py: Add compile option to enable/disable source line numbers.

py/emitbc.c

@@ -249,6 +249,7 @@ static void emit_bc_set_stack_size(emit_t *emit, int size) {
 
 static void emit_bc_set_source_line(emit_t *emit, int source_line) {
     //printf("source: line %d -> %d  offset %d -> %d\n", emit->last_source_line, source_line, emit->last_source_line_offset, emit->byte_code_offset);
+#if MICROPY_ENABLE_SOURCE_LINE
     if (source_line > emit->last_source_line) {
         uint bytes_to_skip = emit->byte_code_offset - emit->last_source_line_offset;
         uint lines_to_skip = source_line - emit->last_source_line;
@@ -257,6 +258,7 @@ static void emit_bc_set_source_line(emit_t *emit, int source_line) {
         emit->last_source_line_offset = emit->byte_code_offset;
         emit->last_source_line = source_line;
     }
+#endif
 }
 
 static void emit_bc_load_id(emit_t *emit, qstr qstr) {

py/mpconfig.h

@@ -76,6 +76,12 @@
 typedef long long mp_longint_impl_t;
 #endif
 
+// Whether to include information in the byte code to determine source
+// line number (increases RAM usage, but doesn't slow byte code execution)
+#ifndef MICROPY_ENABLE_SOURCE_LINE
+#define MICROPY_ENABLE_SOURCE_LINE (0)
+#endif
+
 // Whether to support float and complex types
 #ifndef MICROPY_ENABLE_FLOAT
 #define MICROPY_ENABLE_FLOAT (0)

py/obj.c

@@ -57,7 +57,11 @@ void mp_obj_print_exception(mp_obj_t exc) {
         if (n > 0) {
             printf("Traceback (most recent call last):\n");
             for (int i = n - 3; i >= 0; i -= 3) {
+#if MICROPY_ENABLE_SOURCE_LINE
                 printf("  File \"%s\", line %d, in %s\n", qstr_str(values[i]), (int)values[i + 1], qstr_str(values[i + 2]));
+#else
+                printf("  File \"%s\", in %s\n", qstr_str(values[i]), qstr_str(values[i + 2]));
+#endif
             }
         }
     }

unix/mpconfigport.h

@@ -12,6 +12,7 @@
 #define MICROPY_DEBUG_PRINTERS      (1)
 #define MICROPY_ENABLE_REPL_HELPERS (1)
 #define MICROPY_ENABLE_LEXER_UNIX   (1)
+#define MICROPY_ENABLE_SOURCE_LINE  (1)
 #define MICROPY_ENABLE_FLOAT        (1)
 #define MICROPY_LONGINT_IMPL        (MICROPY_LONGINT_IMPL_LONGLONG)