X-Git-Url: https://sigrok.org/gitweb/?p=libsigrokdecode.git;a=blobdiff_plain;f=decoder.c;h=21b756ba370620bf99db2aefb8a31f0f7f9c6b10;hp=b5909168fec43b15528a1510ecc3d87eb750b9f2;hb=25d3576134e7b57ca169e8e4ebd4e4ce5dcf62dd;hpb=159699490ea4bf2495e99dcd5fb18b240d7499df

diff --git a/decoder.c b/decoder.c
index b590916..21b756b 100644
--- a/decoder.c
+++ b/decoder.c
@@ -1,8 +1,8 @@
 /*
- * This file is part of the sigrok project.
+ * This file is part of the libsigrokdecode project.
  *
  * Copyright (C) 2010 Uwe Hermann <uwe@hermann-uwe.de>
- * Copyright (C) 2011 Bert Vermeulen <bert@biot.com>
+ * Copyright (C) 2012 Bert Vermeulen <bert@biot.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -18,42 +18,80 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "config.h"
-#include "sigrokdecode.h" /* First, so we avoid a _POSIX_C_SOURCE warning. */
-#include "sigrokdecode-internal.h"
-#include <dirent.h>
+#include <config.h>
+#include "libsigrokdecode-internal.h" /* First, so we avoid a _POSIX_C_SOURCE warning. */
+#include "libsigrokdecode.h"
+#include <glib.h>
 
-/* The list of protocol decoders. */
-GSList *pd_list = NULL;
-GSList *di_list = NULL;
+/**
+ * @file
+ *
+ * Listing, loading, unloading, and handling protocol decoders.
+ */
+
+/**
+ * @defgroup grp_decoder Protocol decoders
+ *
+ * Handling protocol decoders.
+ *
+ * @{
+ */
+
+/** @cond PRIVATE */
+
+/* The list of loaded protocol decoders. */
+static GSList *pd_list = NULL;
 
+/* srd.c */
+extern SRD_PRIV GSList *searchpaths;
+
+/* session.c */
+extern SRD_PRIV GSList *sessions;
+extern SRD_PRIV int max_session_id;
+
+/* module_sigrokdecode.c */
+extern SRD_PRIV PyObject *mod_sigrokdecode;
+
+/** @endcond */
+
+static gboolean srd_check_init(void)
+{
+	if (max_session_id < 0) {
+		srd_err("Library is not initialized.");
+		return FALSE;
+	} else
+		return TRUE;
+}
 
 /**
- * Returns the list of supported/loaded protocol decoders.
+ * Returns the list of loaded protocol decoders.
  *
- * This is a GSList containing the names of the decoders as strings.
+ * This is a GSList of pointers to struct srd_decoder items.
  *
  * @return List of decoders, NULL if none are supported or loaded.
+ *
+ * @since 0.2.0
  */
-GSList *srd_list_decoders(void)
+SRD_API const GSList *srd_decoder_list(void)
 {
-
 	return pd_list;
 }
 
-
 /**
  * Get the decoder with the specified ID.
  *
  * @param id The ID string of the decoder to return.
+ *
  * @return The decoder with the specified ID, or NULL if not found.
+ *
+ * @since 0.1.0
  */
-struct srd_decoder *srd_get_decoder_by_id(const char *id)
+SRD_API struct srd_decoder *srd_decoder_get_by_id(const char *id)
 {
 	GSList *l;
 	struct srd_decoder *dec;
 
-	for (l = srd_list_decoders(); l; l = l->next) {
+	for (l = pd_list; l; l = l->next) {
 		dec = l->data;
 		if (!strcmp(dec->id, id))
 			return dec;
@@ -62,186 +100,984 @@ struct srd_decoder *srd_get_decoder_by_id(const char *id)
 	return NULL;
 }
 
