Replace r313747, don't always warn on enums, rework testcases.

As Aaron Ballman has pointed out, that is not really correct.
So the key problem there is the invalidity of the testcase.

Revert r313747, and rework testcase in such a way, so these
details (platform-specific default enum sigdness) are
accounted for.

Also, add a C++-specific testcase.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@313756 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index 9ff8f6347e7edb01f13625355002bd557c4c2a02..87634ad57e51490147f6974bf20576b03bafc09d 100644 (file)
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -8592,26 +8592,22 @@ bool CheckTautologicalComparisonWithZero(Sema &S, BinaryOperator *E) {
 
   bool Match = true;
 
-  if (Op == BO_LT && IsZero(S, RHS) &&
-      (isNonBooleanUnsignedValue(LHS) || HasEnumType(LHS))) {
+  if (Op == BO_LT && isNonBooleanUnsignedValue(LHS) && IsZero(S, RHS)) {
     S.Diag(E->getOperatorLoc(),
            HasEnumType(LHS) ? diag::warn_lunsigned_enum_always_true_comparison
                             : diag::warn_lunsigned_always_true_comparison)
         << "< 0" << false << LHS->getSourceRange() << RHS->getSourceRange();
-  } else if (Op == BO_GE && IsZero(S, RHS) &&
-             (isNonBooleanUnsignedValue(LHS) || HasEnumType(LHS))) {
+  } else if (Op == BO_GE && isNonBooleanUnsignedValue(LHS) && IsZero(S, RHS)) {
     S.Diag(E->getOperatorLoc(),
            HasEnumType(LHS) ? diag::warn_lunsigned_enum_always_true_comparison
                             : diag::warn_lunsigned_always_true_comparison)
         << ">= 0" << true << LHS->getSourceRange() << RHS->getSourceRange();
-  } else if (Op == BO_GT && IsZero(S, LHS) &&
-             (isNonBooleanUnsignedValue(RHS) || HasEnumType(RHS))) {
+  } else if (Op == BO_GT && isNonBooleanUnsignedValue(RHS) && IsZero(S, LHS)) {
     S.Diag(E->getOperatorLoc(),
            HasEnumType(RHS) ? diag::warn_runsigned_enum_always_true_comparison
                             : diag::warn_runsigned_always_true_comparison)
         << "0 >" << false << LHS->getSourceRange() << RHS->getSourceRange();
-  } else if (Op == BO_LE && IsZero(S, LHS) &&
-             (isNonBooleanUnsignedValue(RHS) || HasEnumType(RHS))) {
+  } else if (Op == BO_LE && isNonBooleanUnsignedValue(RHS) && IsZero(S, LHS)) {
     S.Diag(E->getOperatorLoc(),
            HasEnumType(RHS) ? diag::warn_runsigned_enum_always_true_comparison
                             : diag::warn_runsigned_always_true_comparison)

diff --git a/test/Sema/tautological-unsigned-enum-zero-compare.c b/test/Sema/tautological-unsigned-enum-zero-compare.c
index a0c2a30055c8478f1dee7f9ff47de1c846d15254..49982a9fd71f6f24650cf6ab2bfddfaa7674f714 100644 (file)
--- a/test/Sema/tautological-unsigned-enum-zero-compare.c
+++ b/test/Sema/tautological-unsigned-enum-zero-compare.c
@@ -1,11 +1,16 @@
-// RUN: %clang_cc1 -fsyntax-only -DTEST -verify %s
-// RUN: %clang_cc1 -fsyntax-only -Wno-tautological-unsigned-enum-zero-compare -verify %s
+// RUN: %clang_cc1 -triple=x86_64-pc-linux-gnu -fsyntax-only -DALL_WARN -verify %s
+// RUN: %clang_cc1 -triple=x86_64-pc-win32 -fsyntax-only -DSIGN_WARN -verify %s
+// RUN: %clang_cc1 -triple=x86_64-pc-win32 -fsyntax-only -Wno-tautological-unsigned-enum-zero-compare -verify %s
+
+// Okay, this is where it gets complicated.
+// Then default enum sigdness is target-specific.
+// On windows, it is signed by default. We do not want to warn in that case.
 
 int main() {
   enum A { A_foo, A_bar };
   enum A a;
 
