[clang] [Clang] Update missing varargs arg extension warnings (PR #84520)
zibi2 wrote: > Actually, a trailing comma in the macro invocation might work too. It’s been > a while since I last had to deal w/ this. Yes, it does and I think it's cleaner than my proposal. Thank you. https://github.com/llvm/llvm-project/pull/84520 ___ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
[clang] [Clang] Update missing varargs arg extension warnings (PR #84520)
zibi2 wrote: I agree the code is not C++17 compliant. An alternative fix would be to compile this file with `-Wno-c++20-extensions`. https://github.com/llvm/llvm-project/pull/84520 ___ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
[clang] [Clang] Update missing varargs arg extension warnings (PR #84520)
Sirraide wrote: Actually, a trailing comma in the macro invocation might work too. It’s been a while since I last had to deal w/ this. https://github.com/llvm/llvm-project/pull/84520 ___ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
[clang] [Clang] Update missing varargs arg extension warnings (PR #84520)
Sirraide wrote:
> @Sirraide, I noticed the following build issue when new compiler with this
> change (bootstrap compiler) is being used to build one of the files for
> `clangd`:
>
> ```
> .../clang-tools-extra/clangd/unittests/FindTargetTests.cpp:430:29: error:
> passing no argument for the '...' parameter of a variadic macro is a C++20
> extension [-Werror,-Wc++20-extensions]
> 430 | EXPECT_DECLS("AutoTypeLoc");
> | ^
> .../clang-tools-extra/clangd/unittests/FindTargetTests.cpp:98:9: note: macro
> 'EXPECT_DECLS' defined here
>98 | #define EXPECT_DECLS(NodeType, ...)
> \
> | ^
> ```
>
> Do you have suggestion how to fix it or even better provie the fix? Thank
> you, Zibi
I mean, from what I can tell, this isn’t a Clang issue but rather just a result
of this code here not being standards-compliant C++17. Before C++20, afaik the
‘fix’ for this is to have two different macros: one variadic, one not variadic.
It’s not pretty, but that’s why that got changed in C++20.
https://github.com/llvm/llvm-project/pull/84520
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[clang] [Clang] Update missing varargs arg extension warnings (PR #84520)
zibi2 wrote:
@Sirraide, I noticed the following build issue when new compiler with this
change (bootstrap compiler) is being used to build one of the files for
`clangd`:
```
.../clang-tools-extra/clangd/unittests/FindTargetTests.cpp:430:29: error:
passing no argument for the '...' parameter of a variadic macro is a C++20
extension [-Werror,-Wc++20-extensions]
430 | EXPECT_DECLS("AutoTypeLoc");
| ^
.../clang-tools-extra/clangd/unittests/FindTargetTests.cpp:98:9: note: macro
'EXPECT_DECLS' defined here
98 | #define EXPECT_DECLS(NodeType, ...)
\
| ^
```
Do you have suggestion how to fix it or even better provie the fix?
Thank you,
Zibi
https://github.com/llvm/llvm-project/pull/84520
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[clang] [Clang] Update missing varargs arg extension warnings (PR #84520)
https://github.com/Sirraide closed https://github.com/llvm/llvm-project/pull/84520 ___ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
[clang] [Clang] Update missing varargs arg extension warnings (PR #84520)
https://github.com/Sirraide updated
https://github.com/llvm/llvm-project/pull/84520
>From 502692869e3105bb2c55955bc4baff63b1475770 Mon Sep 17 00:00:00 2001
From: Sirraide
Date: Fri, 8 Mar 2024 18:15:07 +0100
Subject: [PATCH 1/3] [Clang] Update missing varargs arg extension warnings
---
clang/docs/ReleaseNotes.rst| 3 +++
.../include/clang/Basic/DiagnosticLexKinds.td | 13 ++---
clang/lib/Lex/PPMacroExpansion.cpp | 13 ++---
clang/test/C/C2x/n2975.c | 4 ++--
clang/test/Lexer/gnu-flags.c | 2 --
clang/test/Preprocessor/empty_va_arg.cpp | 18 +++---
clang/test/Preprocessor/macro_fn.c | 4 ++--
7 files changed, 38 insertions(+), 19 deletions(-)
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 0ff4a93b15ea8f..ffc88e79961ce6 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -212,6 +212,9 @@ Improvements to Clang's diagnostics
- Clang now diagnoses lambda function expressions being implicitly cast to
boolean values, under ``-Wpointer-bool-conversion``.
