r299363 - Enhance -Wshadow to warn when shadowing typedefs or type aliases
Alex Lorenz via cfe-commits
cfe-commits at lists.llvm.org
Mon Apr 3 09:43:21 PDT 2017
Author: arphaman
Date: Mon Apr 3 11:43:21 2017
New Revision: 299363
URL: http://llvm.org/viewvc/llvm-project?rev=299363&view=rev
Log:
Enhance -Wshadow to warn when shadowing typedefs or type aliases
Enhance -Wshadow to emit a warning when typedefs or type aliases are shadowed.
Fixes bug https://bugs.llvm.org//show_bug.cgi?id=28676.
Patch by Ahmed Asadi.
Differential Revision: https://reviews.llvm.org/D31235
Modified:
cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
cfe/trunk/include/clang/Sema/Sema.h
cfe/trunk/lib/Sema/SemaDecl.cpp
cfe/trunk/test/SemaCXX/warn-shadow.cpp
Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=299363&r1=299362&r2=299363&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Mon Apr 3 11:43:21 2017
@@ -369,7 +369,9 @@ def warn_decl_shadow :
"local variable|"
"variable in %2|"
"static data member of %2|"
- "field of %2}1">,
+ "field of %2|"
+ "typedef in %2|"
+ "type alias in %2}1">,
InGroup<Shadow>, DefaultIgnore;
def warn_decl_shadow_uncaptured_local :
Warning<warn_decl_shadow.Text>,
Modified: cfe/trunk/include/clang/Sema/Sema.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Sema/Sema.h?rev=299363&r1=299362&r2=299363&view=diff
==============================================================================
--- cfe/trunk/include/clang/Sema/Sema.h (original)
+++ cfe/trunk/include/clang/Sema/Sema.h Mon Apr 3 11:43:21 2017
@@ -1738,8 +1738,11 @@ public:
static bool adjustContextForLocalExternDecl(DeclContext *&DC);
void DiagnoseFunctionSpecifiers(const DeclSpec &DS);
+ NamedDecl *getShadowedDeclaration(const TypedefNameDecl *D,
+ const LookupResult &R);
NamedDecl *getShadowedDeclaration(const VarDecl *D, const LookupResult &R);
- void CheckShadow(VarDecl *D, NamedDecl *ShadowedDecl, const LookupResult &R);
+ void CheckShadow(NamedDecl *D, NamedDecl *ShadowedDecl,
+ const LookupResult &R);
void CheckShadow(Scope *S, VarDecl *D);
/// Warn if 'E', which is an expression that is about to be modified, refers
Modified: cfe/trunk/lib/Sema/SemaDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=299363&r1=299362&r2=299363&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDecl.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDecl.cpp Mon Apr 3 11:43:21 2017
@@ -5530,6 +5530,10 @@ Sema::CheckTypedefForVariablyModifiedTyp
NamedDecl*
Sema::ActOnTypedefNameDecl(Scope *S, DeclContext *DC, TypedefNameDecl *NewTD,
LookupResult &Previous, bool &Redeclaration) {
+
+ // Find the shadowed declaration before filtering for scope.
+ NamedDecl *ShadowedDecl = getShadowedDeclaration(NewTD, Previous);
+
// Merge the decl with the existing one if appropriate. If the decl is
// in an outer scope, it isn't the same thing.
FilterLookupForScope(Previous, DC, S, /*ConsiderLinkage*/false,
@@ -5540,6 +5544,9 @@ Sema::ActOnTypedefNameDecl(Scope *S, Dec
MergeTypedefNameDecl(S, NewTD, Previous);
}
+ if (ShadowedDecl && !Redeclaration)
+ CheckShadow(NewTD, ShadowedDecl, Previous);
+
// If this is the C FILE type, notify the AST context.
if (IdentifierInfo *II = NewTD->getIdentifier())
if (!NewTD->isInvalidDecl() &&
@@ -6671,13 +6678,25 @@ NamedDecl *Sema::ActOnVariableDeclarator
}
/// Enum describing the %select options in diag::warn_decl_shadow.
