Add Makefile targets to format and indent source code

Makefile.in

@@ -261,6 +261,16 @@ _build/edoc/docs.md: edoc_compile
 _build/edoc/logo.png: edoc_compile
 	wget https://docs.ejabberd.im/assets/img/footer_logo_e.png -O _build/edoc/logo.png
 
+#.
+#' format / indent
+#
+
+format:
+	tools/rebar3-format.sh $(REBAR)
+
+indent:
+	tools/emacs-indent.sh
+
 #.
 #' copy-files
 #
@@ -650,7 +660,7 @@ test:
 .PHONY: src edoc dialyzer Makefile TAGS clean clean-rel distclean prod rel \
 	install uninstall uninstall-binary uninstall-all translations deps test \
 	all dev doap help install-rel relive scripts uninstall-rel update \
-	erlang_plt deps_plt ejabberd_plt xref hooks options
+	erlang_plt deps_plt ejabberd_plt xref hooks options format indent
 
 #.
 #' help
@@ -682,6 +692,9 @@ help:
 	@echo "  translations   Extract translation files"
 	@echo "  TAGS           Generate tags file for text editors"
 	@echo ""
+	@echo "  format         Format source code using rebar3_format [rebar3]"
+	@echo "  indent         Indent source code using erlang-mode [emacs]"
+	@echo ""
 	@echo "  dialyzer       Run Dialyzer static analyzer"
 	@echo "  hooks          Run hooks validator"
 	@echo "  test           Run Common Tests suite [rebar3]"

rebar.config

@@ -152,7 +152,9 @@
                                               {git, "https://github.com/bsanyi/rebar_mix.git",
                                                {branch, "consolidation_fix"}}}
                        }]}}.
-{if_rebar3, {project_plugins, [configure_deps]}}.
+{if_rebar3, {project_plugins, [configure_deps,
+                               {if_var_true, tools, rebar3_format}
+                              ]}}.
 {if_not_rebar3, {plugins, [
                            deps_erl_opts, override_deps_versions2, override_opts, configure_deps
                           ]}}.

tools/emacs-indent.sh

@@ -0,0 +1,27 @@
+#!/bin/bash
+
+# To indent and remove tabs, surround the piece of code with:
+#   %% @indent-begin
+#   %% @indent-end
+#
+# Then run:
+#   make indent
+#
+# Please note this script only indents the first occurrence.
+
+FILES=$(git grep --name-only @indent-begin src/)
+
+for FILENAME in $FILES; do
+    echo "==> Indenting $FILENAME..."
+    emacs -batch $FILENAME \
+       -f "erlang-mode" \
+        --eval "(goto-char (point-min))" \
+        --eval "(re-search-forward \"@indent-begin\" nil t)" \
+        --eval "(setq begin (line-beginning-position))" \
+        --eval "(re-search-forward \"@indent-end\" nil t)" \
+        --eval "(setq end (line-beginning-position))" \
+        --eval "(erlang-indent-region begin end)" \
+        --eval "(untabify begin end)" \
+       -f "delete-trailing-whitespace" \
+       -f "save-buffer"
+done

tools/rebar3-format.sh

@@ -0,0 +1,34 @@
+#!/bin/bash
+
+# To start formatting a file, add a line that contains:
+#   @format-begin
+# Formatting in that file can later be disabled adding another line with:
+#   @format-end
+#
+# It can be reenabled again later in the file.
+#
+# Finally, call: make format
+
+REBAR=$1
+
+ERLS=$(git grep --name-only @format-begin src/)
+
+for ERL in $ERLS; do
+    csplit --quiet --prefix=$ERL-format- $ERL /@format-/ "{*}"
+done
+
+EFMTS=$(find src/*-format-* -type f -exec grep --files-with-matches "@format-begin" '{}' ';')
+EFMTS2=""
+for EFMT in $EFMTS; do
+    EFMTS2="$EFMTS2 --files $EFMT"
+done
+$REBAR format $EFMTS2
+
+for ERL in $ERLS; do
+    SPLITS=$(find $ERL-format-* -type f)
+    rm $ERL
+    for SPLIT in $SPLITS; do
+         cat $SPLIT >> $ERL
+         rm $SPLIT
+    done
+done