r222009 - [Sema]. Warn when logical expression is a pointer
Fariborz Jahanian
fjahanian at apple.com
Fri Nov 14 09:12:51 PST 2014
Author: fjahanian
Date: Fri Nov 14 11:12:50 2014
New Revision: 222009
URL: http://llvm.org/viewvc/llvm-project?rev=222009&view=rev
Log:
[Sema]. Warn when logical expression is a pointer
which evaluates to true. rdar://18716393.
Reviewed by Richard Trieu
Added:
cfe/trunk/test/Sema/warn-tautological-compare.c
Modified:
cfe/trunk/include/clang/Sema/Sema.h
cfe/trunk/lib/Sema/SemaChecking.cpp
cfe/trunk/lib/Sema/SemaExpr.cpp
cfe/trunk/test/Analysis/NSContainers.m
cfe/trunk/test/Analysis/logical-ops.c
cfe/trunk/test/Analysis/objc-boxing.m
cfe/trunk/test/Sema/exprs.c
Modified: cfe/trunk/include/clang/Sema/Sema.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Sema/Sema.h?rev=222009&r1=222008&r2=222009&view=diff
==============================================================================
--- cfe/trunk/include/clang/Sema/Sema.h (original)
+++ cfe/trunk/include/clang/Sema/Sema.h Fri Nov 14 11:12:50 2014
@@ -2771,6 +2771,8 @@ public:
const AttributeList *AttrList);
void checkUnusedDeclAttributes(Declarator &D);
+
+ void CheckBoolLikeConversion(Expr *E, SourceLocation CC);
/// Determine if type T is a valid subject for a nonnull and similar
/// attributes. By default, we look through references (the behavior used by
Modified: cfe/trunk/lib/Sema/SemaChecking.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaChecking.cpp?rev=222009&r1=222008&r2=222009&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaChecking.cpp (original)
+++ cfe/trunk/lib/Sema/SemaChecking.cpp Fri Nov 14 11:12:50 2014
@@ -6559,6 +6559,13 @@ void AnalyzeImplicitConversions(Sema &S,
continue;
AnalyzeImplicitConversions(S, ChildExpr, CC);
}
+ if (BO && BO->isLogicalOp()) {
+ S.CheckBoolLikeConversion(BO->getLHS(), BO->getLHS()->getExprLoc());
+ S.CheckBoolLikeConversion(BO->getRHS(), BO->getRHS()->getExprLoc());
+ }
+ if (const UnaryOperator *U = dyn_cast<UnaryOperator>(E))
+ if (U->getOpcode() == UO_LNot)
+ S.CheckBoolLikeConversion(U->getSubExpr(), CC);
}
} // end anonymous namespace
@@ -6617,6 +6624,18 @@ static bool IsInAnyMacroBody(const Sourc
return false;
}
+/// CheckBoolLikeConversion - Check conversion of given expression to boolean.
+/// Input argument E is a logical expression.
+static void CheckBoolLikeConversion(Sema &S, Expr *E, SourceLocation CC) {
+ if (S.getLangOpts().Bool)
+ return;
+ CheckImplicitConversion(S, E->IgnoreParenImpCasts(), S.Context.BoolTy, CC);
+}
+
+void Sema::CheckBoolLikeConversion(Expr *E, SourceLocation CC) {
+ ::CheckBoolLikeConversion(*this, E, CC);
+}
+
/// \brief Diagnose pointers that are always non-null.
/// \param E the expression containing the pointer
/// \param NullKind NPCK_NotNull if E is a cast to bool, otherwise, E is
Modified: cfe/trunk/lib/Sema/SemaExpr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExpr.cpp?rev=222009&r1=222008&r2=222009&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaExpr.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExpr.cpp Fri Nov 14 11:12:50 2014
@@ -12984,6 +12984,7 @@ ExprResult Sema::CheckBooleanCondition(E
<< T << E->getSourceRange();
return ExprError();
}
+ CheckBoolLikeConversion(E, Loc);
}
return E;
Modified: cfe/trunk/test/Analysis/NSContainers.m
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/NSContainers.m?rev=222009&r1=222008&r2=222009&view=diff
==============================================================================
--- cfe/trunk/test/Analysis/NSContainers.m (original)
+++ cfe/trunk/test/Analysis/NSContainers.m Fri Nov 14 11:12:50 2014
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -analyze -analyzer-checker=core,osx.cocoa.NonNilReturnValue,osx.cocoa.NilArg,osx.cocoa.Loops,debug.ExprInspection -verify -Wno-objc-root-class %s
+// RUN: %clang_cc1 -Wno-objc-literal-conversion -analyze -analyzer-checker=core,osx.cocoa.NonNilReturnValue,osx.cocoa.NilArg,osx.cocoa.Loops,debug.ExprInspection -verify -Wno-objc-root-class %s
void clang_analyzer_eval(int);
Modified: cfe/trunk/test/Analysis/logical-ops.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/logical-ops.c?rev=222009&r1=222008&r2=222009&view=diff
==============================================================================
--- cfe/trunk/test/Analysis/logical-ops.c (original)
+++ cfe/trunk/test/Analysis/logical-ops.c Fri Nov 14 11:12:50 2014
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -analyze -analyzer-checker=core,debug.ExprInspection -verify %s
+// RUN: %clang_cc1 -Wno-pointer-bool-conversion -analyze -analyzer-checker=core,debug.ExprInspection -verify %s
void clang_analyzer_eval(int);
Modified: cfe/trunk/test/Analysis/objc-boxing.m
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/objc-boxing.m?rev=222009&r1=222008&r2=222009&view=diff
