[libgit2.git] / src / diff_driver.c

/*
 * Copyright (C) the libgit2 contributors. All rights reserved.
 *
 * This file is part of libgit2, distributed under the GNU GPL v2 with
 * a Linking Exception. For full terms see the included COPYING file.
 */

#include "diff_driver.h"

#include "git2/attr.h"

#include "common.h"
#include "diff.h"
#include "strmap.h"
#include "map.h"
#include "config.h"
#include "regexp.h"
#include "repository.h"

typedef enum {
	DIFF_DRIVER_AUTO = 0,
	DIFF_DRIVER_BINARY = 1,
	DIFF_DRIVER_TEXT = 2,
	DIFF_DRIVER_PATTERNLIST = 3
} git_diff_driver_t;

typedef struct {
	git_regexp re;
	int flags;
} git_diff_driver_pattern;

enum {
	REG_NEGATE = (1 << 15) /* get out of the way of existing flags */
};

/* data for finding function context for a given file type */
struct git_diff_driver {
	git_diff_driver_t type;
	uint32_t binary_flags;
	uint32_t other_flags;
	git_array_t(git_diff_driver_pattern) fn_patterns;
	git_regexp  word_pattern;
	char name[GIT_FLEX_ARRAY];
};

#include "userdiff.h"

struct git_diff_driver_registry {
	git_strmap *drivers;
};

#define FORCE_DIFFABLE (GIT_DIFF_FORCE_TEXT | GIT_DIFF_FORCE_BINARY)

static git_diff_driver diff_driver_auto =   { DIFF_DRIVER_AUTO,   0, 0 };
static git_diff_driver diff_driver_binary = { DIFF_DRIVER_BINARY, GIT_DIFF_FORCE_BINARY, 0 };
static git_diff_driver diff_driver_text =   { DIFF_DRIVER_TEXT,   GIT_DIFF_FORCE_TEXT, 0 };

git_diff_driver_registry *git_diff_driver_registry_new(void)
{
	git_diff_driver_registry *reg =
		git__calloc(1, sizeof(git_diff_driver_registry));
	if (!reg)
		return NULL;

	if (git_strmap_new(&reg->drivers) < 0) {
		git_diff_driver_registry_free(reg);
		return NULL;
	}

	return reg;
}

void git_diff_driver_registry_free(git_diff_driver_registry *reg)
{
	git_diff_driver *drv;

	if (!reg)
		return;

	git_strmap_foreach_value(reg->drivers, drv, git_diff_driver_free(drv));
	git_strmap_free(reg->drivers);
	git__free(reg);
}

static int diff_driver_add_patterns(
	git_diff_driver *drv, const char *regex_str, int regex_flags)
{
	int error = 0;
	const char *scan, *end;
	git_diff_driver_pattern *pat = NULL;
	git_str buf = GIT_STR_INIT;

	for (scan = regex_str; scan; scan = end) {
		/* get pattern to fill in */
		if ((pat = git_array_alloc(drv->fn_patterns)) == NULL) {
			return -1;
		}

		pat->flags = regex_flags;
		if (*scan == '!') {
			pat->flags |= REG_NEGATE;
			++scan;
		}

		if ((end = strchr(scan, '\n')) != NULL) {
			error = git_str_set(&buf, scan, end - scan);
			end++;
		} else {
			error = git_str_sets(&buf, scan);
		}
		if (error < 0)
			break;

		if ((error = git_regexp_compile(&pat->re, buf.ptr, regex_flags)) != 0) {
			/*
			 * TODO: issue a warning
			 */
		}
	}

	if (error && pat != NULL)
		(void)git_array_pop(drv->fn_patterns); /* release last item */
	git_str_dispose(&buf);

	/* We want to ignore bad patterns, so return success regardless */
	return 0;
}

static int diff_driver_xfuncname(const git_config_entry *entry, void *payload)
{
	return diff_driver_add_patterns(payload, entry->value, 0);
}

static int diff_driver_funcname(const git_config_entry *entry, void *payload)
{
	return diff_driver_add_patterns(payload, entry->value, 0);
}

static git_diff_driver_registry *git_repository_driver_registry(
	git_repository *repo)
{
	git_diff_driver_registry *reg = git_atomic_load(repo->diff_drivers), *newreg;
	if (reg)
		return reg;

	newreg = git_diff_driver_registry_new();
	if (!newreg) {
		git_error_set(GIT_ERROR_REPOSITORY, "unable to create diff driver registry");
		return newreg;
	}
	reg = git_atomic_compare_and_swap(&repo->diff_drivers, NULL, newreg);
	if (!reg) {
		reg = newreg;
	} else {
		/* if we race, free losing allocation */
		git_diff_driver_registry_free(newreg);
	}
	return reg;
}

static int diff_driver_alloc(
	git_diff_driver **out, size_t *namelen_out, const char *name)
{
	git_diff_driver *driver;
	size_t driverlen = sizeof(git_diff_driver),
		namelen = strlen(name),
		alloclen;

