Improve the fix-its for -Wparentheses to ensure that the fix-it
suggestions follow recovery. Additionally, add a note to these
diagnostics which suggests a fix-it for changing the behavior to what
the user probably meant. Examples:
t.cpp:2:9: warning: & has lower precedence than ==; == will be evaluated first
[-Wparentheses]
if (i & j == k) {
^~~~~~~~
( )
t.cpp:2:9: note: place parentheses around the & expression to evaluate it first
if (i & j == k) {
^
( )
t.cpp:14:9: warning: using the result of an assignment as a condition
without
parentheses [-Wparentheses]
if (i = f()) {
~~^~~~~
( )
t.cpp:14:9: note: use '==' to turn this assignment into an equality
comparison
if (i = f()) {
^
==
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@92975 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index 8470ad9..ac6d3ec 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -1563,7 +1563,9 @@
def warn_precedence_bitwise_rel : Warning<
"%0 has lower precedence than %1; %1 will be evaluated first">,
InGroup<Parentheses>;
-
+def note_precedence_bitwise_first : Note<
+ "place parentheses around the %0 expression to evaluate it first">;
+
def err_sizeof_nonfragile_interface : Error<
"invalid application of '%select{alignof|sizeof}1' to interface %0 in "
"non-fragile ABI">;
@@ -1968,6 +1970,8 @@
def warn_condition_is_idiomatic_assignment : Warning<"using the result "
"of an assignment as a condition without parentheses">,
InGroup<DiagGroup<"idiomatic-parentheses">>, DefaultIgnore;
+def note_condition_assign_to_comparison : Note<
+ "use '==' to turn this assignment into an equality comparison">;
def warn_value_always_zero : Warning<
"%0 is always %select{zero|false|NULL}1 in this context">;
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 216e2e6..f131109 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -6150,8 +6150,9 @@
/// ParenRange in parentheses.
static void SuggestParentheses(Sema &Self, SourceLocation Loc,
const PartialDiagnostic &PD,
- SourceRange ParenRange)
-{
+ SourceRange ParenRange,
+ const PartialDiagnostic &SecondPD = PartialDiagnostic(0),
+ SourceRange SecondParenRange = SourceRange()) {
SourceLocation EndLoc = Self.PP.getLocForEndOfToken(ParenRange.getEnd());
if (!ParenRange.getEnd().isFileID() || EndLoc.isInvalid()) {
// We can't display the parentheses, so just dig the
@@ -6163,6 +6164,21 @@
Self.Diag(Loc, PD)
<< CodeModificationHint::CreateInsertion(ParenRange.getBegin(), "(")
<< CodeModificationHint::CreateInsertion(EndLoc, ")");
+
+ if (!SecondPD.getDiagID())
+ return;
+
+ EndLoc = Self.PP.getLocForEndOfToken(SecondParenRange.getEnd());
+ if (!SecondParenRange.getEnd().isFileID() || EndLoc.isInvalid()) {
+ // We can't display the parentheses, so just dig the
+ // warning/error and return.
