THE GREAT CEEIFICATION EVENT

This is a total conversion of SciTECO to plain C (GNU C11).
The chance was taken to improve a lot of internal datastructures,
fix fundamental bugs and lay the foundations of future features.
The GTK user interface is now in an useable state!
All changes have been squashed together.

The language itself has almost not changed at all, except for:

* Detection of string terminators (usually Escape) now takes
  the string building characters into account.
  A string is only terminated outside of string building characters.
  In other words, you can now for instance write
  I^EQ[Hello$world]$
  This removes one of the last bits of shellisms which is out of
  place in SciTECO where no tokenization/lexing is performed.
  Consequently, the current termination character can also be
  escaped using ^Q/^R.
  This is used by auto completions to make sure that strings
  are inserted verbatim and without unwanted sideeffects.
* All strings can now safely contain null-characters
  (see also: 8-bit cleanliness).
  The null-character itself (^@) is not (yet) a valid SciTECO
  command, though.

An incomplete list of changes:

* We got rid of the BSD headers for RB trees and lists/queues.
  The problem with them was that they used a form of metaprogramming
  only to gain a bit of type safety. It also resulted in less
  readble code. This was a C++ desease.
  The new code avoids metaprogramming only to gain type safety.
  The BSD tree.h has been replaced by rb3ptr by Jens Stimpfle
  (https://github.com/jstimpfle/rb3ptr).
  This implementation is also more memory efficient than BSD's.
  The BSD list.h and queue.h has been replaced with a custom
  src/list.h.
* Fixed crashes, performance issues and compatibility issues with
  the Gtk 3 User Interface.
  It is now more or less ready for general use.
  The GDK lock is no longer used to avoid using deprecated functions.
  On the downside, the new implementation (driving the Gtk event loop
  stepwise) is even slower than the old one.
  A few glitches remain (see TODO), but it is hoped that they will
  be resolved by the Scintilla update which will be performed soon.
* A lot of program units have been split up, so they are shorter
  and easier to maintain: core-commands.c, qreg-commands.c,
  goto-commands.c, file-utils.h.
* Parser states are simply structs of callbacks now.
  They still use a kind of polymorphy using a preprocessor trick.
  TECO_DEFINE_STATE() takes an initializer list that will be
  merged with the default list of field initializers.
  To "subclass" states, you can simply define new macros that add
  initializers to existing macros.
* Parsers no longer have a "transitions" table but the input_cb()
  may use switch-case statements.
  There are also teco_machine_main_transition_t now which can
  be used to implement simple transitions. Additionally, you
  can specify functions to execute during transitions.
  This largely avoids long switch-case-statements.
* Parsers are embeddable/reusable now, at least in parse-only mode.
  This does not currently bring any advantages but may later
  be used to write a Scintilla lexer for TECO syntax highlighting.
  Once parsers are fully embeddable, it will also be possible
  to run TECO macros in a kind of coroutine which would allow
  them to process string arguments in real time.
* undo.[ch] still uses metaprogramming extensively but via
  the C preprocessor of course. On the downside, most undo
  token generators must be initiated explicitly (theoretically
  we could have used embedded functions / trampolines to
  instantiate automatically but this has turned out to be
  dangereous).
  There is a TECO_DEFINE_UNDO_CALL() to generate closures for
  arbitrary functions now (ie. to call an arbitrary function
  at undo-time). This simplified a lot of code and is much
  shorter than manually pushing undo tokens in many cases.
* Instead of the ridiculous C++ Curiously Recurring Template
  Pattern to achieve static polymorphy for user interface
  implementations, we now simply declare all functions to
  implement in interface.h and link in the implementations.
  This is possible since we no longer hace to define
  interface subclasses (all state is static variables in
  the interface's *.c files).
* Headers are now significantly shorter than in C++ since
  we can often hide more of our "class" implementations.
* Memory counting is based on dlmalloc for most platforms now.
  Unfortunately, there is no malloc implementation that
  provides an efficient constant-time memory counter that
  is guaranteed to decrease when freeing memory.
  But since we use a defined malloc implementation now,
  malloc_usable_size() can be used safely for tracking memory use.
  malloc() replacement is very tricky on Windows, so we
  use a poll thread on Windows. This can also be enabled
  on other supported platforms using --disable-malloc-replacement.
