Get CC_STAGE0 from the bootstrapping compiler

Rather than using the compiler that configure detects, we use
the "GCC command" field from the --info output of the bootstrapping
compiler (provided it is >= 7.1).

3 files changed, 18 insertions, 1 deletions

diff --git a/aclocal.m4 b/aclocal.m4
index c7002b171f..4b750ef3f2 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -1494,6 +1494,21 @@ case "$1" in
   esac
 ])
 
+# BOOTSTRAPPING_GHC_INFO_FIELD
+# --------------------------------
+# If the bootstrapping compiler is >= 7.1, then set the variable
+# $1 to the value of the ghc --info field $2. Otherwise, set it to
+# $3.
+AC_DEFUN([BOOTSTRAPPING_GHC_INFO_FIELD],[
+if test $GhcCanonVersion -ge 701
+then
+    $1=`"$WithGhc" --info | grep "^ ,(\"$2\"," | sed -e 's/.*","//' -e 's/")$//'`
+else
+    $1=$3
+fi
+AC_SUBST($1)
+])
+
 # LIBRARY_VERSION(lib)
 # --------------------------------
 # Gets the version number of a library.
diff --git a/configure.ac b/configure.ac
index 3eccc088b0..b126d1e0bf 100644
--- a/configure.ac
+++ b/configure.ac
@@ -132,6 +132,8 @@ if test "$WithGhc" != ""; then
   GhcCanonVersion="$GhcMajVersion$GhcMinVersion2"
   if test $GhcCanonVersion -ge 613; then ghc_ge_613=YES; else ghc_ge_613=NO; fi
   AC_SUBST(ghc_ge_613)dnl
+
+  BOOTSTRAPPING_GHC_INFO_FIELD([CC_STAGE0],[GCC command],['$(CC)'])
 fi
 
 dnl ** Must have GHC to build GHC, unless --enable-hc-boot is on
diff --git a/mk/config.mk.in b/mk/config.mk.in
index 01019b825f..f96302b4fe 100644
--- a/mk/config.mk.in
+++ b/mk/config.mk.in
@@ -544,7 +544,7 @@ WhatGccIsCalled = @WhatGccIsCalled@
 GccVersion      = @GccVersion@
 GccLT34         = @GccLT34@
 CC              = $(WhatGccIsCalled)
-CC_STAGE0       = $(CC)
+CC_STAGE0       = @CC_STAGE0@
 CC_STAGE1       = $(CC)
 CC_STAGE2       = $(CC)
 CC_STAGE3       = $(CC)