+ Self.Diag(Loc, SecondPD);
+ return;
+ }
+
+ Self.Diag(Loc, SecondPD)
+ << CodeModificationHint::CreateInsertion(SecondParenRange.getBegin(), "(")
+ << CodeModificationHint::CreateInsertion(EndLoc, ")");
}
/// DiagnoseBitwisePrecedence - Emit a warning when bitwise and comparison
@@ -6194,12 +6210,18 @@
PDiag(diag::warn_precedence_bitwise_rel)
<< SourceRange(lhs->getLocStart(), OpLoc)
<< BinOp::getOpcodeStr(Opc) << BinOp::getOpcodeStr(lhsopc),
+ lhs->getSourceRange(),
+ PDiag(diag::note_precedence_bitwise_first)
+ << BinOp::getOpcodeStr(Opc),
SourceRange(cast<BinOp>(lhs)->getRHS()->getLocStart(), rhs->getLocEnd()));
else if (BinOp::isComparisonOp(rhsopc))
SuggestParentheses(Self, OpLoc,
PDiag(diag::warn_precedence_bitwise_rel)
<< SourceRange(OpLoc, rhs->getLocEnd())
<< BinOp::getOpcodeStr(Opc) << BinOp::getOpcodeStr(rhsopc),
+ rhs->getSourceRange(),
+ PDiag(diag::note_precedence_bitwise_first)
+ << BinOp::getOpcodeStr(Opc),
SourceRange(lhs->getLocEnd(), cast<BinOp>(rhs)->getLHS()->getLocStart()));
}
@@ -7251,6 +7273,8 @@
<< E->getSourceRange()
<< CodeModificationHint::CreateInsertion(Open, "(")
<< CodeModificationHint::CreateInsertion(Close, ")");
+ Diag(Loc, diag::note_condition_assign_to_comparison)
+ << CodeModificationHint::CreateReplacement(Loc, "==");
}
bool Sema::CheckBooleanCondition(Expr *&E, SourceLocation Loc) {
diff --git a/test/Sema/parentheses.c b/test/Sema/parentheses.c
index f7a7fbd..69c91cb 100644
--- a/test/Sema/parentheses.c
+++ b/test/Sema/parentheses.c
@@ -4,14 +4,18 @@
// Test the various warnings under -Wparentheses
void if_assign(void) {
int i;
- if (i = 4) {} // expected-warning {{assignment as a condition}}
+ if (i = 4) {} // expected-warning {{assignment as a condition}} \
+ // expected-note{{use '==' to turn this assignment into an equality comparison}}
if ((i = 4)) {}
}
void bitwise_rel(unsigned i) {
- (void)(i & 0x2 == 0); // expected-warning {{& has lower precedence than ==}}
- (void)(0 == i & 0x2); // expected-warning {{& has lower precedence than ==}}
- (void)(i & 0xff < 30); // expected-warning {{& has lower precedence than <}}
+ (void)(i & 0x2 == 0); // expected-warning {{& has lower precedence than ==}} \
+ // expected-note{{place parentheses around the & expression to evaluate it first}}
+ (void)(0 == i & 0x2); // expected-warning {{& has lower precedence than ==}} \
+ // expected-note{{place parentheses around the & expression to evaluate it first}}
+ (void)(i & 0xff < 30); // expected-warning {{& has lower precedence than <}} \
+ // expected-note{{place parentheses around the & expression to evaluate it first}}
(void)((i & 0x2) == 0);
(void)(i & (0x2 == 0));
// Eager logical op
diff --git a/test/SemaCXX/warn-assignment-condition.cpp b/test/SemaCXX/warn-assignment-condition.cpp
index 1df906d..ce16a68 100644
--- a/test/SemaCXX/warn-assignment-condition.cpp
+++ b/test/SemaCXX/warn-assignment-condition.cpp
@@ -11,26 +11,34 @@
A a, b;
// With scalars.