  All in all, I'm still not pleased with the state of memory
  limiting. It is a mess.
* Error handling uses GError now. This has the advantage that
  the GError codes can be reused once we support error catching
  in the SciTECO language.
* Added a few more test suite cases.
* Haiku is no longer supported as builds are instable and
  I did not manage to debug them - quite possibly Haiku bugs
  were responsible.
* Glib v2.44 or later are now required.
  The GTK UI requires Gtk+ v3.12 or later now.
  The GtkFlowBox fallback and sciteco-wrapper workaround are
  no longer required.
* We now extensively use the GCC/Clang-specific g_auto
  feature (automatic deallocations when leaving the current
  code block).
* Updated copyright to 2021.
  SciTECO has been in continuous development, even though there
  have been no commits since 2018.
* Since these changes are so significant, the target release has
  been set to v2.0.
  It is planned that beginning with v3.0, the language will be
  kept stable.

1 files changed, 439 insertions, 0 deletions

diff --git a/src/view.c b/src/view.c
new file mode 100644
index 0000000..e61c1a6
--- /dev/null
+++ b/src/view.c
@@ -0,0 +1,439 @@
+/*
+ * Copyright (C) 2012-2021 Robin Haberkorn
+ *
+ * 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
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <limits.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/stat.h>
+
+#ifdef HAVE_WINDOWS_H
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+#endif
+
+#include <glib.h>
+#include <glib/gprintf.h>
+#include <glib/gstdio.h>
+
+#include <Scintilla.h>
+
+#include "sciteco.h"
+#include "file-utils.h"
+#include "string-utils.h"
+#include "interface.h"
+#include "undo.h"
+#include "error.h"
+#include "qreg.h"
+#include "eol.h"
+#include "view.h"
+
+/** @memberof teco_view_t */
+void
+teco_view_setup(teco_view_t *ctx)
+{
+	/*
+	 * Start with or without undo collection,
+	 * depending on teco_undo_enabled.
+	 */
+	teco_view_ssm(ctx, SCI_SETUNDOCOLLECTION, teco_undo_enabled, 0);
+
+	teco_view_ssm(ctx, SCI_SETFOCUS, TRUE, 0);
+
+	/*
+	 * Some Scintilla implementations show the horizontal
+	 * scroll bar by default.
+	 * Ensure it is never displayed by default.
+	 */
+	teco_view_ssm(ctx, SCI_SETHSCROLLBAR, FALSE, 0);
+
+	/*
+	 * Only margin 1 is given a width by default.
+	 * To provide a minimalist default view, it is disabled.
+	 */
+	teco_view_ssm(ctx, SCI_SETMARGINWIDTHN, 1, 0);
+
+	/*
+	 * Set some basic styles in order to provide
+	 * a consistent look across UIs if no profile
+	 * is used. This makes writing UI-agnostic profiles
+	 * and color schemes easier.
+	 * FIXME: Some settings like fonts should probably
+	 * be set per UI (i.e. Scinterm doesn't use it,
+	 * GTK might try to use a system-wide default
+	 * monospaced font).
+	 */
+	teco_view_ssm(ctx, SCI_SETCARETSTYLE, CARETSTYLE_BLOCK, 0);
+	teco_view_ssm(ctx, SCI_SETCARETPERIOD, 0, 0);
+	teco_view_ssm(ctx, SCI_SETCARETFORE, 0xFFFFFF, 0);
+
+	teco_view_ssm(ctx, SCI_STYLESETFORE, STYLE_DEFAULT, 0xFFFFFF);
+	teco_view_ssm(ctx, SCI_STYLESETBACK, STYLE_DEFAULT, 0x000000);
+	teco_view_ssm(ctx, SCI_STYLESETFONT, STYLE_DEFAULT, (sptr_t)"Courier");
+	teco_view_ssm(ctx, SCI_STYLECLEARALL, 0, 0);
+
+	/*
+	 * FIXME: The line number background is apparently not
+	 * affected by SCI_STYLECLEARALL
+	 */
+	teco_view_ssm(ctx, SCI_STYLESETBACK, STYLE_LINENUMBER, 0x000000);
+
+	/*
+	 * Use white as the default background color
+	 * for call tips. Necessary since this style is also
+	 * used for popup windows and we need to provide a sane
+	 * default if no color-scheme is applied (and --no-profile).
