// additive folding to tickle the bug. ExprEngine will simplify fully-constrained
+// symbols, so SValBuilder will only see them if they are (a) part of an evaluated
+// SymExpr (e.g. with additive folding) or (b) generated by a checker (e.g.
+// unix.cstring's strlen() modelling).
+void PR12206(int x) {
+ // Build a SymIntExpr, dependent on x.
+ int local = x - 1;
+
+ // Constrain the value of x.
+ int value = 1 + (1 << (8 * sizeof(1 == 1))); // not representable by bool
+ if (x != value) return;
+
+ // Constant-folding will turn (local+1) back into the symbol for x.
+ // The point of this dance is to make SValBuilder be responsible for
+ // turning the symbol into a ConcreteInt, rather than ExprEngine.
+
+ // Test relational operators.
+ if ((local + 1) < 2)
+ malloc(1); // expected-warning{{never executed}}
+ if (2 > (local + 1))
+ malloc(1); // expected-warning{{never executed}}
+
+ // Test equality operators.
+ if ((local + 1) == 1)
+ malloc(1); // expected-warning{{never executed}}
+ if (1 == (local + 1))
+ malloc(1); // expected-warning{{never executed}}
+}
if (strncasecmp("ab\0zz", "ab\0yy", 4) != 0)
(void)*(char*)0; // no-warning
}
+
+//===----------------------------------------------------------------------===
+// Miscellaneous extras.
+//===----------------------------------------------------------------------===
+
+// See additive-folding.cpp for a description of this bug.
+// This test is insurance in case we significantly change how SymExprs are
+// evaluated. It isn't as good as additive-folding.cpp's version
+// because it will only actually be a test on systems where
+// sizeof(1 == 1) < sizeof(size_t).
+// We could add a triple if it becomes necessary.
+void PR12206(const char *x) {
+ // This test is only useful under these conditions.
+ size_t comparisonSize = sizeof(1 == 1);
+ if (sizeof(size_t) <= comparisonSize) return;
+
+ // Create a value that requires more bits to store than a comparison result.
+ size_t value = 1UL;
+ value <<= 8 * comparisonSize;
+ value += 1;
+
+ // Constrain the length of x.
+ if (strlen(x) != value) return;
+
+ // Test relational operators.
+ if (strlen(x) < 2) { (void)*(char*)0; } // no-warning
+ if (2 > strlen(x)) { (void)*(char*)0; } // no-warning
+
+ // Test equality operators.
+ if (strlen(x) == 1) { (void)*(char*)0; } // no-warning
+ if (1 == strlen(x)) { (void)*(char*)0; } // no-warning
+}