Fixes #GH82512.
+- Clang now correctly diagnoses no arguments to a variadic macro parameter as
a C23/C++20 extension.
+ Fixes #GH84495.
+
Improvements to Clang's time-trace
--
diff --git a/clang/include/clang/Basic/DiagnosticLexKinds.td
b/clang/include/clang/Basic/DiagnosticLexKinds.td
index d7c172e6546351..ad6bacfb118d49 100644
--- a/clang/include/clang/Basic/DiagnosticLexKinds.td
+++ b/clang/include/clang/Basic/DiagnosticLexKinds.td
@@ -465,9 +465,16 @@ def err_embedded_directive : Error<
def ext_embedded_directive : Extension<
"embedding a directive within macro arguments has undefined behavior">,
InGroup>;
-def ext_missing_varargs_arg : Extension<
- "must specify at least one argument for '...' parameter of variadic macro">,
- InGroup;
+def ext_c_missing_varargs_arg : Extension<
+ "passing no argument for the '...' parameter of a variadic macro is "
+ "a C23 extension">, InGroup;
+def ext_cxx_missing_varargs_arg : Extension<
+ "passing no argument for the '...' parameter of a variadic macro is "
+ "a C++20 extension">, InGroup;
+def warn_c17_compat_missing_varargs_arg : Warning<
+ "passing no argument for the '...' parameter of a variadic macro is "
+ "incompatible with C standards before C23">,
+ InGroup, DefaultIgnore;
def warn_cxx17_compat_missing_varargs_arg : Warning<
"passing no argument for the '...' parameter of a variadic macro is "
"incompatible with C++ standards before C++20">,
diff --git a/clang/lib/Lex/PPMacroExpansion.cpp
b/clang/lib/Lex/PPMacroExpansion.cpp
index 3017461dc66e86..3cde001e84760e 100644
--- a/clang/lib/Lex/PPMacroExpansion.cpp
+++ b/clang/lib/Lex/PPMacroExpansion.cpp
@@ -995,9 +995,16 @@ MacroArgs *Preprocessor::ReadMacroCallArgumentList(Token
&MacroName,
if (!MI->hasCommaPasting()) {
// C++20 allows this construct, but standards before C++20 and all C
// standards do not allow the construct (we allow it as an extension).
-Diag(Tok, getLangOpts().CPlusPlus20
- ? diag::warn_cxx17_compat_missing_varargs_arg
- : diag::ext_missing_varargs_arg);
+unsigned ID;
+if (getLangOpts().CPlusPlus20)
+ ID = diag::warn_cxx17_compat_missing_varargs_arg;
+else if (getLangOpts().CPlusPlus)
+ ID = diag::ext_cxx_missing_varargs_arg;
+else if (getLangOpts().C23)
+ ID = diag::warn_c17_compat_missing_varargs_arg;
+else
+ ID = diag::ext_c_missing_varargs_arg;
+Diag(Tok, ID);
Diag(MI->getDefinitionLoc(), diag::note_macro_here)
<< MacroName.getIdentifierInfo();
}
diff --git a/clang/test/C/C2x/n2975.c b/clang/test/C/C2x/n2975.c
index 5fc641dd66e781..2269400fe47c34 100644
--- a/clang/test/C/C2x/n2975.c
+++ b/clang/test/C/C2x/n2975.c
@@ -11,7 +11,7 @@
void func(...) { // expected-warning {{'...' as the only parameter of a
function is incompatible with C standards before C23}}
// Show that va_start doesn't require the second argument in C23 mode.
va_list list;
- va_start(list); // FIXME: it would be nice to issue a portability warning to
C17 and earlier here.
+ va_start(list); // expected-warning {{passing no argument for the '...'
parameter of a variadic macro is incompatible with C standards before C23}}
expected-note@* {{macro 'va_start' defined here}}
va_end(list);
// Show that va_start doesn't expand or evaluate the second argument.
@@ -26,7 +26,7 @@ void func(...) { // expected-warning {{'...' as the only
parameter of a function
__builtin_va_start(list); // expected-error {{too few arguments to function
call, expected 2, have 1}}
// Verify that the return type of a call to va_start is 'void'.