-#ifdef TEST
+#ifdef ALL_WARN
   if (a < 0) // expected-warning {{comparison of unsigned enum expression < 0 is always false}}
     return 0;
   if (a >= 0) // expected-warning {{comparison of unsigned enum expression >= 0 is always true}}
@@ -22,6 +27,23 @@ int main() {
     return 0;
   if (0U > a) // expected-warning {{comparison of 0 > unsigned enum expression is always false}}
     return 0;
+#elif defined(SIGN_WARN)
+  if (a < 0) // ok
+    return 0;
+  if (a >= 0) // ok
+    return 0;
+  if (0 <= a) // ok
+    return 0;
+  if (0 > a) // ok
+    return 0;
+  if (a < 0U) // expected-warning {{comparison of unsigned enum expression < 0 is always false}}
+    return 0;
+  if (a >= 0U) // expected-warning {{comparison of unsigned enum expression >= 0 is always true}}
+    return 0;
+  if (0U <= a) // expected-warning {{comparison of 0 <= unsigned enum expression is always true}}
+    return 0;
+  if (0U > a) // expected-warning {{comparison of 0 > unsigned enum expression is always false}}
+    return 0;
 #else
   // expected-no-diagnostics
   if (a < 0)

diff --git a/test/Sema/tautological-unsigned-enum-zero-compare.cpp b/test/Sema/tautological-unsigned-enum-zero-compare.cpp
new file mode 100644 (file)
index 0000000..3e78626
--- /dev/null
+++ b/test/Sema/tautological-unsigned-enum-zero-compare.cpp
@@ -0,0 +1,176 @@
+// RUN: %clang_cc1 -std=c++11 -triple=x86_64-pc-linux-gnu -fsyntax-only -DALL_WARN -verify %s
+// RUN: %clang_cc1 -std=c++11 -triple=x86_64-pc-win32 -fsyntax-only -DSIGN_WARN -verify %s
+// RUN: %clang_cc1 -std=c++11 -triple=x86_64-pc-win32 -fsyntax-only -Wno-tautological-unsigned-enum-zero-compare -verify %s
+
+// Okay, this is where it gets complicated.
+// Then default enum sigdness is target-specific.
+// On windows, it is signed by default. We do not want to warn in that case.
+
+int main() {
+  enum A { A_foo, A_bar };
+  enum A a;
+
+  enum B : unsigned { B_foo, B_bar };
+  enum B b;
+
+  enum C : signed { c_foo, c_bar };
+  enum C c;
+
+#ifdef ALL_WARN
+  if (a < 0) // expected-warning {{comparison of unsigned enum expression < 0 is always false}}
+    return 0;
+  if (a >= 0) // expected-warning {{comparison of unsigned enum expression >= 0 is always true}}
+    return 0;
+  if (0 <= a) // expected-warning {{comparison of 0 <= unsigned enum expression is always true}}
+    return 0;
+  if (0 > a) // expected-warning {{comparison of 0 > unsigned enum expression is always false}}
+    return 0;
+  if (a < 0U) // expected-warning {{comparison of unsigned enum expression < 0 is always false}}
+    return 0;
+  if (a >= 0U) // expected-warning {{comparison of unsigned enum expression >= 0 is always true}}
+    return 0;
+  if (0U <= a) // expected-warning {{comparison of 0 <= unsigned enum expression is always true}}
+    return 0;
+  if (0U > a) // expected-warning {{comparison of 0 > unsigned enum expression is always false}}
+    return 0;
+
+  if (b < 0) // expected-warning {{comparison of unsigned enum expression < 0 is always false}}
+    return 0;
+  if (b >= 0) // expected-warning {{comparison of unsigned enum expression >= 0 is always true}}
+    return 0;
+  if (0 <= b) // expected-warning {{comparison of 0 <= unsigned enum expression is always true}}
+    return 0;
+  if (0 > b) // expected-warning {{comparison of 0 > unsigned enum expression is always false}}
+    return 0;
+  if (b < 0U) // expected-warning {{comparison of unsigned enum expression < 0 is always false}}
+    return 0;
+  if (b >= 0U) // expected-warning {{comparison of unsigned enum expression >= 0 is always true}}
+    return 0;
+  if (0U <= b) // expected-warning {{comparison of 0 <= unsigned enum expression is always true}}