+	 */
+	teco_view_ssm(ctx, SCI_STYLESETFORE, STYLE_CALLTIP, 0x000000);
+	teco_view_ssm(ctx, SCI_STYLESETBACK, STYLE_CALLTIP, 0xFFFFFF);
+}
+
+TECO_DEFINE_UNDO_CALL(teco_view_ssm, teco_view_t *, unsigned int, uptr_t, sptr_t);
+
+/** @memberof teco_view_t */
+void
+teco_view_set_representations(teco_view_t *ctx)
+{
+	static const char *reps[] = {
+		"^@", "^A", "^B", "^C", "^D", "^E", "^F", "^G",
+		"^H", "TAB" /* ^I */, "LF" /* ^J */, "^K", "^L", "CR" /* ^M */, "^N", "^O",
+		"^P", "^Q", "^R", "^S", "^T", "^U", "^V", "^W",
+		"^X", "^Y", "^Z", "$" /* ^[ */, "^\\", "^]", "^^", "^_"
+	};
+
+	for (guint cc = 0; cc < G_N_ELEMENTS(reps); cc++) {
+		gchar buf[] = {(gchar)cc, '\0'};
+		teco_view_ssm(ctx, SCI_SETREPRESENTATION, (uptr_t)buf, (sptr_t)reps[cc]);
+	}
+}
+
+TECO_DEFINE_UNDO_CALL(teco_view_set_representations, teco_view_t *);
+
+/**
+ * Loads the view's document by reading all data from
+ * a GIOChannel.
+ * The EOL style is guessed from the channel's data
+ * (if AUTOEOL is enabled).
+ * This assumes that the channel is blocking.
+ * Also it tries to guess the size of the file behind
+ * channel in order to preallocate memory in Scintilla.
+ *
+ * Any error reading the GIOChannel is propagated as
+ * an exception.
+ *
+ * @param ctx The view to load.
+ * @param channel Channel to read from.
+ * @param error A GError.
+ * @return FALSE in case of a GError.
+ *
+ * @memberof teco_view_t
+ */
+gboolean
+teco_view_load_from_channel(teco_view_t *ctx, GIOChannel *channel, GError **error)
+{
+	teco_view_ssm(ctx, SCI_BEGINUNDOACTION, 0, 0);
+	teco_view_ssm(ctx, SCI_CLEARALL, 0, 0);
+
+	/*
+	 * Preallocate memory based on the file size.
+	 * May waste a few bytes if file contains DOS EOLs
+	 * and EOL translation is enabled, but is faster.
+	 * NOTE: g_io_channel_unix_get_fd() should report the correct fd
+	 * on Windows, too.
+	 */
+	struct stat stat_buf = {.st_size = 0};
+	if (!fstat(g_io_channel_unix_get_fd(channel), &stat_buf) &&
+	    stat_buf.st_size > 0)
+		teco_view_ssm(ctx, SCI_ALLOCATE, stat_buf.st_size, 0);
+
+	g_auto(teco_eol_reader_t) reader;
+	teco_eol_reader_init_gio(&reader, channel);
+
+	for (;;) {
+		/*
+		 * NOTE: We don't have to free this data since teco_eol_reader_gio_convert()
+		 * will point it into its internal buffer.
+		 */
+		teco_string_t str;
+
+		GIOStatus rc = teco_eol_reader_convert(&reader, &str.data, &str.len, error);
+		if (rc == G_IO_STATUS_ERROR) {
+			teco_view_ssm(ctx, SCI_ENDUNDOACTION, 0, 0);
+			return FALSE;
+		}
+		if (rc == G_IO_STATUS_EOF)
+			break;
+
+		teco_view_ssm(ctx, SCI_APPENDTEXT, str.len, (sptr_t)str.data);
+	}
+
+	/*
+	 * EOL-style guessed.
+	 * Save it as the buffer's EOL mode, so save()
+	 * can restore the original EOL-style.
+	 * If auto-EOL-translation is disabled, this cannot
+	 * have been guessed and the buffer's EOL mode should
+	 * have a platform default.
+	 * If it is enabled but the stream does not contain any
+	 * EOL characters, the platform default is still assumed.