- _Static_assert(__builtin_types_compatible_p(__typeof__(va_start(list)),
void), "");
+ _Static_
[clang] [Clang] Update missing varargs arg extension warnings (PR #84520)
https://github.com/Sirraide updated
https://github.com/llvm/llvm-project/pull/84520
>From 502692869e3105bb2c55955bc4baff63b1475770 Mon Sep 17 00:00:00 2001
From: Sirraide
Date: Fri, 8 Mar 2024 18:15:07 +0100
Subject: [PATCH 1/3] [Clang] Update missing varargs arg extension warnings
---
clang/docs/ReleaseNotes.rst| 3 +++
.../include/clang/Basic/DiagnosticLexKinds.td | 13 ++---
clang/lib/Lex/PPMacroExpansion.cpp | 13 ++---
clang/test/C/C2x/n2975.c | 4 ++--
clang/test/Lexer/gnu-flags.c | 2 --
clang/test/Preprocessor/empty_va_arg.cpp | 18 +++---
clang/test/Preprocessor/macro_fn.c | 4 ++--
7 files changed, 38 insertions(+), 19 deletions(-)
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 0ff4a93b15ea8f..ffc88e79961ce6 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -212,6 +212,9 @@ Improvements to Clang's diagnostics
- Clang now diagnoses lambda function expressions being implicitly cast to
boolean values, under ``-Wpointer-bool-conversion``.
Fixes #GH82512.
+- Clang now correctly diagnoses no arguments to a variadic macro parameter as
a C23/C++20 extension.
+ Fixes #GH84495.
+
Improvements to Clang's time-trace
--
diff --git a/clang/include/clang/Basic/DiagnosticLexKinds.td
b/clang/include/clang/Basic/DiagnosticLexKinds.td
index d7c172e6546351..ad6bacfb118d49 100644
--- a/clang/include/clang/Basic/DiagnosticLexKinds.td
+++ b/clang/include/clang/Basic/DiagnosticLexKinds.td
@@ -465,9 +465,16 @@ def err_embedded_directive : Error<
def ext_embedded_directive : Extension<
"embedding a directive within macro arguments has undefined behavior">,
InGroup>;
-def ext_missing_varargs_arg : Extension<
- "must specify at least one argument for '...' parameter of variadic macro">,
- InGroup;
+def ext_c_missing_varargs_arg : Extension<
+ "passing no argument for the '...' parameter of a variadic macro is "
+ "a C23 extension">, InGroup;
+def ext_cxx_missing_varargs_arg : Extension<
+ "passing no argument for the '...' parameter of a variadic macro is "
+ "a C++20 extension">, InGroup;
+def warn_c17_compat_missing_varargs_arg : Warning<
+ "passing no argument for the '...' parameter of a variadic macro is "
+ "incompatible with C standards before C23">,
+ InGroup, DefaultIgnore;
def warn_cxx17_compat_missing_varargs_arg : Warning<
"passing no argument for the '...' parameter of a variadic macro is "
"incompatible with C++ standards before C++20">,
diff --git a/clang/lib/Lex/PPMacroExpansion.cpp
b/clang/lib/Lex/PPMacroExpansion.cpp
index 3017461dc66e86..3cde001e84760e 100644
--- a/clang/lib/Lex/PPMacroExpansion.cpp
+++ b/clang/lib/Lex/PPMacroExpansion.cpp
@@ -995,9 +995,16 @@ MacroArgs *Preprocessor::ReadMacroCallArgumentList(Token
&MacroName,
if (!MI->hasCommaPasting()) {
// C++20 allows this construct, but standards before C++20 and all C
// standards do not allow the construct (we allow it as an extension).
-Diag(Tok, getLangOpts().CPlusPlus20
- ? diag::warn_cxx17_compat_missing_varargs_arg
- : diag::ext_missing_varargs_arg);
+unsigned ID;
+if (getLangOpts().CPlusPlus20)
+ ID = diag::warn_cxx17_compat_missing_varargs_arg;
+else if (getLangOpts().CPlusPlus)
+ ID = diag::ext_cxx_missing_varargs_arg;
+else if (getLangOpts().C23)
+ ID = diag::warn_c17_compat_missing_varargs_arg;
+else
+ ID = diag::ext_c_missing_varargs_arg;
+Diag(Tok, ID);
Diag(MI->getDefinitionLoc(), diag::note_macro_here)
<< MacroName.getIdentifierInfo();
}
diff --git a/clang/test/C/C2x/n2975.c b/clang/test/C/C2x/n2975.c
index 5fc641dd66e781..2269400fe47c34 100644
--- a/clang/test/C/C2x/n2975.c
+++ b/clang/test/C/C2x/n2975.c
@@ -11,7 +11,7 @@
void func(...) { // expected-warning {{'...' as the only parameter of a
function is incompatible with C standards before C23}}
// Show that va_start doesn't require the second argument in C23 mode.