	GIT_ERROR_CHECK_ALLOC_ADD(&alloclen, driverlen, namelen);
	GIT_ERROR_CHECK_ALLOC_ADD(&alloclen, alloclen, 1);

	driver = git__calloc(1, alloclen);
	GIT_ERROR_CHECK_ALLOC(driver);

	memcpy(driver->name, name, namelen);

	*out = driver;

	if (namelen_out)
		*namelen_out = namelen;

	return 0;
}

static int git_diff_driver_builtin(
	git_diff_driver **out,
	git_diff_driver_registry *reg,
	const char *driver_name)
{
	git_diff_driver_definition *ddef = NULL;
	git_diff_driver *drv = NULL;
	int error = 0;
	size_t idx;

	for (idx = 0; idx < ARRAY_SIZE(builtin_defs); ++idx) {
		if (!strcasecmp(driver_name, builtin_defs[idx].name)) {
			ddef = &builtin_defs[idx];
			break;
		}
	}
	if (!ddef)
		goto done;

	if ((error = diff_driver_alloc(&drv, NULL, ddef->name)) < 0)
		goto done;

	drv->type = DIFF_DRIVER_PATTERNLIST;

	if (ddef->fns &&
		(error = diff_driver_add_patterns(
			drv, ddef->fns, ddef->flags)) < 0)
		goto done;

	if (ddef->words &&
	    (error = git_regexp_compile(&drv->word_pattern, ddef->words, ddef->flags)) < 0)
		goto done;

	if ((error = git_strmap_set(reg->drivers, drv->name, drv)) < 0)
		goto done;

done:
	if (error && drv)
		git_diff_driver_free(drv);
	else
		*out = drv;

	return error;
}

static int git_diff_driver_load(
	git_diff_driver **out, git_repository *repo, const char *driver_name)
{
	int error = 0;
	git_diff_driver_registry *reg;
	git_diff_driver *drv;
	size_t namelen;
	git_config *cfg = NULL;
	git_str name = GIT_STR_INIT;
	git_config_entry *ce = NULL;
	bool found_driver = false;

	if ((reg = git_repository_driver_registry(repo)) == NULL)
		return -1;

	if ((drv = git_strmap_get(reg->drivers, driver_name)) != NULL) {
		*out = drv;
		return 0;
	}

	if ((error = diff_driver_alloc(&drv, &namelen, driver_name)) < 0)
		goto done;

	drv->type = DIFF_DRIVER_AUTO;

	/* if you can't read config for repo, just use default driver */
	if (git_repository_config_snapshot(&cfg, repo) < 0) {
		git_error_clear();
		goto done;
	}

	if ((error = git_str_printf(&name, "diff.%s.binary", driver_name)) < 0)
		goto done;

	switch (git_config__get_bool_force(cfg, name.ptr, -1)) {
	case true:
		/* if diff.<driver>.binary is true, just return the binary driver */
		*out = &diff_driver_binary;
		goto done;
	case false:
		/* if diff.<driver>.binary is false, force binary checks off */
		/* but still may have custom function context patterns, etc. */
		drv->binary_flags = GIT_DIFF_FORCE_TEXT;
		found_driver = true;
		break;
	default:
		/* diff.<driver>.binary unspecified or "auto", so just continue */
		break;
	}

	/* TODO: warn if diff.<name>.command or diff.<name>.textconv are set */

	git_str_truncate(&name, namelen + strlen("diff.."));
	if ((error = git_str_PUTS(&name, "xfuncname")) < 0)
		goto done;

	if ((error = git_config_get_multivar_foreach(
			cfg, name.ptr, NULL, diff_driver_xfuncname, drv)) < 0) {
		if (error != GIT_ENOTFOUND)
			goto done;
		git_error_clear(); /* no diff.<driver>.xfuncname, so just continue */
	}

	git_str_truncate(&name, namelen + strlen("diff.."));
	if ((error = git_str_PUTS(&name, "funcname")) < 0)
		goto done;

	if ((error = git_config_get_multivar_foreach(
			cfg, name.ptr, NULL, diff_driver_funcname, drv)) < 0) {
		if (error != GIT_ENOTFOUND)
			goto done;
		git_error_clear(); /* no diff.<driver>.funcname, so just continue */
	}

	/* if we found any patterns, set driver type to use correct callback */
	if (git_array_size(drv->fn_patterns) > 0) {
		drv->type = DIFF_DRIVER_PATTERNLIST;
		found_driver = true;
	}

	git_str_truncate(&name, namelen + strlen("diff.."));
	if ((error = git_str_PUTS(&name, "wordregex")) < 0)
		goto done;

	if ((error = git_config__lookup_entry(&ce, cfg, name.ptr, false)) < 0)
		goto done;
	if (!ce || !ce->value)
		/* no diff.<driver>.wordregex, so just continue */;
	else if (!(error = git_regexp_compile(&drv->word_pattern, ce->value, 0)))
		found_driver = true;
	else {
		/* TODO: warn about bad regex instead of failure */
		goto done;
	}

	/* TODO: look up diff.<driver>.algorithm to turn on minimal / patience
	 * diff in drv->other_flags
	 */