+	 */
+	if (reader.eol_style >= 0)
+		teco_view_ssm(ctx, SCI_SETEOLMODE, reader.eol_style, 0);
+
+	if (reader.eol_style_inconsistent)
+		teco_interface_msg(TECO_MSG_WARNING,
+		                   "Inconsistent EOL styles normalized");
+
+	teco_view_ssm(ctx, SCI_ENDUNDOACTION, 0, 0);
+	return TRUE;
+}
+
+/**
+ * Load view's document from file.
+ *
+ * @memberof teco_view_t
+ */
+gboolean
+teco_view_load_from_file(teco_view_t *ctx, const gchar *filename, GError **error)
+{
+	g_autoptr(GIOChannel) channel = g_io_channel_new_file(filename, "r", error);
+	if (!channel)
+		return FALSE;
+
+	/*
+	 * The file loading algorithm does not need buffered
+	 * streams, so disabling buffering should increase
+	 * performance (slightly).
+	 */
+	g_io_channel_set_encoding(channel, NULL, NULL);
+	g_io_channel_set_buffered(channel, FALSE);
+
+	if (!teco_view_load_from_channel(ctx, channel, error)) {
+		g_prefix_error(error, "Error reading file \"%s\": ", filename);
+		return FALSE;
+	}
+
+	return TRUE;
+}
+
+#if 0
+
+/*
+ * TODO: on UNIX it may be better to open() the current file, unlink() it
+ * and keep the file descriptor in the undo token.
+ * When the operation is undone, the file descriptor's contents are written to
+ * the file (which should be efficient enough because it is written to the same
+ * filesystem). This way we could avoid messing around with save point files.
+ */
+
+#else
+
+static gint savepoint_id = 0;
+
+typedef struct {
+#ifdef G_OS_WIN32
+	teco_file_attributes_t orig_attrs;
+#endif
+
+	gchar *savepoint;
+	gchar filename[];
+} teco_undo_restore_savepoint_t;
+
+static void
+teco_undo_restore_savepoint_action(teco_undo_restore_savepoint_t *ctx, gboolean run)
+{
+	if (!run) {
+		g_unlink(ctx->savepoint);
+	} else if (!g_rename(ctx->savepoint, ctx->filename)) {
+#ifdef G_OS_WIN32
+		if (ctx->orig_attrs != TECO_FILE_INVALID_ATTRIBUTES)
+			teco_file_set_attributes(ctx->filename, ctx->orig_attrs);
+#endif
+	} else {
+		teco_interface_msg(TECO_MSG_WARNING,
+		                   "Unable to restore save point file \"%s\"",
+		                   ctx->savepoint);
+	}
+
+	g_free(ctx->savepoint);
+	savepoint_id--;
+}
+
+static void
+teco_undo_restore_savepoint_push(gchar *savepoint, const gchar *filename)
+{
+	teco_undo_restore_savepoint_t *ctx;
+
+	ctx = teco_undo_push_size((teco_undo_action_t)teco_undo_restore_savepoint_action,
+	                          sizeof(*ctx) + strlen(filename) + 1);
+	if (ctx) {
+		ctx->savepoint = savepoint;
+		strcpy(ctx->filename, filename);
+
+#ifdef G_OS_WIN32
+		ctx->orig_attrs = teco_file_get_attributes(filename);
+		if (ctx->orig_attrs != TECO_FILE_INVALID_ATTRIBUTES)
+			teco_file_set_attributes(savepoint,
+			                         ctx->orig_attrs | FILE_ATTRIBUTE_HIDDEN);
+#endif
+	} else {
+		g_unlink(savepoint);
+		g_free(savepoint);
+		savepoint_id--;
+	}
+}
+
+static void
+teco_make_savepoint(const gchar *filename)
+{
+	gchar savepoint_basename[FILENAME_MAX];
+
+	g_autofree gchar *basename = g_path_get_basename(filename);
+	g_snprintf(savepoint_basename, sizeof(savepoint_basename),
+		   ".teco-%d-%s~", savepoint_id, basename);
+	g_autofree gchar *dirname = g_path_get_dirname(filename);
+	gchar *savepoint = g_build_filename(dirname, savepoint_basename, NULL);
+
+	if (g_rename(filename, savepoint)) {
+		teco_interface_msg(TECO_MSG_WARNING,
+		                   "Unable to create save point file \"%s\"",
+		                   savepoint);
+		g_free(savepoint);
+		return;
+	}
+	savepoint_id++;
+
+	/*
+	 * NOTE: passes ownership of savepoint string to undo token.