va_list list;
- va_start(list); // FIXME: it would be nice to issue a portability warning to
C17 and earlier here.
+ va_start(list); // expected-warning {{passing no argument for the '...'
parameter of a variadic macro is incompatible with C standards before C23}}
expected-note@* {{macro 'va_start' defined here}}
va_end(list);
// Show that va_start doesn't expand or evaluate the second argument.
@@ -26,7 +26,7 @@ void func(...) { // expected-warning {{'...' as the only
parameter of a function
__builtin_va_start(list); // expected-error {{too few arguments to function
call, expected 2, have 1}}
// Verify that the return type of a call to va_start is 'void'.
- _Static_assert(__builtin_types_compatible_p(__typeof__(va_start(list)),
void), "");
+ _Static_
[clang] [Clang] Update missing varargs arg extension warnings (PR #84520)
@@ -993,11 +993,18 @@ MacroArgs *Preprocessor::ReadMacroCallArgumentList(Token
&MacroName,
// If the macro contains the comma pasting extension, the diagnostic
// is suppressed; we know we'll get another diagnostic later.
if (!MI->hasCommaPasting()) {
-// C++20 allows this construct, but standards before C++20 and all C
-// standards do not allow the construct (we allow it as an extension).
-Diag(Tok, getLangOpts().CPlusPlus20
- ? diag::warn_cxx17_compat_missing_varargs_arg
- : diag::ext_missing_varargs_arg);
+// C++20 and C23 allow this construct, but standards before that
+// do not (we allow it as an extension).
Sirraide wrote:
Sure, will do.
https://github.com/llvm/llvm-project/pull/84520
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[clang] [Clang] Update missing varargs arg extension warnings (PR #84520)
https://github.com/AaronBallman approved this pull request. LGTM aside from a comment request https://github.com/llvm/llvm-project/pull/84520 ___ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
[clang] [Clang] Update missing varargs arg extension warnings (PR #84520)
@@ -993,11 +993,18 @@ MacroArgs *Preprocessor::ReadMacroCallArgumentList(Token
&MacroName,
// If the macro contains the comma pasting extension, the diagnostic
// is suppressed; we know we'll get another diagnostic later.
if (!MI->hasCommaPasting()) {
-// C++20 allows this construct, but standards before C++20 and all C
-// standards do not allow the construct (we allow it as an extension).
-Diag(Tok, getLangOpts().CPlusPlus20
- ? diag::warn_cxx17_compat_missing_varargs_arg
- : diag::ext_missing_varargs_arg);
+// C++20 and C23 allow this construct, but standards before that
+// do not (we allow it as an extension).
AaronBallman wrote:
I think it's worth adding the standards citation just the same, even if we
don't copy the text from the standard. e.g.,
```
// C++20 [cpp.replace]p15, C23 6.10.5p12
```
https://github.com/llvm/llvm-project/pull/84520
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[clang] [Clang] Update missing varargs arg extension warnings (PR #84520)
https://github.com/AaronBallman edited https://github.com/llvm/llvm-project/pull/84520 ___ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
[clang] [Clang] Update missing varargs arg extension warnings (PR #84520)
https://github.com/shafik edited https://github.com/llvm/llvm-project/pull/84520 ___ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
[clang] [Clang] Update missing varargs arg extension warnings (PR #84520)
https://github.com/shafik commented: Just a nit here. https://github.com/llvm/llvm-project/pull/84520 ___ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
[clang] [Clang] Update missing varargs arg extension warnings (PR #84520)
@@ -993,11 +993,18 @@ MacroArgs *Preprocessor::ReadMacroCallArgumentList(Token
&MacroName,
// If the macro contains the comma pasting extension, the diagnostic
// is suppressed; we know we'll get another diagnostic later.
if (!MI->hasCommaPasting()) {
-// C++20 allows this construct, but standards before C++20 and all C
-// standards do not allow the construct (we allow it as an extension).