+    return 0;
+  if (0U > b) // expected-warning {{comparison of 0 > unsigned enum expression is always false}}
+    return 0;
+
+  if (c < 0) // ok
+    return 0;
+  if (c >= 0) // ok
+    return 0;
+  if (0 <= c) // ok
+    return 0;
+  if (0 > c) // ok
+    return 0;
+  if (c < 0U) // expected-warning {{comparison of unsigned enum expression < 0 is always false}}
+    return 0;
+  if (c >= 0U) // expected-warning {{comparison of unsigned enum expression >= 0 is always true}}
+    return 0;
+  if (0U <= c) // expected-warning {{comparison of 0 <= unsigned enum expression is always true}}
+    return 0;
+  if (0U > c) // expected-warning {{comparison of 0 > unsigned enum expression is always false}}
+    return 0;
+#elif defined(SIGN_WARN)
+  if (a < 0) // ok
+    return 0;
+  if (a >= 0) // ok
+    return 0;
+  if (0 <= a) // ok
+    return 0;
+  if (0 > a) // ok
+    return 0;
+  if (a < 0U) // expected-warning {{comparison of unsigned enum expression < 0 is always false}}
+    return 0;
+  if (a >= 0U) // expected-warning {{comparison of unsigned enum expression >= 0 is always true}}
+    return 0;
+  if (0U <= a) // expected-warning {{comparison of 0 <= unsigned enum expression is always true}}
+    return 0;
+  if (0U > a) // expected-warning {{comparison of 0 > unsigned enum expression is always false}}
+    return 0;
+
+  if (b < 0) // expected-warning {{comparison of unsigned enum expression < 0 is always false}}
+    return 0;
+  if (b >= 0) // expected-warning {{comparison of unsigned enum expression >= 0 is always true}}
+    return 0;
+  if (0 <= b) // expected-warning {{comparison of 0 <= unsigned enum expression is always true}}
+    return 0;
+  if (0 > b) // expected-warning {{comparison of 0 > unsigned enum expression is always false}}
+    return 0;
+  if (b < 0U) // expected-warning {{comparison of unsigned enum expression < 0 is always false}}
+    return 0;
+  if (b >= 0U) // expected-warning {{comparison of unsigned enum expression >= 0 is always true}}
+    return 0;
+  if (0U <= b) // expected-warning {{comparison of 0 <= unsigned enum expression is always true}}
+    return 0;
+  if (0U > b) // expected-warning {{comparison of 0 > unsigned enum expression is always false}}
+    return 0;
+
+  if (c < 0) // ok
+    return 0;
+  if (c >= 0) // ok
+    return 0;
+  if (0 <= c) // ok
+    return 0;
+  if (0 > c) // ok
+    return 0;
+  if (c < 0U) // expected-warning {{comparison of unsigned enum expression < 0 is always false}}
+    return 0;
+  if (c >= 0U) // expected-warning {{comparison of unsigned enum expression >= 0 is always true}}
+    return 0;
+  if (0U <= c) // expected-warning {{comparison of 0 <= unsigned enum expression is always true}}
+    return 0;
+  if (0U > c) // expected-warning {{comparison of 0 > unsigned enum expression is always false}}
+    return 0;
+#else
+  // expected-no-diagnostics
+  if (a < 0)
+    return 0;
+  if (a >= 0)
+    return 0;
+  if (0 <= a)
+    return 0;
+  if (0 > a)
+    return 0;
+  if (a < 0U)
+    return 0;
+  if (a >= 0U)
+    return 0;
+  if (0U <= a)
+    return 0;
+  if (0U > a)
+    return 0;
+
+  if (b < 0)
+    return 0;
+  if (b >= 0)
+    return 0;
+  if (0 <= b)
+    return 0;
+  if (0 > b)
+    return 0;
+  if (b < 0U)
+    return 0;
+  if (b >= 0U)
+    return 0;
+  if (0U <= b)
+    return 0;
+  if (0U > b)
+    return 0;
+
+  if (c < 0)
+    return 0;
+  if (c >= 0)
+    return 0;
+  if (0 <= c)
+    return 0;
+  if (0 > c)
+    return 0;
+  if (c < 0U)
+    return 0;
+  if (c >= 0U)
+    return 0;
+  if (0U <= c)
+    return 0;
+  if (0U > c)
+    return 0;
+#endif
+
+  return 1;
+}