	/* if no driver config found at all, fall back on AUTO driver */
	if (!found_driver)
		goto done;

	/* store driver in registry */
	if ((error = git_strmap_set(reg->drivers, drv->name, drv)) < 0)
		goto done;

	*out = drv;

done:
	git_config_entry_free(ce);
	git_str_dispose(&name);
	git_config_free(cfg);

	if (!*out) {
		int error2 = git_diff_driver_builtin(out, reg, driver_name);
		if (!error)
			error = error2;
	}

	if (drv && drv != *out)
		git_diff_driver_free(drv);

	return error;
}

int git_diff_driver_lookup(
	git_diff_driver **out, git_repository *repo,
	git_attr_session *attrsession, const char *path)
{
	int error = 0;
	const char *values[1], *attrs[] = { "diff" };

	GIT_ASSERT_ARG(out);
	*out = NULL;

	if (!repo || !path || !strlen(path))
		/* just use the auto value */;
	else if ((error = git_attr_get_many_with_session(values, repo,
			attrsession, 0, path, 1, attrs)) < 0)
		/* return error below */;

	else if (GIT_ATTR_IS_UNSPECIFIED(values[0]))
		/* just use the auto value */;
	else if (GIT_ATTR_IS_FALSE(values[0]))
		*out = &diff_driver_binary;
	else if (GIT_ATTR_IS_TRUE(values[0]))
		*out = &diff_driver_text;

	/* otherwise look for driver information in config and build driver */
	else if ((error = git_diff_driver_load(out, repo, values[0])) < 0) {
		if (error == GIT_ENOTFOUND) {
			error = 0;
			git_error_clear();
		}
	}

	if (!*out)
		*out = &diff_driver_auto;

	return error;
}

void git_diff_driver_free(git_diff_driver *driver)
{
	git_diff_driver_pattern *pat;

	if (!driver)
		return;

	while ((pat = git_array_pop(driver->fn_patterns)) != NULL)
		git_regexp_dispose(&pat->re);
	git_array_clear(driver->fn_patterns);

	git_regexp_dispose(&driver->word_pattern);

	git__free(driver);
}

void git_diff_driver_update_options(
	uint32_t *option_flags, git_diff_driver *driver)
{
	if ((*option_flags & FORCE_DIFFABLE) == 0)
		*option_flags |= driver->binary_flags;

	*option_flags |= driver->other_flags;
}

int git_diff_driver_content_is_binary(
	git_diff_driver *driver, const char *content, size_t content_len)
{
	git_str search = GIT_STR_INIT;

	GIT_UNUSED(driver);

	git_str_attach_notowned(&search, content,
		min(content_len, GIT_FILTER_BYTES_TO_CHECK_NUL));

	/* TODO: provide encoding / binary detection callbacks that can
	 * be UTF-8 aware, etc.  For now, instead of trying to be smart,
	 * let's just use the simple NUL-byte detection that core git uses.
	 */

	/* previously was: if (git_str_is_binary(&search)) */
	if (git_str_contains_nul(&search))
		return 1;

	return 0;
}

static int diff_context_line__simple(
	git_diff_driver *driver, git_str *line)
{
	char firstch = line->ptr[0];
	GIT_UNUSED(driver);
	return (git__isalpha(firstch) || firstch == '_' || firstch == '$');
}

static int diff_context_line__pattern_match(
	git_diff_driver *driver, git_str *line)
{
	size_t i, maxi = git_array_size(driver->fn_patterns);
	git_regmatch pmatch[2];

	for (i = 0; i < maxi; ++i) {
		git_diff_driver_pattern *pat = git_array_get(driver->fn_patterns, i);

		if (!git_regexp_search(&pat->re, line->ptr, 2, pmatch)) {
			if (pat->flags & REG_NEGATE)
				return false;

			/* use pmatch data to trim line data */
			i = (pmatch[1].start >= 0) ? 1 : 0;
			git_str_consume(line, git_str_cstr(line) + pmatch[i].start);
			git_str_truncate(line, pmatch[i].end - pmatch[i].start);
			git_str_rtrim(line);

			return true;
		}
	}

	return false;
}

static long diff_context_find(
	const char *line,
	long line_len,
	char *out,
	long out_size,
	void *payload)
{
	git_diff_find_context_payload *ctxt = payload;

	if (git_str_set(&ctxt->line, line, (size_t)line_len) < 0)
		return -1;
	git_str_rtrim(&ctxt->line);

	if (!ctxt->line.size)
		return -1;

	if (!ctxt->match_line || !ctxt->match_line(ctxt->driver, &ctxt->line))
		return -1;

	if (out_size > (long)ctxt->line.size)
		out_size = (long)ctxt->line.size;
	memcpy(out, ctxt->line.ptr, (size_t)out_size);

	return out_size;
}

void git_diff_find_context_init(
	git_diff_find_context_fn *findfn_out,
	git_diff_find_context_payload *payload_out,
	git_diff_driver *driver)
{
	*findfn_out = driver ? diff_context_find : NULL;

