1 files changed, 117 insertions, 0 deletions
diff --git a/uscript/us_debug.c b/uscript/us_debug.c
new file mode 100644
index 0000000..8d5dfe3
--- /dev/null
+++ b/uscript/us_debug.c
@@ -0,0 +1,117 @@
+#include "us_debug.h"
+
+#include <assert.h>
+
+#include "dyn_arr.h"
+#include "vm.h"
+
+static
+char *bc_names[] = {
+#define BC(name) "BC_" #name,
+#include "xbytecode.h"
+#undef BC
+};
+
+int print_instruction(struct us_proto *proto, int idx)
+{
+        enum bytecode instruction = proto->bytecode[idx];
+        fprintf(stderr, "%04d %-15s ", idx, bc_names[instruction]);
+        switch (instruction) {
+        case BC_LOAD: {
+                int const_idx = proto->bytecode[idx + 1];
+                char *const_str = val_to_str(proto->constants[const_idx], NULL);
+                fprintf(
+                        stderr,
+                        "%d (%s)\n",
+                        const_idx,
+                        const_str
+                );
+                mem_free(const_str);
+                return idx + 2;
+        }
+        case BC_LOAD_FUNC: {
+                int const_idx = proto->bytecode[idx + 1];
+                assert(proto->constants[const_idx].type == VAL_PROTO);
+                struct us_proto *p = get_proto(proto->constants[const_idx]);
+                int upvalc = p->upvalc;
+                fprintf(
+                        stderr,
+                        "%.*s() %d\n",
+                        (int)p->name->len, p->name->chars,
+                        upvalc
+                );
+                return idx + 2 + upvalc * 2;
+        }
+        case BC_SET_UPVAL:
+        case BC_GET_UPVAL:
+        case BC_SET_LOCAL:
+        case BC_GET_LOCAL: {
+                int local_idx = proto->bytecode[idx + 1];
+                fprintf(
+                        stderr,
+                        "%d\n",
+                        local_idx
+                );
+                return idx + 2;
+        }
+        case BC_CALL:
+        case BC_SMALL_INT: {
+                fprintf(
+                        stderr,
+                        "%d\n",
+                        proto->bytecode[idx + 1]
+                );
+                return idx + 2;
+        }
+        case BC_JMP:
+        case BC_LOOP:
+        case BC_FALSEY_JMP: {
+                u16 jmp = (u16)(proto->bytecode[idx + 1] << 8) | proto->bytecode[idx + 2];
+                int dst = idx + jmp + 3;
+                if (instruction == BC_LOOP) {
+                        dst = idx + 3 - jmp;
+                }
+                fprintf(
+                        stderr,
+                        "-> %04d\n",
+                        dst
+                );
+                return idx + 3;
+        }
+        case BC_PRINT:
+        case BC_TRUE:
+        case BC_FALSE:
+        case BC_ZILCH:
+        case BC_POP:
+        case BC_POP_UPVAL:
+        case BC_ADD:
+        case BC_SUB:
+        case BC_MULT:
+        case BC_DIV:
+        case BC_MOD:
+        case BC_NEG:
+        case BC_NOT:
+        case BC_CONCAT:
+        case BC_EQL:
+        case BC_NEQL:
+        case BC_GT:
+        case BC_LT:
+        case BC_GTE:
+        case BC_LTE:
+        case BC_RET:
+                putc('\n', stderr);
+                return idx + 1;
+        }
+
+        // unreachable
+        return idx + 1;
+}
+
+void print_func(struct us_proto *func)
+{
+        fprintf(stderr, "%s():\n", func->name->chars);
+        for (int i = 0; i < da_len(func->bytecode);) {
+                putc('\t', stderr);
+                i = print_instruction(func, i);
+        }
+}