diff mbox series

c++: Comment out announce_function to prevent ICE [PR102426]

Message ID 20211008043101.8568-1-nickhuang99@gmail.com
State New
Headers
Series c++: Comment out announce_function to prevent ICE [PR102426] |

Commit Message

Nick Huang Oct. 8, 2021, 4:31 a.m. UTC 
  This "announce_function" is not a purely readonly
function. Instead it calls tsubst which modifies
global variable "current_function_decl". If it is
placed at parser code directory level, recursion
might happen and set/reset variable might interleave
and can cause ICE. No test case is provided because
this segment fault only occurs when compiler option
"-quiet" is not set which is usually set by driver.
That is why usual testcases cannot expose this issue.
Even though this issue usually doesn't affect endusers,
however, it is a headache for development.

gcc/cp/ChangeLog:
	PR c++/102426
	* decl.c (start_preparsed_function): Comment
	out announce_function.
	(emit_coro_helper): Comment out
	announce_function.

gcc/ChangeLog:
	PR c++/102426
	* toplev.c (get_src_pwd): Add comment
	to note announce_function usage.

Signed-off-by: qingzhe huang <nickhuang99@gmail.com>
---
 gcc/cp/decl.c | 4 ----
 gcc/toplev.c  | 5 ++++-
 2 files changed, 4 insertions(+), 5 deletions(-)

Comments

Nick Huang Oct. 8, 2021, 4:44 a.m. UTC | #1 
I am terribly sorry for my typo of wrong PR #, it should be 102624.
Please ignore this email thread and I resend the patch in next email
with correct subject:
[PATCH] c++: Comment out announce_function to prevent ICE [PR102624]

Once again my apologies for spam.

On Fri, Oct 8, 2021 at 12:31 AM qingzhe huang <nickhuang99@gmail.com> wrote:
>
> This "announce_function" is not a purely readonly
> function. Instead it calls tsubst which modifies
> global variable "current_function_decl". If it is
> placed at parser code directory level, recursion
> might happen and set/reset variable might interleave
> and can cause ICE. No test case is provided because
> this segment fault only occurs when compiler option
> "-quiet" is not set which is usually set by driver.
> That is why usual testcases cannot expose this issue.
> Even though this issue usually doesn't affect endusers,
> however, it is a headache for development.
>
> gcc/cp/ChangeLog:
>         PR c++/102426
>         * decl.c (start_preparsed_function): Comment
>         out announce_function.
>         (emit_coro_helper): Comment out
>         announce_function.
>
> gcc/ChangeLog:
>         PR c++/102426
>         * toplev.c (get_src_pwd): Add comment
>         to note announce_function usage.
>
> Signed-off-by: qingzhe huang <nickhuang99@gmail.com>
> ---
>  gcc/cp/decl.c | 4 ----
>  gcc/toplev.c  | 5 ++++-
>  2 files changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
> index 2d30c790b93..94d3a2c1cba 100644
> --- a/gcc/cp/decl.c
> +++ b/gcc/cp/decl.c
> @@ -16904,9 +16904,6 @@ start_preparsed_function (tree decl1, tree attrs, int flags)
>       where store_parm_decls will find them.  */
>    tree current_function_parms = DECL_ARGUMENTS (decl1);
>
> -  /* Let the user know we're compiling this function.  */
> -  announce_function (decl1);
> -
>    gcc_assert (DECL_INITIAL (decl1));
>
>    /* This function may already have been parsed, in which case just
> @@ -17472,7 +17469,6 @@ emit_coro_helper (tree helper)
>    current_function_decl = helper;
>    begin_scope (sk_function_parms, NULL);
>    store_parm_decls (DECL_ARGUMENTS (helper));
> -  announce_function (helper);
>    allocate_struct_function (helper, false);
>    cfun->language = ggc_cleared_alloc<language_function> ();
>    poplevel (1, 0, 1);
> diff --git a/gcc/toplev.c b/gcc/toplev.c
> index 1bb1794be96..4a3ca1aef4a 100644
> --- a/gcc/toplev.c
> +++ b/gcc/toplev.c
> @@ -221,7 +221,10 @@ get_src_pwd (void)
>  }
>
>  /* Called when the start of a function definition is parsed,
> -   this function prints on stderr the name of the function.  */
> +   this function prints on stderr the name of the function.
> +   NOTE: Do not use this function at directory gcc/cp level
> +   or below because it might recurse and interleave with
> +   function frame parsing which can cause crash. */
>  void
>  announce_function (tree decl)
>  {
> --
> 2.17.1
>
diff mbox series

Patch

diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 2d30c790b93..94d3a2c1cba 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -16904,9 +16904,6 @@  start_preparsed_function (tree decl1, tree attrs, int flags)
      where store_parm_decls will find them.  */
   tree current_function_parms = DECL_ARGUMENTS (decl1);
 
-  /* Let the user know we're compiling this function.  */
-  announce_function (decl1);
-
   gcc_assert (DECL_INITIAL (decl1));
 
   /* This function may already have been parsed, in which case just
@@ -17472,7 +17469,6 @@  emit_coro_helper (tree helper)
   current_function_decl = helper;
   begin_scope (sk_function_parms, NULL);
   store_parm_decls (DECL_ARGUMENTS (helper));
-  announce_function (helper);
   allocate_struct_function (helper, false);
   cfun->language = ggc_cleared_alloc<language_function> ();
   poplevel (1, 0, 1);
diff --git a/gcc/toplev.c b/gcc/toplev.c
index 1bb1794be96..4a3ca1aef4a 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -221,7 +221,10 @@  get_src_pwd (void)
 }
 
 /* Called when the start of a function definition is parsed,
-   this function prints on stderr the name of the function.  */
+   this function prints on stderr the name of the function.
+   NOTE: Do not use this function at directory gcc/cp level
+   or below because it might recurse and interleave with
+   function frame parsing which can cause crash. */
 void
 announce_function (tree decl)
 {