	memset(payload_out, 0, sizeof(*payload_out));
	if (driver) {
		payload_out->driver = driver;
		payload_out->match_line = (driver->type == DIFF_DRIVER_PATTERNLIST) ?
			diff_context_line__pattern_match : diff_context_line__simple;
		git_str_init(&payload_out->line, 0);
	}
}

void git_diff_find_context_clear(git_diff_find_context_payload *payload)
{
	if (payload) {
		git_str_dispose(&payload->line);
		payload->driver = NULL;
	}
}
Commit	Line	Data
114f5a6c RB	1	/*
	2	* Copyright (C) the libgit2 contributors. All rights reserved.
	3	*
	4	* This file is part of libgit2, distributed under the GNU GPL v2 with
	5	* a Linking Exception. For full terms see the included COPYING file.
	6	*/
eae0bfdc PP	7
eae0bfdc PP	8	#include "diff_driver.h"
114f5a6c RB	9
	10	#include "git2/attr.h"
	11
22a2d3d5	12	#include "common.h"
114f5a6c	13	#include "diff.h"
114f5a6c	14	#include "strmap.h"
114f5a6c	15	#include "map.h"
9f77b3f6	16	#include "config.h"
22a2d3d5	17	#include "regexp.h"
5dc98298	18	#include "repository.h"
114f5a6c RB	19
	20	typedef enum {
	21	DIFF_DRIVER_AUTO = 0,
5dc98298 RB	22	DIFF_DRIVER_BINARY = 1,
5dc98298 RB	23	DIFF_DRIVER_TEXT = 2,
e579e0f7	24	DIFF_DRIVER_PATTERNLIST = 3
114f5a6c RB	25	} git_diff_driver_t;
114f5a6c RB	26
a5a38643	27	typedef struct {
22a2d3d5	28	git_regexp re;
a5a38643 RB	29	int flags;
	30	} git_diff_driver_pattern;
	31
114f5a6c	32	enum {
a5a38643	33	REG_NEGATE = (1 << 15) /* get out of the way of existing flags */
114f5a6c RB	34	};
	35
	36	/* data for finding function context for a given file type */
	37	struct git_diff_driver {
	38	git_diff_driver_t type;
5dc98298 RB	39	uint32_t binary_flags;
5dc98298 RB	40	uint32_t other_flags;
a5a38643	41	git_array_t(git_diff_driver_pattern) fn_patterns;
22a2d3d5	42	git_regexp word_pattern;
42e6cf78	43	char name[GIT_FLEX_ARRAY];
114f5a6c RB	44	};
114f5a6c RB	45
c7c260a5	46	#include "userdiff.h"
2c65602e	47
114f5a6c RB	48	struct git_diff_driver_registry {
114f5a6c RB	49	git_strmap *drivers;
114f5a6c RB	50	};
114f5a6c RB	51
5dc98298 RB	52	#define FORCE_DIFFABLE (GIT_DIFF_FORCE_TEXT \| GIT_DIFF_FORCE_BINARY)
5dc98298 RB	53
e579e0f7 MB	54	static git_diff_driver diff_driver_auto = { DIFF_DRIVER_AUTO, 0, 0 };
	55	static git_diff_driver diff_driver_binary = { DIFF_DRIVER_BINARY, GIT_DIFF_FORCE_BINARY, 0 };
	56	static git_diff_driver diff_driver_text = { DIFF_DRIVER_TEXT, GIT_DIFF_FORCE_TEXT, 0 };
114f5a6c	57
8fd74c08	58	git_diff_driver_registry *git_diff_driver_registry_new(void)
114f5a6c	59	{
3eadfecd RB	60	git_diff_driver_registry *reg =
	61	git__calloc(1, sizeof(git_diff_driver_registry));
	62	if (!reg)
	63	return NULL;
	64
22a2d3d5	65	if (git_strmap_new(&reg->drivers) < 0) {
3eadfecd RB	66	git_diff_driver_registry_free(reg);
	67	return NULL;
	68	}
	69
	70	return reg;
114f5a6c RB	71	}
	72
	73	void git_diff_driver_registry_free(git_diff_driver_registry *reg)
	74	{
5dc98298 RB	75	git_diff_driver *drv;
5dc98298 RB	76
3eadfecd RB	77	if (!reg)
	78	return;
	79
5dc98298	80	git_strmap_foreach_value(reg->drivers, drv, git_diff_driver_free(drv));
3eadfecd	81	git_strmap_free(reg->drivers);
114f5a6c RB	82	git__free(reg);
	83	}
	84
a5a38643 RB	85	static int diff_driver_add_patterns(
a5a38643 RB	86	git_diff_driver drv, const char regex_str, int regex_flags)
5dc98298	87	{
a5a38643 RB	88	int error = 0;
	89	const char scan, end;
	90	git_diff_driver_pattern *pat = NULL;
e579e0f7	91	git_str buf = GIT_STR_INIT;
a5a38643 RB	92
	93	for (scan = regex_str; scan; scan = end) {
	94	/* get pattern to fill in */
	95	if ((pat = git_array_alloc(drv->fn_patterns)) == NULL) {
e451cd5c	96	return -1;
a5a38643	97	}
5dc98298	98
a5a38643 RB	99	pat->flags = regex_flags;
