Eliminate some false positives due to a thinko in the "'blah' is
always zero in this context" warning logic. Also, make the diagnostic
itself more precise when referring to pointer values ("NULL" vs. "zero").
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@86143 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index 2309908..06b09a0 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -1787,8 +1787,8 @@
"assignment as a condition without parentheses">,
InGroup<Parentheses>;
-def warn_value_always_zero : Warning<"%0 is always zero in this context">;
-def warn_value_always_false : Warning<"%0 is always false in this context">;
+def warn_value_always_zero : Warning<
+ "%0 is always %select{zero|false|NULL}1 in this context">;
// assignment related diagnostics (also for argument passing, returning, etc).
// FIXME: %2 is an english string here.
diff --git a/include/clang/Parse/Scope.h b/include/clang/Parse/Scope.h
index 480b94f..c6a1e53 100644
--- a/include/clang/Parse/Scope.h
+++ b/include/clang/Parse/Scope.h
@@ -275,7 +275,8 @@
AnyParent = Parent;
Depth = AnyParent ? AnyParent->Depth+1 : 0;
Flags = ScopeFlags;
-
+ WithinElse = false;
+
if (AnyParent) {
FnParent = AnyParent->FnParent;
BreakParent = AnyParent->BreakParent;
@@ -283,13 +284,10 @@
ControlParent = AnyParent->ControlParent;
BlockParent = AnyParent->BlockParent;
TemplateParamParent = AnyParent->TemplateParamParent;
- WithinElse = AnyParent->WithinElse;
-
} else {
FnParent = BreakParent = ContinueParent = BlockParent = 0;
ControlParent = 0;
TemplateParamParent = 0;
- WithinElse = false;
}
// If this scope is a function or contains breaks/continues, remember it.
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index f1d6f2b..f940171 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -814,22 +814,18 @@
// information to check this property.
if (Var->isDeclaredInCondition() && Var->getType()->isScalarType()) {
Scope *CheckS = S;
- while (CheckS) {
+ while (CheckS && CheckS->getControlParent()) {
if (CheckS->isWithinElse() &&
CheckS->getControlParent()->isDeclScope(DeclPtrTy::make(Var))) {
- if (Var->getType()->isBooleanType())
- ExprError(Diag(Loc, diag::warn_value_always_false)
- << Var->getDeclName());
- else
- ExprError(Diag(Loc, diag::warn_value_always_zero)
- << Var->getDeclName());
+ ExprError(Diag(Loc, diag::warn_value_always_zero)
+ << Var->getDeclName()
+ << (Var->getType()->isPointerType()? 2 :
+ Var->getType()->isBooleanType()? 1 : 0));
break;
}
- // Move up one more control parent to check again.
- CheckS = CheckS->getControlParent();
- if (CheckS)
- CheckS = CheckS->getParent();
+ // Move to the parent of this scope.
+ CheckS = CheckS->getParent();
}
}
} else if (FunctionDecl *Func = dyn_cast<FunctionDecl>(D)) {
diff --git a/test/SemaCXX/warn-for-var-in-else.cpp b/test/SemaCXX/warn-for-var-in-else.cpp
index f73c606..c46b306 100644
--- a/test/SemaCXX/warn-for-var-in-else.cpp
+++ b/test/SemaCXX/warn-for-var-in-else.cpp
@@ -2,6 +2,7 @@
// rdar://6425550
int bar();
void do_something(int);
+int *get_ptr();
int foo() {
if (int X = bar()) {
@@ -25,7 +26,20 @@
do_something(B); // expected-warning{{'B' is always false in this context}}
} else if (B2) { // expected-warning{{'B2' is always false in this context}}
do_something(B); // expected-warning{{'B' is always false in this context}}
+ do_something(B2); // expected-warning{{'B2' is always false in this context}}
}
return B; // expected-warning{{'B' is always false in this context}}
}
}
+
+void foo3() {
+ if (int *P1 = get_ptr())
+ do_something(*P1);
+ else if (int *P2 = get_ptr()) {
+ do_something(*P1); // expected-warning{{'P1' is always NULL in this context}}
+ do_something(*P2);
+ } else {
+ do_something(*P1); // expected-warning{{'P1' is always NULL in this context}}
+ do_something(*P2); // expected-warning{{'P2' is always NULL in this context}}
+ }
+}