-Diag(Tok, getLangOpts().CPlusPlus20
- ? diag::warn_cxx17_compat_missing_varargs_arg
- : diag::ext_missing_varargs_arg);
+// C++20 and C23 allow this construct, but standards before that
+// do not (we allow it as an extension).
shafik wrote:
CC @AaronBallman should we add a standard quote like we normally do for C++? It
looks like it should be 6.10.5 p12. It took me a but to remember in C they are
referred to as *variable arguments* and not variadic like in C++.
https://github.com/llvm/llvm-project/pull/84520
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[clang] [Clang] Update missing varargs arg extension warnings (PR #84520)
https://github.com/Sirraide updated
https://github.com/llvm/llvm-project/pull/84520
>From 502692869e3105bb2c55955bc4baff63b1475770 Mon Sep 17 00:00:00 2001
From: Sirraide
Date: Fri, 8 Mar 2024 18:15:07 +0100
Subject: [PATCH 1/2] [Clang] Update missing varargs arg extension warnings
---
clang/docs/ReleaseNotes.rst| 3 +++
.../include/clang/Basic/DiagnosticLexKinds.td | 13 ++---
clang/lib/Lex/PPMacroExpansion.cpp | 13 ++---
clang/test/C/C2x/n2975.c | 4 ++--
clang/test/Lexer/gnu-flags.c | 2 --
clang/test/Preprocessor/empty_va_arg.cpp | 18 +++---
clang/test/Preprocessor/macro_fn.c | 4 ++--
7 files changed, 38 insertions(+), 19 deletions(-)
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 0ff4a93b15ea8f..ffc88e79961ce6 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -212,6 +212,9 @@ Improvements to Clang's diagnostics
- Clang now diagnoses lambda function expressions being implicitly cast to
boolean values, under ``-Wpointer-bool-conversion``.
Fixes #GH82512.
+- Clang now correctly diagnoses no arguments to a variadic macro parameter as
a C23/C++20 extension.
+ Fixes #GH84495.
+
Improvements to Clang's time-trace
--
diff --git a/clang/include/clang/Basic/DiagnosticLexKinds.td
b/clang/include/clang/Basic/DiagnosticLexKinds.td
index d7c172e6546351..ad6bacfb118d49 100644
--- a/clang/include/clang/Basic/DiagnosticLexKinds.td
+++ b/clang/include/clang/Basic/DiagnosticLexKinds.td
@@ -465,9 +465,16 @@ def err_embedded_directive : Error<
def ext_embedded_directive : Extension<
"embedding a directive within macro arguments has undefined behavior">,
InGroup>;
-def ext_missing_varargs_arg : Extension<
- "must specify at least one argument for '...' parameter of variadic macro">,
- InGroup;
+def ext_c_missing_varargs_arg : Extension<
+ "passing no argument for the '...' parameter of a variadic macro is "
+ "a C23 extension">, InGroup;
+def ext_cxx_missing_varargs_arg : Extension<
+ "passing no argument for the '...' parameter of a variadic macro is "
+ "a C++20 extension">, InGroup;
+def warn_c17_compat_missing_varargs_arg : Warning<
+ "passing no argument for the '...' parameter of a variadic macro is "
+ "incompatible with C standards before C23">,
+ InGroup, DefaultIgnore;
def warn_cxx17_compat_missing_varargs_arg : Warning<
"passing no argument for the '...' parameter of a variadic macro is "
"incompatible with C++ standards before C++20">,
diff --git a/clang/lib/Lex/PPMacroExpansion.cpp
b/clang/lib/Lex/PPMacroExpansion.cpp
index 3017461dc66e86..3cde001e84760e 100644
--- a/clang/lib/Lex/PPMacroExpansion.cpp
+++ b/clang/lib/Lex/PPMacroExpansion.cpp
@@ -995,9 +995,16 @@ MacroArgs *Preprocessor::ReadMacroCallArgumentList(Token
&MacroName,
if (!MI->hasCommaPasting()) {
// C++20 allows this construct, but standards before C++20 and all C
// standards do not allow the construct (we allow it as an extension).
