r313756 - Replace r313747, don't always warn on enums, rework testcases.

Roman Lebedev via cfe-commits cfe-commits at lists.llvm.org
Wed Sep 20 06:50:01 PDT 2017


Author: lebedevri
Date: Wed Sep 20 06:50:01 2017
New Revision: 313756

URL: http://llvm.org/viewvc/llvm-project?rev=313756&view=rev
Log:
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.

Added:
    cfe/trunk/test/Sema/tautological-unsigned-enum-zero-compare.cpp
Modified:
    cfe/trunk/lib/Sema/SemaChecking.cpp
    cfe/trunk/test/Sema/tautological-unsigned-enum-zero-compare.c

Modified: cfe/trunk/lib/Sema/SemaChecking.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaChecking.cpp?rev=313756&r1=313755&r2=313756&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaChecking.cpp (original)
+++ cfe/trunk/lib/Sema/SemaChecking.cpp Wed Sep 20 06:50:01 2017
@@ -8592,26 +8592,22 @@ bool CheckTautologicalComparisonWithZero
 
   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)

Modified: cfe/trunk/test/Sema/tautological-unsigned-enum-zero-compare.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/tautological-unsigned-enum-zero-compare.c?rev=313756&r1=313755&r2=313756&view=diff
==============================================================================
--- cfe/trunk/test/Sema/tautological-unsigned-enum-zero-compare.c (original)
+++ cfe/trunk/test/Sema/tautological-unsigned-enum-zero-compare.c Wed Sep 20 06:50:01 2017
@@ -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}}
@@ -16,6 +21,23 @@ int main() {
     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;
+#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}}

Added: cfe/trunk/test/Sema/tautological-unsigned-enum-zero-compare.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/tautological-unsigned-enum-zero-compare.cpp?rev=313756&view=auto
==============================================================================
--- cfe/trunk/test/Sema/tautological-unsigned-enum-zero-compare.cpp (added)
+++ cfe/trunk/test/Sema/tautological-unsigned-enum-zero-compare.cpp Wed Sep 20 06:50:01 2017
@@ -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;
+}




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