+static void channel_free(void *data)
+{
+	struct srd_channel *ch = data;
+
+	if (!ch)
+		return;
+
+	g_free(ch->desc);
+	g_free(ch->name);
+	g_free(ch->id);
+	g_free(ch);
+}
+
+static void variant_free(void *data)
+{
+	GVariant *var = data;
+
+	if (!var)
+		return;
+
+	g_variant_unref(var);
+}
+
+static void annotation_row_free(void *data)
+{
+	struct srd_decoder_annotation_row *row = data;
+
+	if (!row)
+		return;
+
+	g_slist_free(row->ann_classes);
+	g_free(row->desc);
+	g_free(row->id);
+	g_free(row);
+}
+
+static void decoder_option_free(void *data)
+{
+	struct srd_decoder_option *opt = data;
+
+	if (!opt)
+		return;
+
+	g_slist_free_full(opt->values, &variant_free);
+	variant_free(opt->def);
+	g_free(opt->desc);
+	g_free(opt->id);
+	g_free(opt);
+}
+
+static void decoder_free(struct srd_decoder *dec)
+{
+	PyGILState_STATE gstate;
+
+	if (!dec)
+		return;
+
+	gstate = PyGILState_Ensure();
+	Py_XDECREF(dec->py_dec);
+	Py_XDECREF(dec->py_mod);
+	PyGILState_Release(gstate);
+
+	g_slist_free_full(dec->options, &decoder_option_free);
+	g_slist_free_full(dec->binary, (GDestroyNotify)&g_strfreev);
+	g_slist_free_full(dec->annotation_rows, &annotation_row_free);
+	g_slist_free_full(dec->annotations, (GDestroyNotify)&g_strfreev);
+	g_slist_free_full(dec->opt_channels, &channel_free);
+	g_slist_free_full(dec->channels, &channel_free);
+
+	g_slist_free_full(dec->outputs, g_free);
+	g_slist_free_full(dec->inputs, g_free);
+	g_free(dec->license);
+	g_free(dec->desc);
+	g_free(dec->longname);
+	g_free(dec->name);
+	g_free(dec->id);
+
+	g_free(dec);
+}
+
+static int get_channels(const struct srd_decoder *d, const char *attr,
+		GSList **out_pdchl, int offset)
+{
+	PyObject *py_channellist, *py_entry;
+	struct srd_channel *pdch;
+	GSList *pdchl;
+	ssize_t i;
+	PyGILState_STATE gstate;
+
+	gstate = PyGILState_Ensure();
+
+	if (!PyObject_HasAttrString(d->py_dec, attr)) {
+		/* No channels of this type specified. */
+		PyGILState_Release(gstate);
+		return SRD_OK;
+	}
+
+	pdchl = NULL;
+
+	py_channellist = PyObject_GetAttrString(d->py_dec, attr);
+	if (!py_channellist)
+		goto except_out;
+
+	if (!PyTuple_Check(py_channellist)) {
+		srd_err("Protocol decoder %s %s attribute is not a tuple.",
+			d->name, attr);
+		goto err_out;
+	}
+
+	for (i = PyTuple_Size(py_channellist) - 1; i >= 0; i--) {
+		py_entry = PyTuple_GetItem(py_channellist, i);
+		if (!py_entry)
+			goto except_out;
+
+		if (!PyDict_Check(py_entry)) {
+			srd_err("Protocol decoder %s %s attribute is not "
+				"a list of dict elements.", d->name, attr);
+			goto err_out;
+		}
+		pdch = g_malloc(sizeof(struct srd_channel));
+		/* Add to list right away so it doesn't get lost. */
+		pdchl = g_slist_prepend(pdchl, pdch);
+
+		if (py_dictitem_as_str(py_entry, "id", &pdch->id) != SRD_OK)
+			goto err_out;
+		if (py_dictitem_as_str(py_entry, "name", &pdch->name) != SRD_OK)
+			goto err_out;
+		if (py_dictitem_as_str(py_entry, "desc", &pdch->desc) != SRD_OK)
+			goto err_out;
+
+		pdch->order = offset + i;
+	}
+
+	Py_DECREF(py_channellist);
+	*out_pdchl = pdchl;
+
+	PyGILState_Release(gstate);
+
+	return SRD_OK;
+
+except_out:
+	srd_exception_catch("Failed to get %s list of %s decoder",
+			attr, d->name);
+err_out:
+	g_slist_free_full(pdchl, &channel_free);
+	Py_XDECREF(py_channellist);
+	PyGILState_Release(gstate);
+
+	return SRD_ERR_PYTHON;
+}
+
+static int get_options(struct srd_decoder *d)
+{
+	PyObject *py_opts, *py_opt, *py_str, *py_values, *py_default, *py_item;
+	GSList *options;
+	struct srd_decoder_option *o;
+	GVariant *gvar;
+	ssize_t opt, i;
+	PyGILState_STATE gstate;
+
+	gstate = PyGILState_Ensure();
+
+	if (!PyObject_HasAttrString(d->py_dec, "options")) {
+		/* No options, that's fine. */
+		PyGILState_Release(gstate);
+		return SRD_OK;
+	}
+
+	options = NULL;
+
+	/* If present, options must be a tuple. */
+	py_opts = PyObject_GetAttrString(d->py_dec, "options");
+	if (!py_opts)
+		goto except_out;
+
+	if (!PyTuple_Check(py_opts)) {
+		srd_err("Protocol decoder %s: options attribute is not "
+				"a tuple.", d->id);
+		goto err_out;
+	}
+
+	for (opt = PyTuple_Size(py_opts) - 1; opt >= 0; opt--) {
+		py_opt = PyTuple_GetItem(py_opts, opt);
+		if (!py_opt)
+			goto except_out;
+
+		if (!PyDict_Check(py_opt)) {
+			srd_err("Protocol decoder %s options: each option "
+					"must consist of a dictionary.", d->name);
+			goto err_out;
+		}
+
+		o = g_malloc0(sizeof(struct srd_decoder_option));
+		/* Add to list right away so it doesn't get lost. */
+		options = g_slist_prepend(options, o);
+
+		py_str = PyDict_GetItemString(py_opt, "id");
+		if (!py_str) {
+			srd_err("Protocol decoder %s option %zd has no ID.",
+				d->name, opt);
+			goto err_out;
+		}
+		if (py_str_as_str(py_str, &o->id) != SRD_OK)
+			goto err_out;
+
+		py_str = PyDict_GetItemString(py_opt, "desc");
+		if (py_str) {
+			if (py_str_as_str(py_str, &o->desc) != SRD_OK)
+				goto err_out;
+		}
+
+		py_default = PyDict_GetItemString(py_opt, "default");
+		if (py_default) {
+			gvar = py_obj_to_variant(py_default);
+			if (!gvar) {
+				srd_err("Protocol decoder %s option 'default' has "
+					"invalid default value.", d->name);
+				goto err_out;
+			}
+			o->def = g_variant_ref_sink(gvar);
+		}
+
+		py_values = PyDict_GetItemString(py_opt, "values");
+		if (py_values) {
+			/* A default is required if a list of values is
+			 * given, since it's used to verify their type. */
+			if (!o->def) {
+				srd_err("No default for option '%s'.", o->id);
+				goto err_out;
+			}
+			if (!PyTuple_Check(py_values)) {
+				srd_err("Option '%s' values should be a tuple.", o->id);
+				goto err_out;
+			}
+
+			for (i = PyTuple_Size(py_values) - 1; i >= 0; i--) {
+				py_item = PyTuple_GetItem(py_values, i);
+				if (!py_item)
+					goto except_out;
+
+				if (Py_TYPE(py_default) != Py_TYPE(py_item)) {
+					srd_err("All values for option '%s' must be "
+						"of the same type as the default.",
+						o->id);
+					goto err_out;
+				}
+				gvar = py_obj_to_variant(py_item);
+				if (!gvar) {
+					srd_err("Protocol decoder %s option 'values' "
+						"contains invalid value.", d->name);
+					goto err_out;
+				}
+				o->values = g_slist_prepend(o->values,
+						g_variant_ref_sink(gvar));
+			}
+		}
+	}
+	d->options = options;
+	Py_DECREF(py_opts);
+	PyGILState_Release(gstate);
+
+	return SRD_OK;
+
+except_out:
+	srd_exception_catch("Failed to get %s decoder options", d->name);
+err_out:
+	g_slist_free_full(options, &decoder_option_free);
+	Py_XDECREF(py_opts);
+	PyGILState_Release(gstate);
+
+	return SRD_ERR_PYTHON;
+}
+
+/* Convert annotation class attribute to GSList of char **.
+ */