-Diag(Tok, getLangOpts().CPlusPlus20
- ? diag::warn_cxx17_compat_missing_varargs_arg
- : diag::ext_missing_varargs_arg);
+unsigned ID;
+if (getLangOpts().CPlusPlus20)
+ ID = diag::warn_cxx17_compat_missing_varargs_arg;
+else if (getLangOpts().CPlusPlus)
+ ID = diag::ext_cxx_missing_varargs_arg;
+else if (getLangOpts().C23)
+ ID = diag::warn_c17_compat_missing_varargs_arg;
+else
+ ID = diag::ext_c_missing_varargs_arg;
+Diag(Tok, ID);
Diag(MI->getDefinitionLoc(), diag::note_macro_here)
<< MacroName.getIdentifierInfo();
}
diff --git a/clang/test/C/C2x/n2975.c b/clang/test/C/C2x/n2975.c
index 5fc641dd66e781..2269400fe47c34 100644
--- a/clang/test/C/C2x/n2975.c
+++ b/clang/test/C/C2x/n2975.c
@@ -11,7 +11,7 @@
void func(...) { // expected-warning {{'...' as the only parameter of a
function is incompatible with C standards before C23}}
// Show that va_start doesn't require the second argument in C23 mode.
va_list list;
- va_start(list); // FIXME: it would be nice to issue a portability warning to
C17 and earlier here.
+ va_start(list); // expected-warning {{passing no argument for the '...'
parameter of a variadic macro is incompatible with C standards before C23}}
expected-note@* {{macro 'va_start' defined here}}
va_end(list);
// Show that va_start doesn't expand or evaluate the second argument.
@@ -26,7 +26,7 @@ void func(...) { // expected-warning {{'...' as the only
parameter of a function
__builtin_va_start(list); // expected-error {{too few arguments to function
call, expected 2, have 1}}
// Verify that the return type of a call to va_start is 'void'.
- _Static_assert(__builtin_types_compatible_p(__typeof__(va_start(list)),
void), "");
+ _Static_
[clang] [Clang] Update missing varargs arg extension warnings (PR #84520)
llvmbot wrote:
@llvm/pr-subscribers-clang
Author: None (Sirraide)
Changes
This updates a few warnings that were diagnosing no arguments for a `...`
variadic macro parameter as a GNU extension when it actually is a C++20/C23
extension now.
This fixes #84495.
---
Full diff: https://github.com/llvm/llvm-project/pull/84520.diff
7 Files Affected:
- (modified) clang/docs/ReleaseNotes.rst (+3)
- (modified) clang/include/clang/Basic/DiagnosticLexKinds.td (+10-3)
- (modified) clang/lib/Lex/PPMacroExpansion.cpp (+10-3)
- (modified) clang/test/C/C2x/n2975.c (+2-2)
- (modified) clang/test/Lexer/gnu-flags.c (-2)
- (modified) clang/test/Preprocessor/empty_va_arg.cpp (+11-7)
- (modified) clang/test/Preprocessor/macro_fn.c (+2-2)
``diff
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 0ff4a93b15ea8f..ffc88e79961ce6 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -212,6 +212,9 @@ Improvements to Clang's diagnostics
- Clang now diagnoses lambda function expressions being implicitly cast to
boolean values, under ``-Wpointer-bool-conversion``.
Fixes #GH82512.
+- Clang now correctly diagnoses no arguments to a variadic macro parameter as
a C23/C++20 extension.
+ Fixes #GH84495.