==============================================================================
--- cfe/trunk/test/Analysis/objc-boxing.m (original)
+++ cfe/trunk/test/Analysis/objc-boxing.m Fri Nov 14 11:12:50 2014
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -analyze -analyzer-checker=core,unix.Malloc,osx.cocoa.NonNilReturnValue,debug.ExprInspection -analyzer-store=region -verify %s
+// RUN: %clang_cc1 -Wno-objc-literal-conversion -analyze -analyzer-checker=core,unix.Malloc,osx.cocoa.NonNilReturnValue,debug.ExprInspection -analyzer-store=region -verify %s
void clang_analyzer_eval(int);
Modified: cfe/trunk/test/Sema/exprs.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/exprs.c?rev=222009&r1=222008&r2=222009&view=diff
==============================================================================
--- cfe/trunk/test/Sema/exprs.c (original)
+++ cfe/trunk/test/Sema/exprs.c Fri Nov 14 11:12:50 2014
@@ -244,6 +244,10 @@ void test22() {
if ("help")
(void) 0;
- if (test22)
+ if (test22) // expected-warning {{address of function 'test22' will always evaluate to 'true'}} \
+ // expected-note {{prefix with the address-of operator to silence this warning}}
+ (void) 0;
+
+ if (&test22)
(void) 0;
}
Added: cfe/trunk/test/Sema/warn-tautological-compare.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/warn-tautological-compare.c?rev=222009&view=auto
==============================================================================
--- cfe/trunk/test/Sema/warn-tautological-compare.c (added)
+++ cfe/trunk/test/Sema/warn-tautological-compare.c Fri Nov 14 11:12:50 2014
@@ -0,0 +1,80 @@
+// RUN: %clang_cc1 -triple x86_64-apple-darwin -fsyntax-only -verify %s
+// rdar://18716393
+
+extern int a[] __attribute__((weak));
+int b[] = {8,13,21};
+struct {
+ int x[10];
+} c;
+const char str[] = "text";
+
+void ignore() {
+ if (!a) {}
+}
+void test() {
+ if (!b) {} // expected-warning {{address of array 'b' will always evaluate to 'true'}}
+ if (b == 0) {} // expected-warning {{comparison of array 'b' equal to a null pointer is always false}}
+ if (!c.x) {} // expected-warning {{address of array 'c.x' will always evaluate to 'true'}}
+ if (c.x == 0) {} // expected-warning {{comparison of array 'c.x' equal to a null pointer is always false}}
+ if (!str) {} // expected-warning {{address of array 'str' will always evaluate to 'true'}}
+ if (0 == str) {} // expected-warning {{comparison of array 'str' equal to a null pointer is always false}}
+}
+
+int array[2];
+int test1()
+{
+ if (!array) { // expected-warning {{address of array 'array' will always evaluate to 'true'}}
+ return array[0];
+ } else if (array != 0) { // expected-warning {{comparison of array 'array' not equal to a null pointer is always true}}
+ return array[1];
+ }
+ if (array == 0) // expected-warning {{comparison of array 'array' equal to a null pointer is always false}}
+ return 1;
+ return 0;
+}
+
+#define NULL (void*)0
+
+int test2(int* pointer, char ch, void * pv) {
+ if (!&pointer) { // expected-warning {{address of 'pointer' will always evaluate to 'true'}}
+ return 0;
+ }
+
+ if (&pointer) { // expected-warning {{address of 'pointer' will always evaluate to 'true'}}
+ return 0;
+ }
+
+ if (&pointer == NULL) {} // expected-warning {{comparison of address of 'pointer' equal to a null pointer is always false}}
+
+ if (&pointer != NULL) {} // expected-warning {{comparison of address of 'pointer' not equal to a null pointer is always true}}
+
+ return 1;
+}
+
+void test3() {
+ if (array) { } // expected-warning {{address of array 'array' will always evaluate to 'true'}}
+ if (array != 0) {} // expected-warning {{comparison of array 'array' not equal to a null pointer is always true}}
+ if (!array) { } // expected-warning {{address of array 'array' will always evaluate to 'true'}}
+ if (array == 0) {} // expected-warning {{comparison of array 'array' equal to a null pointer is always false}}
+
+ if (array[0] &&
+ array) {} // expected-warning {{address of array 'array' will always evaluate to 'true'}}
+
+ if (array[0] ||
+ array) {} // expected-warning {{address of array 'array' will always evaluate to 'true'}}
+
+ if (array[0] &&
+ !array) {} // expected-warning {{address of array 'array' will always evaluate to 'true'}}
+ if (array[0] ||
+ !array) {} // expected-warning {{address of array 'array' will always evaluate to 'true'}}
+
+ if (array && // expected-warning {{address of array 'array' will always evaluate to 'true'}}
+ array[0]) {}
+ if (!array || // expected-warning {{address of array 'array' will always evaluate to 'true'}}
+ array[0]) {}
+
+ if (array || // expected-warning {{address of array 'array' will always evaluate to 'true'}}
+ (!array && array[0])) {} // expected-warning {{address of array 'array' will always evaluate to 'true'}}
+ }
+
+
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