py/asmxtensa: Replace printf messages with exceptions.

This commit removes old raw printf calls happening inside certain branch
opcode emitters, indicating the target label is out of range for the
opcode.  They have been replaced with a RuntimeError being raised in
these cases, using a parameterised qstr instead.

Whilst this technically breaks runtime behaviour expectations, the
generated code would not have worked anyway so it's better to catch
those cases early.  This should be updated to always emit long jumps
unless jumps are backwards and short enough, following the other ports,
but that's something coming later.

This is actually needed because there are test files that do not work
when processed through mpy-cross and entirely converted to native code.
The original implementation would still generate mostly-valid code that
was bound to crash on the device, whilst this change would prevent
invalid code to even be emitted in the first place.

Signed-off-by: Alessandro Gatti <a.gatti@frob.it>

1 files changed, 4 insertions, 2 deletions

diff --git a/py/asmxtensa.c b/py/asmxtensa.c
index 0fbe351dc..41bfcb54e 100644
--- a/py/asmxtensa.c
+++ b/py/asmxtensa.c
@@ -38,6 +38,8 @@
 #define SIGNED_FIT8(x) ((((x) & 0xffffff80) == 0) || (((x) & 0xffffff80) == 0xffffff80))
 #define SIGNED_FIT12(x) ((((x) & 0xfffff800) == 0) || (((x) & 0xfffff800) == 0xfffff800))
 
+#define ET_OUT_OF_RANGE MP_ERROR_TEXT("ERROR: xtensa %q out of range")
+
 void asm_xtensa_end_pass(asm_xtensa_t *as) {
     as->num_const = as->cur_const;
     as->cur_const = 0;
@@ -150,7 +152,7 @@ void asm_xtensa_bccz_reg_label(asm_xtensa_t *as, uint cond, uint reg, uint label
     uint32_t dest = get_label_dest(as, label);
     int32_t rel = dest - as->base.code_offset - 4;
     if (as->base.pass == MP_ASM_PASS_EMIT && !SIGNED_FIT12(rel)) {
-        printf("ERROR: xtensa bccz out of range\n");
+        mp_raise_msg_varg(&mp_type_RuntimeError, ET_OUT_OF_RANGE, MP_QSTR_bccz);
     }
     asm_xtensa_op_bccz(as, cond, reg, rel);
 }
@@ -159,7 +161,7 @@ void asm_xtensa_bcc_reg_reg_label(asm_xtensa_t *as, uint cond, uint reg1, uint r
     uint32_t dest = get_label_dest(as, label);
     int32_t rel = dest - as->base.code_offset - 4;
     if (as->base.pass == MP_ASM_PASS_EMIT && !SIGNED_FIT8(rel)) {
-        printf("ERROR: xtensa bcc out of range\n");
+        mp_raise_msg_varg(&mp_type_RuntimeError, ET_OUT_OF_RANGE, MP_QSTR_bcc);
     }
     asm_xtensa_op_bcc(as, cond, reg1, reg2, rel);
 }