r327558 - [Parser] (C++) Make -Wextra-semi slightly more useful
Roman Lebedev via cfe-commits
cfe-commits at lists.llvm.org
Wed Mar 14 12:31:34 PDT 2018
Author: lebedevri
Date: Wed Mar 14 12:31:34 2018
New Revision: 327558
URL: http://llvm.org/viewvc/llvm-project?rev=327558&view=rev
Log:
[Parser] (C++) Make -Wextra-semi slightly more useful
Summary:
Let's suppose the `-Weverything` is passed.
Given code like
```
void F() {}
;
```
If the code is compiled with `-std=c++03`, it would diagnose that extra sema:
```
<source>:2:1: warning: extra ';' outside of a function is a C++11 extension [-Wc++11-extra-semi]
;
^~
```
If the code is compiled with `-std=c++11`, it also would diagnose that extra sema:
```
<source>:2:1: warning: extra ';' outside of a function is incompatible with C++98 [-Wc++98-compat-pedantic]
;
^~
```
But, let's suppose the C++11 or higher is used, and the used does not care
about `-Wc++98-compat-pedantic`, so he disables that diagnostic.
And that silences the complaint about extra `;` too.
And there is no way to re-enable that particular diagnostic, passing `-Wextra-semi` does nothing...
Now, there is also a related `no newline at end of file` diagnostic, which is also emitted by `-Wc++98-compat-pedantic`
```
<source>:2:2: warning: C++98 requires newline at end of file [-Wc++98-compat-pedantic]
;
^
```
But unlike the previous case, if `-Wno-c++98-compat-pedantic` is passed, that diagnostic stays displayed:
```
<source>:2:2: warning: no newline at end of file [-Wnewline-eof]
;
^
```
This diff refactors the code so `-Wc++98-compat-extra-semi` can be re-enabled, after the `-Wc++98-compat-pedantic` was disabled.
This seems ugly, but there does not seem to be any saner way.
Testing: `$ ninja check-clang`
Reviewers: rsmith, rtrieu, aaron.ballman
Reviewed By: aaron.ballman
Subscribers: jordan_rose, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D43162
Added:
cfe/trunk/test/SemaCXX/extra-semi.cpp
Modified:
cfe/trunk/include/clang/Basic/DiagnosticGroups.td
cfe/trunk/include/clang/Basic/DiagnosticParseKinds.td
cfe/trunk/test/Parser/cxx-extra-semi.cpp
Modified: cfe/trunk/include/clang/Basic/DiagnosticGroups.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticGroups.td?rev=327558&r1=327557&r2=327558&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticGroups.td (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticGroups.td Wed Mar 14 12:31:34 2018
@@ -151,8 +151,10 @@ def Exceptions : DiagGroup<"exceptions">
def GNUEmptyInitializer : DiagGroup<"gnu-empty-initializer">;
def GNUEmptyStruct : DiagGroup<"gnu-empty-struct">;
def ExtraTokens : DiagGroup<"extra-tokens">;
+def CXX98CompatExtraSemi : DiagGroup<"c++98-compat-extra-semi">;
def CXX11ExtraSemi : DiagGroup<"c++11-extra-semi">;
-def ExtraSemi : DiagGroup<"extra-semi", [CXX11ExtraSemi]>;
+def ExtraSemi : DiagGroup<"extra-semi", [CXX98CompatExtraSemi,
+ CXX11ExtraSemi]>;
def GNUFlexibleArrayInitializer : DiagGroup<"gnu-flexible-array-initializer">;
def GNUFlexibleArrayUnionMember : DiagGroup<"gnu-flexible-array-union-member">;
@@ -196,6 +198,7 @@ def CXX98Compat : DiagGroup<"c++98-compa
def CXX98CompatPedantic : DiagGroup<"c++98-compat-pedantic",
[CXX98Compat,
CXX98CompatBindToTemporaryCopy,
+ CXX98CompatExtraSemi,
CXXPre14CompatPedantic,
CXXPre17CompatPedantic,
CXXPre2aCompatPedantic]>;
Modified: cfe/trunk/include/clang/Basic/DiagnosticParseKinds.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticParseKinds.td?rev=327558&r1=327557&r2=327558&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticParseKinds.td (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticParseKinds.td Wed Mar 14 12:31:34 2018
@@ -39,7 +39,7 @@ def ext_empty_translation_unit : Extensi
InGroup<DiagGroup<"empty-translation-unit">>;
def warn_cxx98_compat_top_level_semi : Warning<
"extra ';' outside of a function is incompatible with C++98">,
- InGroup<CXX98CompatPedantic>, DefaultIgnore;
+ InGroup<CXX98CompatExtraSemi>, DefaultIgnore;
def ext_extra_semi : Extension<
"extra ';' %select{"
"outside of a function|"
Modified: cfe/trunk/test/Parser/cxx-extra-semi.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Parser/cxx-extra-semi.cpp?rev=327558&r1=327557&r2=327558&view=diff
==============================================================================
--- cfe/trunk/test/Parser/cxx-extra-semi.cpp (original)
+++ cfe/trunk/test/Parser/cxx-extra-semi.cpp Wed Mar 14 12:31:34 2018
@@ -38,4 +38,7 @@ union B {
#if __cplusplus < 201103L
// expected-warning at -3{{extra ';' outside of a function is a C++11 extension}}
// expected-warning at -3{{extra ';' outside of a function is a C++11 extension}}
+#elif !defined(PEDANTIC)
+// expected-warning at -6{{extra ';' outside of a function is incompatible with C++98}}
+// expected-warning at -6{{extra ';' outside of a function is incompatible with C++98}}
#endif
Added: cfe/trunk/test/SemaCXX/extra-semi.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/extra-semi.cpp?rev=327558&view=auto
==============================================================================
--- cfe/trunk/test/SemaCXX/extra-semi.cpp (added)
+++ cfe/trunk/test/SemaCXX/extra-semi.cpp Wed Mar 14 12:31:34 2018
@@ -0,0 +1,29 @@
+// RUN: %clang_cc1 -verify -std=c++98 -Wextra-semi %s
+// RUN: %clang_cc1 -verify -std=c++03 -Wextra-semi %s
+// RUN: %clang_cc1 -verify -std=c++11 -Wextra-semi %s
+// RUN: %clang_cc1 -verify -std=c++17 -Wextra-semi %s
+// RUN: %clang_cc1 -verify -std=c++2a -Wextra-semi %s
+// RUN: %clang_cc1 -verify -Weverything -Wno-c++98-compat %s
+// RUN: %clang_cc1 -verify -Weverything -Wno-c++98-compat-pedantic -Wc++98-compat-extra-semi %s
+
+// Last RUN line checks that c++98-compat-extra-semi can still be re-enabled.
+
+void F();
+
+void F(){}
+;
+#if __cplusplus < 201103L
+// expected-warning at -2{{extra ';' outside of a function is a C++11 extension}}
+#else
+// expected-warning at -4{{extra ';' outside of a function is incompatible with C++98}}
+#endif
+
+namespace ns {
+class C {
+ void F() const;
+};
+}
+; // expected-warning {{extra ';' outside of a function is}}
+
+void ns::C::F() const {}
+; // expected-warning {{extra ';' outside of a function is}}
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