Revert "Build system: don't create mk/are-validating.mk"

Summary:
This reverts commit aecf4a5f96d0d3ffcf4cb2c67a20a610d7c64486.

It turns out the Simons are relying on 'mk/are-validating.mk', see
D1307.

The workflow they are using is:
  * run ./validate
  * find a bug in the compiler
  * try to fix the bug, running 'make 1' (or 'make 2') repeatedly. Because
    of 'mk/are-validating.mk', this uses the same build settings as validate.
  * continue ./validate (--no-clean)

I suggested two alternatives:

  A. run 'make 1 Validating=YES' instead of 'make 1'

     Problem: when running `./validate --fast` or `./validate --hpc`
     instead of a normal `./validate`, validate sets ValidateSpeed and
     ValdateHpc in mk/are-validating.mk. You would for example have to run
     'make 1 Validating=YES ValidateSpeed=FAST' instead of 'make 1' to get the
     same build settings as `./validate --fast`, which is entirely too long and
     error prone.

  B. uncomment `#BuildFlavour=validate` in mk/build.mk, and include
     'mk/validate.mk'.

     Problems:
      * any other settings you have in build.mk will also get used.
      * the distinction between 'mk/validate.mk' and 'mk/build.mk' becomes less
        clear.
      * it is easy to forget to include 'mk/validate.mk'.
      * the build system again doesn't have access to the ValidateSpeed and
        ValdateHpc settings set by validate.

Neither of these two options is entirely satisfactory.

Reviewers: austin, bgamari

Differential Revision: https://phabricator.haskell.org/D1383

1 files changed, 11 insertions, 7 deletions

diff --git a/validate b/validate
index 827815fa20..4c123fe844 100755
--- a/validate
+++ b/validate
@@ -174,7 +174,9 @@ fi
 
 thisdir=`utils/ghc-pwd/dist-boot/ghc-pwd`
 
-make_settings="Validating=YES ValidateSpeed=$speed ValidateHpc=$hpc"
+echo "Validating=YES"       >  mk/are-validating.mk
+echo "ValidateSpeed=$speed" >> mk/are-validating.mk
+echo "ValidateHpc=$hpc"     >> mk/are-validating.mk
 
 # Note [Default build system verbosity].
 #
@@ -188,14 +190,16 @@ make_settings="Validating=YES ValidateSpeed=$speed ValidateHpc=$hpc"
 # `make -s`, when user explicitly asks for it with `./validate --quiet`.
 if [ $be_quiet -eq 1 ]; then
     # See Note [Default build system verbosity].
-    make_settings="$make_settings V=0"
+    echo "V=0"                  >> mk/are-validating.mk # Less gunk
 fi
 
 if [ $use_dph -eq 1 ]; then
-    make_settings="$make_settings BUILD_DPH=YES"
+    echo "BUILD_DPH=YES"    >> mk/are-validating.mk
+else
+    echo "BUILD_DPH=NO"     >> mk/are-validating.mk
 fi
 
-$make -j$threads $make_settings
+$make -j$threads
 # For a "debug make", add "--debug=b --debug=m"
 
 check_packages post-build
@@ -205,8 +209,8 @@ check_packages post-build
 
 if [ $speed != "FAST" ]; then
 
-    $make binary-dist-prep $make_settings
-    $make test_bindist TEST_PREP=YES $make_settings
+    $make binary-dist-prep
+    $make test_bindist TEST_PREP=YES
 
     #
     # Install the xhtml package into the bindist.
@@ -217,7 +221,7 @@ if [ $speed != "FAST" ]; then
 
     check_packages post-install
 
-    $make validate_build_xhtml BINDIST_PREFIX="$thisdir/$bindistdir" $make_settings
+    $make validate_build_xhtml BINDIST_PREFIX="$thisdir/$bindistdir"
 
     check_packages post-xhtml
 fi