-enum ShadowedDeclKind { SDK_Local, SDK_Global, SDK_StaticMember, SDK_Field };
+enum ShadowedDeclKind {
+ SDK_Local,
+ SDK_Global,
+ SDK_StaticMember,
+ SDK_Field,
+ SDK_Typedef,
+ SDK_Using
+};
/// Determine what kind of declaration we're shadowing.
static ShadowedDeclKind computeShadowedDeclKind(const NamedDecl *ShadowedDecl,
const DeclContext *OldDC) {
- if (isa<RecordDecl>(OldDC))
+ if (isa<TypeAliasDecl>(ShadowedDecl))
+ return SDK_Using;
+ else if (isa<TypedefDecl>(ShadowedDecl))
+ return SDK_Typedef;
+ else if (isa<RecordDecl>(OldDC))
return isa<FieldDecl>(ShadowedDecl) ? SDK_Field : SDK_StaticMember;
+
return OldDC->isFileContext() ? SDK_Global : SDK_Local;
}
@@ -6692,28 +6711,44 @@ static SourceLocation getCaptureLocation
return SourceLocation();
}
+static bool shouldWarnIfShadowedDecl(const DiagnosticsEngine &Diags,
+ const LookupResult &R) {
+ // Only diagnose if we're shadowing an unambiguous field or variable.
+ if (R.getResultKind() != LookupResult::Found)
+ return false;
+
+ // Return false if warning is ignored.
+ return !Diags.isIgnored(diag::warn_decl_shadow, R.getNameLoc());
+}
+
/// \brief Return the declaration shadowed by the given variable \p D, or null
/// if it doesn't shadow any declaration or shadowing warnings are disabled.
NamedDecl *Sema::getShadowedDeclaration(const VarDecl *D,
const LookupResult &R) {
- // Return if warning is ignored.
- if (Diags.isIgnored(diag::warn_decl_shadow, R.getNameLoc()))
+ if (!shouldWarnIfShadowedDecl(Diags, R))
return nullptr;
// Don't diagnose declarations at file scope.
if (D->hasGlobalStorage())
return nullptr;
- // Only diagnose if we're shadowing an unambiguous field or variable.
- if (R.getResultKind() != LookupResult::Found)
- return nullptr;
-
NamedDecl *ShadowedDecl = R.getFoundDecl();
return isa<VarDecl>(ShadowedDecl) || isa<FieldDecl>(ShadowedDecl)
? ShadowedDecl
: nullptr;
}
+/// \brief Return the declaration shadowed by the given typedef \p D, or null
+/// if it doesn't shadow any declaration or shadowing warnings are disabled.
+NamedDecl *Sema::getShadowedDeclaration(const TypedefNameDecl *D,
+ const LookupResult &R) {
+ if (!shouldWarnIfShadowedDecl(Diags, R))
+ return nullptr;
+
+ NamedDecl *ShadowedDecl = R.getFoundDecl();
+ return isa<TypedefNameDecl>(ShadowedDecl) ? ShadowedDecl : nullptr;
+}
+
/// \brief Diagnose variable or built-in function shadowing. Implements
/// -Wshadow.
///
@@ -6723,7 +6758,7 @@ NamedDecl *Sema::getShadowedDeclaration(
/// \param ShadowedDecl the declaration that is shadowed by the given variable
/// \param R the lookup of the name
///
-void Sema::CheckShadow(VarDecl *D, NamedDecl *ShadowedDecl,
+void Sema::CheckShadow(NamedDecl *D, NamedDecl *ShadowedDecl,
const LookupResult &R) {
DeclContext *NewDC = D->getDeclContext();
@@ -6735,13 +6770,13 @@ void Sema::CheckShadow(VarDecl *D, Named
// Fields shadowed by constructor parameters are a special case. Usually
// the constructor initializes the field with the parameter.
- if (isa<CXXConstructorDecl>(NewDC) && isa<ParmVarDecl>(D)) {
- // Remember that this was shadowed so we can either warn about its
- // modification or its existence depending on warning settings.
