Merge #607

607: Remove split-stack from backend r=tschwinge a=dkm

From Mark Wielaard : https://gcc.gnu.org/pipermail/gcc-rust/2021-August/000110.html

> The backend was derived from the go backend which enables split stack
> support by default. This inserts a __morestack call at the start of
> each function. This is not needed for the rust backend. Remove the
> split stack support code from the rust backend and spec.


Co-authored-by: Mark Wielaard <mark@klomp.org>

1 files changed, 0 insertions, 47 deletions

diff --git a/gcc/rust/rustspec.cc b/gcc/rust/rustspec.cc
index 28c2d9a..12ec874 100644
--- a/gcc/rust/rustspec.cc
+++ b/gcc/rust/rustspec.cc
@@ -104,9 +104,6 @@ lang_specific_driver (struct cl_decoded_option **in_decoded_options,
   /* The total number of arguments with the new stuff.  */
   int num_args = 1;
 
-  /* Supports split stack */
-  int supports_split_stack = 0;
-
   /* Whether the -o option was used.  */
   bool saw_opt_o = false;
 
@@ -118,11 +115,6 @@ lang_specific_driver (struct cl_decoded_option **in_decoded_options,
   /* Whether the -S option was used.  */
   bool saw_opt_S = false;
 
-#ifdef TARGET_CAN_SPLIT_STACK_64BIT
-  /* Whether the -m64 option is in force. */
-  bool is_m64 = TARGET_CAN_SPLIT_STACK_64BIT;
-#endif
-
   /* The first input file with an extension of .go.  */
   const char *first_go_file = NULL;
 
@@ -159,16 +151,6 @@ lang_specific_driver (struct cl_decoded_option **in_decoded_options,
 	    library = (library == 0) ? 1 : library;
 	  break;
 
-#ifdef TARGET_CAN_SPLIT_STACK_64BIT
-	case OPT_m32:
-	  is_m64 = false;
-	  break;
-
-	case OPT_m64:
-	  is_m64 = true;
-	  break;
-#endif
-
 	case OPT_pg:
 	case OPT_p:
 	  saw_profile_flag = true;
@@ -253,23 +235,6 @@ lang_specific_driver (struct cl_decoded_option **in_decoded_options,
   /* Copy the 0th argument, i.e., the name of the program itself.  */
   new_decoded_options[j++] = decoded_options[i++];
 
-#ifdef TARGET_CAN_SPLIT_STACK
-  supports_split_stack = 1;
-#endif
-
-#ifdef TARGET_CAN_SPLIT_STACK_64BIT
-  if (is_m64)
-    supports_split_stack = 1;
-#endif
-
-  /* If we are linking, pass -fsplit-stack if it is supported.  */
-  if ((library >= 0) && supports_split_stack)
-    {
-      generate_option (OPT_fsplit_stack, NULL, 1, CL_DRIVER,
-		       &new_decoded_options[j]);
-      j++;
-    }
-
   /* NOTE: We start at 1 now, not 0.  */
   while (i < argc)
     {
@@ -402,18 +367,6 @@ lang_specific_driver (struct cl_decoded_option **in_decoded_options,
     generate_option (OPT_shared_libgcc, NULL, 1, CL_DRIVER,
 		     &new_decoded_options[j++]);
 
-  /* libgcc wraps pthread_create to support split stack, however, due to
-     relative ordering of -lpthread and -lgcc, we can't just mark
-     __real_pthread_create in libgcc as non-weak.  But we need to link in
-     pthread_create from pthread if we are statically linking, so we work-
-     around by passing -u pthread_create to the linker. */
-  if (static_link && supports_split_stack)
-    {
-      generate_option (OPT_Wl_, "-u,pthread_create", 1, CL_DRIVER,
-		       &new_decoded_options[j]);
-      j++;
-    }
-
 #if defined(TARGET_SOLARIS) && !defined(USE_GLD)
   /* We use a common symbol for go$zerovalue.  On Solaris, when not
      using the GNU linker, the Solaris linker needs an option to not