+
Improvements to Clang's time-trace
--
diff --git a/clang/include/clang/Basic/DiagnosticLexKinds.td
b/clang/include/clang/Basic/DiagnosticLexKinds.td
index d7c172e6546351..ad6bacfb118d49 100644
--- a/clang/include/clang/Basic/DiagnosticLexKinds.td
+++ b/clang/include/clang/Basic/DiagnosticLexKinds.td
@@ -465,9 +465,16 @@ def err_embedded_directive : Error<
def ext_embedded_directive : Extension<
"embedding a directive within macro arguments has undefined behavior">,
InGroup>;
-def ext_missing_varargs_arg : Extension<
- "must specify at least one argument for '...' parameter of variadic macro">,
- InGroup;
+def ext_c_missing_varargs_arg : Extension<
+ "passing no argument for the '...' parameter of a variadic macro is "
+ "a C23 extension">, InGroup;
+def ext_cxx_missing_varargs_arg : Extension<
+ "passing no argument for the '...' parameter of a variadic macro is "
+ "a C++20 extension">, InGroup;
+def warn_c17_compat_missing_varargs_arg : Warning<
+ "passing no argument for the '...' parameter of a variadic macro is "
+ "incompatible with C standards before C23">,
+ InGroup, DefaultIgnore;
def warn_cxx17_compat_missing_varargs_arg : Warning<
"passing no argument for the '...' parameter of a variadic macro is "
"incompatible with C++ standards before C++20">,
diff --git a/clang/lib/Lex/PPMacroExpansion.cpp
b/clang/lib/Lex/PPMacroExpansion.cpp
index 3017461dc66e86..3cde001e84760e 100644
--- a/clang/lib/Lex/PPMacroExpansion.cpp
+++ b/clang/lib/Lex/PPMacroExpansion.cpp
@@ -995,9 +995,16 @@ MacroArgs *Preprocessor::ReadMacroCallArgumentList(Token
&MacroName,
if (!MI->hasCommaPasting()) {
// C++20 allows this construct, but standards before C++20 and all C
// standards do not allow the construct (we allow it as an extension).
-Diag(Tok, getLangOpts().CPlusPlus20
- ? diag::warn_cxx17_compat_missing_varargs_arg
- : diag::ext_missing_varargs_arg);
+unsigned ID;
+if (getLangOpts().CPlusPlus20)
+ ID = diag::warn_cxx17_compat_missing_varargs_arg;
+else if (getLangOpts().CPlusPlus)
+ ID = diag::ext_cxx_missing_varargs_arg;
+else if (getLangOpts().C23)
+ ID = diag::warn_c17_compat_missing_varargs_arg;
+else
+ ID = diag::ext_c_missing_varargs_arg;
+Diag(Tok, ID);
Diag(MI->getDefinitionLoc(), diag::note_macro_here)
<< MacroName.getIdentifierInfo();
}
diff --git a/clang/test/C/C2x/n2975.c b/clang/test/C/C2x/n2975.c
index 5fc641dd66e781..2269400fe47c34 100644
--- a/clang/test/C/C2x/n2975.c
+++ b/clang/test/C/C2x/n2975.c
@@ -11,7 +11,7 @@
void func(...) { // expected-warning {{'...' as the only parameter of a
function is incompatible with C standards before C23}}
// Show that va_start doesn't require the second argument in C23 mode.
va_list list;
- va_start(list); // FIXME: it would be nice to issue a portability warning to
C17 and earlier here.
+ va_start(list); // expected-warning {{passing no argument for the '...'
parameter of a variadic macro is incompatible with C standards before C23}}
expected-note@* {{macro 'va_start' defined here}}
va_end(list);
// Show that va_start doesn't expand or evaluate the second argument.
@@ -26,7 +26,7 @@ void func(...) { // expected-warning {{'...' as the only
parameter of a function
__builtin_va_start(list); // expected-error {{too few arguments to function
call, expected 2, have 1}}
// Verify that the return type of a call to va_start is 'void'.
- _Static_assert(__builtin_types_compatible_p(__typeof__(va_start(list)),
void), "");
+ _Static_assert(__builtin
[clang] [Clang] Update missing varargs arg extension warnings (PR #84520)
https://github.com/Sirraide created
https://github.com/llvm/llvm-project/pull/84520
This updates a few warnings that were diagnosing no arguments for a `...`
variadic macro parameter as a GNU extension when it actually is a C++20/C23
extension now.
This fixes #84495.
>From 502692869e3105bb2c55955bc4baff63b1475770 Mon Sep 17 00:00:00 2001
From: Sirraide
Date: Fri, 8 Mar 2024 18:15:07 +0100
Subject: [PATCH] [Clang] Update missing varargs arg extension warnings
---
clang/docs/ReleaseNotes.rst| 3 +++
.../include/clang/Basic/DiagnosticLexKinds.td | 13 ++---
clang/lib/Lex/PPMacroExpansion.cpp | 13 ++---
clang/test/C/C2x/n2975.c | 4 ++--
clang/test/Lexer/gnu-flags.c | 2 --
clang/test/Preprocessor/empty_va_arg.cpp | 18 +++---
clang/test/Preprocessor/macro_fn.c | 4 ++--
7 files changed, 38 insertions(+), 19 deletions(-)
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 0ff4a93b15ea8f..ffc88e79961ce6 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -212,6 +212,9 @@ Improvements to Clang's diagnostics
- Clang now diagnoses lambda function expressions being implicitly cast to
boolean values, under ``-Wpointer-bool-conversion``.