- if (x = 7) {} // expected-warning {{using the result of an assignment as a condition without parentheses}}
+ if (x = 7) {} // expected-warning {{using the result of an assignment as a condition without parentheses}} \
+ // expected-note{{use '==' to turn this assignment into an equality comparison}}
if ((x = 7)) {}
do {
- } while (x = 7); // expected-warning {{using the result of an assignment as a condition without parentheses}}
+ } while (x = 7); // expected-warning {{using the result of an assignment as a condition without parentheses}} \
+ // expected-note{{use '==' to turn this assignment into an equality comparison}}
do {
} while ((x = 7));
- while (x = 7) {} // expected-warning {{using the result of an assignment as a condition without parentheses}}
+ while (x = 7) {} // expected-warning {{using the result of an assignment as a condition without parentheses}} \
+ // expected-note{{use '==' to turn this assignment into an equality comparison}}
while ((x = 7)) {}
- for (; x = 7; ) {} // expected-warning {{using the result of an assignment as a condition without parentheses}}
+ for (; x = 7; ) {} // expected-warning {{using the result of an assignment as a condition without parentheses}} \
+ // expected-note{{use '==' to turn this assignment into an equality comparison}}
for (; (x = 7); ) {}
- if (p = p) {} // expected-warning {{using the result of an assignment as a condition without parentheses}}
+ if (p = p) {} // expected-warning {{using the result of an assignment as a condition without parentheses}} \
+ // expected-note{{use '==' to turn this assignment into an equality comparison}}
if ((p = p)) {}
do {
- } while (p = p); // expected-warning {{using the result of an assignment as a condition without parentheses}}
+ } while (p = p); // expected-warning {{using the result of an assignment as a condition without parentheses}} \
+ // expected-note{{use '==' to turn this assignment into an equality comparison}}
do {
} while ((p = p));
- while (p = p) {} // expected-warning {{using the result of an assignment as a condition without parentheses}}
+ while (p = p) {} // expected-warning {{using the result of an assignment as a condition without parentheses}} \
+ // expected-note{{use '==' to turn this assignment into an equality comparison}}
while ((p = p)) {}
- for (; p = p; ) {} // expected-warning {{using the result of an assignment as a condition without parentheses}}
+ for (; p = p; ) {} // expected-warning {{using the result of an assignment as a condition without parentheses}} \
+ // expected-note{{use '==' to turn this assignment into an equality comparison}}
for (; (p = p); ) {}
// Initializing variables (shouldn't warn).
@@ -40,26 +48,34 @@
while (A y = a) {}
// With temporaries.
- if (x = (b+b).foo()) {} // expected-warning {{using the result of an assignment as a condition without parentheses}}
+ if (x = (b+b).foo()) {} // expected-warning {{using the result of an assignment as a condition without parentheses}} \
+ // expected-note{{use '==' to turn this assignment into an equality comparison}}
if ((x = (b+b).foo())) {}
do {
- } while (x = (b+b).foo()); // expected-warning {{using the result of an assignment as a condition without parentheses}}
+ } while (x = (b+b).foo()); // expected-warning {{using the result of an assignment as a condition without parentheses}} \
+ // expected-note{{use '==' to turn this assignment into an equality comparison}}
do {
} while ((x = (b+b).foo()));
- while (x = (b+b).foo()) {} // expected-warning {{using the result of an assignment as a condition without parentheses}}
+ while (x = (b+b).foo()) {} // expected-warning {{using the result of an assignment as a condition without parentheses}} \
+ // expected-note{{use '==' to turn this assignment into an equality comparison}}
while ((x = (b+b).foo())) {}
- for (; x = (b+b).foo(); ) {} // expected-warning {{using the result of an assignment as a condition without parentheses}}
+ for (; x = (b+b).foo(); ) {} // expected-warning {{using the result of an assignment as a condition without parentheses}} \
+ // expected-note{{use '==' to turn this assignment into an equality comparison}}
for (; (x = (b+b).foo()); ) {}
// With a user-defined operator.
- if (a = b + b) {} // expected-warning {{using the result of an assignment as a condition without parentheses}}
+ if (a = b + b) {} // expected-warning {{using the result of an assignment as a condition without parentheses}} \
+ // expected-note{{use '==' to turn this assignment into an equality comparison}}
if ((a = b + b)) {}
do {
- } while (a = b + b); // expected-warning {{using the result of an assignment as a condition without parentheses}}
+ } while (a = b + b); // expected-warning {{using the result of an assignment as a condition without parentheses}} \
+ // expected-note{{use '==' to turn this assignment into an equality comparison}}
do {
} while ((a = b + b));
- while (a = b + b) {} // expected-warning {{using the result of an assignment as a condition without parentheses}}
+ while (a = b + b) {} // expected-warning {{using the result of an assignment as a condition without parentheses}} \
+ // expected-note{{use '==' to turn this assignment into an equality comparison}}
while ((a = b + b)) {}
- for (; a = b + b; ) {} // expected-warning {{using the result of an assignment as a condition without parentheses}}
+ for (; a = b + b; ) {} // expected-warning {{using the result of an assignment as a condition without parentheses}} \
+ // expected-note{{use '==' to turn this assignment into an equality comparison}}
for (; (a = b + b); ) {}
}