+static int get_annotations(struct srd_decoder *dec)
+{
+	PyObject *py_annlist, *py_ann;
+	GSList *annotations;
+	char **annpair;
+	ssize_t i;
+	PyGILState_STATE gstate;
+
+	gstate = PyGILState_Ensure();
+
+	if (!PyObject_HasAttrString(dec->py_dec, "annotations")) {
+		PyGILState_Release(gstate);
+		return SRD_OK;
+	}
+
+	annotations = NULL;
+
+	py_annlist = PyObject_GetAttrString(dec->py_dec, "annotations");
+	if (!py_annlist)
+		goto except_out;
+
+	if (!PyTuple_Check(py_annlist)) {
+		srd_err("Protocol decoder %s annotations should "
+			"be a tuple.", dec->name);
+		goto err_out;
+	}
+
+	for (i = PyTuple_Size(py_annlist) - 1; i >= 0; i--) {
+		py_ann = PyTuple_GetItem(py_annlist, i);
+		if (!py_ann)
+			goto except_out;
+
+		if (!PyTuple_Check(py_ann) || PyTuple_Size(py_ann) != 2) {
+			srd_err("Protocol decoder %s annotation %zd should "
+				"be a tuple with two elements.",
+				dec->name, i + 1);
+			goto err_out;
+		}
+		if (py_strseq_to_char(py_ann, &annpair) != SRD_OK)
+			goto err_out;
+
+		annotations = g_slist_prepend(annotations, annpair);
+	}
+	dec->annotations = annotations;
+	Py_DECREF(py_annlist);
+	PyGILState_Release(gstate);
+
+	return SRD_OK;
+
+except_out:
+	srd_exception_catch("Failed to get %s decoder annotations", dec->name);
+err_out:
+	g_slist_free_full(annotations, (GDestroyNotify)&g_strfreev);
+	Py_XDECREF(py_annlist);
+	PyGILState_Release(gstate);
+
+	return SRD_ERR_PYTHON;
+}
+
+/* Convert annotation_rows to GSList of 'struct srd_decoder_annotation_row'.
+ */
+static int get_annotation_rows(struct srd_decoder *dec)
+{
+	PyObject *py_ann_rows, *py_ann_row, *py_ann_classes, *py_item;
+	GSList *annotation_rows;
+	struct srd_decoder_annotation_row *ann_row;
+	ssize_t i, k;
+	size_t class_idx;
+	PyGILState_STATE gstate;
+
+	gstate = PyGILState_Ensure();
+
+	if (!PyObject_HasAttrString(dec->py_dec, "annotation_rows")) {
+		PyGILState_Release(gstate);
+		return SRD_OK;
+	}
+
+	annotation_rows = NULL;
+
+	py_ann_rows = PyObject_GetAttrString(dec->py_dec, "annotation_rows");
+	if (!py_ann_rows)
+		goto except_out;
+
+	if (!PyTuple_Check(py_ann_rows)) {
+		srd_err("Protocol decoder %s annotation_rows "
+			"must be a tuple.", dec->name);
+		goto err_out;
+	}
+
+	for (i = PyTuple_Size(py_ann_rows) - 1; i >= 0; i--) {
+		py_ann_row = PyTuple_GetItem(py_ann_rows, i);
+		if (!py_ann_row)
+			goto except_out;
+
+		if (!PyTuple_Check(py_ann_row) || PyTuple_Size(py_ann_row) != 3) {
+			srd_err("Protocol decoder %s annotation_rows "
+				"must contain only tuples of 3 elements.",
+				dec->name);
+			goto err_out;
+		}
+		ann_row = g_malloc0(sizeof(struct srd_decoder_annotation_row));
+		/* Add to list right away so it doesn't get lost. */
+		annotation_rows = g_slist_prepend(annotation_rows, ann_row);
+
+		py_item = PyTuple_GetItem(py_ann_row, 0);
+		if (!py_item)
+			goto except_out;
+		if (py_str_as_str(py_item, &ann_row->id) != SRD_OK)
+			goto err_out;
+
+		py_item = PyTuple_GetItem(py_ann_row, 1);
+		if (!py_item)
+			goto except_out;
+		if (py_str_as_str(py_item, &ann_row->desc) != SRD_OK)
+			goto err_out;
+
+		py_ann_classes = PyTuple_GetItem(py_ann_row, 2);
+		if (!py_ann_classes)
+			goto except_out;
+
+		if (!PyTuple_Check(py_ann_classes)) {
+			srd_err("Protocol decoder %s annotation_rows tuples "
+				"must have a tuple of numbers as 3rd element.",
+				dec->name);
+			goto err_out;
+		}
+
+		for (k = PyTuple_Size(py_ann_classes) - 1; k >= 0; k--) {
+			py_item = PyTuple_GetItem(py_ann_classes, k);
+			if (!py_item)
+				goto except_out;
+
+			if (!PyLong_Check(py_item)) {
+				srd_err("Protocol decoder %s annotation row "
+					"class tuple must only contain numbers.",
+					dec->name);
+				goto err_out;
+			}
+			class_idx = PyLong_AsSize_t(py_item);
+			if (PyErr_Occurred())
+				goto except_out;
+
+			ann_row->ann_classes = g_slist_prepend(ann_row->ann_classes,
+					GSIZE_TO_POINTER(class_idx));
+		}
+	}
+	dec->annotation_rows = annotation_rows;
+	Py_DECREF(py_ann_rows);
+	PyGILState_Release(gstate);
+
+	return SRD_OK;
+
+except_out:
+	srd_exception_catch("Failed to get %s decoder annotation rows",
+			dec->name);
+err_out:
+	g_slist_free_full(annotation_rows, &annotation_row_free);
+	Py_XDECREF(py_ann_rows);
+	PyGILState_Release(gstate);
+
+	return SRD_ERR_PYTHON;
+}
+
+/* Convert binary classes to GSList of char **.
+ */
+static int get_binary_classes(struct srd_decoder *dec)
+{
+	PyObject *py_bin_classes, *py_bin_class;
+	GSList *bin_classes;
+	char **bin;
+	ssize_t i;
+	PyGILState_STATE gstate;
+
+	gstate = PyGILState_Ensure();
+
+	if (!PyObject_HasAttrString(dec->py_dec, "binary")) {
+		PyGILState_Release(gstate);
+		return SRD_OK;
+	}
+
+	bin_classes = NULL;
+
+	py_bin_classes = PyObject_GetAttrString(dec->py_dec, "binary");
+	if (!py_bin_classes)
+		goto except_out;
+
+	if (!PyTuple_Check(py_bin_classes)) {
+		srd_err("Protocol decoder %s binary classes should "
+			"be a tuple.", dec->name);
+		goto err_out;
+	}
+
+	for (i = PyTuple_Size(py_bin_classes) - 1; i >= 0; i--) {
+		py_bin_class = PyTuple_GetItem(py_bin_classes, i);
+		if (!py_bin_class)
+			goto except_out;
+
+		if (!PyTuple_Check(py_bin_class)
+				|| PyTuple_Size(py_bin_class) != 2) {
+			srd_err("Protocol decoder %s binary classes should "
+				"consist only of tuples of 2 elements.",
+				dec->name);
+			goto err_out;
+		}
+		if (py_strseq_to_char(py_bin_class, &bin) != SRD_OK)
+			goto err_out;
+
+		bin_classes = g_slist_prepend(bin_classes, bin);
+	}
+	dec->binary = bin_classes;
+	Py_DECREF(py_bin_classes);
+	PyGILState_Release(gstate);
+
+	return SRD_OK;
+
+except_out:
+	srd_exception_catch("Failed to get %s decoder binary classes",
+			dec->name);
+err_out:
+	g_slist_free_full(bin_classes, (GDestroyNotify)&g_strfreev);
+	Py_XDECREF(py_bin_classes);
+	PyGILState_Release(gstate);
+
+	return SRD_ERR_PYTHON;
+}
+
+/* Check whether the Decoder class defines the named method.
+ */
+static int check_method(PyObject *py_dec, const char *mod_name,
+		const char *method_name)
+{
+	PyObject *py_method;
+	int is_callable;
+	PyGILState_STATE gstate;
+
+	gstate = PyGILState_Ensure();
+
+	py_method = PyObject_GetAttrString(py_dec, method_name);
+	if (!py_method) {
+		srd_exception_catch("Protocol decoder %s Decoder class "
+				"has no %s() method", mod_name, method_name);
+		PyGILState_Release(gstate);
+		return SRD_ERR_PYTHON;
+	}
+
+	is_callable = PyCallable_Check(py_method);
+	Py_DECREF(py_method);
+
+	PyGILState_Release(gstate);
+
+	if (!is_callable) {
+		srd_err("Protocol decoder %s Decoder class attribute '%s' "
+			"is not a method.", mod_name, method_name);
+		return SRD_ERR_PYTHON;
+	}
+
+	return SRD_OK;
+}
 
