Author: akirtzidis
Date: Tue Feb 1 12:24:22 2011
New Revision: 124668
URL: http://llvm.org/viewvc/llvm-project?rev=124668&view=rev
Log:
Warn for "if ((a == b))" where the equality expression is needlessly wrapped
inside parentheses.
It's highly likely that the user intended an assignment used as condition.
Addresses rdar://8848646.
Modified:
cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
cfe/trunk/include/clang/Sema/Sema.h
cfe/trunk/lib/Sema/SemaExpr.cpp
cfe/trunk/test/Analysis/self-init.m
cfe/trunk/test/SemaCXX/warn-assignment-condition.cpp
Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=124668&r1=124667&r2=124668&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Tue Feb 1 12:24:22
2011
@@ -2853,6 +2853,13 @@
def note_condition_assign_silence : Note<
"place parentheses around the assignment to silence this warning">;
+def warn_equality_with_extra_parens : Warning<"equality comparison with "
+ "extraneous parentheses">, InGroup<Parentheses>;
+def note_equality_comparison_to_assign : Note<
+ "use '=' to turn this equality comparison into an assignment">;
+def note_equality_comparison_silence : Note<
+ "remove extraneous parentheses around the comparison to silence this
warning">;
+
def warn_synthesized_ivar_access : Warning<
"direct access of synthesized ivar by using property access %0">,
InGroup<NonfragileAbi2>, DefaultIgnore;
Modified: cfe/trunk/include/clang/Sema/Sema.h
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Sema/Sema.h?rev=124668&r1=124667&r2=124668&view=diff
==============================================================================
--- cfe/trunk/include/clang/Sema/Sema.h (original)
+++ cfe/trunk/include/clang/Sema/Sema.h Tue Feb 1 12:24:22 2011
@@ -4734,6 +4734,10 @@
/// being used as a boolean condition, warn if it's an assignment.
void DiagnoseAssignmentAsCondition(Expr *E);
+ /// \brief Redundant parentheses over an equality comparison can indicate
+ /// that the user intended an assignment used as condition.
+ void DiagnoseEqualityWithExtraParens(ParenExpr *parenE);
+
/// CheckCXXBooleanCondition - Returns true if conversion to bool is invalid.
bool CheckCXXBooleanCondition(Expr *&CondExpr);
Modified: cfe/trunk/lib/Sema/SemaExpr.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExpr.cpp?rev=124668&r1=124667&r2=124668&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaExpr.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExpr.cpp Tue Feb 1 12:24:22 2011
@@ -9225,8 +9225,30 @@
<< FixItHint::CreateInsertion(Close, ")");
}
+/// \brief Redundant parentheses over an equality comparison can indicate
+/// that the user intended an assignment used as condition.
+void Sema::DiagnoseEqualityWithExtraParens(ParenExpr *parenE) {
+ Expr *E = parenE->IgnoreParens();
+
+ if (BinaryOperator *opE = dyn_cast<BinaryOperator>(E))
+ if (opE->getOpcode() == BO_EQ) {
+ SourceLocation Loc = opE->getOperatorLoc();
+
+ Diag(Loc, diag::warn_equality_with_extra_parens) << E->getSourceRange();
+
+ Diag(Loc, diag::note_equality_comparison_to_assign)
+ << FixItHint::CreateReplacement(Loc, "=");
+
+ Diag(Loc, diag::note_equality_comparison_silence)
+ << FixItHint::CreateRemoval(parenE->getSourceRange().getBegin())
+ << FixItHint::CreateRemoval(parenE->getSourceRange().getEnd());
+ }
+}
+
bool Sema::CheckBooleanCondition(Expr *&E, SourceLocation Loc) {
DiagnoseAssignmentAsCondition(E);
+ if (ParenExpr *parenE = dyn_cast<ParenExpr>(E))
+ DiagnoseEqualityWithExtraParens(parenE);
if (!E->isTypeDependent()) {
if (E->isBoundMemberFunction(Context))
Modified: cfe/trunk/test/Analysis/self-init.m
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/self-init.m?rev=124668&r1=124667&r2=124668&view=diff
==============================================================================
--- cfe/trunk/test/Analysis/self-init.m (original)
+++ cfe/trunk/test/Analysis/self-init.m Tue Feb 1 12:24:22 2011
@@ -135,7 +135,7 @@
}
-(id)init13 {
- if ((self == [super init])) {
+ if (self == [super init]) {
myivar = 0; // expected-warning {{Instance variable used}}
}
return self; // expected-warning {{Returning 'self'}}
Modified: cfe/trunk/test/SemaCXX/warn-assignment-condition.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/warn-assignment-condition.cpp?rev=124668&r1=124667&r2=124668&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/warn-assignment-condition.cpp (original)
+++ cfe/trunk/test/SemaCXX/warn-assignment-condition.cpp Tue Feb 1 12:24:22
2011
@@ -105,4 +105,8 @@
if (a |= b) {} // expected-warning {{using the result of an assignment as a
condition without parentheses}} \
// expected-note{{use '!=' to turn this compound assignment
into an inequality comparison}} \
// expected-note{{place parentheses around the assignment to silence this
warning}}
+
+ if ((x == 5)) {} // expected-warning {{equality comparison with extraneous
parentheses}} \
+ // expected-note {{use '=' to turn this equality comparison
into an assignment}} \
+ // expected-note {{remove extraneous parentheses around the
comparison to silence this warning}}
}
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