[gcc r12-5704] d: Disable the D runtime garbage collector after initializing (PR103520)

[gcc r12-5704] d: Disable the D runtime garbage collector after initializing (PR103520)

[Iain Buclaw]

https://gcc.gnu.org/g:fa10faa72d8e9e97b6e564f8b0a7b602538d0da0

commit r12-5704-gfa10faa72d8e9e97b6e564f8b0a7b602538d0da0
Author: Iain Buclaw <ibuclaw@gdcproject.org>
Date:   Wed Dec 1 23:56:28 2021 +0100

    d: Disable the D runtime garbage collector after initializing (PR103520)
    
    Not all targets that support building libdruntime have a stable garbage
    collector, so to avoid running into problems where live memory allocated
    by the D GC is freed, disable all in-flight collections until a time
    when scanning is more reliably implemented everywhere.
    
            PR d/103520
    
    gcc/d/ChangeLog:
    
            * d-frontend.h (gc_disable): Declare.
            * d-lang.cc (d_init_options): Disable the D runtime garbage collector
            after initializing.

Diff:
---
 gcc/d/d-frontend.h | 2 +-
 gcc/d/d-lang.cc    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/gcc/d/d-frontend.h b/gcc/d/d-frontend.h
index 3edf812212a..e7695d5718b 100644
--- a/gcc/d/d-frontend.h
+++ b/gcc/d/d-frontend.h
@@ -21,7 +21,7 @@ along with GCC; see the file COPYING3.  If not see
 /* These functions are defined in D runtime.  */
 extern "C" int rt_init (void);
 extern "C" int rt_term (void);
-//extern "C" void gc_disable (void);
+extern "C" void gc_disable (void);
 extern "C" void *gc_malloc (size_t sz, unsigned ba = 0, const void *ti = NULL);
 extern "C" void gc_free (void *);
 extern "C" void gc_collect (void);
diff --git a/gcc/d/d-lang.cc b/gcc/d/d-lang.cc
index d20370e5d8a..dbf7a8b60b9 100644
--- a/gcc/d/d-lang.cc
+++ b/gcc/d/d-lang.cc
@@ -288,7 +288,7 @@ d_init_options (unsigned int, cl_decoded_option *decoded_options)
 {
   /* Initialize the D runtime.  */
   rt_init ();
-//  gc_disable ();
+  gc_disable ();
 
   /* Set default values.  */
   global._init ();