 /**
- * Load a protocol decoder module into the embedded python interpreter.
+ * Get the API version of the specified decoder.
+ *
+ * @param d The decoder to use. Must not be NULL.
  *
- * @param name The module name to be loaded.
- * @param dec Pointer to the struct srd_decoder filled with the loaded module.
+ * @return The API version of the decoder, or 0 upon errors.
+ *
+ * @private
+ */
+SRD_PRIV long srd_decoder_apiver(const struct srd_decoder *d)
+{
+	PyObject *py_apiver;
+	long apiver;
+	PyGILState_STATE gstate;
+
+	if (!d)
+		return 0;
+
+	gstate = PyGILState_Ensure();
+
+	py_apiver = PyObject_GetAttrString(d->py_dec, "api_version");
+	apiver = (py_apiver && PyLong_Check(py_apiver))
+			? PyLong_AsLong(py_apiver) : 0;
+	Py_XDECREF(py_apiver);
+
+	PyGILState_Release(gstate);
+
+	return apiver;
+}
+
+/**
+ * Load a protocol decoder module into the embedded Python interpreter.
+ *
+ * @param module_name The module name to be loaded.
  *
  * @return SRD_OK upon success, a (negative) error code otherwise.
+ *
+ * @since 0.1.0
  */
-int srd_load_decoder(const char *name, struct srd_decoder **dec)
+SRD_API int srd_decoder_load(const char *module_name)
 {
-	PyObject *py_mod, *py_res, *py_annlist, *py_ann;
+	PyObject *py_basedec;
 	struct srd_decoder *d;
-	int alen, r, i;
-	char **ann;
+	long apiver;
+	int is_subclass;
+	const char *fail_txt;
+	PyGILState_STATE gstate;
+
+	if (!srd_check_init())
+		return SRD_ERR;
+
+	if (!module_name)
+		return SRD_ERR_ARG;
 
