Don't let configure perform trivial substitutions (#21846)

Hadrian now performs substitutions, especially to generate .cabal files
from .cabal.in files. Two benefits:

1. We won't have to re-configure when we modify thing.cabal.in. Hadrian
   will take care of this for us.

2. It paves the way to allow the same package to be configured
   differently by Hadrian in the same session. This will be useful to
   fix #19174: we want to build a stage2 cross-compiler for the host
   platform and a stage1 compiler for the cross target platform in the
   same Hadrian session.

1 files changed, 15 insertions, 39 deletions

diff --git a/configure.ac b/configure.ac
index bf4f597572..b5855f4ef0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -943,9 +943,9 @@ AC_CHECK_LIB(m, atan, HaveLibM=YES, HaveLibM=NO)
 if test $HaveLibM = YES
 then
   AC_DEFINE([HAVE_LIBM], [1], [Define to 1 if you need to link with libm])
-  AC_SUBST([CabalHaveLibm],[True])
+  AC_SUBST([UseLibm],[YES])
 else
-  AC_SUBST([CabalHaveLibm],[False])
+  AC_SUBST([UseLibm],[NO])
 fi
 TargetHasLibm=$HaveLibM
 AC_SUBST(TargetHasLibm)
@@ -958,15 +958,11 @@ dnl ################################################################
 
 FP_FIND_LIBFFI
 AC_SUBST(UseSystemLibFFI)
-AS_IF([test "x$with_system_libffi" = "xyes"],
-  [CabalUseSystemLibFFI="True"],
-  [CabalUseSystemLibFFI="False"]
-)
-AC_SUBST(CabalUseSystemLibFFI)
 
 dnl ** check whether we need -ldl to get dlopen()
 AC_CHECK_LIB([dl], [dlopen])
-AC_CHECK_LIB([dl], [dlopen], [AC_SUBST([CabalHaveLibdl], [True])], [AC_SUBST([CabalHaveLibdl], [False])])
+AC_CHECK_LIB([dl], [dlopen], HaveLibdl=YES, HaveLibdl=NO)
+AC_SUBST([UseLibdl],[$HaveLibdl])
 dnl ** check whether we have dlinfo
 AC_CHECK_FUNCS([dlinfo])
 
@@ -1003,7 +999,13 @@ FP_MUSTTAIL
 
 dnl ** check for librt
 AC_CHECK_LIB([rt], [clock_gettime])
-AC_CHECK_LIB([rt], [clock_gettime], [AC_SUBST([CabalHaveLibrt], [True])], [AC_SUBST([CabalHaveLibrt], [False])])
+AC_CHECK_LIB([rt], [clock_gettime], HaveLibrt=YES, HaveLibrt=NO)
+if test $HaveLibrt = YES
+then
+  AC_SUBST([UseLibrt],[YES])
+else
+  AC_SUBST([UseLibrt],[NO])
+fi
 AC_CHECK_FUNCS(clock_gettime timer_settime)
 FP_CHECK_TIMER_CREATE
 
@@ -1119,11 +1121,6 @@ AC_DEFINE_UNQUOTED([RTS_LINKER_USE_MMAP], [$RtsLinkerUseMmap],
 
 GHC_ADJUSTORS_METHOD([Target])
 AC_SUBST([UseLibffiForAdjustors])
-AS_IF([test x"${UseLibffiForAdjustors}" = x"YES"],
-  [CabalLibffiAdjustors=True],
-  [CabalLibffiAdjustors=False]
-)
-AC_SUBST([CabalLibffiAdjustors])
 
 dnl ** Other RTS features
 dnl --------------------------------------------------------------
@@ -1173,12 +1170,6 @@ if grep '	' compiler/ghc.cabal.in 2>&1 >/dev/null; then
    AC_MSG_ERROR([compiler/ghc.cabal.in contains tab characters; please remove them])
 fi
 
-# Create the configuration for the Hadrian build system if it is present
-if test -e hadrian/cfg/system.config.in; then
-    AC_CONFIG_FILES([hadrian/cfg/system.config])
-    AC_CONFIG_FILES([hadrian/ghci-cabal hadrian/ghci-stack hadrian/ghci-multi-cabal])
-fi
-
 # We got caught by
 #     http://savannah.gnu.org/bugs/index.php?1516
 #     $(eval ...) inside conditionals causes errors
@@ -1202,27 +1193,12 @@ checkMake380() {
 checkMake380 make
 checkMake380 gmake
 
-AC_CONFIG_FILES([ mk/project.mk ])
-
-dnl When adding things to this list be sure to update hadrian's
-dnl Rules.Configure.configureResults list.
 AC_CONFIG_FILES(
-[ rts/rts.cabal
-  compiler/ghc.cabal
-  ghc/ghc-bin.cabal
-  utils/runghc/runghc.cabal
-  driver/ghci/ghci-wrapper.cabal
-  utils/iserv/iserv.cabal
-  utils/ghc-pkg/ghc-pkg.cabal
-  utils/remote-iserv/remote-iserv.cabal
-  libraries/ghc-boot/ghc-boot.cabal
-  libraries/ghc-boot-th/ghc-boot-th.cabal
-  libraries/ghci/ghci.cabal
-  libraries/ghc-heap/ghc-heap.cabal
-  libraries/libiserv/libiserv.cabal
-  libraries/template-haskell/template-haskell.cabal
+[ mk/project.mk
+  hadrian/cfg/system.config
+  hadrian/ghci-cabal
+  hadrian/ghci-stack
   docs/users_guide/ghc_config.py
-  libraries/prologue.txt
   distrib/configure.ac
 ])