Start fleshing out new extension API.

1 files changed, 339 insertions, 0 deletions

diff --git a/gawkapi.c b/gawkapi.c
new file mode 100644
index 00000000..059d49e5
--- /dev/null
+++ b/gawkapi.c
@@ -0,0 +1,339 @@
+/*
+ * gawkapi.c -- Implement the functions defined for gawkapi.h
+ */
+
+/* 
+ * Copyright (C) 2012, the Free Software Foundation, Inc.
+ * 
+ * This file is part of GAWK, the GNU implementation of the
+ * AWK Programming Language.
+ * 
+ * GAWK is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * GAWK is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ */
+
+#include "awk.h"
+
+/*
+ * Get the count'th paramater, zero-based.
+ * Returns NULL if count is out of range, or if actual paramater
+ * does not match what is specified in wanted.
+ */
+static awk_value_t *
+api_get_curfunc_param(awk_ext_id_t id, size_t count,
+			awk_param_type_t wanted)
+{
+	return NULL;	/* for now */
+}
+
+/* Set the return value. Gawk takes ownership of string memory */
+static void
+api_set_return_value(awk_ext_id_t id, const awk_value_t *retval)
+{
+}
+
+/* Functions to print messages */
+/* FIXME: Code duplicate from msg.c. Fix this. */
+static void
+api_fatal(awk_ext_id_t id, const char *format, ...)
+{
+	va_list args;
+	va_start(args, format);
+	err(_("fatal: "), format, args);
+	va_end(args);
+#ifdef GAWKDEBUG
+	abort();
+#endif
+	gawk_exit(EXIT_FATAL);
+}
+
+static void
+api_warning(awk_ext_id_t id, const char *format, ...)
+{
+	va_list args;
+	va_start(args, format);
+	err(_("warning: "), format, args);
+	va_end(args);
+}
+
+static void
+api_lintwarn(awk_ext_id_t id, const char *format, ...)
+{
+	va_list args;
+	va_start(args, format);
+	if (lintwarn == r_fatal) {
+		err(_("fatal: "), format, args);
+		va_end(args);
+#ifdef GAWKDEBUG
+		abort();
+#endif
+		gawk_exit(EXIT_FATAL);
+	} else {
+		err(_("warning: "), format, args);
+		va_end(args);
+	}
+}
+
+/* Register an open hook; for opening files read-only */
+static awk_bool_t
+api_register_open_hook(awk_ext_id_t id, void* (*open_func)(IOBUF *))
+{
+	return true;	/* for now */
+}
+
+/* Functions to update ERRNO */
+static void
+api_update_ERRNO_int(awk_ext_id_t id, int errno_val)
+{
+	update_ERRNO_int(errno_val);
+}
+
+static void
+api_update_ERRNO_string(awk_ext_id_t id, const char *string,
+		awk_bool_t translate)
+{
+	update_ERRNO_string(string, translate);
+}
+
+static void
+api_unset_ERRNO(awk_ext_id_t id)
+{
+	unset_ERRNO();
+}
+
+
+/* Add a function to the interpreter, returns true upon success */
+static awk_bool_t
+api_add_ext_func(awk_ext_id_t id, const awk_ext_func_t *func)
+{
+	return true;	/* for now */
+}
+
+/* Stuff for exit handler - do it as linked list */
+
+struct ext_exit_handler {
+	struct ext_exit_handler *next;
+	void (*funcp)(void *data, int exit_status);
+	void *arg0;
+};
+static struct ext_exit_handler *list_head = NULL;
+
+/* run_ext_exit_handlers --- run the extension exit handlers, LIFO order */
+
+void
+run_ext_exit_handlers(int exitval)
+{
+	struct ext_exit_handler *p, *next;
+
+	for (p = list_head; p != NULL; p = next) {
+		next = p->next;
+		p->funcp(p->arg0, exitval);
+		free(p);
+	}
+	list_head = NULL;
+}
+
+/* Add an exit call back, returns true upon success */
+static awk_bool_t
+api_awk_atexit(awk_ext_id_t id,
+		void (*funcp)(void *data, int exit_status),
+		void *arg0)
+{
+	struct ext_exit_handler *p;
+
+	/* allocate memory */
+	emalloc(p, struct ext_exit_handler *, sizeof(struct ext_exit_handler), "api_awk_atexit");
+
+	/* fill it in */
+	p->funcp = funcp;
+	p->arg0 = arg0;
+
+	/* add to linked list, LIFO order */
+	p->next = list_head;
+	list_head = p;
+	return true;	/* for now */
+}
+
+/*
+ * Symbol table access:
+ * 	- No access to special variables (NF, etc.)