	100	if (*scan == '!') {
	101	pat->flags \|= REG_NEGATE;
	102	++scan;
	103	}
	104
	105	if ((end = strchr(scan, '\n')) != NULL) {
e579e0f7	106	error = git_str_set(&buf, scan, end - scan);
a5a38643 RB	107	end++;
a5a38643 RB	108	} else {
e579e0f7	109	error = git_str_sets(&buf, scan);
a5a38643 RB	110	}
	111	if (error < 0)
	112	break;
	113
22a2d3d5	114	if ((error = git_regexp_compile(&pat->re, buf.ptr, regex_flags)) != 0) {
e451cd5c CMN	115	/*
	116	* TODO: issue a warning
	117	*/
a5a38643	118	}
5dc98298 RB	119	}
5dc98298 RB	120
a5a38643 RB	121	if (error && pat != NULL)
a5a38643 RB	122	(void)git_array_pop(drv->fn_patterns); /* release last item */
e579e0f7	123	git_str_dispose(&buf);
5dc98298	124
e451cd5c CMN	125	/* We want to ignore bad patterns, so return success regardless */
e451cd5c CMN	126	return 0;
5dc98298 RB	127	}
	128
	129	static int diff_driver_xfuncname(const git_config_entry entry, void payload)
	130	{
22a2d3d5	131	return diff_driver_add_patterns(payload, entry->value, 0);
5dc98298 RB	132	}
	133
	134	static int diff_driver_funcname(const git_config_entry entry, void payload)
	135	{
a5a38643	136	return diff_driver_add_patterns(payload, entry->value, 0);
5dc98298 RB	137	}
	138
	139	static git_diff_driver_registry *git_repository_driver_registry(
	140	git_repository *repo)
	141	{
c25aa7cd PP	142	git_diff_driver_registry reg = git_atomic_load(repo->diff_drivers), newreg;
	143	if (reg)
	144	return reg;
5dc98298	145
c25aa7cd PP	146	newreg = git_diff_driver_registry_new();
c25aa7cd PP	147	if (!newreg) {
ac3d33df	148	git_error_set(GIT_ERROR_REPOSITORY, "unable to create diff driver registry");
c25aa7cd PP	149	return newreg;
	150	}
	151	reg = git_atomic_compare_and_swap(&repo->diff_drivers, NULL, newreg);
	152	if (!reg) {
	153	reg = newreg;
	154	} else {
	155	/* if we race, free losing allocation */
	156	git_diff_driver_registry_free(newreg);
	157	}
	158	return reg;
5dc98298 RB	159	}
5dc98298 RB	160
392702ee ET	161	static int diff_driver_alloc(
	162	git_diff_driver *out, size_t namelen_out, const char *name)
	163	{
	164	git_diff_driver *driver;
	165	size_t driverlen = sizeof(git_diff_driver),
f1453c59 ET	166	namelen = strlen(name),
f1453c59 ET	167	alloclen;
392702ee	168
ac3d33df JK	169	GIT_ERROR_CHECK_ALLOC_ADD(&alloclen, driverlen, namelen);
ac3d33df JK	170	GIT_ERROR_CHECK_ALLOC_ADD(&alloclen, alloclen, 1);
392702ee	171
f1453c59	172	driver = git__calloc(1, alloclen);
ac3d33df	173	GIT_ERROR_CHECK_ALLOC(driver);
392702ee ET	174
	175	memcpy(driver->name, name, namelen);
	176
	177	*out = driver;
	178
	179	if (namelen_out)
	180	*namelen_out = namelen;
	181
	182	return 0;
	183	}
	184
a5a38643 RB	185	static int git_diff_driver_builtin(
	186	git_diff_driver **out,
	187	git_diff_driver_registry *reg,
	188	const char *driver_name)
	189	{
a5a38643 RB	190	git_diff_driver_definition *ddef = NULL;
a5a38643 RB	191	git_diff_driver *drv = NULL;
22a2d3d5	192	int error = 0;
392702ee	193	size_t idx;
a5a38643 RB	194
	195	for (idx = 0; idx < ARRAY_SIZE(builtin_defs); ++idx) {
	196	if (!strcasecmp(driver_name, builtin_defs[idx].name)) {
	197	ddef = &builtin_defs[idx];
	198	break;
	199	}
	200	}
	201	if (!ddef)
	202	goto done;
	203
392702ee ET	204	if ((error = diff_driver_alloc(&drv, NULL, ddef->name)) < 0)
392702ee ET	205	goto done;
a5a38643 RB	206
a5a38643 RB	207	drv->type = DIFF_DRIVER_PATTERNLIST;
a5a38643 RB	208
	209	if (ddef->fns &&
	210	(error = diff_driver_add_patterns(
22a2d3d5	211	drv, ddef->fns, ddef->flags)) < 0)
a5a38643 RB	212	goto done;
	213
	214	if (ddef->words &&
22a2d3d5	215	(error = git_regexp_compile(&drv->word_pattern, ddef->words, ddef->flags)) < 0)