Fixes #GH82512.
+- Clang now correctly diagnoses no arguments to a variadic macro parameter as
a C23/C++20 extension.
+ Fixes #GH84495.
+
Improvements to Clang's time-trace
--
diff --git a/clang/include/clang/Basic/DiagnosticLexKinds.td
b/clang/include/clang/Basic/DiagnosticLexKinds.td
index d7c172e6546351..ad6bacfb118d49 100644
--- a/clang/include/clang/Basic/DiagnosticLexKinds.td
+++ b/clang/include/clang/Basic/DiagnosticLexKinds.td
@@ -465,9 +465,16 @@ def err_embedded_directive : Error<
def ext_embedded_directive : Extension<
"embedding a directive within macro arguments has undefined behavior">,
InGroup>;
-def ext_missing_varargs_arg : Extension<
- "must specify at least one argument for '...' parameter of variadic macro">,
- InGroup;
+def ext_c_missing_varargs_arg : Extension<
+ "passing no argument for the '...' parameter of a variadic macro is "
+ "a C23 extension">, InGroup;
+def ext_cxx_missing_varargs_arg : Extension<
+ "passing no argument for the '...' parameter of a variadic macro is "
+ "a C++20 extension">, InGroup;
+def warn_c17_compat_missing_varargs_arg : Warning<
+ "passing no argument for the '...' parameter of a variadic macro is "
+ "incompatible with C standards before C23">,
+ InGroup, DefaultIgnore;
def warn_cxx17_compat_missing_varargs_arg : Warning<
"passing no argument for the '...' parameter of a variadic macro is "
"incompatible with C++ standards before C++20">,
diff --git a/clang/lib/Lex/PPMacroExpansion.cpp
b/clang/lib/Lex/PPMacroExpansion.cpp
index 3017461dc66e86..3cde001e84760e 100644
--- a/clang/lib/Lex/PPMacroExpansion.cpp
+++ b/clang/lib/Lex/PPMacroExpansion.cpp
@@ -995,9 +995,16 @@ MacroArgs *Preprocessor::ReadMacroCallArgumentList(Token
&MacroName,
if (!MI->hasCommaPasting()) {
// C++20 allows this construct, but standards before C++20 and all C
// standards do not allow the construct (we allow it as an extension).
-Diag(Tok, getLangOpts().CPlusPlus20
- ? diag::warn_cxx17_compat_missing_varargs_arg
- : diag::ext_missing_varargs_arg);
+unsigned ID;
+if (getLangOpts().CPlusPlus20)
+ ID = diag::warn_cxx17_compat_missing_varargs_arg;
+else if (getLangOpts().CPlusPlus)
+ ID = diag::ext_cxx_missing_varargs_arg;
+else if (getLangOpts().C23)
+ ID = diag::warn_c17_compat_missing_varargs_arg;
+else
+ ID = diag::ext_c_missing_varargs_arg;
+Diag(Tok, ID);
Diag(MI->getDefinitionLoc(), diag::note_macro_here)
<< MacroName.getIdentifierInfo();
}
diff --git a/clang/test/C/C2x/n2975.c b/clang/test/C/C2x/n2975.c
index 5fc641dd66e781..2269400fe47c34 100644
--- a/clang/test/C/C2x/n2975.c
+++ b/clang/test/C/C2x/n2975.c
@@ -11,7 +11,7 @@
void func(...) { // expected-warning {{'...' as the only parameter of a
function is incompatible with C standards before C23}}
// Show that va_start doesn't require the second argument in C23 mode.
va_list list;
- va_start(list); // FIXME: it would be nice to issue a portability warning to
C17 and earlier here.
+ va_start(list); // expected-warning {{passing no argument for the '...'
parameter of a variadic macro is incompatible with C standards before C23}}
expected-note@* {{macro 'va_start' defined here}}
va_end(list);
// Show that va_start doesn't expand or evaluate the second argument.
@@ -26,7 +26,7 @@ void func(...) { // expected-warning {{'...' as the only
parameter of a function
__builtin_va_start(list); // expected-error {{too few arguments to function
call, expec
