#include "common.h"

#include "git2/attr.h"

#include "diff.h"

#include "diff_patch.h"

#include "diff_driver.h"

#include "strmap.h"

#include "map.h"

#include "buf_text.h"

#include "config.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 {

regex_t re;

int flags;

} git_diff_driver_pattern;

enum {

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

};

struct git_diff_driver {

};

#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 global_drivers[3] = {

{ DIFF_DRIVER_AUTO, 0, 0, },

{ DIFF_DRIVER_BINARY, GIT_DIFF_FORCE_BINARY, 0 },

{ DIFF_DRIVER_TEXT, GIT_DIFF_FORCE_TEXT, 0 },

};

git_diff_driver_registry *git_diff_driver_registry_new()

{

git_diff_driver_registry *reg =

git__calloc(1, sizeof(git_diff_driver_registry));

if (!reg)

return NULL;

if (git_strmap_alloc(&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_buf buf = GIT_BUF_INIT;

for (scan = regex_str; scan; scan = end) {

/* get pattern to fill in */

if ((pat = git_array_alloc(drv->fn_patterns)) == NULL) {

error = -1;

break;

}

pat->flags = regex_flags;

if (*scan == '!') {

pat->flags |= REG_NEGATE;

++scan;

}

if ((end = strchr(scan, '\n')) != NULL) {

error = git_buf_set(&buf, scan, end - scan);

end++;

} else {

error = git_buf_sets(&buf, scan);

}

if (error < 0)

break;

if ((error = regcomp(&pat->re, buf.ptr, regex_flags)) < 0) {

/* if regex fails to compile, warn? fail? */

error = giterr_set_regex(&pat->re, error);

regfree(&pat->re);

break;

}

}

if (error && pat != NULL)

(void)git_array_pop(drv->fn_patterns); /* release last item */

git_buf_free(&buf);

return error;

}

static int diff_driver_xfuncname(const git_config_entry *entry, void *payload)

{

return diff_driver_add_patterns(payload, entry->value, REG_EXTENDED);

}

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)

{

if (!repo->diff_drivers) {

git_diff_driver_registry *reg = git_diff_driver_registry_new();

reg = git__compare_and_swap(&repo->diff_drivers, NULL, reg);

if (reg != NULL) /* if we race, free losing allocation */

git_diff_driver_registry_free(reg);

}

if (!repo->diff_drivers)

giterr_set(GITERR_REPOSITORY, "Unable to create diff driver registry");

return repo->diff_drivers;

}

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;

GITERR_CHECK_ALLOC_ADD(&alloclen, driverlen, namelen);

GITERR_CHECK_ALLOC_ADD(&alloclen, alloclen, 1);

driver = git__calloc(1, alloclen);

GITERR_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)

{

int error = 0;

git_diff_driver_definition *ddef = NULL;

git_diff_driver *drv = NULL;

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 | REG_EXTENDED)) < 0)

goto done;

if (ddef->words &&

(error = regcomp(

&drv->word_pattern, ddef->words, ddef->flags | REG_EXTENDED)))

{

error = giterr_set_regex(&drv->word_pattern, error);

goto done;

}

git_strmap_insert(reg->drivers, drv->name, drv, error);

if (error > 0)

error = 0;

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 = NULL;

size_t namelen;

khiter_t pos;

git_config *cfg = NULL;

git_buf name = GIT_BUF_INIT;

const git_config_entry *ce;

bool found_driver = false;

if ((reg = git_repository_driver_registry(repo)) == NULL)

return -1;

pos = git_strmap_lookup_index(reg->drivers, driver_name);

if (git_strmap_valid_index(reg->drivers, pos)) {

*out = git_strmap_value_at(reg->drivers, pos);

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) {

giterr_clear();

goto done;

