1 files changed, 58 insertions, 15 deletions
diff --git a/ship/build b/ship/build
index 486f4bed..3c510f91 100755
--- a/ship/build
+++ b/ship/build
@@ -12,6 +12,25 @@ build() {
   esac
 }
 
+## usage: init
+init() {
+  directive_pattern='s:^ *\\([0-9]\\+\\) \1$:\2 \3:'
+
+  input_parser="$(make_input_parser "$0")"
+  debug_script input_parser '$0'
+
+  build_directives="$(make_build_directives "$0")"
+  debug_script build_directives '$0'
+
+  build_x_directive_loader="$(make_build_x_directive_loader "$0")"
+  debug_script build_x_directive_loader '$0'
+
+  eval "$build_x_directive_loader"
+
+  needs_compilation_sentinel="$(make_needs_compilation_sentinel $build_directives)"
+  debug_script needs_compilation_sentinel 'build_directives'
+}
+
 # usage: debug_script VARNAME [DESCRIPTION]
 debug_script() {
   if test "${debug-false}" = true; then
@@ -22,18 +41,7 @@ debug_script() {
   fi
 }
 
-## build directives
-build_info_directive='#@info'
-build_include_directive='#@include \([0-9A-Za-z]\+\)'
-
-input_parser="\
-s:^ *\([0-9]\+\) "$build_info_directive"$:build_info \1:
-s:^ *\([0-9]\+\) "$build_include_directive"$:build_include \1 \2:
-t
-s:^ *\([0-9]\+\) .*:echo \1p:"
-debug_script input_parser
-
-## usage: build_include LINENO LIBNAME
+## usage: #@include \([0-9A-Za-z]\+\) -> build_include \1 \2
 build_include() { cat<<EOF
 $1a\\
 # begin $2
@@ -43,7 +51,7 @@ $1a\\
 EOF
 }
 
-## usage: build_info LINENO
+## usage: #@info -> build_info \1
 build_info() { cat<<EOF
 $1a\\
 # this file was generated by //ship/build\\
@@ -70,8 +78,7 @@ build_compile() {
 ## usage: needs_compilation SHELLSCRIPT
 # Returns true if SRCFILE contains compilation directives.
 needs_compilation() {
-  echo "$1" |
-      grep -q "^\\($build_include_directive\\|$build_info_directive\\)$"
+  echo "$1" | grep -q "$needs_compilation_sentinel"
 }
 
 ## usage: make_sedscript_maker_shellscript SRCFILE
@@ -118,4 +125,40 @@ build_resolve() {
   }
 }
 
+## usage: make_input_parser FILENAME
+make_input_parser() {
+  echo "$(sed -n '
+    s/^## usage: \(.*\) -> \([^ ]\+\) \(.*\)$/s:^ *\\([0-9]\\+\\) \1$:\2 \3:/p
+    $a\
+t;s:^ *\\([0-9]\\+\\) .*:echo \\1p:
+  ' "$1")"
+}
+
+## usage: make_build_directives FILENAME
+make_build_directives() {
+  echo "$(sed -n '
+    s/^## usage: \(.*\) -> \([^ ]\+\) \(.*\)$/\2_directive/p
+  ' "$0")"
+}
+
+## usage: make_build_x_directive_loader FILENAME
+make_build_x_directive_loader() {
+  sed -n '
+    s/^## usage: \(.*\) -> \([^ ]\+\) \(.*\)$/\2_directive='"'"'\1'"'"'/p
+  ' "$1"
+}
+
+## usage: make_needs_compilation_sentinel BUILD_DIRECTIVES...
+make_needs_compilation_sentinel() {
+  echo "^\\($(
+    for directive; do
+      eval echo \"\$$directive\"
+    done |
+      tr \\n \| |
+      sed 's/|/\\|/'
+  )\\)$"
+}
+
+## main
+init
 build "$@"