a5a38643	216	goto done;
a5a38643	217
22a2d3d5 UG	218	if ((error = git_strmap_set(reg->drivers, drv->name, drv)) < 0)
22a2d3d5 UG	219	goto done;
a5a38643 RB	220
a5a38643 RB	221	done:
2c65602e	222	if (error && drv)
a5a38643	223	git_diff_driver_free(drv);
2c65602e	224	else
a5a38643	225	*out = drv;
a5a38643 RB	226
	227	return error;
	228	}
	229
3eadfecd	230	static int git_diff_driver_load(
5dc98298	231	git_diff_driver *out, git_repository repo, const char *driver_name)
3eadfecd	232	{
9f77b3f6	233	int error = 0;
5dc98298	234	git_diff_driver_registry *reg;
22a2d3d5 UG	235	git_diff_driver *drv;
22a2d3d5 UG	236	size_t namelen;
392702ee	237	git_config *cfg = NULL;
e579e0f7	238	git_str name = GIT_STR_INIT;
9a97f49e	239	git_config_entry *ce = NULL;
42e6cf78	240	bool found_driver = false;
5dc98298	241
a5a38643	242	if ((reg = git_repository_driver_registry(repo)) == NULL)
5dc98298	243	return -1;
a5a38643	244
22a2d3d5 UG	245	if ((drv = git_strmap_get(reg->drivers, driver_name)) != NULL) {
22a2d3d5 UG	246	*out = drv;
a5a38643	247	return 0;
5dc98298 RB	248	}
5dc98298 RB	249
392702ee ET	250	if ((error = diff_driver_alloc(&drv, &namelen, driver_name)) < 0)
	251	goto done;
	252
a37aa82e	253	drv->type = DIFF_DRIVER_AUTO;
a37aa82e	254
5dc98298	255	/* if you can't read config for repo, just use default driver */
ac99d86b	256	if (git_repository_config_snapshot(&cfg, repo) < 0) {
ac3d33df	257	git_error_clear();
a5a38643	258	goto done;
5dc98298 RB	259	}
5dc98298 RB	260
e579e0f7	261	if ((error = git_str_printf(&name, "diff.%s.binary", driver_name)) < 0)
54faddd2	262	goto done;
9f77b3f6 RB	263
	264	switch (git_config__get_bool_force(cfg, name.ptr, -1)) {
	265	case true:
5dc98298	266	/* if diff.<driver>.binary is true, just return the binary driver */
e579e0f7	267	*out = &diff_driver_binary;
54faddd2	268	goto done;
9f77b3f6	269	case false:
5dc98298 RB	270	/* if diff.<driver>.binary is false, force binary checks off */
	271	/* but still may have custom function context patterns, etc. */
	272	drv->binary_flags = GIT_DIFF_FORCE_TEXT;
42e6cf78	273	found_driver = true;
9f77b3f6 RB	274	break;
9f77b3f6 RB	275	default:
a5a38643	276	/* diff.<driver>.binary unspecified or "auto", so just continue */
9f77b3f6	277	break;
5dc98298 RB	278	}
	279
	280	/* TODO: warn if diff.<name>.command or diff.<name>.textconv are set */
	281
e579e0f7 MB	282	git_str_truncate(&name, namelen + strlen("diff.."));
e579e0f7 MB	283	if ((error = git_str_PUTS(&name, "xfuncname")) < 0)
22a2d3d5 UG	284	goto done;
22a2d3d5 UG	285
4efa3290	286	if ((error = git_config_get_multivar_foreach(
5dc98298 RB	287	cfg, name.ptr, NULL, diff_driver_xfuncname, drv)) < 0) {
5dc98298 RB	288	if (error != GIT_ENOTFOUND)
54faddd2	289	goto done;
ac3d33df	290	git_error_clear(); /* no diff.<driver>.xfuncname, so just continue */
5dc98298	291	}
3eadfecd	292
e579e0f7 MB	293	git_str_truncate(&name, namelen + strlen("diff.."));
e579e0f7 MB	294	if ((error = git_str_PUTS(&name, "funcname")) < 0)
22a2d3d5 UG	295	goto done;
22a2d3d5 UG	296
4efa3290	297	if ((error = git_config_get_multivar_foreach(
5dc98298 RB	298	cfg, name.ptr, NULL, diff_driver_funcname, drv)) < 0) {
5dc98298 RB	299	if (error != GIT_ENOTFOUND)
54faddd2	300	goto done;
ac3d33df	301	git_error_clear(); /* no diff.<driver>.funcname, so just continue */
5dc98298 RB	302	}
	303
	304	/* if we found any patterns, set driver type to use correct callback */
42e6cf78	305	if (git_array_size(drv->fn_patterns) > 0) {
5dc98298	306	drv->type = DIFF_DRIVER_PATTERNLIST;
42e6cf78 RB	307	found_driver = true;
42e6cf78 RB	308	}
5dc98298	309
e579e0f7 MB	310	git_str_truncate(&name, namelen + strlen("diff.."));
