A new conversion warning for when an Objective-C object literal is implicitly
cast into a boolean true value. This warning will catch code like:
if (@0) {}
if (@"foo") {}
llvm-svn: 200356
diff --git a/clang/include/clang/Basic/DiagnosticGroups.td b/clang/include/clang/Basic/DiagnosticGroups.td
index 110c53e..8e9ef68 100644
--- a/clang/include/clang/Basic/DiagnosticGroups.td
+++ b/clang/include/clang/Basic/DiagnosticGroups.td
@@ -44,6 +44,7 @@
def NullConversion : DiagGroup<"null-conversion">;
def ImplicitConversionFloatingPointToBool :
DiagGroup<"implicit-conversion-floating-point-to-bool">;
+def ObjCLiteralConversion : DiagGroup<"objc-literal-conversion">;
def BadArrayNewLength : DiagGroup<"bad-array-new-length">;
def BuiltinMacroRedefined : DiagGroup<"builtin-macro-redefined">;
def BuiltinRequiresHeader : DiagGroup<"builtin-requires-header">;
@@ -446,6 +447,7 @@
LiteralConversion,
NonLiteralNullConversion, // (1-1)->pointer (etc)
NullConversion, // NULL->non-pointer
+ ObjCLiteralConversion,
SignConversion,
StringConversion]>,
DiagCategory<"Value Conversion Issue">;
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index b682505..67f5837 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -2296,6 +2296,10 @@
"prefix with the address-of operator to silence this warning">;
def note_function_to_bool_call : Note<
"suffix with parentheses to turn this into a function call">;
+def warn_impcast_objective_c_literal_to_bool : Warning<
+ "implicit boolean conversion of Objective-C object literal always "
+ "evaluates to true">,
+ InGroup<ObjCLiteralConversion>;
def warn_cast_align : Warning<
"cast from %0 to %1 increases required alignment from %2 to %3">,
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 0dffa53..ee0e670 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -5358,6 +5358,13 @@
// prevented by a check in AnalyzeImplicitConversions().
return DiagnoseImpCast(S, E, T, CC,
diag::warn_impcast_string_literal_to_bool);
+ if (isa<ObjCStringLiteral>(E) || isa<ObjCArrayLiteral>(E) ||
+ isa<ObjCDictionaryLiteral>(E) || isa<ObjCBoxedExpr>(E)) {
+ // This covers the literal expressions that evaluate to Objective-C
+ // objects.
+ return DiagnoseImpCast(S, E, T, CC,
+ diag::warn_impcast_objective_c_literal_to_bool);
+ }
if (Source->isFunctionType()) {
// Warn on function to bool. Checks free functions and static member
// functions. Weakly imported functions are excluded from the check,
diff --git a/clang/test/Analysis/objc-string.mm b/clang/test/Analysis/objc-string.mm
index c67ab5e..a32b740 100644
--- a/clang/test/Analysis/objc-string.mm
+++ b/clang/test/Analysis/objc-string.mm
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -analyze -analyzer-checker=core,debug.ExprInspection -verify %s
+// RUN: %clang_cc1 -analyze -analyzer-checker=core,debug.ExprInspection -verify -Wno-objc-literal-conversion %s
void clang_analyzer_eval(bool);
@class NSString;
diff --git a/clang/test/SemaObjCXX/warn-objc-literal-conversion.mm b/clang/test/SemaObjCXX/warn-objc-literal-conversion.mm
new file mode 100644
index 0000000..4464561
--- /dev/null
+++ b/clang/test/SemaObjCXX/warn-objc-literal-conversion.mm
@@ -0,0 +1,74 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -Wobjc-literal-conversion %s
+
+@class NSString;
+
+@interface NSNumber
++ (NSNumber *)numberWithChar:(char)value;
++ (NSNumber *)numberWithInt:(int)value;
++ (NSNumber *)numberWithLongLong:(long long)value;
++ (NSNumber *)numberWithFloat:(float)value;
++ (NSNumber *)numberWithDouble:(double)value;
++ (NSNumber *)numberWithBool:(bool)value;
+@end
+
+@interface NSArray
++ (id)arrayWithObjects:(const id [])objects count:(int)cnt;
+@end
+
+@interface NSDictionary
++ (id)dictionaryWithObjects:(const id [])objects forKeys:(const id [])keys count:(unsigned long)cnt;
+@end
+
+void char_test() {
+ if (@'a') {}
+ // expected-warning@-1{{implicit boolean conversion of Objective-C object literal always evaluates to true}}
+}
+
+void int_test() {
+ if (@12) {}
+ // expected-warning@-1{{implicit boolean conversion of Objective-C object literal always evaluates to true}}
+ if (@-12) {}
+ // expected-warning@-1{{implicit boolean conversion of Objective-C object literal always evaluates to true}}
+ if (@12LL) {}
+ // expected-warning@-1{{implicit boolean conversion of Objective-C object literal always evaluates to true}}
+ if (@-12LL) {}
+ // expected-warning@-1{{implicit boolean conversion of Objective-C object literal always evaluates to true}}
+}
+
+void float_test() {
+ if (@12.55) {}
+ // expected-warning@-1{{implicit boolean conversion of Objective-C object literal always evaluates to true}}
+ if (@-12.55) {}
+ // expected-warning@-1{{implicit boolean conversion of Objective-C object literal always evaluates to true}}
+ if (@12.55F) {}
+ // expected-warning@-1{{implicit boolean conversion of Objective-C object literal always evaluates to true}}
+ if (@-12.55F) {}
+ // expected-warning@-1{{implicit boolean conversion of Objective-C object literal always evaluates to true}}
+}
+
+void bool_test() {
+ if (@true) {}
+ // expected-warning@-1{{implicit boolean conversion of Objective-C object literal always evaluates to true}}
+ if (@false) {}
+ // expected-warning@-1{{implicit boolean conversion of Objective-C object literal always evaluates to true}}
+}
+
+void string_test() {
+ if (@"asdf") {}
+ // expected-warning@-1{{implicit boolean conversion of Objective-C object literal always evaluates to true}}
+}
+
+void array_test() {
+ if (@[ @313, @331, @367, @379 ]) {}
+ // expected-warning@-1{{implicit boolean conversion of Objective-C object literal always evaluates to true}}
+}
+
+void dictionary_test() {
+ if (@{ @0: @0, @1: @1, @2: @1, @3: @3 }) {}
+ // expected-warning@-1{{implicit boolean conversion of Objective-C object literal always evaluates to true}}
+}
+
+void objc_bool_test () {
+ if (__objc_yes) {}
+ if (__objc_no) {}
+}