+	 */
+	teco_undo_restore_savepoint_push(savepoint, filename);
+}
+
+#endif
+
+/*
+ * NOTE: Does not simply undo__g_unlink() since `filename` needs to be
+ * memory managed.
+ */
+static void
+sciteo_undo_remove_file_action(gchar *filename, gboolean run)
+{
+	if (run)
+		g_unlink(filename);
+}
+
+static inline void
+teco_undo_remove_file_push(const gchar *filename)
+{
+	gchar *ctx = teco_undo_push_size((teco_undo_action_t)sciteo_undo_remove_file_action,
+	                                 strlen(filename)+1);
+	if (ctx)
+		strcpy(ctx, filename);
+}
+
+gboolean
+teco_view_save_to_channel(teco_view_t *ctx, GIOChannel *channel, GError **error)
+{
+	g_auto(teco_eol_writer_t) writer;
+	teco_eol_writer_init_gio(&writer, teco_view_ssm(ctx, SCI_GETEOLMODE, 0, 0), channel);
+
+	/* write part of buffer before gap */
+	sptr_t gap = teco_view_ssm(ctx, SCI_GETGAPPOSITION, 0, 0);
+	if (gap > 0) {
+		const gchar *buffer = (const gchar *)teco_view_ssm(ctx, SCI_GETRANGEPOINTER, 0, gap);
+		gssize bytes_written = teco_eol_writer_convert(&writer, buffer, gap, error);
+		if (bytes_written < 0)
+			return FALSE;
+		g_assert(bytes_written == (gsize)gap);
+	}
+
+	/* write part of buffer after gap */
+	gsize size = teco_view_ssm(ctx, SCI_GETLENGTH, 0, 0) - gap;
+	if (size > 0) {
+		const gchar *buffer = (const gchar *)teco_view_ssm(ctx, SCI_GETRANGEPOINTER, gap, (sptr_t)size);
+		gssize bytes_written = teco_eol_writer_convert(&writer, buffer, size, error);
+		if (bytes_written < 0)
+			return FALSE;
+		g_assert(bytes_written == size);
+	}
+
+	return TRUE;
+}
+
+/** @memberof teco_view_t */
+gboolean
+teco_view_save_to_file(teco_view_t *ctx, const gchar *filename, GError **error)
+{
+#ifdef G_OS_UNIX
+	GStatBuf file_stat;
+	file_stat.st_uid = -1;
+	file_stat.st_gid = -1;
+#endif
+	teco_file_attributes_t attributes = TECO_FILE_INVALID_ATTRIBUTES;
+
+	if (teco_undo_enabled) {
+		if (g_file_test(filename, G_FILE_TEST_IS_REGULAR)) {
+#ifdef G_OS_UNIX
+			g_stat(filename, &file_stat);
+#endif
+			attributes = teco_file_get_attributes(filename);
+			teco_make_savepoint(filename);
+		} else {
+			teco_undo_remove_file_push(filename);
+		}
+	}
+
+	/* leaves access mode intact if file still exists */
+	g_autoptr(GIOChannel) channel = g_io_channel_new_file(filename, "w", error);
+	if (!channel)
+		return FALSE;
+
+	/*
+	 * teco_view_save_to_channel() expects a buffered and blocking channel
+	 */
+	g_io_channel_set_encoding(channel, NULL, NULL);
+	g_io_channel_set_buffered(channel, TRUE);
+
+	if (!teco_view_save_to_channel(ctx, channel, error)) {
+		g_prefix_error(error, "Error writing file \"%s\": ", filename);
+		return FALSE;
+	}
+
+	/* if file existed but has been renamed, restore attributes */
+	if (attributes != TECO_FILE_INVALID_ATTRIBUTES)
+		teco_file_set_attributes(filename, attributes);
+#ifdef G_OS_UNIX
+	/*
+	 * only a good try to inherit owner since process user must have
+	 * CHOWN capability traditionally reserved to root only.
+	 * FIXME: We should probably fall back to another save point
+	 * strategy.
+	 */
+	if (fchown(g_io_channel_unix_get_fd(channel),
+	           file_stat.st_uid, file_stat.st_gid))
+		teco_interface_msg(TECO_MSG_WARNING,
+		                   "Unable to preserve owner of \"%s\": %s",
+		                   filename, g_strerror(errno));
+#endif
+
+	return TRUE;
+}