[PATCH] D108003: [Clang] Extend -Wbool-operation to warn about bitwise and of bools with side effects

[Dávid Bolvanský via Phabricator via cfe-commits]

xbolva00 updated this revision to Diff 366490.
xbolva00 added a comment.

Rebased.
Changed the warning text.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D108003/new/

https://reviews.llvm.org/D108003

Files:
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/lib/Sema/SemaChecking.cpp
  clang/test/Sema/warn-bitwise-and-bool.c


Index: clang/lib/Sema/SemaChecking.cpp
===================================================================
--- clang/lib/Sema/SemaChecking.cpp
+++ clang/lib/Sema/SemaChecking.cpp
@@ -13101,6 +13101,16 @@
           << OrigE->getSourceRange() << T->isBooleanType()
           << FixItHint::CreateReplacement(UO->getBeginLoc(), "!");
 
+  if (const auto *BO = dyn_cast<BinaryOperator>(SourceExpr))
+    if (BO->getOpcode() == BO_And &&
+        BO->getLHS()->isKnownToHaveBooleanValue() &&
+        BO->getRHS()->isKnownToHaveBooleanValue() &&
+        BO->getRHS()->HasSideEffects(S.Context))
+      S.Diag(BO->getBeginLoc(), diag::warn_bitwise_instead_of_logical)
+          << "&"
+          << "&&" << OrigE->getSourceRange()
+          << FixItHint::CreateReplacement(BO->getOperatorLoc(), "&&");
+
   // For conditional operators, we analyze the arguments as if they
   // were being fed directly into the output.
   if (auto *CO = dyn_cast<AbstractConditionalOperator>(SourceExpr)) {
Index: clang/include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -7421,6 +7421,9 @@
   "member %0 declared here">;
 def note_member_first_declared_here : Note<
   "member %0 first declared here">;
+def warn_bitwise_instead_of_logical : Warning<
+  "use of bitwise '%0' with boolean operands; did you mean logical '%1'?">,
+  InGroup<BoolOperation>, DefaultIgnore;
 def warn_bitwise_negation_bool : Warning<
   "bitwise negation of a boolean expression%select{;| always evaluates to 'true';}0 "
   "did you mean logical negation?">,
Index: clang/test/Sema/warn-bitwise-and-bool.c
===================================================================
--- /dev/null
+++ clang/test/Sema/warn-bitwise-and-bool.c
@@ -0,0 +1,52 @@
+// RUN: %clang_cc1 -x c -fsyntax-only -verify -Wbool-operation %s
+// RUN: %clang_cc1 -x c -fsyntax-only -verify -Wall %s
+// RUN: %clang_cc1 -x c -fsyntax-only -Wbool-operation -fdiagnostics-parseable-fixits %s 2>&1 | FileCheck %s
+// RUN: %clang_cc1 -x c++ -fsyntax-only -verify -Wbool-operation %s
+// RUN: %clang_cc1 -x c++ -fsyntax-only -verify -Wall %s
+// RUN: %clang_cc1 -x c++ -fsyntax-only -Wbool-operation -fdiagnostics-parseable-fixits %s 2>&1 | FileCheck %s
+
+#ifdef __cplusplus
+typedef bool boolean;
+#else
+typedef _Bool boolean;
+#endif
+
+boolean foo(void);
+boolean bar(void);
+boolean baz(void) __attribute__((const));
+void sink(boolean);
+
+#define FOO foo()
+
+void test(boolean a, boolean b, int *p, volatile int *q, int i) {
+  b = a & b;
+  b = foo() & a;
+  b = (p != 0) & (*p == 42);
+  b = (q != 0) & (*q == 42); // expected-warning {{use of bitwise '&' with boolean operands; did you mean logical '&&'?}}
+  b = a & foo();      // expected-warning {{se of bitwise '&' with boolean operands; did you mean logical '&&'?}}
+                      // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:9-[[@LINE-1]]:10}:"&&"
+  b = foo() & bar();  // expected-warning {{se of bitwise '&' with boolean operands; did you mean logical '&&'?}}
+                      // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:13-[[@LINE-1]]:14}:"&&"
+  b = foo() & !bar(); // expected-warning {{se of bitwise '&' with boolean operands; did you mean logical '&&'?}}
+                      // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:13-[[@LINE-1]]:14}:"&&"
+  b = a & baz();
+  b = a & FOO;    // expected-warning {{se of bitwise '&' with boolean operands; did you mean logical '&&'?}}
+                  // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:9-[[@LINE-1]]:10}:"&&"
+  b = !b & foo(); // expected-warning {{se of bitwise '&' with boolean operands; did you mean logical '&&'?}}
+                  // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:10-[[@LINE-1]]:11}:"&&"
+  b = bar() & (i > 4);
+  b = (i == 7) & foo(); // expected-warning {{se of bitwise '&' with boolean operands; did you mean logical '&&'?}}
+#ifdef __cplusplus
+  b = a bitand foo(); // expected-warning {{se of bitwise '&' with boolean operands; did you mean logical '&&'?}}
+#endif
+
+  if (foo() & bar()) // expected-warning {{se of bitwise '&' with boolean operands; did you mean logical '&&'?}}
+    ;
+
+  sink(a & b);
+  sink(a & foo()); // expected-warning {{se of bitwise '&' with boolean operands; did you mean logical '&&'?}}
+  sink(foo() & bar()); // expected-warning {{se of bitwise '&' with boolean operands; did you mean logical '&&'?}}
+
+  int n = i + 10;
+  b = (n & (n-1));
+}
\ No newline at end of file


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