Note: this list is generated by pattern matching, so it may include some functions that are not actually implementations of this hook.

bartik_preprocess_block in themes/bartik/template.php
Override or insert variables into the block template.
bartik_preprocess_html in themes/bartik/template.php
Add body classes if certain regions have content.
bartik_preprocess_maintenance_page in themes/bartik/template.php
Implements hook_preprocess_maintenance_page().
bartik_preprocess_node in themes/bartik/template.php
Override or insert variables into the node template.
garland_preprocess_block in themes/garland/template.php
Override or insert variables into the block template.
garland_preprocess_comment in themes/garland/template.php
Override or insert variables into the comment template.
garland_preprocess_html in themes/garland/template.php
Override or insert variables into the html template.
garland_preprocess_maintenance_page in themes/garland/template.php
Override or insert variables into the maintenance page template.
garland_preprocess_node in themes/garland/template.php
Override or insert variables into the node template.
garland_preprocess_page in themes/garland/template.php
Override or insert variables into the page template.
garland_preprocess_region in themes/garland/template.php
Override or insert variables into the region template.
overlay_preprocess_html in modules/overlay/overlay.module
Implements hook_preprocess_html().
overlay_preprocess_maintenance_page in modules/overlay/overlay.module
Implements hook_preprocess_maintenance_page().
overlay_preprocess_page in modules/overlay/overlay.module
Implements hook_preprocess_page().
rdf_preprocess_comment in modules/rdf/rdf.module
Implements MODULE_preprocess_HOOK().
rdf_preprocess_field in modules/rdf/rdf.module
Implements MODULE_preprocess_HOOK().
rdf_preprocess_image in modules/rdf/rdf.module
Implements MODULE_preprocess_HOOK().
rdf_preprocess_node in modules/rdf/rdf.module
Implements MODULE_preprocess_HOOK().
rdf_preprocess_taxonomy_term in modules/rdf/rdf.module
Implements MODULE_preprocess_HOOK().
rdf_preprocess_username in modules/rdf/rdf.module
Implements MODULE_preprocess_HOOK().
rdf_preprocess_user_profile in modules/rdf/rdf.module
Implements MODULE_preprocess_HOOK().
search_embedded_form_preprocess_search_result in modules/search/tests/search_embedded_form.module
Adds the test form to search results.
seven_preprocess_html in themes/seven/template.php
Override or insert variables into the html template.
seven_preprocess_maintenance_page in themes/seven/template.php
Override or insert variables into the maintenance page template.
seven_preprocess_page in themes/seven/template.php
Override or insert variables into the page template.
shortcut_preprocess_page in modules/shortcut/shortcut.module
Implements hook_preprocess_page().
system_preprocess_block in modules/system/system.module
Implements hook_preprocess_block().
template_preprocess_aggregator_feed_source in modules/aggregator/aggregator.pages.inc
Processes variables for aggregator-feed-source.tpl.php.
template_preprocess_aggregator_item in modules/aggregator/aggregator.pages.inc
Processes variables for aggregator-item.tpl.php.
template_preprocess_aggregator_summary_item in modules/aggregator/aggregator.pages.inc
Processes variables for aggregator-summary-item.tpl.php.
template_preprocess_aggregator_summary_items in modules/aggregator/aggregator.pages.inc
Processes variables for aggregator-summary-items.tpl.php.
template_preprocess_aggregator_wrapper in modules/aggregator/aggregator.pages.inc
Processes variables for aggregator-wrapper.tpl.php.
template_preprocess_announcements_feed in modules/announcements_feed/announcements_feed.module
Processes variables for announcements-feed.tpl.php.
template_preprocess_block in modules/block/block.module
Processes variables for block.tpl.php.
template_preprocess_block_admin_display_form in modules/block/block.admin.inc
Processes variables for block-admin-display-form.tpl.php.
template_preprocess_book_all_books_block in modules/book/book.module
Processes variables for book-all-books-block.tpl.php.