}

if ((error = git_buf_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 = &global_drivers[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_buf_truncate(&name, namelen + strlen("diff.."));

git_buf_put(&name, "xfuncname", strlen("xfuncname"));

if ((error = git_config_get_multivar_foreach(

cfg, name.ptr, NULL, diff_driver_xfuncname, drv)) < 0) {

if (error != GIT_ENOTFOUND)

goto done;

giterr_clear(); /* no diff.<driver>.xfuncname, so just continue */

}

git_buf_truncate(&name, namelen + strlen("diff.."));

git_buf_put(&name, "funcname", strlen("funcname"));

if ((error = git_config_get_multivar_foreach(

cfg, name.ptr, NULL, diff_driver_funcname, drv)) < 0) {

if (error != GIT_ENOTFOUND)

goto done;

giterr_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_buf_truncate(&name, namelen + strlen("diff.."));

git_buf_put(&name, "wordregex", strlen("wordregex"));

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 = regcomp(&drv->word_pattern, ce->value, REG_EXTENDED)))

found_driver = true;

else {

/* TODO: warn about bad regex instead of failure */

error = giterr_set_regex(&drv->word_pattern, error);

goto done;

}

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

/* if no driver config found at all, fall back on AUTO driver */

if (!found_driver)

goto done;

/* store driver in registry */

git_strmap_insert(reg->drivers, drv->name, drv, error);

if (error < 0)

goto done;

error = 0;

*out = drv;

done:

git_buf_free(&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, const char *path)

{

int error = 0;

const char *value;

assert(out);

*out = NULL;

if (!repo || !path || !strlen(path))

/* just use the auto value */;

else if ((error = git_attr_get(&value, repo, 0, path, "diff")) < 0)

/* return error below */;

else if (GIT_ATTR_UNSPECIFIED(value))

/* just use the auto value */;

else if (GIT_ATTR_FALSE(value))

*out = &global_drivers[DIFF_DRIVER_BINARY];

else if (GIT_ATTR_TRUE(value))

*out = &global_drivers[DIFF_DRIVER_TEXT];

/* otherwise look for driver information in config and build driver */

else if ((error = git_diff_driver_load(out, repo, value)) < 0) {

if (error == GIT_ENOTFOUND) {

error = 0;

giterr_clear();

}

}

if (!*out)

*out = &global_drivers[DIFF_DRIVER_AUTO];

return error;

}

void git_diff_driver_free(git_diff_driver *driver)

{

size_t i;

if (!driver)

return;

for (i = 0; i < git_array_size(driver->fn_patterns); ++i)

regfree(& git_array_get(driver->fn_patterns, i)->re);

git_array_clear(driver->fn_patterns);

regfree(&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_buf search;

search.ptr = (char *)content;

search.size = min(content_len, GIT_FILTER_BYTES_TO_CHECK_NUL);

search.asize = 0;

GIT_UNUSED(driver);

/* TODO: provide encoding / binary detection callbacks that can

/* previously was: if (git_buf_text_is_binary(&search)) */

if (git_buf_text_contains_nul(&search))

return 1;

return 0;

}

static int diff_context_line__simple(

git_diff_driver *driver, git_buf *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_buf *line)

{

size_t i, maxi = git_array_size(driver->fn_patterns);

regmatch_t pmatch[2];

for (i = 0; i < maxi; ++i) {

git_diff_driver_pattern *pat = git_array_get(driver->fn_patterns, i);

if (!regexec(&pat->re, line->ptr, 2, pmatch, 0)) {

if (pat->flags & REG_NEGATE)

return false;

/* use pmatch data to trim line data */

i = (pmatch[1].rm_so >= 0) ? 1 : 0;

git_buf_consume(line, git_buf_cstr(line) + pmatch[i].rm_so);

git_buf_truncate(line, pmatch[i].rm_eo - pmatch[i].rm_so);

git_buf_rtrim(line);

return true;

}

}

return false;

}

static long diff_context_find(

void *payload)

{

git_diff_find_context_payload *ctxt = payload;

if (git_buf_set(&ctxt->line, line, (size_t)line_len) < 0)

return -1;

git_buf_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_buf_init(&payload_out->line, 0);

}

}

void git_diff_find_context_clear(git_diff_find_context_payload *payload)

{

if (payload) {

git_buf_free(&payload->line);

payload->driver = NULL;

}

}