Add support for emscripten platform

5 files changed, 30 insertions, 2 deletions

diff --git a/alloc.c b/alloc.c
index 25bb31ea..d8fb954f 100644
--- a/alloc.c
+++ b/alloc.c
@@ -202,11 +202,15 @@ GC_API GC_stop_func GC_CALL GC_get_stop_func(void)
 static word min_bytes_allocd(void)
 {
     word result;
-#   ifdef STACK_GROWS_UP
+#   ifdef __EMSCRIPTEN__
+      word stack_size = 0;
+#   else 
+#     ifdef STACK_GROWS_UP
       word stack_size = GC_approx_sp() - GC_stackbottom;
             /* GC_stackbottom is used only for a single-threaded case.  */
-#   else
+#     else
       word stack_size = GC_stackbottom - GC_approx_sp();
+#     endif
 #   endif
 
     word total_root_size;       /* includes double stack size,  */
diff --git a/include/private/gcconfig.h b/include/private/gcconfig.h
index 7d0fc0df..4eed1842 100644
--- a/include/private/gcconfig.h
+++ b/include/private/gcconfig.h
@@ -558,6 +558,12 @@
 #   define mach_type_known
 # endif
 
+# if defined(__EMSCRIPTEN__)
+#   define I386
+#   define ALIGNMENT 4
+#   define mach_type_known
+# endif
+
 /* Feel free to add more clauses here */
 
 /* Or manually define the machine type here.  A machine type is         */
@@ -754,6 +760,14 @@
 #   define DATAEND NULL
 # endif
 
+# ifdef __EMSCRIPTEN__
+#   define OS_TYPE "EMSCRIPTEN"
+#   define CPP_WORDSZ 32
+#   define ALIGNMENT 4
+#   define DATASTART NULL
+#   define DATAEND NULL
+# endif
+
 # define STACK_GRAN 0x1000000
 # ifdef M68K
 #   define MACH_TYPE "M68K"
diff --git a/mach_dep.c b/mach_dep.c
index 9c95e698..a882c76d 100644
--- a/mach_dep.c
+++ b/mach_dep.c
@@ -181,6 +181,11 @@
       }
 #     define HAVE_PUSH_REGS
 #   endif /* __MWERKS__ */
+# elif defined(EMSCRIPTEN)
+      void GC_push_regs(void)
+      {
+      }
+#     define HAVE_PUSH_REGS
 # endif /* MACOS */
 
 #endif /* !USE_ASM_PUSH_REGS */
diff --git a/mark_rts.c b/mark_rts.c
index a8dc04a2..53341586 100644
--- a/mark_rts.c
+++ b/mark_rts.c
@@ -810,7 +810,9 @@ GC_INNER void GC_push_roots(GC_bool all, ptr_t cold_gc_frame)
      * This is usually done by saving the current context on the
      * stack, and then just tracing from the stack.
      */
+#ifndef __EMSCRIPTEN__
       GC_push_regs_and_stack(cold_gc_frame);
+#endif
 
     if (GC_push_other_roots != 0) (*GC_push_other_roots)();
         /* In the threads case, this also pushes thread stacks. */
diff --git a/misc.c b/misc.c
index 68667eef..526eb989 100644
--- a/misc.c
+++ b/misc.c
@@ -349,6 +349,9 @@ GC_INNER void GC_extend_size_map(size_t i)
 /* another frame.                                                       */
 GC_API void * GC_CALL GC_clear_stack(void *arg)
 {
+#ifdef __EMSCRIPTEN__
+    return arg;
+#endif
     ptr_t sp = GC_approx_sp();  /* Hotter than actual sp */
 #   ifdef THREADS
         word volatile dummy[SMALL_CLEAR_SIZE];