template_preprocess_book_export_html in modules/book/book.module
Processes variables for book-export-html.tpl.php.
template_preprocess_book_navigation in modules/book/book.module
Processes variables for book-navigation.tpl.php.
template_preprocess_book_node_export_html in modules/book/book.module
Processes variables for book-node-export-html.tpl.php.
template_preprocess_comment in modules/comment/comment.module
Process variables for comment.tpl.php.
template_preprocess_comment_wrapper in modules/comment/comment.module
Process variables for comment-wrapper.tpl.php.
template_preprocess_dashboard_admin_display_form in modules/dashboard/dashboard.module
Preprocesses variables for block-admin-display-form.tpl.php.
template_preprocess_field in modules/field/field.module
Theme preprocess function for theme_field() and field.tpl.php.
template_preprocess_forums in modules/forum/forum.module
Preprocesses variables for forums.tpl.php.
template_preprocess_forum_icon in modules/forum/forum.module
Preprocesses variables for forum-icon.tpl.php.
template_preprocess_forum_list in modules/forum/forum.module
Preprocesses variables for forum-list.tpl.php.
template_preprocess_forum_submitted in modules/forum/forum.module
Preprocesses variables for forum-submitted.tpl.php.
template_preprocess_forum_topic_list in modules/forum/forum.module
Preprocesses variables for forum-topic-list.tpl.php.
template_preprocess_html in includes/theme.inc
Preprocess variables for html.tpl.php
template_preprocess_maintenance_page in includes/theme.inc
Process variables for maintenance-page.tpl.php.
template_preprocess_menu_tree in includes/menu.inc
Implements template_preprocess_HOOK() for theme_menu_tree().
template_preprocess_node in modules/node/node.module
Processes variables for node.tpl.php
template_preprocess_overlay in modules/overlay/overlay.module
Implements template_preprocess_HOOK() for overlay.tpl.php
template_preprocess_page in includes/theme.inc
Preprocess variables for page.tpl.php
template_preprocess_poll_bar in modules/poll/poll.module
Preprocess the poll_bar theme hook.
template_preprocess_poll_results in modules/poll/poll.module
Preprocess the poll_results theme hook.
template_preprocess_poll_vote in modules/poll/poll.module
Themes the voting form for a poll.
template_preprocess_profile_block in modules/profile/profile.module
Process variables for profile-block.tpl.php.
template_preprocess_profile_listing in modules/profile/profile.module
Process variables for profile-listing.tpl.php.
template_preprocess_profile_wrapper in modules/profile/profile.module
Process variables for profile-wrapper.tpl.php.
template_preprocess_region in includes/theme.inc
Preprocess variables for region.tpl.php
template_preprocess_search_block_form in modules/search/search.module
Process variables for search-block-form.tpl.php.
template_preprocess_search_result in modules/search/search.pages.inc
Process variables for search-result.tpl.php.
template_preprocess_search_results in modules/search/search.pages.inc
Process variables for search-results.tpl.php.
template_preprocess_taxonomy_term in modules/taxonomy/taxonomy.module
Process variables for taxonomy-term.tpl.php.
template_preprocess_theme_test in modules/simpletest/tests/theme_test.inc
Preprocesses variables for theme_theme_test().
template_preprocess_username in includes/theme.inc
Preprocesses variables for theme_username().
template_preprocess_user_picture in modules/user/user.module
Process variables for user-picture.tpl.php.
template_preprocess_user_profile in modules/user/user.pages.inc
Process variables for user-profile.tpl.php.
template_preprocess_user_profile_category in modules/user/user.pages.inc
Process variables for user-profile-category.tpl.php.
template_preprocess_user_profile_item in modules/user/user.pages.inc
Process variables for user-profile-item.tpl.php.
toolbar_preprocess_html in modules/toolbar/toolbar.module
Implements hook_preprocess_html().
toolbar_preprocess_toolbar in modules/toolbar/toolbar.module
Implements hook_preprocess_toolbar().