mds-kbdc: split out and dedup include stack

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

1 files changed, 170 insertions, 0 deletions

diff --git a/src/mds-kbdc/include-stack.c b/src/mds-kbdc/include-stack.c
new file mode 100644
index 0000000..e3aff48
--- /dev/null
+++ b/src/mds-kbdc/include-stack.c
@@ -0,0 +1,170 @@
+/**
+ * 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 "include-stack.h"
+
+#include <alloca.h>
+#include <stdlib.h>
+#include <errno.h>
+
+
+
+/**
+ * Variable whether the latest created error is stored
+ */
+static mds_kbdc_parse_error_t* error;
+
+/**
+ * The `result` parameter of root procedure that requires the include stack
+ */
+static mds_kbdc_parsed_t* restrict result;
+
+/**
+ * The original value of `result->pathname`
+ */
+static char* original_pathname;
+
+/**
+ * The original value of `result->source_code`
+ */
+static mds_kbdc_source_code_t* original_source_code;
+
+/**
+ * Stack of visited include-statements
+ */
+static mds_kbdc_tree_include_t** restrict includes = NULL;
+
+/**
+ * The number elements allocated for `includes`
+ */
+static size_t includes_size = 0;
+
+/**
+ * The number elements stored in `includes`
+ */
+size_t includes_ptr = 0;
+
+
+
+/**
+ * Add “included from here”-notes
+ * 
+ * @param   ptr  The number of “included from here”-notes
+ * @return       Zero on success, -1 on error
+ */
+int mds_kbdc_include_stack_dump(size_t ptr)
+{
+  char* old_pathname = result->pathname;
+  mds_kbdc_source_code_t* old_source_code = result->source_code;
+  while (ptr--)
+    {
+      result->pathname = ptr ? includes[ptr - 1]->filename : original_pathname;
+      result->source_code = ptr ? includes[ptr - 1]->source_code : original_source_code;
+      NEW_ERROR_WITHOUT_INCLUDES(includes[ptr], NOTE, "included from here");
+    }
+  result->pathname = old_pathname;
+  result->source_code = old_source_code;
+  return 0;
+ pfail:
+  result->pathname = old_pathname;
+  result->source_code = old_source_code;
+  return -1;
+} 
+
+
+/**
+ * Mark the root of the tree as included
+ * 
+ * @param  result_  The `result` parameter of root procedure that requires the include stack
+ */
+void mds_kbdc_include_stack_begin(mds_kbdc_parsed_t* restrict result_)
+{
+  result = result_;
+  original_pathname = result_->pathname;
+  original_source_code = result_->source_code;
+}
+
+
+/**
+ * Mark the root of the tree as no longer being visited,
+ * and release clean up after the use of this module
+ * 
+ * This function is guaranteed not to modify `errno`
+ */
+void mds_kbdc_include_stack_end(void)
+{
+  int saved_errno = errno;
+  result->pathname = original_pathname;
+  result->source_code = original_source_code;
+  free(includes), includes = NULL;
+  includes_size = includes_ptr = 0;
+  errno = saved_errno;
+}
+
+
+/**
+ * Mark an include-statement as visited
+ * 
+ * @param   tree  The visisted include-statement
+ * @param   data  Output parameter with stack information that should be passed to
+ *                the corresponding call to `mds_kbdc_include_stack_pop`, `*data`
+ *                is undefined on error
+ * @return        Zero on success, -1 on error
+ */
+int mds_kbdc_include_stack_push(mds_kbdc_tree_include_t* restrict tree, void** data)
+{
+  mds_kbdc_tree_include_t** old = NULL;
+  int saved_errno;
+  
+  if (includes_ptr == includes_size)
+    fail_if (xxrealloc(old, includes, includes_size += 4, mds_kbdc_tree_include_t*));
+  
+  fail_if (xmalloc(*data, 2, void*));
+  
+  includes[includes_ptr++] = tree;
+  
+  ((char**)(*data))[0] = result->pathname;
+  ((mds_kbdc_source_code_t**)(*data))[1] = result->source_code;
+  
+  result->pathname = tree->filename;
+  result->source_code = tree->source_code;
+  
+  return 0;
+ pfail:
+  saved_errno = errno;
+  free(old);
+  return errno = saved_errno, -1;
+}
+
+
+/**
+ * Undo the lasted not-undone call to `mds_kbdc_include_stack_push`
+ * 
+ * This function is guaranteed not to modify `errno`
+ * 
+ * @param  data  `*data` from `mds_kbdc_include_stack_push`
+ */
+void mds_kbdc_include_stack_pop(void* data)
+{
+  int saved_errno = errno;
+  result->pathname = ((char**)data)[0];
+  result->source_code = ((mds_kbdc_source_code_t**)data)[1];
+  includes_ptr--;
+  free(data);
+  errno = saved_errno;
+}
+