-	fprintf(stdout, "%s: %s\n", __func__, name);
+	gstate = PyGILState_Ensure();
 
-	/* "Import" the Python module. */
-	if (!(py_mod = PyImport_ImportModule(name))) { /* NEWREF */
-		PyErr_Print(); /* Returns void. */
-		return SRD_ERR_PYTHON; /* TODO: More specific error? */
+	if (PyDict_GetItemString(PyImport_GetModuleDict(), module_name)) {
+		/* Module was already imported. */
+		PyGILState_Release(gstate);
+		return SRD_OK;
+	}
+
+	d = g_malloc0(sizeof(struct srd_decoder));
+	fail_txt = NULL;
+
+	d->py_mod = py_import_by_name(module_name);
+	if (!d->py_mod) {
+		fail_txt = "import by name failed";
+		goto except_out;
+	}
+
+	if (!mod_sigrokdecode) {
+		srd_err("sigrokdecode module not loaded.");
+		fail_txt = "sigrokdecode(3) not loaded";
+		goto err_out;
 	}
 
 	/* Get the 'Decoder' class as Python object. */
-	py_res = PyObject_GetAttrString(py_mod, "Decoder"); /* NEWREF */
-	if (!py_res) {
-		if (PyErr_Occurred())
-			PyErr_Print(); /* Returns void. */
-		Py_XDECREF(py_mod);
-		fprintf(stderr, "Decoder class not found in PD module %s\n", name);
-		return SRD_ERR_PYTHON; /* TODO: More specific error? */
+	d->py_dec = PyObject_GetAttrString(d->py_mod, "Decoder");
+	if (!d->py_dec) {
+		fail_txt = "no 'Decoder' attribute in imported module";
+		goto except_out;
+	}
+
+	py_basedec = PyObject_GetAttrString(mod_sigrokdecode, "Decoder");
+	if (!py_basedec) {
+		fail_txt = "no 'Decoder' attribute in sigrokdecode(3)";
+		goto except_out;
 	}
 
-	if (!(d = malloc(sizeof(struct srd_decoder))))
-		return SRD_ERR_MALLOC;
+	is_subclass = PyObject_IsSubclass(d->py_dec, py_basedec);
+	Py_DECREF(py_basedec);
 
