thodg/libgit2/src/crlf.c

• Show log

  Commit

• Hash : 658022c4
  Author :
  Date : 2019-07-18T13:53:41
  

  configuration: cvar -> configmap `cvar` is an unhelpful name. Refactor its usage to `configmap` for more clarity.

Download

• src/crlf.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 "common.h"
  
  #include "git2/attr.h"
  #include "git2/blob.h"
  #include "git2/index.h"
  #include "git2/sys/filter.h"
  
  #include "fileops.h"
  #include "hash.h"
  #include "filter.h"
  #include "buf_text.h"
  #include "repository.h"
  
  typedef enum {
  	GIT_CRLF_UNDEFINED,
  	GIT_CRLF_BINARY,
  	GIT_CRLF_TEXT,
  	GIT_CRLF_TEXT_INPUT,
  	GIT_CRLF_TEXT_CRLF,
  	GIT_CRLF_AUTO,
  	GIT_CRLF_AUTO_INPUT,
  	GIT_CRLF_AUTO_CRLF,
  } git_crlf_t;
  
  struct crlf_attrs {
  	int attr_action; /* the .gitattributes setting */
  	int crlf_action; /* the core.autocrlf setting */
  
  	int auto_crlf;
  	int safe_crlf;
  	int core_eol;
  };
  
  struct crlf_filter {
  	git_filter f;
  };
  
  static git_crlf_t check_crlf(const char *value)
  {
  	if (GIT_ATTR_IS_TRUE(value))
  		return GIT_CRLF_TEXT;
  	else if (GIT_ATTR_IS_FALSE(value))
  		return GIT_CRLF_BINARY;
  	else if (GIT_ATTR_IS_UNSPECIFIED(value))
  		;
  	else if (strcmp(value, "input") == 0)
  		return GIT_CRLF_TEXT_INPUT;
  	else if (strcmp(value, "auto") == 0)
  		return GIT_CRLF_AUTO;
  
  	return GIT_CRLF_UNDEFINED;
  }
  
  static git_configmap_value check_eol(const char *value)
  {
  	if (GIT_ATTR_IS_UNSPECIFIED(value))
  		;
  	else if (strcmp(value, "lf") == 0)
  		return GIT_EOL_LF;
  	else if (strcmp(value, "crlf") == 0)
  		return GIT_EOL_CRLF;
  
  	return GIT_EOL_UNSET;
  }
  
  static int has_cr_in_index(const git_filter_source *src)
  {
  	git_repository *repo = git_filter_source_repo(src);
  	const char *path = git_filter_source_path(src);
  	git_index *index;
  	const git_index_entry *entry;
  	git_blob *blob;
  	const void *blobcontent;
  	git_off_t blobsize;
  	bool found_cr;
  
  	if (!path)
  		return false;
  
  	if (git_repository_index__weakptr(&index, repo) < 0) {
  		git_error_clear();
  		return false;
  	}
  
  	if (!(entry = git_index_get_bypath(index, path, 0)) &&
  		!(entry = git_index_get_bypath(index, path, 1)))
  		return false;
  
  	if (!S_ISREG(entry->mode)) /* don't crlf filter non-blobs */
  		return true;
  
  	if (git_blob_lookup(&blob, repo, &entry->id) < 0)
  		return false;
  
  	blobcontent = git_blob_rawcontent(blob);
  	blobsize    = git_blob_rawsize(blob);
  	if (!git__is_sizet(blobsize))
  		blobsize = (size_t)-1;
  
  	found_cr = (blobcontent != NULL &&
  		blobsize > 0 &&
  		memchr(blobcontent, '\r', (size_t)blobsize) != NULL);
  
  	git_blob_free(blob);
  	return found_cr;
  }
  
  static int text_eol_is_crlf(struct crlf_attrs *ca)
  {
  	if (ca->auto_crlf == GIT_AUTO_CRLF_TRUE)
  		return 1;
  	else if (ca->auto_crlf == GIT_AUTO_CRLF_INPUT)
  		return 0;
  
  	if (ca->core_eol == GIT_EOL_CRLF)
  		return 1;
  	if (ca->core_eol == GIT_EOL_UNSET && GIT_EOL_NATIVE == GIT_EOL_CRLF)
  		return 1;
  
  	return 0;
  }
  
  static git_configmap_value output_eol(struct crlf_attrs *ca)
  {
  	switch (ca->crlf_action) {
  	case GIT_CRLF_BINARY:
  		return GIT_EOL_UNSET;
  	case GIT_CRLF_TEXT_CRLF:
  		return GIT_EOL_CRLF;
  	case GIT_CRLF_TEXT_INPUT:
  		return GIT_EOL_LF;
  	case GIT_CRLF_UNDEFINED:
  	case GIT_CRLF_AUTO_CRLF:
  		return GIT_EOL_CRLF;
  	case GIT_CRLF_AUTO_INPUT:
  		return GIT_EOL_LF;
  	case GIT_CRLF_TEXT:
  	case GIT_CRLF_AUTO:
  		return text_eol_is_crlf(ca) ? GIT_EOL_CRLF : GIT_EOL_LF;
  	}
  
