1 files changed, 16 insertions, 1 deletions
diff --git a/ship/build b/ship/build
index 6c26e6f3..cb4c20af 100755
--- a/ship/build
+++ b/ship/build
@@ -13,6 +13,7 @@ build() {
 }
 
 ## build directives
+build_info_directive='#@info'
 build_include_directive='#@include \([0-9A-Za-z]\+\)'
 
 ## usage: build_compile SRCFILE DSTFILE
@@ -31,7 +32,7 @@ build_compile() {
 ## usage: needs_compilation SRCFILE
 # Returns true if SRCFILE contains compilation directives.
 needs_compilation() {
-  grep -q "^$build_include_directive$" "$1"
+  grep -q "^\\($build_include_directive\\|$build_info_directive\\)$" "$1"
 }
 
 ## usage: make_sedscript_maker_shellscript SRCFILE
@@ -39,18 +40,32 @@ needs_compilation() {
 # directives in SRCFILE.
 make_sedscript_maker_shellscript() {
   echo 'set -euf'
+
+  echo "_build_info='$(
+    echo "# This file was generated by //ship/build \\"
+    echo "#   Date: $(date -u --rfc-3339=s) \\"
+    echo "#   Git-Commit: $(git show --pretty=oneline | awk '{print$1}')"
+  )'"
+
   deps="$(build_deps "$1")"
   for lib in $deps; do
     echo "_build_include_$(basename $lib)=$lib"
   done
+
   nl -b a -s ' ' "$1" |
   sed '
     s:^ *::
+
+    s:^\([0-9]\+\) '"$build_info_directive"'$:\1a\\\\\
+$_build_info\
+      :
+
     s:^\([0-9]\+\) '"$build_include_directive"'$:\1a\\\\\
 # BEGIN \2\
       \1r\$_build_include_\2\
       \1a\\\\\
 # END \2:
+
     s:^\([0-9]\+\) .*:\1p:
   
     1s:^:echo ":