+ * 	- One special exception: PROCINFO.
+ *	- Use sym_update() to change a value, including from UNDEFINED
+ *	  to scalar or array. 
+ */
+/*
+ * Lookup a variable, return its value. No messing with the value
+ * returned. Return value is NULL if the variable doesn't exist.
+ */
+static const awk_value_t *const
+api_sym_lookup(awk_ext_id_t id, const char *name)
+{
+	return NULL;	/* for now */
+}
+
+/*
+ * Update a value. Adds it to the symbol table if not there.
+ * Changing types is not allowed.
+ */
+static awk_bool_t
+api_sym_update(awk_ext_id_t id, const char *name, awk_value_t *value)
+{
+	return true;	/* for now */
+}
+
+/* Array management */
+/*
+ * Return the value of an element - read only!
+ * Use set_array_element to change it.
+ */
+static const awk_value_t *const
+api_get_array_element(awk_ext_id_t id,
+		awk_array_t a_cookie, const awk_value_t *const index)
+{
+	return NULL;	/* for now */
+}
+
+/*
+ * Change (or create) element in existing array with
+ * element->index and element->value.
+ */
+static awk_bool_t
+api_set_array_element(awk_ext_id_t id, awk_array_t a_cookie,
+				awk_element_t *element)
+{
+	return true;	/* for now */
+}
+
+/*
+ * Remove the element with the given index.
+ * Returns success if removed or if element did not exist.
+ */
+static awk_bool_t
+api_del_array_element(awk_ext_id_t id,
+		awk_array_t a_cookie, const awk_value_t* const index)
+{
+	return true;	/* for now */
+}
+
+/*
+ * Retrieve total number of elements in array.
+ * Returns false if some kind of error.
+ */
+static awk_bool_t
+api_get_element_count(awk_ext_id_t id,
+		awk_array_t a_cookie, size_t *count)
+{
+	return true;	/* for now */
+}
+
+/* Create a new array cookie to which elements may be added */
+static awk_array_t
+api_create_array(awk_ext_id_t id)
+{
+	return NULL;	/* for now */
+}
+
+/* Clear out an array */
+static awk_bool_t
+api_clear_array(awk_ext_id_t id, awk_array_t a_cookie)
+{
+	return true;	/* for now */
+}
+
+/* Flatten out an array so that it can be looped over easily. */
+static awk_bool_t
+api_flatten_array(awk_ext_id_t id,
+		awk_array_t a_cookie,
+		size_t *count,
+		awk_element_t **data)
+{
+	return true;	/* for now */
+}
+
+/*
+ * When done, release the memory, delete any marked elements
+ * Count must match what gawk thinks the size is.
+ */
+static awk_bool_t
+api_release_flattened_array(awk_ext_id_t id,
+		awk_array_t a_cookie,
+		size_t count,
+		awk_element_t *data)
+{
+	return true;	/* for now */
+}
+
+/* Constructor functions */
+static awk_value_t *
+api_make_string(awk_ext_id_t id,
+		const char *string, size_t length)
+{
+	static awk_value_t result;
+
+	result.val_type = AWK_STRING;
+	result.str_value.str = (char *) string;
+	result.str_value.len = length;
+
+	return & result;
+}
+
+static awk_value_t *
+api_make_number(awk_ext_id_t id, double num)
+{
+	static awk_value_t result;
+
+	result.val_type = AWK_NUMBER;
+	result.num_value = num;
+
+	return & result;
+}
+
+static gawk_api_t api_impl = {
+	GAWK_API_MAJOR_VERSION,	/* major and minor versions */
+	GAWK_API_MINOR_VERSION,
+	{ 0 },			/* do_flags */
+
+	api_get_curfunc_param,
+	api_set_return_value,
+
+	api_fatal,
+	api_warning,
+	api_lintwarn,
+
+	api_register_open_hook,
+
+	api_update_ERRNO_int,
+	api_update_ERRNO_string,
+	api_unset_ERRNO,
+
+	api_add_ext_func,
+
+	api_awk_atexit,
+
+	api_sym_lookup,
+	api_sym_update,
+
+	api_get_array_element,
+	api_set_array_element,
+	api_del_array_element,
+	api_get_element_count,
+	api_create_array,
+	api_clear_array,
+	api_flatten_array,
+	api_release_flattened_array,
+
+	/* Constructor functions */
+	api_make_string,
+	api_make_number,
+};