e579e0f7 MB	311	if ((error = git_str_PUTS(&name, "wordregex")) < 0)
22a2d3d5 UG	312	goto done;
22a2d3d5 UG	313
9f77b3f6	314	if ((error = git_config__lookup_entry(&ce, cfg, name.ptr, false)) < 0)
54faddd2	315	goto done;
9f77b3f6 RB	316	if (!ce \|\| !ce->value)
9f77b3f6 RB	317	/* no diff.<driver>.wordregex, so just continue */;
22a2d3d5	318	else if (!(error = git_regexp_compile(&drv->word_pattern, ce->value, 0)))
42e6cf78	319	found_driver = true;
9f77b3f6 RB	320	else {
9f77b3f6 RB	321	/* TODO: warn about bad regex instead of failure */
9f77b3f6	322	goto done;
5dc98298 RB	323	}
	324
	325	/* TODO: look up diff.<driver>.algorithm to turn on minimal / patience
	326	* diff in drv->other_flags
	327	*/
	328
54faddd2	329	/* if no driver config found at all, fall back on AUTO driver */
42e6cf78	330	if (!found_driver)
54faddd2	331	goto done;
42e6cf78 RB	332
42e6cf78 RB	333	/* store driver in registry */
22a2d3d5	334	if ((error = git_strmap_set(reg->drivers, drv->name, drv)) < 0)
54faddd2	335	goto done;
42e6cf78	336
5dc98298	337	*out = drv;
5dc98298	338
54faddd2	339	done:
9a97f49e	340	git_config_entry_free(ce);
e579e0f7	341	git_str_dispose(&name);
29c4cb09	342	git_config_free(cfg);
54faddd2	343
a5a38643 RB	344	if (!*out) {
	345	int error2 = git_diff_driver_builtin(out, reg, driver_name);
	346	if (!error)
	347	error = error2;
	348	}
54faddd2 RB	349
	350	if (drv && drv != *out)
	351	git_diff_driver_free(drv);
	352
5dc98298	353	return error;
3eadfecd RB	354	}
3eadfecd RB	355
114f5a6c	356	int git_diff_driver_lookup(
eae0bfdc PP	357	git_diff_driver *out, git_repository repo,
eae0bfdc PP	358	git_attr_session attrsession, const char path)
114f5a6c	359	{
3eadfecd	360	int error = 0;
eae0bfdc	361	const char values[1], attrs[] = { "diff" };
114f5a6c	362
c25aa7cd	363	GIT_ASSERT_ARG(out);
2c65602e	364	*out = NULL;
114f5a6c RB	365
114f5a6c RB	366	if (!repo \|\| !path \|\| !strlen(path))
2c65602e	367	/* just use the auto value */;
eae0bfdc PP	368	else if ((error = git_attr_get_many_with_session(values, repo,
eae0bfdc PP	369	attrsession, 0, path, 1, attrs)) < 0)
2c65602e	370	/* return error below */;
eae0bfdc	371
22a2d3d5	372	else if (GIT_ATTR_IS_UNSPECIFIED(values[0]))
42e6cf78	373	/* just use the auto value */;
22a2d3d5	374	else if (GIT_ATTR_IS_FALSE(values[0]))
e579e0f7	375	*out = &diff_driver_binary;
22a2d3d5	376	else if (GIT_ATTR_IS_TRUE(values[0]))
e579e0f7	377	*out = &diff_driver_text;
114f5a6c RB	378
114f5a6c RB	379	/* otherwise look for driver information in config and build driver */
eae0bfdc	380	else if ((error = git_diff_driver_load(out, repo, values[0])) < 0) {
2c65602e RB	381	if (error == GIT_ENOTFOUND) {
2c65602e RB	382	error = 0;
ac3d33df	383	git_error_clear();
2c65602e	384	}
3eadfecd	385	}
114f5a6c	386
42e6cf78	387	if (!*out)
e579e0f7	388	*out = &diff_driver_auto;
42e6cf78	389
2c65602e	390	return error;
114f5a6c RB	391	}
	392
	393	void git_diff_driver_free(git_diff_driver *driver)
	394	{
c25aa7cd	395	git_diff_driver_pattern *pat;
5dc98298 RB	396
	397	if (!driver)
	398	return;
	399
c25aa7cd PP	400	while ((pat = git_array_pop(driver->fn_patterns)) != NULL)
c25aa7cd PP	401	git_regexp_dispose(&pat->re);
5dc98298 RB	402	git_array_clear(driver->fn_patterns);
5dc98298 RB	403
22a2d3d5	404	git_regexp_dispose(&driver->word_pattern);
5dc98298 RB	405
5dc98298 RB	406	git__free(driver);
114f5a6c RB	407	}
114f5a6c RB	408
5dc98298 RB	409	void git_diff_driver_update_options(
5dc98298 RB	410	uint32_t option_flags, git_diff_driver driver)
114f5a6c	411	{
5dc98298 RB	412	if ((*option_flags & FORCE_DIFFABLE) == 0)
	413	*option_flags \|= driver->binary_flags;
	414
	415	*option_flags \|= driver->other_flags;
