https://github.com/Sirraide updated
https://github.com/llvm/llvm-project/pull/129737
>From f0605e803b6e7748913515a4b0ffe34fa7eedc24 Mon Sep 17 00:00:00 2001
From: Sirraide <aeternalm...@gmail.com>
Date: Tue, 4 Mar 2025 17:36:30 +0100
Subject: [PATCH 1/2] [Clang] Allow non-local/non-variable declarations in for
loop
---
clang/docs/ReleaseNotes.rst | 2 ++
.../clang/Basic/DiagnosticSemaKinds.td | 17 ++++++++++++++
clang/lib/Sema/SemaStmt.cpp | 13 ++++++-----
clang/test/Sema/for.c | 22 +++++++++++++------
4 files changed, 42 insertions(+), 12 deletions(-)
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 97b8e32f03b57..cf205e7064aa8 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -237,6 +237,8 @@ Bug Fixes in This Version
when it can affect template argument deduction (#GH122306).
- Fix crash on code completion of function calls involving partial order of
function templates
(#GH125500).
+- Non-local variable and non-variable declarations in the first clause of a
``for`` loop in C are no longer erroneously
+ considered an error in C23 mode and are allowed as an extension in earlier
language modes.
Bug Fixes to Compiler Builtins
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td
b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index d89648a8a2e83..c87ef62310cb9 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -10794,6 +10794,23 @@ def err_non_local_variable_decl_in_for : Error<
"declaration of non-local variable in 'for' loop">;
def err_non_variable_decl_in_for : Error<
"non-variable declaration in 'for' loop">;
+
+def ext_c23_non_local_variable_decl_in_for : Extension<
+ "declaration of non-local variable in 'for' loop is a C23 extension">,
+ InGroup<C23>;
+
+def warn_c17_non_local_variable_decl_in_for : Warning<
+ "declaration of non-local variable in 'for' loop is incompatible with C
standards before C23">,
+ DefaultIgnore, InGroup<CPre23Compat>;
+
+def ext_c23_non_variable_decl_in_for : Extension<
+ "non-variable declaration in 'for' loop is a C23 extension">,
+ InGroup<C23>;
+
+def warn_c17_non_variable_decl_in_for : Warning<
+ "non-variable declaration in 'for' loop is incompatible with C standards
before C23">,
+ DefaultIgnore, InGroup<CPre23Compat>;
+
def err_toomany_element_decls : Error<
"only one element declaration is allowed">;
def err_selector_element_not_lvalue : Error<
diff --git a/clang/lib/Sema/SemaStmt.cpp b/clang/lib/Sema/SemaStmt.cpp
index d0b713f074c33..0a193b5299bcc 100644
--- a/clang/lib/Sema/SemaStmt.cpp
+++ b/clang/lib/Sema/SemaStmt.cpp
@@ -2269,10 +2269,11 @@ StmtResult Sema::ActOnForStmt(SourceLocation ForLoc,
SourceLocation LParenLoc,
for (auto *DI : DS->decls()) {
if (VarDecl *VD = dyn_cast<VarDecl>(DI)) {
VarDeclSeen = true;
- if (VD->isLocalVarDecl() && !VD->hasLocalStorage()) {
- Diag(DI->getLocation(), diag::err_non_local_variable_decl_in_for);
- DI->setInvalidDecl();
- }
+ if (VD->isLocalVarDecl() && !VD->hasLocalStorage())
+ Diag(DI->getLocation(),
+ getLangOpts().C23
+ ? diag::warn_c17_non_local_variable_decl_in_for
+ : diag::ext_c23_non_local_variable_decl_in_for);
} else if (!NonVarSeen) {
// Keep track of the first non-variable declaration we saw so that
// we can diagnose if we don't see any variable declarations. This
@@ -2284,7 +2285,9 @@ StmtResult Sema::ActOnForStmt(SourceLocation ForLoc,
SourceLocation LParenLoc,
// Diagnose if we saw a non-variable declaration but no variable
// declarations.