- D = D->getCanonicalDecl();
- ShadowingDecls.insert({D, FD});
- return;
- }
+ if (isa<CXXConstructorDecl>(NewDC))
+ if (const auto PVD = dyn_cast<ParmVarDecl>(D)) {
+ // Remember that this was shadowed so we can either warn about its
+ // modification or its existence depending on warning settings.
+ ShadowingDecls.insert({PVD->getCanonicalDecl(), FD});
+ return;
+ }
}
if (VarDecl *shadowedVar = dyn_cast<VarDecl>(ShadowedDecl))
@@ -6759,7 +6794,8 @@ void Sema::CheckShadow(VarDecl *D, Named
unsigned WarningDiag = diag::warn_decl_shadow;
SourceLocation CaptureLoc;
- if (isa<VarDecl>(ShadowedDecl) && NewDC && isa<CXXMethodDecl>(NewDC)) {
+ if (isa<VarDecl>(D) && isa<VarDecl>(ShadowedDecl) && NewDC &&
+ isa<CXXMethodDecl>(NewDC)) {
if (const auto *RD = dyn_cast<CXXRecordDecl>(NewDC->getParent())) {
if (RD->isLambda() && OldDC->Encloses(NewDC->getLexicalParent())) {
if (RD->getLambdaCaptureDefault() == LCD_None) {
@@ -6773,7 +6809,8 @@ void Sema::CheckShadow(VarDecl *D, Named
// Remember that this was shadowed so we can avoid the warning if the
// shadowed decl isn't captured and the warning settings allow it.
cast<LambdaScopeInfo>(getCurFunction())
- ->ShadowingDecls.push_back({D, cast<VarDecl>(ShadowedDecl)});
+ ->ShadowingDecls.push_back(
+ {cast<VarDecl>(D), cast<VarDecl>(ShadowedDecl)});
return;
}
}
Modified: cfe/trunk/test/SemaCXX/warn-shadow.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/warn-shadow.cpp?rev=299363&r1=299362&r2=299363&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/warn-shadow.cpp (original)
+++ cfe/trunk/test/SemaCXX/warn-shadow.cpp Mon Apr 3 11:43:21 2017
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -verify -fsyntax-only -Wshadow-all %s
+// RUN: %clang_cc1 -verify -fsyntax-only -std=c++11 -Wshadow-all %s
namespace {
int i; // expected-note {{previous declaration is here}}
@@ -7,14 +7,21 @@ namespace {
namespace one {
namespace two {
int j; // expected-note {{previous declaration is here}}
+ typedef int jj; // expected-note 2 {{previous declaration is here}}
+ using jjj=int; // expected-note 2 {{previous declaration is here}}
}
}
namespace xx {
int m;
+ typedef int mm;
+ using mmm=int;
+
}
namespace yy {
int m;
+ typedef char mm;
+ using mmm=char;
}
using namespace one::two;
@@ -25,14 +32,19 @@ void foo() {
int i; // expected-warning {{declaration shadows a variable in namespace '(anonymous)'}}
int j; // expected-warning {{declaration shadows a variable in namespace 'one::two'}}
int m;
+ int mm;
+ int mmm;
}
class A {
- static int data; // expected-note {{previous declaration}}
- // expected-note at +1 {{previous declaration}}
+ static int data; // expected-note 1 {{previous declaration}}
+ // expected-note at +1 1 {{previous declaration}}
int field;
int f1, f2, f3, f4; // expected-note 8 {{previous declaration is here}}
+ typedef int a1; // expected-note 2 {{previous declaration}}
+ using a2=int; // expected-note 2 {{previous declaration}}
+
// The initialization is safe, but the modifications are not.
