py/emitndebug: Add native debug emitter.

This emitter prints out pseudo-machine instructions, instead of the usual
output of the native emitter.  It can be enabled on any port via
`MICROPY_EMIT_NATIVE_DEBUG` (make sure other native emitters are disabled)
but the easiest way to use it is with mpy-cross:

    $ mpy-cross -march=debug file.py

Signed-off-by: Damien George <[email protected]>

Author: dpgeorge

mpy-cross/main.c

@@ -54,7 +54,7 @@ static void stdout_print_strn(void *env, const char *str, size_t len) {
     (void)dummy;
 }
 
-static const mp_print_t mp_stdout_print = {NULL, stdout_print_strn};
+const mp_print_t mp_stdout_print = {NULL, stdout_print_strn};
 
 static void stderr_print_strn(void *env, const char *str, size_t len) {
     (void)env;
@@ -130,7 +130,7 @@ static int usage(char **argv) {
         "Target specific options:\n"
         "-msmall-int-bits=number : set the maximum bits used to encode a small-int\n"
         "-march=<arch> : set architecture for native emitter;\n"
-        "                x86, x64, armv6, armv6m, armv7m, armv7em, armv7emsp, armv7emdp, xtensa, xtensawin, rv32imc\n"
+        "                x86, x64, armv6, armv6m, armv7m, armv7em, armv7emsp, armv7emdp, xtensa, xtensawin, rv32imc, debug\n"
         "\n"
         "Implementation specific options:\n", argv[0]
         );
@@ -316,6 +316,9 @@ MP_NOINLINE int main_(int argc, char **argv) {
                 } else if (strcmp(arch, "rv32imc") == 0) {
                     mp_dynamic_compiler.native_arch = MP_NATIVE_ARCH_RV32IMC;
                     mp_dynamic_compiler.nlr_buf_num_regs = MICROPY_NLR_NUM_REGS_RV32I;
+                } else if (strcmp(arch, "debug") == 0) {
+                    mp_dynamic_compiler.native_arch = MP_NATIVE_ARCH_DEBUG;
+                    mp_dynamic_compiler.nlr_buf_num_regs = 0;
                 } else if (strcmp(arch, "host") == 0) {
                     #if defined(__i386__) || defined(_M_IX86)
                     mp_dynamic_compiler.native_arch = MP_NATIVE_ARCH_X86;

mpy-cross/mpconfigport.h

@@ -47,6 +47,8 @@
 #define MICROPY_EMIT_INLINE_XTENSA  (1)
 #define MICROPY_EMIT_XTENSAWIN      (1)
 #define MICROPY_EMIT_RV32           (1)
+#define MICROPY_EMIT_NATIVE_DEBUG   (1)
+#define MICROPY_EMIT_NATIVE_DEBUG_PRINTER (&mp_stdout_print)
 
 #define MICROPY_DYNAMIC_COMPILER    (1)
 #define MICROPY_COMP_CONST_FOLDING  (1)
@@ -164,3 +166,5 @@ typedef int ssize_t;
 typedef mp_off_t off_t;
 
 #endif
+
+extern const struct _mp_print_t mp_stdout_print;

py/asmbase.c

@@ -30,6 +30,7 @@
 #include "py/obj.h"
 #include "py/misc.h"
 #include "py/asmbase.h"
+#include "py/persistentcode.h"
 
 #if MICROPY_EMIT_MACHINE_CODE
 
@@ -91,6 +92,11 @@ void mp_asm_base_label_assign(mp_asm_base_t *as, size_t label) {
     } else {
         // ensure label offset has not changed from PASS_COMPUTE to PASS_EMIT
         assert(as->label_offsets[label] == as->code_offset);
+        #if MICROPY_DYNAMIC_COMPILER && MICROPY_EMIT_NATIVE_DEBUG
+        if (mp_dynamic_compiler.native_arch == MP_NATIVE_ARCH_DEBUG) {
+            mp_printf(MICROPY_EMIT_NATIVE_DEBUG_PRINTER, "label(label_%u)\n", (unsigned int)label);
+        }
+        #endif
     }
 }
 

py/compile.c

@@ -103,6 +103,7 @@ static const emit_method_table_t *emit_native_table[] = {
     &emit_native_xtensa_method_table,
     &emit_native_xtensawin_method_table,
     &emit_native_rv32_method_table,
+    &emit_native_debug_method_table,
 };
 
