mds-kbdc: use absolute and relative paths

Signed-off-by: Mattias Andrée <maandree@operamail.com>

5 files changed, 227 insertions, 19 deletions

diff --git a/Makefile b/Makefile
index 27d92e8..295f762 100644
--- a/Makefile
+++ b/Makefile
@@ -33,7 +33,7 @@ OBJ_mds-registry_ = mds-registry util globals reexec registry signals   \
 OBJ_mds-kbdc_     = mds-kbdc globals raw-data functions string tree     \
                     make-tree parse-error simplify-tree parsed          \
                     process-includes validate-tree eliminate-dead-code  \
-                    include-stack
+                    paths include-stack
 
 OBJ_mds-server    = $(foreach O,$(OBJ_mds-server_),obj/mds-server/$(O).o)
 OBJ_mds-registry  = $(foreach O,$(OBJ_mds-registry_),obj/mds-registry/$(O).o)
diff --git a/src/mds-kbdc/make-tree.c b/src/mds-kbdc/make-tree.c
index a8f20ee..989cd2b 100644
--- a/src/mds-kbdc/make-tree.c
+++ b/src/mds-kbdc/make-tree.c
@@ -17,6 +17,8 @@
  */
 #include "make-tree.h"
 
+#include "paths.h"
+
 #include <limits.h>
 #include <stdlib.h>
 #include <libgen.h>
@@ -711,32 +713,18 @@ static mds_kbdc_parse_error_t* error;
  */
 static int get_pathname(const char* restrict filename, state_t* restrict state)
 {
-  size_t cwd_size = 4096 >> 1;
   char* cwd = NULL;
-  char* old = NULL;
   int saved_errno;
   
   /* Get a non-relative pathname for the file, relative filenames
    * can be misleading as the program can have changed working
    * directory to be able to resolve filenames. */
-  parsing_result->pathname = realpath(filename, NULL); /* XXX use absolute path */
+  parsing_result->pathname = abspath(filename);
   if (parsing_result->pathname == NULL)
     {
       fail_if (errno != ENOENT);
       saved_errno = errno;
-      
-      /* Get the current working directory. */
-      /* glibc offers ways to do this in just one function call,
-       * but we will not assume that glibc is used here. */
-      for (;;)
-	{
-	  fail_if (xxrealloc(old, cwd, cwd_size <<= 1, char));
-	  if (getcwd(cwd, cwd_size))
-	    break;
-	  else
-	    fail_if (errno != ERANGE);
-	}
-      
+      fail_if ((cwd = curpath(), cwd == NULL));
       parsing_result->pathname = strdup(filename);
       fail_if (parsing_result->pathname == NULL);
       NEW_ERROR_(parsing_result, ERROR, 0, 0, 0, 0, 1, "no such file or directory in ‘%s’", cwd);
@@ -758,7 +746,6 @@ static int get_pathname(const char* restrict filename, state_t* restrict state)
  pfail:
   saved_errno = errno;
   free(cwd);
-  free(old);
   return errno = saved_errno, -1;
 }
 
diff --git a/src/mds-kbdc/parse-error.c b/src/mds-kbdc/parse-error.c
index 92e5ab0..f7db9ad 100644
--- a/src/mds-kbdc/parse-error.c
+++ b/src/mds-kbdc/parse-error.c
@@ -17,6 +17,8 @@
  */
 #include "parse-error.h"
 
+#include "paths.h"
+
 #include <stdlib.h>
 #include <alloca.h>
 #include <string.h>
@@ -34,6 +36,7 @@ static void print(const mds_kbdc_parse_error_t* restrict this, FILE* restrict ou
 {
   size_t i, n, start = 0, end = 0;
   const char* restrict code = this->code;
+  char* restrict path = relpath(this->pathname, NULL);
   
   /* Convert bytes count to character count for the code position. */
   for (i = 0, n = this->start; i < n; i++)
@@ -45,7 +48,8 @@ static void print(const mds_kbdc_parse_error_t* restrict this, FILE* restrict ou
   end += start;
   