-	if ((r = h_str(py_res, "id", &(d->id))) < 0)
-		return r;
+	if (!is_subclass) {
+		srd_err("Decoder class in protocol decoder module %s is not "
+			"a subclass of sigrokdecode.Decoder.", module_name);
+		fail_txt = "not a subclass of sigrokdecode.Decoder";
+		goto err_out;
+	}
 
-	if ((r = h_str(py_res, "name", &(d->name))) < 0)
-		return r;
+	/*
+	 * Check that this decoder has the correct PD API version.
+	 * PDs of different API versions are incompatible and cannot work.
+	 */
+	apiver = srd_decoder_apiver(d);
+	if (apiver != 3) {
+		srd_exception_catch("Only PD API version 3 is supported, "
+			"decoder %s has version %ld", module_name, apiver);
+		fail_txt = "API version mismatch";
+		goto err_out;
+	}
 
-	if ((r = h_str(py_res, "longname", &(d->longname))) < 0)
-		return r;
+	/* Check Decoder class for required methods.
+	 */
+	if (check_method(d->py_dec, module_name, "start") != SRD_OK) {
+		fail_txt = "no 'start()' method";
+		goto err_out;
+	}
 
-	if ((r = h_str(py_res, "desc", &(d->desc))) < 0)
-		return r;
+	if (check_method(d->py_dec, module_name, "decode") != SRD_OK) {
+		fail_txt = "no 'decode()' method";
+		goto err_out;
+	}
 
-	if ((r = h_str(py_res, "longdesc", &(d->longdesc))) < 0)
-		return r;
+	/* Store required fields in newly allocated strings. */
+	if (py_attr_as_str(d->py_dec, "id", &(d->id)) != SRD_OK) {
+		fail_txt = "no 'id' attribute";
+		goto err_out;
+	}
 
-	if ((r = h_str(py_res, "author", &(d->author))) < 0)
-		return r;
+	if (py_attr_as_str(d->py_dec, "name", &(d->name)) != SRD_OK) {
+		fail_txt = "no 'name' attribute";
+		goto err_out;
+	}
 
-	if ((r = h_str(py_res, "email", &(d->email))) < 0)
-		return r;
+	if (py_attr_as_str(d->py_dec, "longname", &(d->longname)) != SRD_OK) {
+		fail_txt = "no 'longname' attribute";
+		goto err_out;
+	}
 
-	if ((r = h_str(py_res, "license", &(d->license))) < 0)
-		return r;
+	if (py_attr_as_str(d->py_dec, "desc", &(d->desc)) != SRD_OK) {
+		fail_txt = "no 'desc' attribute";
+		goto err_out;
+	}
 
-	d->py_mod = py_mod;
-	d->py_decobj = py_res;
+	if (py_attr_as_str(d->py_dec, "license", &(d->license)) != SRD_OK) {
+		fail_txt = "no 'license' attribute";
+		goto err_out;
+	}
 
-	/* TODO: Handle func, inputformats, outputformats. */
-	/* Note: They must at least be set to NULL, will segfault otherwise. */
-	d->func = NULL;
-	d->inputformats = NULL;
-	d->outputformats = NULL;
+	if (py_attr_as_strlist(d->py_dec, "inputs", &(d->inputs)) != SRD_OK) {
+		fail_txt = "missing or malformed 'inputs' attribute";
+		goto err_out;
+	}
 
-	/* Convert class annotation attribute to GSList of **char */
-	d->annotation = NULL;
-	if ((py_annlist = PyObject_GetAttrString(py_res, "annotation"))) {
-		if (!PyList_Check(py_annlist)) {
-			srd_err("Protocol decoder module %s annotation should be a list", name);
-			return SRD_ERR_PYTHON;
-		}
-		alen = PyList_Size(py_annlist);
-		for (i = 0; i < alen; i++) {
-			py_ann = PyList_GetItem(py_annlist, i);
-			if (!PyList_Check(py_ann) || PyList_Size(py_ann) != 2) {
-				srd_err("Protocol decoder module %s annotation %d should be a list with two elements",
-						name, i+1);
-				return SRD_ERR_PYTHON;
-			}
+	if (py_attr_as_strlist(d->py_dec, "outputs", &(d->outputs)) != SRD_OK) {
+		fail_txt = "missing or malformed 'outputs' attribute";
+		goto err_out;
+	}
 
-			if (py_strlist_to_char(py_ann, &ann) != SRD_OK)
-				return SRD_ERR_PYTHON;
-			d->annotation = g_slist_append(d->annotation, ann);
-		}
+	/* All options and their default values. */
+	if (get_options(d) != SRD_OK) {
+		fail_txt = "cannot get options";
+		goto err_out;
 	}
 