114f5a6c RB	416	}
	417
	418	int git_diff_driver_content_is_binary(
	419	git_diff_driver driver, const char content, size_t content_len)
	420	{
e579e0f7	421	git_str search = GIT_STR_INIT;
114f5a6c RB	422
	423	GIT_UNUSED(driver);
	424
e579e0f7	425	git_str_attach_notowned(&search, content,
d4cf1675 ET	426	min(content_len, GIT_FILTER_BYTES_TO_CHECK_NUL));
d4cf1675 ET	427
114f5a6c RB	428	/* TODO: provide encoding / binary detection callbacks that can
	429	* be UTF-8 aware, etc. For now, instead of trying to be smart,
	430	* let's just use the simple NUL-byte detection that core git uses.
	431	*/
	432
e579e0f7 MB	433	/* previously was: if (git_str_is_binary(&search)) */
e579e0f7 MB	434	if (git_str_contains_nul(&search))
114f5a6c RB	435	return 1;
	436
	437	return 0;
	438	}
	439
5dc98298	440	static int diff_context_line__simple(
e579e0f7	441	git_diff_driver driver, git_str line)
5dc98298	442	{
a5a38643	443	char firstch = line->ptr[0];
5dc98298	444	GIT_UNUSED(driver);
a5a38643	445	return (git__isalpha(firstch) \|\| firstch == '_' \|\| firstch == '$');
5dc98298 RB	446	}
	447
	448	static int diff_context_line__pattern_match(
e579e0f7	449	git_diff_driver driver, git_str line)
5dc98298	450	{
b8e86c62	451	size_t i, maxi = git_array_size(driver->fn_patterns);
22a2d3d5	452	git_regmatch pmatch[2];
5dc98298	453
b8e86c62	454	for (i = 0; i < maxi; ++i) {
a5a38643 RB	455	git_diff_driver_pattern *pat = git_array_get(driver->fn_patterns, i);
a5a38643 RB	456
22a2d3d5	457	if (!git_regexp_search(&pat->re, line->ptr, 2, pmatch)) {
a5a38643 RB	458	if (pat->flags & REG_NEGATE)
a5a38643 RB	459	return false;
b8e86c62 RB	460
b8e86c62 RB	461	/* use pmatch data to trim line data */
22a2d3d5	462	i = (pmatch[1].start >= 0) ? 1 : 0;
e579e0f7 MB	463	git_str_consume(line, git_str_cstr(line) + pmatch[i].start);
	464	git_str_truncate(line, pmatch[i].end - pmatch[i].start);
	465	git_str_rtrim(line);
b8e86c62	466
5dc98298	467	return true;
a5a38643	468	}
5dc98298 RB	469	}
	470
	471	return false;
	472	}
	473
114f5a6c RB	474	static long diff_context_find(
	475	const char *line,
	476	long line_len,
	477	char *out,
	478	long out_size,
	479	void *payload)
	480	{
5dc98298	481	git_diff_find_context_payload *ctxt = payload;
114f5a6c	482
e579e0f7	483	if (git_str_set(&ctxt->line, line, (size_t)line_len) < 0)
114f5a6c	484	return -1;
e579e0f7	485	git_str_rtrim(&ctxt->line);
114f5a6c	486
5dc98298	487	if (!ctxt->line.size)
114f5a6c RB	488	return -1;
114f5a6c RB	489
a5a38643	490	if (!ctxt->match_line \|\| !ctxt->match_line(ctxt->driver, &ctxt->line))
5dc98298	491	return -1;
114f5a6c	492
a5f9b5f8	493	if (out_size > (long)ctxt->line.size)
584f2d30	494	out_size = (long)ctxt->line.size;
a5f9b5f8	495	memcpy(out, ctxt->line.ptr, (size_t)out_size);
114f5a6c	496
a5f9b5f8	497	return out_size;
5dc98298	498	}
114f5a6c	499
5dc98298 RB	500	void git_diff_find_context_init(
	501	git_diff_find_context_fn *findfn_out,
	502	git_diff_find_context_payload *payload_out,
	503	git_diff_driver *driver)
	504	{
	505	*findfn_out = driver ? diff_context_find : NULL;
	506
	507	memset(payload_out, 0, sizeof(*payload_out));
	508	if (driver) {
	509	payload_out->driver = driver;
	510	payload_out->match_line = (driver->type == DIFF_DRIVER_PATTERNLIST) ?
	511	diff_context_line__pattern_match : diff_context_line__simple;
e579e0f7	512	git_str_init(&payload_out->line, 0);
5dc98298	513	}
114f5a6c RB	514	}
114f5a6c RB	515
5dc98298	516	void git_diff_find_context_clear(git_diff_find_context_payload *payload)
114f5a6c	517	{
5dc98298	518	if (payload) {
e579e0f7	519	git_str_dispose(&payload->line);
5dc98298 RB	520	payload->driver = NULL;
5dc98298 RB	521	}
114f5a6c	522	}