if (NonVarSeen && !VarDeclSeen)
- Diag(NonVarSeen->getLocation(), diag::err_non_variable_decl_in_for);
+ Diag(NonVarSeen->getLocation(),
+ getLangOpts().C23 ? diag::warn_c17_non_variable_decl_in_for
+ : diag::ext_c23_non_variable_decl_in_for);
}
}
diff --git a/clang/test/Sema/for.c b/clang/test/Sema/for.c
index d0c2f7f21a960..c21ef62247037 100644
--- a/clang/test/Sema/for.c
+++ b/clang/test/Sema/for.c
@@ -1,13 +1,21 @@
-// RUN: %clang_cc1 -fsyntax-only -verify %s
+// RUN: %clang_cc1 -fsyntax-only -verify=c11 -std=c11 -pedantic %s
+// RUN: %clang_cc1 -fsyntax-only -verify=c23 -std=c23 -Wpre-c23-compat %s
// Check C99 6.8.5p3
void b1 (void) { for (void (*f) (void);;); }
-void b2 (void) { for (void f (void);;); } // expected-error {{non-variable
declaration in 'for' loop}}
-void b3 (void) { for (static int f;;); } // expected-error {{declaration of
non-local variable}}
-void b4 (void) { for (typedef int f;;); } // expected-error {{non-variable
declaration in 'for' loop}}
+void b2 (void) { for (void f (void);;); } /* c11-warning {{non-variable
declaration in 'for' loop is a C23 extension}}
+ c23-warning {{non-variable
declaration in 'for' loop is incompatible with C standards before C23}} */
+void b3 (void) { for (static int f;;); } /* c11-warning {{declaration of
non-local variable in 'for' loop is a C23 extension}}
+ c23-warning {{declaration of
non-local variable in 'for' loop is incompatible with C standards before C23}}
*/
+
+void b4 (void) { for (typedef int f;;); } /* c11-warning {{non-variable
declaration in 'for' loop is a C23 extension}}
+ c23-warning {{non-variable
declaration in 'for' loop is incompatible with C standards before C23}} */
void b5 (void) { for (struct { int i; } s;;); }
void b6 (void) { for (enum { zero, ten = 10 } i;;); }
-void b7 (void) { for (struct s { int i; };;); } // expected-error
{{non-variable declaration in 'for' loop}}
-void b8 (void) { for (static struct { int i; } s;;); } // expected-error
{{declaration of non-local variable}}
+void b7 (void) { for (struct s { int i; };;); } /* c11-warning {{non-variable
declaration in 'for' loop is a C23 extension}}
+ c23-warning {{non-variable
declaration in 'for' loop is incompatible with C standards before C23}} */
+void b8 (void) { for (static struct { int i; } s;;); } /* c11-warning
{{declaration of non-local variable in 'for' loop is a C23 extension}}
+ c23-warning
{{declaration of non-local variable in 'for' loop is incompatible with C
standards before C23}} */
void b9 (void) { for (struct { int i; } (*s)(struct { int j; } o) = 0;;); }
-void b10(void) { for (typedef struct { int i; } (*s)(struct { int j; });;); }
// expected-error {{non-variable declaration in 'for' loop}}
+void b10(void) { for (typedef struct { int i; } (*s)(struct { int j; });;); }
/* c11-warning {{non-variable declaration in 'for' loop is a C23 extension}}
+
c23-warning {{non-variable declaration in 'for' loop is incompatible with C
standards before C23}} */
>From 3ab8a48d7d7c050e7a8a1ed98a2fb84a0e2e79c5 Mon Sep 17 00:00:00 2001
From: Sirraide <aeternalm...@gmail.com>
Date: Wed, 5 Mar 2025 20:06:47 +0100
Subject: [PATCH 2/2] Update release notes
---
clang/docs/ReleaseNotes.rst | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index cf205e7064aa8..160a5947d6a50 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -237,7 +237,7 @@ Bug Fixes in This Version
when it can affect template argument deduction (#GH122306).
- Fix crash on code completion of function calls involving partial order of
function templates
(#GH125500).
-- Non-local variable and non-variable declarations in the first clause of a
``for`` loop in C are no longer erroneously
+- Non-local variable and non-variable declarations in the first clause of a
``for`` loop in C are no longer incorrectly
considered an error in C23 mode and are allowed as an extension in earlier
language modes.
Bug Fixes to Compiler Builtins
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