[v3,4/6] c++: Update mangling of lambdas in expressions

Message ID 677bcb40.170a0220.24b8d0.1211@mx.google.com
State New
Headers
Series c++: Add some missing LAMBDA_EXPR_EXTRA_SCOPEs |

Commit Message

Nathaniel Shead Jan. 6, 2025, 12:23 p.m. UTC
  https://github.com/itanium-cxx-abi/cxx-abi/pull/85 clarifies that
mangling a lambda expression should use 'L' rather than "tl".  This only
affects C++20 (and later) so no ABI flag is given.

gcc/cp/ChangeLog:

	* mangle.cc (write_expression): Update mangling for lambdas.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp2a/lambda-generic-mangle1.C: Update mangling.
	* g++.dg/cpp2a/lambda-generic-mangle1a.C: Likewise.

Signed-off-by: Nathaniel Shead <nathanieloshead@gmail.com>
---
 gcc/cp/mangle.cc                                     | 2 +-
 gcc/testsuite/g++.dg/cpp2a/lambda-generic-mangle1.C  | 2 +-
 gcc/testsuite/g++.dg/cpp2a/lambda-generic-mangle1a.C | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)
  

Comments

Jason Merrill Jan. 23, 2025, 3:04 a.m. UTC | #1
On 1/6/25 7:23 AM, Nathaniel Shead wrote:
> https://github.com/itanium-cxx-abi/cxx-abi/pull/85 clarifies that
> mangling a lambda expression should use 'L' rather than "tl".  This only
> affects C++20 (and later) so no ABI flag is given.

OK.

> gcc/cp/ChangeLog:
> 
> 	* mangle.cc (write_expression): Update mangling for lambdas.
> 
> gcc/testsuite/ChangeLog:
> 
> 	* g++.dg/cpp2a/lambda-generic-mangle1.C: Update mangling.
> 	* g++.dg/cpp2a/lambda-generic-mangle1a.C: Likewise.
> 
> Signed-off-by: Nathaniel Shead <nathanieloshead@gmail.com>
> ---
>   gcc/cp/mangle.cc                                     | 2 +-
>   gcc/testsuite/g++.dg/cpp2a/lambda-generic-mangle1.C  | 2 +-
>   gcc/testsuite/g++.dg/cpp2a/lambda-generic-mangle1a.C | 2 +-
>   3 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/gcc/cp/mangle.cc b/gcc/cp/mangle.cc
> index 9d457e2a2f3..e2e8fb2c71b 100644
> --- a/gcc/cp/mangle.cc
> +++ b/gcc/cp/mangle.cc
> @@ -3769,7 +3769,7 @@ write_expression (tree expr)
>   	 equivalent.
>   
>   	 So just use the closure type mangling.  */
> -      write_string ("tl");
> +      write_char ('L');
>         write_type (LAMBDA_EXPR_CLOSURE (expr));
>         write_char ('E');
>       }
> diff --git a/gcc/testsuite/g++.dg/cpp2a/lambda-generic-mangle1.C b/gcc/testsuite/g++.dg/cpp2a/lambda-generic-mangle1.C
> index 0051307f53d..306959a4f9f 100644
> --- a/gcc/testsuite/g++.dg/cpp2a/lambda-generic-mangle1.C
> +++ b/gcc/testsuite/g++.dg/cpp2a/lambda-generic-mangle1.C
> @@ -6,4 +6,4 @@ struct C {
>     void f(decltype([](T, auto) { return 0; })) {}
>   };
>   void g() { C().f<int>({}); }
> -// { dg-final { scan-assembler "_ZN1C1fIiEEvDTtlNS_UlT_TL0__E_EEE" } }
> +// { dg-final { scan-assembler "_ZN1C1fIiEEvDTLNS_UlT_TL0__E_EEE" } }
> diff --git a/gcc/testsuite/g++.dg/cpp2a/lambda-generic-mangle1a.C b/gcc/testsuite/g++.dg/cpp2a/lambda-generic-mangle1a.C
> index dc7b0125631..b7bd4ecdd46 100644
> --- a/gcc/testsuite/g++.dg/cpp2a/lambda-generic-mangle1a.C
> +++ b/gcc/testsuite/g++.dg/cpp2a/lambda-generic-mangle1a.C
> @@ -7,4 +7,4 @@ struct C {
>     void f(decltype([](T, auto) { return 0; })) {}
>   };
>   void g() { C().f<int>({}); }
> -// { dg-final { scan-assembler "_ZN1C1fIiEEvDTtlNS_UlT_T_E_EEE" } }
> +// { dg-final { scan-assembler "_ZN1C1fIiEEvDTLNS_UlT_T_E_EEE" } }
  

Patch

diff --git a/gcc/cp/mangle.cc b/gcc/cp/mangle.cc
index 9d457e2a2f3..e2e8fb2c71b 100644
--- a/gcc/cp/mangle.cc
+++ b/gcc/cp/mangle.cc
@@ -3769,7 +3769,7 @@  write_expression (tree expr)
 	 equivalent.
 
 	 So just use the closure type mangling.  */
-      write_string ("tl");
+      write_char ('L');
       write_type (LAMBDA_EXPR_CLOSURE (expr));
       write_char ('E');
     }
diff --git a/gcc/testsuite/g++.dg/cpp2a/lambda-generic-mangle1.C b/gcc/testsuite/g++.dg/cpp2a/lambda-generic-mangle1.C
index 0051307f53d..306959a4f9f 100644
--- a/gcc/testsuite/g++.dg/cpp2a/lambda-generic-mangle1.C
+++ b/gcc/testsuite/g++.dg/cpp2a/lambda-generic-mangle1.C
@@ -6,4 +6,4 @@  struct C {
   void f(decltype([](T, auto) { return 0; })) {}
 };
 void g() { C().f<int>({}); }
-// { dg-final { scan-assembler "_ZN1C1fIiEEvDTtlNS_UlT_TL0__E_EEE" } }
+// { dg-final { scan-assembler "_ZN1C1fIiEEvDTLNS_UlT_TL0__E_EEE" } }
diff --git a/gcc/testsuite/g++.dg/cpp2a/lambda-generic-mangle1a.C b/gcc/testsuite/g++.dg/cpp2a/lambda-generic-mangle1a.C
index dc7b0125631..b7bd4ecdd46 100644
--- a/gcc/testsuite/g++.dg/cpp2a/lambda-generic-mangle1a.C
+++ b/gcc/testsuite/g++.dg/cpp2a/lambda-generic-mangle1a.C
@@ -7,4 +7,4 @@  struct C {
   void f(decltype([](T, auto) { return 0; })) {}
 };
 void g() { C().f<int>({}); }
-// { dg-final { scan-assembler "_ZN1C1fIiEEvDTtlNS_UlT_T_E_EEE" } }
+// { dg-final { scan-assembler "_ZN1C1fIiEEvDTLNS_UlT_T_E_EEE" } }