* A primitive operation `dependencyClosure' to do automatic dependency

  determination (e.g., finding the header files dependencies of a C
  file) in Nix low-level builds automatically.

  For instance, in the function `compileC' in make/lib/default.nix, we
  find the header file dependencies of C file `main' as follows:

    localIncludes =
      dependencyClosure {
        scanner = file:
          import (findIncludes {
            inherit file;
          });
        startSet = [main];
      };

  The function works by "growing" the set of dependencies, starting
  with the set `startSet', and calling the function `scanner' for each
  file to get its dependencies (which should yield a list of strings
  representing relative paths).  For instance, when `scanner' is
  called on a file `foo.c' that includes the line

    #include "../bar/fnord.h"

  then `scanner' should yield ["../bar/fnord.h"].  This list of
  dependencies is absolutised relative to the including file and added
  to the set of dependencies.  The process continues until no more
  dependencies are found (hence its a closure).

  `dependencyClosure' yields a list that contains in alternation a
  dependency, and its relative path to the directory of the start
  file, e.g.,

    [ /bla/bla/foo.c
      "foo.c"
      /bla/bar/fnord.h
      "../bar/fnord.h"
    ]

  These relative paths are necessary for the builder that compiles
  foo.c to reconstruct the relative directory structure expected by
  foo.c.

  The advantage of `dependencyClosure' over the old approach (using
  the impure `__currentTime') is that it's completely pure, and more
  efficient because it only rescans for dependencies (i.e., by
  building the derivations yielded by `scanner') if sources have
  actually changed.  The old approach rescanned every time.

1 files changed, 0 insertions, 20 deletions

diff --git a/make/lib/find-includes.sh b/make/lib/find-includes.sh
deleted file mode 100644
index 4824207c2917..000000000000
--- a/make/lib/find-includes.sh
+++ /dev/null
@@ -1,20 +0,0 @@
-. $stdenv/setup
-
-echo "finding includes of \`$(basename $main)'..."
-
-makefile=$NIX_BUILD_TOP/makefile
-
-mainDir=$(dirname $main)
-(cd $mainDir && gcc $cFlags -MM $(basename $main) -MF $makefile) || false
-
-echo "[" >$out
-
-while read line; do
-    line=$(echo "$line" | sed 's/.*://')
-    for i in $line; do
-        fullPath=$(readlink -f $mainDir/$i)
-        echo "  [ $fullPath \"$i\" ]" >>$out
-    done
-done < $makefile
-
-echo "]" >>$out