-	*dec = d;
+	/* Check and import required channels. */
+	if (get_channels(d, "channels", &d->channels, 0) != SRD_OK) {
+		fail_txt = "cannot get channels";
+		goto err_out;
+	}
+
+	/* Check and import optional channels. */
+	if (get_channels(d, "optional_channels", &d->opt_channels,
+				g_slist_length(d->channels)) != SRD_OK) {
+		fail_txt = "cannot get optional channels";
+		goto err_out;
+	}
+
+	if (get_annotations(d) != SRD_OK) {
+		fail_txt = "cannot get annotations";
+		goto err_out;
+	}
+
+	if (get_annotation_rows(d) != SRD_OK) {
+		fail_txt = "cannot get annotation rows";
+		goto err_out;
+	}
+
+	if (get_binary_classes(d) != SRD_OK) {
+		fail_txt = "cannot get binary classes";
+		goto err_out;
+	}
+
+	PyGILState_Release(gstate);
+
+	/* Append it to the list of loaded decoders. */
+	pd_list = g_slist_append(pd_list, d);
 
 	return SRD_OK;
+
+except_out:
+	/* Don't show a message for the "common" directory, it's not a PD. */
+	if (strcmp(module_name, "common")) {
+		srd_exception_catch("Failed to load decoder %s: %s",
+				    module_name, fail_txt);
+	}
+	fail_txt = NULL;
+err_out:
+	if (fail_txt)
+		srd_err("Failed to load decoder %s: %s", module_name, fail_txt);
+	decoder_free(d);
+	PyGILState_Release(gstate);
+
+	return SRD_ERR_PYTHON;
 }
 
+/**
+ * Return a protocol decoder's docstring.
+ *
+ * @param dec The loaded protocol decoder.
+ *
+ * @return A newly allocated buffer containing the protocol decoder's
+ *         documentation. The caller is responsible for free'ing the buffer.
+ *
+ * @since 0.1.0
+ */
+SRD_API char *srd_decoder_doc_get(const struct srd_decoder *dec)
+{
+	PyObject *py_str;
+	char *doc;
+	PyGILState_STATE gstate;
+
+	if (!srd_check_init())
+		return NULL;
+
+	if (!dec)
+		return NULL;
+
+	gstate = PyGILState_Ensure();
+
+	if (!PyObject_HasAttrString(dec->py_mod, "__doc__"))
+		goto err;
+
+	if (!(py_str = PyObject_GetAttrString(dec->py_mod, "__doc__"))) {
+		srd_exception_catch("Failed to get docstring");
+		goto err;
+	}
+
+	doc = NULL;
+	if (py_str != Py_None)
+		py_str_as_str(py_str, &doc);
+	Py_DECREF(py_str);
+
+	PyGILState_Release(gstate);
+
+	return doc;
+
+err:
+	PyGILState_Release(gstate);
+
+	return NULL;
+}
 
 /**
- * TODO
+ * Unload the specified protocol decoder.
+ *
+ * @param dec The struct srd_decoder to be unloaded.
+ *
+ * @return SRD_OK upon success, a (negative) error code otherwise.
+ *
+ * @since 0.1.0
  */
-int srd_unload_decoder(struct srd_decoder *dec)
+SRD_API int srd_decoder_unload(struct srd_decoder *dec)
 {
-	g_free(dec->id);
-	g_free(dec->name);
-	g_free(dec->desc);
-	g_free(dec->func);
+	struct srd_session *sess;
+	GSList *l;
 
-	/* TODO: Free everything in inputformats and outputformats. */
+	if (!srd_check_init())
+		return SRD_ERR;
 
-	if (dec->inputformats != NULL)
-		g_slist_free(dec->inputformats);
-	if (dec->outputformats != NULL)
-		g_slist_free(dec->outputformats);
+	if (!dec)
+		return SRD_ERR_ARG;
 
-	Py_XDECREF(dec->py_decobj);
-	Py_XDECREF(dec->py_mod);
+	/*
+	 * Since any instances of this decoder need to be released as well,
+	 * but they could be anywhere in the stack, just free the entire
+	 * stack. A frontend reloading a decoder thus has to restart all
+	 * instances, and rebuild the stack.
+	 */
+	for (l = sessions; l; l = l->next) {
+		sess = l->data;
+		srd_inst_free_all(sess);
+	}
+
+	/* Remove the PD from the list of loaded decoders. */
+	pd_list = g_slist_remove(pd_list, dec);
 
-	/* TODO: (g_)free dec itself? */
+	decoder_free(dec);
 
 	return SRD_OK;
 }
 
-
-int srd_load_all_decoders(void)
+static void srd_decoder_load_all_zip_path(char *path)
 {
-	DIR *dir;
-	struct dirent *dp;
-	int ret;
-	char *decodername;
-	struct srd_decoder *dec;
+	PyObject *zipimport_mod, *zipimporter_class, *zipimporter;
+	PyObject *prefix_obj, *files, *key, *value, *set, *modname;
+	Py_ssize_t pos = 0;
+	char *prefix;
+	size_t prefix_len;
+	PyGILState_STATE gstate;
 
-	if (!(dir = opendir(DECODERS_DIR))) {
-		Py_Finalize(); /* Returns void. */
-		return SRD_ERR_DECODERS_DIR;
-	}
+	set = files = prefix_obj = zipimporter = zipimporter_class = NULL;
+
+	gstate = PyGILState_Ensure();
+
+	zipimport_mod = py_import_by_name("zipimport");
+	if (zipimport_mod == NULL)
+		goto err_out;
+
+	zipimporter_class = PyObject_GetAttrString(zipimport_mod, "zipimporter");
+	if (zipimporter_class == NULL)
+		goto err_out;
+
+	zipimporter = PyObject_CallFunction(zipimporter_class, "s", path);
+	if (zipimporter == NULL)
+		goto err_out;
+
+	prefix_obj = PyObject_GetAttrString(zipimporter, "prefix");
+	if (prefix_obj == NULL)
+		goto err_out;
 
