mie: pass: add a group of builtin passes

right now, the group only contains a single pass: prefix-func-with-underscore.
this is a test pass that visits instances of func.func and prepends
an underscore to the func's symbol name.

mie/include/mie/pass/builtin.h

@@ -0,0 +1,10 @@
+#ifndef MIE_PASS_BUILTIN_H_
+#define MIE_PASS_BUILTIN_H_
+
+#include <mie/misc.h>
+
+struct mie_ctx;
+
+MIE_API enum mie_status mie_builtin_passes_register(struct mie_ctx *);
+
+#endif

mie/pass/builtin/builtin.c

@@ -0,0 +1,7 @@
+#include <mie/ctx.h>
+#include <mie/macros.h>
+#include <mie/pass/pass-definition.h>
+
+MIE_PASS_GROUP_BEGIN(mie_builtin)
+	MIE_PASS_GROUP_ADD_PASS(prefix_func_with_underscore);
+MIE_PASS_GROUP_END()

mie/pass/builtin/prefix-func-with-underscore.c

@@ -0,0 +1,35 @@
+#include <mie/ctx.h>
+#include <mie/dialect/builtin.h>
+#include <mie/ir/op.h>
+#include <mie/macros.h>
+#include <mie/pass/pass-definition.h>
+#include <mie/pass/pass.h>
+
+static struct mie_pass_result transform(
+	struct mie_pass *pass, struct mie_op *op, struct mie_pass_args *args)
+{
+	const struct mie_attribute *sym_name_attr
+		= mie_attribute_map_get(&op->op_attrib, "sym_name");
+	const char *sym_name = mie_string_get_cstr(sym_name_attr);
+
+	char tmp[256];
+	snprintf(tmp, sizeof tmp, "_%s", sym_name);
+	const struct mie_attribute *new_name
+		= mie_ctx_get_string(args->p_ctx, tmp);
+
+	mie_attribute_map_put(
+		&op->op_attrib, "sym_name", new_name, MIE_ATTRMAP_F_REPLACE);
+
+	printf("%s: taking a look at @%s\n", mie_pass_get_name(pass), sym_name);
+
+	return MIE_PASS_CONTINUE;
+}
+
+MIE_PASS_DEFINITION_BEGIN(prefix_func_with_underscore)
+	MIE_PASS_NAME("prefix-func-with-underscore");
+	MIE_PASS_DESCRIPTION(
+		"Test pass that prefixes the identifier of every function with "
+		"an underscore.");
+	MIE_PASS_TRANSFORM(transform);
+	MIE_PASS_FILTER_OP("func", "func");
+MIE_PASS_DEFINITION_END()