  	/* TODO: warn when available */
  	return ca->core_eol;
  }
  
  GIT_INLINE(int) check_safecrlf(
  	struct crlf_attrs *ca,
  	const git_filter_source *src,
  	git_buf_text_stats *stats)
  {
  	const char *filename = git_filter_source_path(src);
  
  	if (!ca->safe_crlf)
  		return 0;
  
  	if (output_eol(ca) == GIT_EOL_LF) {
  		/*
  		 * CRLFs would not be restored by checkout:
  		 * check if we'd remove CRLFs
  		 */
  		if (stats->crlf) {
  			if (ca->safe_crlf == GIT_SAFE_CRLF_WARN) {
  				/* TODO: issue a warning when available */
  			} else {
  				if (filename && *filename)
  					git_error_set(
  						GIT_ERROR_FILTER, "CRLF would be replaced by LF in '%s'",
  						filename);
  				else
  					git_error_set(
  						GIT_ERROR_FILTER, "CRLF would be replaced by LF");
  
  				return -1;
  			}
  		}
  	} else if (output_eol(ca) == GIT_EOL_CRLF) {
  		/*
  		 * CRLFs would be added by checkout:
  		 * check if we have "naked" LFs
  		 */
  		if (stats->crlf != stats->lf) {
  			if (ca->safe_crlf == GIT_SAFE_CRLF_WARN) {
  				/* TODO: issue a warning when available */
  			} else {
  				if (filename && *filename)
  					git_error_set(
  						GIT_ERROR_FILTER, "LF would be replaced by CRLF in '%s'",
  						filename);
  				else
  					git_error_set(
  						GIT_ERROR_FILTER, "LF would be replaced by CRLF");
  
  				return -1;
  			}
  		}
  	}
  
  	return 0;
  }
  
  static int crlf_apply_to_odb(
  	struct crlf_attrs *ca,
  	git_buf *to,
  	const git_buf *from,
  	const git_filter_source *src)
  {
  	git_buf_text_stats stats;
  	bool is_binary;
  	int error;
  
  	/* Binary attribute? Empty file? Nothing to do */
  	if (ca->crlf_action == GIT_CRLF_BINARY || !git_buf_len(from))
  		return GIT_PASSTHROUGH;
  
  	is_binary = git_buf_text_gather_stats(&stats, from, false);
  
  	/* Heuristics to see if we can skip the conversion.
  	 * Straight from Core Git.
  	 */
  	if (ca->crlf_action == GIT_CRLF_AUTO ||
  		ca->crlf_action == GIT_CRLF_AUTO_INPUT ||
  		ca->crlf_action == GIT_CRLF_AUTO_CRLF) {
  
  		if (is_binary)
  			return GIT_PASSTHROUGH;
  
  		/*
  		 * If the file in the index has any CR in it, do not convert.
  		 * This is the new safer autocrlf handling.
  		 */
  		if (has_cr_in_index(src))
  			return GIT_PASSTHROUGH;
  	}
  
  	if ((error = check_safecrlf(ca, src, &stats)) < 0)
  		return error;
  
  	/* If there are no CR characters to filter out, then just pass */
  	if (!stats.crlf)
  		return GIT_PASSTHROUGH;
  
  	/* Actually drop the carriage returns */
  	return git_buf_text_crlf_to_lf(to, from);
  }
  
  static int crlf_apply_to_workdir(
  	struct crlf_attrs *ca,
  	git_buf *to,
  	const git_buf *from)
  {
  	git_buf_text_stats stats;
  	bool is_binary;
  
  	/* Empty file? Nothing to do. */
  	if (git_buf_len(from) == 0 || output_eol(ca) != GIT_EOL_CRLF)
  		return GIT_PASSTHROUGH;
  
  	is_binary = git_buf_text_gather_stats(&stats, from, false);
  
  	/* If there are no LFs, or all LFs are part of a CRLF, nothing to do */
  	if (stats.lf == 0 || stats.lf == stats.crlf)
  		return GIT_PASSTHROUGH;
  
  	if (ca->crlf_action == GIT_CRLF_AUTO ||
  		ca->crlf_action == GIT_CRLF_AUTO_INPUT ||
  		ca->crlf_action == GIT_CRLF_AUTO_CRLF) {
  
  		/* If we have any existing CR or CRLF line endings, do nothing */
  		if (stats.cr > 0)
  			return GIT_PASSTHROUGH;
  
  		/* Don't filter binary files */
  		if (is_binary)
  			return GIT_PASSTHROUGH;
  	}
  
  	return git_buf_text_lf_to_crlf(to, from);
  }
  
  static int convert_attrs(
  	struct crlf_attrs *ca,
  	const char **attr_values,
  	const git_filter_source *src)
  {
  	int error;
  
  	memset(ca, 0, sizeof(struct crlf_attrs));
  
  	if ((error = git_repository__configmap_lookup(&ca->auto_crlf,
  		 git_filter_source_repo(src), GIT_CONFIGMAP_AUTO_CRLF)) < 0 ||
  		(error = git_repository__configmap_lookup(&ca->safe_crlf,
  		 git_filter_source_repo(src), GIT_CONFIGMAP_SAFE_CRLF)) < 0 ||
  		(error = git_repository__configmap_lookup(&ca->core_eol,
  		 git_filter_source_repo(src), GIT_CONFIGMAP_EOL)) < 0)
  		return error;
  