-	while ((dp = readdir(dir)) != NULL) {
-		/* Ignore filenames which don't end with ".py". */
-		if (!g_str_has_suffix(dp->d_name, ".py"))
-			continue;
+	files = PyObject_GetAttrString(zipimporter, "_files");
+	if (files == NULL || !PyDict_Check(files))
+		goto err_out;
 
-		/* Decoder name == filename (without .py suffix). */
-		decodername = g_strndup(dp->d_name, strlen(dp->d_name) - 3);
+	set = PySet_New(NULL);
+	if (set == NULL)
+		goto err_out;
 
-		/* TODO: Error handling. Use g_try_malloc(). */
-		if (!(dec = malloc(sizeof(struct srd_decoder)))) {
-			Py_Finalize(); /* Returns void. */
-			return SRD_ERR_MALLOC;
+	if (py_str_as_str(prefix_obj, &prefix) != SRD_OK)
+		goto err_out;
+
+	prefix_len = strlen(prefix);
+
+	while (PyDict_Next(files, &pos, &key, &value)) {
+		char *path, *slash;
+		if (py_str_as_str(key, &path) == SRD_OK) {
+			if (strlen(path) > prefix_len
+					&& memcmp(path, prefix, prefix_len) == 0
+					&& (slash = strchr(path + prefix_len, '/'))) {
+
+				modname = PyUnicode_FromStringAndSize(path + prefix_len,
+							slash - (path + prefix_len));
+				if (modname == NULL) {
+					PyErr_Clear();
+				} else {
+					PySet_Add(set, modname);
+					Py_DECREF(modname);
+				}
+			}
+			g_free(path);
 		}
+	}
+	g_free(prefix);
 
-		/* Load the decoder. */
-		/* TODO: Warning if loading fails for a decoder. */
-		if ((ret = srd_load_decoder(decodername, &dec)) == SRD_OK) {
-			/* Append it to the list of supported/loaded decoders. */
-			pd_list = g_slist_append(pd_list, dec);
+	while ((modname = PySet_Pop(set))) {
+		char *modname_str;
+		if (py_str_as_str(modname, &modname_str) == SRD_OK) {
+			/* The directory name is the module name (e.g. "i2c"). */
+			srd_decoder_load(modname_str);
+			g_free(modname_str);
 		}
+		Py_DECREF(modname);
 	}
-	closedir(dir);
 
-	return SRD_OK;
+err_out:
+	Py_XDECREF(set);
+	Py_XDECREF(files);
+	Py_XDECREF(prefix_obj);
+	Py_XDECREF(zipimporter);
+	Py_XDECREF(zipimporter_class);
+	Py_XDECREF(zipimport_mod);
+	PyErr_Clear();
+	PyGILState_Release(gstate);
 }
 
+static void srd_decoder_load_all_path(char *path)
+{
+	GDir *dir;
+	const gchar *direntry;
+
+	if (!(dir = g_dir_open(path, 0, NULL))) {
+		/* Not really fatal */
+		/* Try zipimport method too */
+		srd_decoder_load_all_zip_path(path);
+		return;
+	}
+
+	/* This ignores errors returned by srd_decoder_load(). That
+	 * function will have logged the cause, but in any case we
+	 * want to continue anyway. */
+	while ((direntry = g_dir_read_name(dir)) != NULL) {
+		/* The directory name is the module name (e.g. "i2c"). */
+		srd_decoder_load(direntry);
+	}
+	g_dir_close(dir);
+
+}
 
 /**
- * TODO
+ * Load all installed protocol decoders.
+ *
+ * @return SRD_OK upon success, a (negative) error code otherwise.
+ *
+ * @since 0.1.0
  */
-int srd_unload_all_decoders(void)
+SRD_API int srd_decoder_load_all(void)
 {
 	GSList *l;
-	struct srd_decoder *dec;
 
-	for (l = srd_list_decoders(); l; l = l->next) {
-		dec = l->data;
-		/* TODO: Error handling. */
-		srd_unload_decoder(dec);
-	}
+	if (!srd_check_init())
+		return SRD_ERR;
+
+	for (l = searchpaths; l; l = l->next)
+		srd_decoder_load_all_path(l->data);
 
 	return SRD_OK;
 }
 
+/**
+ * Unload all loaded protocol decoders.
+ *
+ * @return SRD_OK upon success, a (negative) error code otherwise.
+ *
+ * @since 0.1.0
+ */
+SRD_API int srd_decoder_unload_all(void)
+{
+	g_slist_foreach(pd_list, (GFunc)srd_decoder_unload, NULL);
+	g_slist_free(pd_list);
+	pd_list = NULL;
 
+	return SRD_OK;
+}
 
+/** @} */