   /* Print error information. */
-  fprintf(output, "\033[01m%s\033[21m:", this->pathname); /* TODO should be relative to the current dir */
+  fprintf(output, "\033[01m%s\033[21m:", path ? path : this->pathname);
+  free(path);
   if (this->error_is_in_file)
     fprintf(output, "%zu:%zu–%zu:", this->line + 1, start, end);
   switch (this->severity)
diff --git a/src/mds-kbdc/paths.c b/src/mds-kbdc/paths.c
new file mode 100644
index 0000000..d66ae99
--- /dev/null
+++ b/src/mds-kbdc/paths.c
@@ -0,0 +1,168 @@
+/**
+ * mds — A micro-display server
+ * Copyright © 2014  Mattias Andrée (maandree@member.fsf.org)
+ * 
+ * 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/>.
+ */
+#include "paths.h"
+
+#include <libmdsserver/macros.h>
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+
+
+/**
+ * Get the current working directory
+ * 
+ * @return  The current working directory
+ */
+char* curpath(void)
+{
+  static size_t cwd_size = 4096 >> 1;
+  char* cwd = NULL;
+  char* old = NULL;
+  int saved_errno;
+  
+  /* glibc offers ways to do this in just one function call,
+   * but we will not assume that glibc is used here. */
+  for (;;)
+    {
+      fail_if (xxrealloc(old, cwd, (cwd_size <<= 1) + 1, char));
+      if (getcwd(cwd, cwd_size))
+	break;
+      else
+	fail_if (errno != ERANGE);
+    }
+  
+  return cwd;
+ pfail:
+  saved_errno = errno;
+  free(old);
+  free(cwd);
+  errno = saved_errno;
+  return NULL;
+}
+
+
+/**
+ * Get the absolute path of a file
+ * 
+ * @param   path  The filename of the file
+ * @return        The file's absolute path, `NULL` on error
+ */
+char* abspath(const char* path)
+{
+  char* cwd = NULL;
+  char* buf = NULL;
+  int saved_errno, slash = 1;
+  size_t size, p;
+  
+  if (*path == '/')
+    return strdup(path);
+  
+  fail_if ((cwd = curpath(), cwd == NULL));
+  size = (p = strlen(cwd)) + strlen(path) + 2;
+  fail_if (xmalloc(buf, size + 1, char));
+  memcpy(buf, cwd, (p + 1) * sizeof(char));
+  if (buf[p - 1] != '/')
+    buf[p++] = '/';
+  
+  while (*path)
+    if (slash && (path[0] == '/'))
+      path += 1;
+    else if (slash && (path[0] == '.') && (path[1] == '/'))
+      path += 2;
+    else if (slash && (path[0] == '.') && (path[1] == '.') && (path[2] == '/'))
+      {
+	path += 3;
+	p--;
+	while (p && (buf[--p] != '/'));
+	p++;
+      }
+    else
+      {
+	buf[p++] = *path;
+	slash = (*path++ == '/');
+      }
+  
+  buf[p] = '\0';
+  
+  free(cwd);
+  return buf;
+ pfail:
+  saved_errno = errno;
+  free(cwd);
+  errno = saved_errno;
+  return NULL;
+}
+
+
+/**
+ * Get a relative path of a file
+ * 
+ * @param   path  The filename of the file
+ * @param   base  The pathname of the base directory,
+ *                `NULL` for the current working directroy
+ * @return        The file's relative path, `NULL` on error
+ */
+char* relpath(const char* path, const char* base)
+{
+  char* abs = abspath(path);
+  char* absbase = NULL;
+  char* buf = NULL;
+  char* old = NULL;
+  int saved_errno;
+  size_t p, slash = 1, back = 0;
+  
+  fail_if (abs == NULL);
+  absbase = base ? abspath(base) : curpath();
+  fail_if (absbase == NULL);
+  
+  if (absbase[strlen(absbase) - 1] != '/')
+    /* Both `abspath` and `curpath` (and `relpath`) allocates one extra slot. */
+    absbase[strlen(absbase) + 1] = '\0', absbase[strlen(absbase)] = '/';
+  
+  fprintf(stderr, "abs: %s\n", abs);
+  fprintf(stderr, "absbase: %s\n\n", absbase);
+  
+  for (p = 1; abs[p] && absbase[p] && (abs[p] == absbase[p]); p++)
+    if (abs[p] == '/')
+      slash = p + 1;
+  
+  for (p = slash; absbase[p]; p++)
+    if (absbase[p] == '/')
+      back++;
+  
+  fail_if (xmalloc(buf, back * 3 + strlen(abs + slash) + 2, char));
+  
+  for (p = 0; back--;)
+    buf[p++] = '.', buf[p++] = '.', buf[p++] = '/';
+  memcpy(buf + p, abs + slash, (strlen(abs + slash) + 1) * sizeof(char));
+  
+  free(abs);
+  free(absbase);
+  return buf;
+ pfail:
+  saved_errno = errno;
+  free(abs);
+  free(absbase);
+  free(old);
+  errno = saved_errno;
+  return NULL;
+}
+
diff --git a/src/mds-kbdc/paths.h b/src/mds-kbdc/paths.h
new file mode 100644
index 0000000..a045334
--- /dev/null
+++ b/src/mds-kbdc/paths.h
@@ -0,0 +1,49 @@
+/**
+ * mds — A micro-display server
+ * Copyright © 2014  Mattias Andrée (maandree@member.fsf.org)
+ * 
+ * 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/>.
+ */
+#ifndef MDS_MDS_KBDC_PATHS_H
+#define MDS_MDS_KBDC_PATHS_H
+
+
+/**
+ * Get the current working directory
+ * 
+ * @return  The current working directory
+ */
+char* curpath(void);
+
+/**
+ * Get the absolute path of a file
+ * 
+ * @param   path  The filename of the file
+ * @return        The file's absolute path, `NULL` on error
+ */
+char* abspath(const char* path);
+
+/**
+ * Get a relative path of a file
+ * 
+ * @param   path  The filename of the file
+ * @param   base  The pathname of the base directory,
+ *                `NULL` for the current working directroy
+ * @return        The file's relative path, `NULL` on error
+ */
+char* relpath(const char* path, const char* base);
+
+
+#endif
+