A(int f1, int f2, int f3, int f4) // expected-note-re 4 {{variable 'f{{[0-4]}}' is declared here}}
: f1(f1) {
@@ -50,6 +62,28 @@ class A {
void test() {
char *field; // expected-warning {{declaration shadows a field of 'A'}}
char *data; // expected-warning {{declaration shadows a static data member of 'A'}}
+ char *a1; // no warning
+ char *a2; // no warning
+ char *jj; // no warning
+ char *jjj; // no warning
+ }
+
+ void test2() {
+ typedef char field; // no warning
+ typedef char data; // no warning
+ typedef char a1; // expected-warning {{declaration shadows a typedef in 'A'}}
+ typedef char a2; // expected-warning {{declaration shadows a type alias in 'A'}}
+ typedef char jj; // expected-warning {{declaration shadows a typedef in namespace 'one::two'}}
+ typedef char jjj; // expected-warning {{declaration shadows a type alias in namespace 'one::two'}}
+ }
+
+ void test3() {
+ using field=char; // no warning
+ using data=char; // no warning
+ using a1=char; // expected-warning {{declaration shadows a typedef in 'A'}}
+ using a2=char; // expected-warning {{declaration shadows a type alias in 'A'}}
+ using jj=char; // expected-warning {{declaration shadows a typedef in namespace 'one::two'}}
+ using jjj=char; // expected-warning {{declaration shadows a type alias in namespace 'one::two'}}
}
};
@@ -63,6 +97,8 @@ class B : A {
namespace rdar8900456 {
struct Foo {
static void Baz();
+ static void Baz1();
+ static void Baz2();
private:
int Bar;
};
@@ -70,6 +106,14 @@ private:
void Foo::Baz() {
double Bar = 12; // Don't warn.
}
+
+void Foo::Baz1() {
+ typedef int Bar; // Don't warn.
+}
+
+void Foo::Baz2() {
+ using Bar=int; // Don't warn.
+}
}
// http://llvm.org/PR9160
@@ -87,7 +131,9 @@ struct S {
};
}
-extern int bob; // expected-note {{previous declaration is here}}
+extern int bob; // expected-note 1 {{previous declaration is here}}
+typedef int bob1; // expected-note 2 {{previous declaration is here}}
+using bob2=int; // expected-note 2 {{previous declaration is here}}
// rdar://8883302
void rdar8883302() {
@@ -96,6 +142,20 @@ void rdar8883302() {
void test8() {
int bob; // expected-warning {{declaration shadows a variable in the global namespace}}
+ int bob1; //no warning
+ int bob2; // no warning
+}
+
+void test9() {
+ typedef int bob; // no warning
+ typedef int bob1; // expected-warning {{declaration shadows a typedef in the global namespace}}
+ typedef int bob2; // expected-warning {{declaration shadows a type alias in the global namespace}}
+}
+
+void test10() {
+ using bob=int; // no warning
+ using bob1=int; // expected-warning {{declaration shadows a typedef in the global namespace}}
+ using bob2=int; // expected-warning {{declaration shadows a type alias in the global namespace}}
}
namespace rdar29067894 {
@@ -104,6 +164,35 @@ void avoidWarningWhenRedefining(int b) {
int a = 0; // expected-note {{previous definition is here}}
int a = 1; // expected-error {{redefinition of 'a'}}
int b = 2; // expected-error {{redefinition of 'b'}}
+
+ using c=char; // expected-note {{previous definition is here}}
+ using c=int; // expected-error {{type alias redefinition with different types ('int' vs 'char')}}
+
+ typedef char d; // expected-note {{previous definition is here}}
+ typedef int d; // expected-error {{typedef redefinition with different types ('int' vs 'char')}}
+
+ using e=char; // expected-note {{previous definition is here}}
+ typedef int e; // expected-error {{type alias redefinition with different types ('int' vs 'char')}}
+
+ int f; // expected-note {{previous definition is here}}
+ using f=int; // expected-error {{redefinition of 'f'}}
+
+ using g=int; // expected-note {{previous definition is here}}
+ int g; // expected-error {{redefinition of 'g'}}
+
+ typedef int h; // expected-note {{previous definition is here}}
+ int h; // expected-error {{redefinition of 'h'}}
+
+ int k; // expected-note {{previous definition is here}}
+ typedef int k; // expected-error {{redefinition of 'k'}}
+
+ using l=char; // no warning or error.
+ using l=char; // no warning or error.
+ typedef char l; // no warning or error.
+
+ typedef char n; // no warning or error.
+ typedef char n; // no warning or error.
+ using n=char; // no warning or error.
}
}
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