  	/* downgrade FAIL to WARN if ALLOW_UNSAFE option is used */
  	if ((git_filter_source_flags(src) & GIT_FILTER_ALLOW_UNSAFE) &&
  		ca->safe_crlf == GIT_SAFE_CRLF_FAIL)
  		ca->safe_crlf = GIT_SAFE_CRLF_WARN;
  
  	if (attr_values) {
  		/* load the text attribute */
  		ca->crlf_action = check_crlf(attr_values[2]); /* text */
  
  		if (ca->crlf_action == GIT_CRLF_UNDEFINED)
  			ca->crlf_action = check_crlf(attr_values[0]); /* crlf */
  
  		if (ca->crlf_action != GIT_CRLF_BINARY) {
  			/* load the eol attribute */
  			int eol_attr = check_eol(attr_values[1]);
  
  			if (ca->crlf_action == GIT_CRLF_AUTO && eol_attr == GIT_EOL_LF)
  				ca->crlf_action = GIT_CRLF_AUTO_INPUT;
  			else if (ca->crlf_action == GIT_CRLF_AUTO && eol_attr == GIT_EOL_CRLF)
  				ca->crlf_action = GIT_CRLF_AUTO_CRLF;
  			else if (eol_attr == GIT_EOL_LF)
  				ca->crlf_action = GIT_CRLF_TEXT_INPUT;
  			else if (eol_attr == GIT_EOL_CRLF)
  				ca->crlf_action = GIT_CRLF_TEXT_CRLF;
  		}
  
  		ca->attr_action = ca->crlf_action;
  	} else {
  		ca->crlf_action = GIT_CRLF_UNDEFINED;
  	}
  
  	if (ca->crlf_action == GIT_CRLF_TEXT)
  		ca->crlf_action = text_eol_is_crlf(ca) ? GIT_CRLF_TEXT_CRLF : GIT_CRLF_TEXT_INPUT;
  	if (ca->crlf_action == GIT_CRLF_UNDEFINED && ca->auto_crlf == GIT_AUTO_CRLF_FALSE)
  		ca->crlf_action = GIT_CRLF_BINARY;
  	if (ca->crlf_action == GIT_CRLF_UNDEFINED && ca->auto_crlf == GIT_AUTO_CRLF_TRUE)
  		ca->crlf_action = GIT_CRLF_AUTO_CRLF;
  	if (ca->crlf_action == GIT_CRLF_UNDEFINED && ca->auto_crlf == GIT_AUTO_CRLF_INPUT)
  		ca->crlf_action = GIT_CRLF_AUTO_INPUT;
  
  	return 0;
  }
  
  static int crlf_check(
  	git_filter *self,
  	void **payload, /* points to NULL ptr on entry, may be set */
  	const git_filter_source *src,
  	const char **attr_values)
  {
  	struct crlf_attrs ca;
  
  	GIT_UNUSED(self);
  
  	convert_attrs(&ca, attr_values, src);
  
  	if (ca.crlf_action == GIT_CRLF_BINARY)
  		return GIT_PASSTHROUGH;
  
  	*payload = git__malloc(sizeof(ca));
  	GIT_ERROR_CHECK_ALLOC(*payload);
  	memcpy(*payload, &ca, sizeof(ca));
  
  	return 0;
  }
  
  static int crlf_apply(
  	git_filter *self,
  	void **payload, /* may be read and/or set */
  	git_buf *to,
  	const git_buf *from,
  	const git_filter_source *src)
  {
  	/* initialize payload in case `check` was bypassed */
  	if (!*payload) {
  		int error = crlf_check(self, payload, src, NULL);
  
  		if (error < 0)
  			return error;
  	}
  
  	if (git_filter_source_mode(src) == GIT_FILTER_SMUDGE)
  		return crlf_apply_to_workdir(*payload, to, from);
  	else
  		return crlf_apply_to_odb(*payload, to, from, src);
  }
  
  static void crlf_cleanup(
  	git_filter *self,
  	void       *payload)
  {
  	GIT_UNUSED(self);
  	git__free(payload);
  }
  
  git_filter *git_crlf_filter_new(void)
  {
  	struct crlf_filter *f = git__calloc(1, sizeof(struct crlf_filter));
  	if (f == NULL)
  		return NULL;
  
  	f->f.version = GIT_FILTER_VERSION;
  	f->f.attributes = "crlf eol text";
  	f->f.initialize = NULL;
  	f->f.shutdown = git_filter_free;
  	f->f.check    = crlf_check;
  	f->f.apply    = crlf_apply;
  	f->f.cleanup  = crlf_cleanup;
  
  	return (git_filter *)f;
  }
  

Download