all: Factor gchelper code to one place and use it for unix & ARM ports.

No functionality change is intended with this commit, it just consolidates
the separate implementations of GC helper code to the lib/utils/ directory
as a general set of helper functions useful for any port.  This reduces
duplication of code, and makes it easier for future ports or embedders to
get the GC implementation correct.

Ports should now link against gchelper_native.c and either gchelper_m0.s or
gchelper_m3.s (currently only Cortex-M is supported but other architectures
can follow), or use the fallback gchelper_generic.c which will work on
x86/x64/ARM.

The gc_helper_get_sp function from gchelper_m3.s is not really GC related
and was only used by cc3200, so it has been moved to that port and renamed
to cortex_m3_get_sp.

1 files changed, 3 insertions, 110 deletions

diff --git a/mpy-cross/gccollect.c b/mpy-cross/gccollect.c
index f655a07da..120f1a225 100644
--- a/mpy-cross/gccollect.c
+++ b/mpy-cross/gccollect.c
@@ -29,120 +29,13 @@
 #include "py/mpstate.h"
 #include "py/gc.h"
 
-#if MICROPY_ENABLE_GC
-
-// Even if we have specific support for an architecture, it is
-// possible to force use of setjmp-based implementation.
-#if !MICROPY_GCREGS_SETJMP
-
-// We capture here callee-save registers, i.e. ones which may contain
-// interesting values held there by our callers. It doesn't make sense
-// to capture caller-saved registers, because they, well, put on the
-// stack already by the caller.
-#if defined(__x86_64__)
-typedef mp_uint_t regs_t[6];
-
-STATIC void gc_helper_get_regs(regs_t arr) {
-    register long rbx asm ("rbx");
-    register long rbp asm ("rbp");
-    register long r12 asm ("r12");
-    register long r13 asm ("r13");
-    register long r14 asm ("r14");
-    register long r15 asm ("r15");
-    #ifdef __clang__
-    // TODO:
-    // This is dirty workaround for Clang. It tries to get around
-    // uncompliant (wrt to GCC) behavior of handling register variables.
-    // Application of this patch here is random, and done only to unbreak
-    // MacOS build. Better, cross-arch ways to deal with Clang issues should
-    // be found.
-    asm ("" : "=r" (rbx));
-    asm ("" : "=r" (rbp));
-    asm ("" : "=r" (r12));
-    asm ("" : "=r" (r13));
-    asm ("" : "=r" (r14));
-    asm ("" : "=r" (r15));
-    #endif
-    arr[0] = rbx;
-    arr[1] = rbp;
-    arr[2] = r12;
-    arr[3] = r13;
-    arr[4] = r14;
-    arr[5] = r15;
-}
-
-#elif defined(__i386__)
-
-typedef mp_uint_t regs_t[4];
-
-STATIC void gc_helper_get_regs(regs_t arr) {
-    register long ebx asm ("ebx");
-    register long esi asm ("esi");
-    register long edi asm ("edi");
-    register long ebp asm ("ebp");
-    arr[0] = ebx;
-    arr[1] = esi;
-    arr[2] = edi;
-    arr[3] = ebp;
-}
-
-#elif defined(__thumb2__) || defined(__thumb__) || defined(__arm__)
-
-typedef mp_uint_t regs_t[10];
+#include "lib/utils/gchelper.h"
 
-STATIC void gc_helper_get_regs(regs_t arr) {
-    register long r4 asm ("r4");
-    register long r5 asm ("r5");
-    register long r6 asm ("r6");
-    register long r7 asm ("r7");
-    register long r8 asm ("r8");
-    register long r9 asm ("r9");
-    register long r10 asm ("r10");
-    register long r11 asm ("r11");
-    register long r12 asm ("r12");
-    register long r13 asm ("r13");
-    arr[0] = r4;
-    arr[1] = r5;
-    arr[2] = r6;
-    arr[3] = r7;
-    arr[4] = r8;
-    arr[5] = r9;
-    arr[6] = r10;
-    arr[7] = r11;
-    arr[8] = r12;
-    arr[9] = r13;
-}
-
-#else
-
-// If we don't have architecture-specific optimized support,
-// just fall back to setjmp-based implementation.
-#undef MICROPY_GCREGS_SETJMP
-#define MICROPY_GCREGS_SETJMP (1)
-
-#endif // Arch-specific selection
-#endif // !MICROPY_GCREGS_SETJMP
-
-// If MICROPY_GCREGS_SETJMP was requested explicitly, or if
-// we enabled it as a fallback above.
-#if MICROPY_GCREGS_SETJMP
-#include <setjmp.h>
-
-typedef jmp_buf regs_t;
-
-STATIC void gc_helper_get_regs(regs_t arr) {
-    setjmp(arr);
-}
-
-#endif // MICROPY_GCREGS_SETJMP
+#if MICROPY_ENABLE_GC
 
 void gc_collect(void) {
     gc_collect_start();
-    regs_t regs;
-    gc_helper_get_regs(regs);
-    // GC stack (and regs because we captured them)
-    void **regs_ptr = (void **)(void *)&regs;
-    gc_collect_root(regs_ptr, ((mp_uint_t)MP_STATE_THREAD(stack_top) - (mp_uint_t)&regs) / sizeof(mp_uint_t));
+    gc_helper_collect_regs_and_stack();
     gc_collect_end();
 }