 #elif MICROPY_EMIT_NATIVE
@@ -121,6 +122,8 @@ static const emit_method_table_t *emit_native_table[] = {
 #define NATIVE_EMITTER(f) emit_native_xtensawin_##f
 #elif MICROPY_EMIT_RV32
 #define NATIVE_EMITTER(f) emit_native_rv32_##f
+#elif MICROPY_EMIT_NATIVE_DEBUG
+#define NATIVE_EMITTER(f) emit_native_debug_##f
 #else
 #error "unknown native emitter"
 #endif

py/emit.h

@@ -202,6 +202,7 @@ extern const emit_method_table_t emit_native_arm_method_table;
 extern const emit_method_table_t emit_native_xtensa_method_table;
 extern const emit_method_table_t emit_native_xtensawin_method_table;
 extern const emit_method_table_t emit_native_rv32_method_table;
+extern const emit_method_table_t emit_native_debug_method_table;
 
 extern const mp_emit_method_table_id_ops_t mp_emit_bc_method_table_load_id_ops;
 extern const mp_emit_method_table_id_ops_t mp_emit_bc_method_table_store_id_ops;
@@ -215,6 +216,7 @@ emit_t *emit_native_arm_new(mp_emit_common_t *emit_common, mp_obj_t *error_slot,
 emit_t *emit_native_xtensa_new(mp_emit_common_t *emit_common, mp_obj_t *error_slot, uint *label_slot, mp_uint_t max_num_labels);
 emit_t *emit_native_xtensawin_new(mp_emit_common_t *emit_common, mp_obj_t *error_slot, uint *label_slot, mp_uint_t max_num_labels);
 emit_t *emit_native_rv32_new(mp_emit_common_t *emit_common, mp_obj_t *error_slot, uint *label_slot, mp_uint_t max_num_labels);
+emit_t *emit_native_debug_new(mp_emit_common_t *emit_common, mp_obj_t *error_slot, uint *label_slot, mp_uint_t max_num_labels);
 
 void emit_bc_set_max_num_labels(emit_t *emit, mp_uint_t max_num_labels);
 
@@ -226,6 +228,7 @@ void emit_native_arm_free(emit_t *emit);
 void emit_native_xtensa_free(emit_t *emit);
 void emit_native_xtensawin_free(emit_t *emit);
 void emit_native_rv32_free(emit_t *emit);
+void emit_native_debug_free(emit_t *emit);
 
 void mp_emit_bc_start_pass(emit_t *emit, pass_kind_t pass, scope_t *scope);
 bool mp_emit_bc_end_pass(emit_t *emit);

py/emitnative.c

@@ -59,7 +59,7 @@
 #endif
 
 // wrapper around everything in this file
-#if N_X64 || N_X86 || N_THUMB || N_ARM || N_XTENSA || N_XTENSAWIN || N_RV32
+#if N_X64 || N_X86 || N_THUMB || N_ARM || N_XTENSA || N_XTENSAWIN || N_RV32 || N_DEBUG
 
 // C stack layout for native functions:
 //  0:                          nlr_buf_t [optional]
@@ -348,6 +348,8 @@ static void emit_native_mov_reg_state_addr(emit_t *emit, int reg_dest, int local
 static void emit_native_mov_reg_qstr(emit_t *emit, int arg_reg, qstr qst) {
     #if MICROPY_PERSISTENT_CODE_SAVE
     ASM_LOAD16_REG_REG_OFFSET(emit->as, arg_reg, REG_QSTR_TABLE, mp_emit_common_use_qstr(emit->emit_common, qst));
+    #elif defined(ASM_MOV_REG_QSTR)
+    ASM_MOV_REG_QSTR(emit->as, arg_reg, qst);
     #else
     ASM_MOV_REG_IMM(emit->as, arg_reg, qst);
     #endif
@@ -2604,6 +2606,8 @@ static void emit_native_binary_op(emit_t *emit, mp_binary_op_t op) {
                 default:
                     break;
             }
+            #elif N_DEBUG
+            asm_debug_setcc_reg_reg_reg(emit->as, op_idx, REG_RET, REG_ARG_2, reg_rhs);
             #else
             #error not implemented
             #endif