[PATCH 12/14] Refactor code requiring compilers in testsuite.

[Stefano Lattarini]

Second refactoring of this part of code.  The result is admittedly
more unelegant and "spaghetti-code-style", but it's necessary to
the next patch ("Clobber global CFLAGS etc. when requiring GNU
compilers.")

Regads,
   Stefano

-*-*-*-

Refactor code requiring compilers in testsuite.

* tests/defs.in (require_gnu_compilers): Removed, merged ...
(require_compiler): ... with this one, and added knowledge of
which compilers/variables should be used with which language (e.g.
gcc, $CC for the C language, g++, $CXX for C++, etc).
All usages updated accordingly.
---
 ChangeLog     |    7 ++++
 tests/defs.in |  111 +++++++++++++++++++++++++++++++++-----------------------
 2 files changed, 72 insertions(+), 46 deletions(-)

From 3e874d9a21214789bdda6a2b6c77d5887533c7ba Mon Sep 17 00:00:00 2001
From: Stefano Lattarini <address@hidden>
Date: Fri, 2 Jul 2010 12:41:30 +0200
Subject: [PATCH 12/14] Refactor code requiring compilers in testsuite.

* tests/defs.in (require_gnu_compilers): Removed, merged ...
(require_compiler): ... with this one, and added knowledge of
which compilers/variables should be used with which language (e.g.
gcc, $CC for the C language, g++, $CXX for C++, etc).
All usages updated accordingly.
---
 ChangeLog     |    7 ++++
 tests/defs.in |  111 +++++++++++++++++++++++++++++++++-----------------------
 2 files changed, 72 insertions(+), 46 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 6a1d5a0..0d1e536 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,12 @@
 2010-07-02  Stefano Lattarini  <address@hidden>
 
+       Refactor code requiring compilers in testsuite.
+       * tests/defs.in (require_gnu_compilers): Removed, merged ...
+       (require_compiler): ... with this one, and added knowledge of
+       which compilers/variables should be used with which language (e.g.
+       gcc, $CC for the C language, g++, $CXX for C++, etc).
+       All usages updated accordingly.
+
        Fix code for requiring gfortran in tests.
        * tests/defs.in: Correctly set and export F77 and/or FC when
        gfortran is in $required.
diff --git a/tests/defs.in b/tests/defs.in
index 42a23ef..d34d425 100644
--- a/tests/defs.in
+++ b/tests/defs.in
@@ -88,51 +88,71 @@ echo "$PATH"
 # (See note about `export' in the Autoconf manual.)
 export PATH
 
-# Usage: require_compiler ENV-VARIABLE [FALLBACK-GNU-COMPILERS]
+# require_compiler [--force-gnu|--avoid-gnu] {c|c++|gcj|f9x|f77}
 # Presently, this function is meant for internal use only.
 require_compiler()
 {
-  eval compiler=\$$1
-  if eval test x"$compiler" = x"no"; then
+  what_gnu=try
+  case $1 in
+    --force-gnu) what_gnu=force; shift;;
+    --avoid-gnu) what_gnu=avoid; shift;;
+    -*) echo "$me: require_compiler: $1: invalid option" >&2; exit 99;;
+  esac
+
+  case $1 in
+    c)
+      compiler_variable=CC
+      gnu_compiler_candidates=gcc;;
+    c++)
+      compiler_variable=CXX
+      gnu_compiler_candidates=g++;;
+    f77)
+      compiler_variable=F77
+      # gfortran should be able to seamlessly compile Fortran 77 code
+      gnu_compiler_candidates='g77 gfortran';;
+    f9x)
+      compiler_variable=FC
+      gnu_compiler_candidates=gfortran;;
+    gcj)
+      compiler_variable=GCJ
+      gnu_compiler_candidates=gcj;;
+    *)
+      echo "$me: $1: invalid compiler language" >&2; exit 99;;
+  esac
+
+  eval compiler=\$$compiler_variable
+
+  if test x"$what_gnu" != x"force" && test x"$compiler" = x"no"; then
     # The user told explicitly he doesn't want a compiler of this kind
     # to be used.
-    echo "$me: \$$1 is \"no\", skipping test"
+    echo "$me: \$$compiler_variable is \"no\", skipping test"
     exit 77
-  elif test -z "$compiler"; then
-    if test $# -gt 1; then
-      # The user specified no explicit compiler in its environment, so
-      # we try to force the use of a GNU compiler.
-      require_gnu_compiler "$@"
-    else
-      echo "$me: \$$1 is unset or empty, and no default GNU compiler" \
-           "has been specified"
-      exit 77
-    fi
   fi
-  unset compiler
-}
 
-# Usage: require_gnu_compiler ENV-VARIABLE GNU-COMPILER [OTHER-GNU-COMPILERS]
-# Presently, this function is meant for internal use only.
-require_gnu_compiler()
-{
-  environment_variable=$1
-  shift
-  have_gnu_compiler=false
-  for gnu_compiler in ${1+"$@"}; do
-    echo "$me: running $gnu_compiler --version"
-    "$gnu_compiler" --version || continue
-    # This gives more information about the compiler, and also checks for
-    # e.g. broken gcj installations.
-    echo "$me: running $gnu_compiler -v"
-    "$gnu_compiler" -v || continue
-    echo # gracefully separate verbose information from rest of testlog
-    have_gnu_compiler=:
-  done
-  $have_gnu_compiler || exit 77
-  eval $environment_variable=\$gnu_compiler
-  export $environment_variable
-  unset environment_variable gnu_compiler have_gnu_compiler
+  if { test x"$what_gnu" = x"try" && test -z "$compiler"; } \
+       || test x"$what_gnu" = x"force"; then
+    # Either the user specified no explicit compiler in its environment,
+    # or the script asked to force the use of a GNU compiler, so we try
+    # to enable the use of a GNU compiler.
+    have_gnu_compiler=false
+    for compiler in $gnu_compiler_candidates; do
+      echo "$me: running $compiler --version"
+      "$compiler" --version || continue
+      # This gives more information about the compiler, and also checks
+      # for e.g. broken gcj installations.
+      echo "$me: running $compiler -v"
+      "$compiler" -v || continue
+      echo # gracefully separate verbose information from rest of testlog
+      have_gnu_compiler=:
+    done
+    $have_gnu_compiler || exit 77
+    eval "$compiler_variable=\$compiler"
+    export $compiler_variable
+  fi
+ 
+  # Remove local variables.
+  unset what_gnu compiler_variable compiler
+  unset gnu_compiler_candidates have_gnu_compiler
 }
 
 for tool in : $required
@@ -168,29 +188,28 @@ do
       ( $MAKE --version -v | grep GNU ) || exit 77
       ;;
     cc)
-      require_compiler 'CC' gcc
+      require_compiler c
       ;;
     gcc)
-      require_gnu_compiler 'CC' gcc
+      require_compiler --force-gnu c
       ;;
     gcj)
-      require_gnu_compiler 'GCJ' gcj
+      require_compiler --force-gnu gcj
       ;;
     c++)
-      require_compiler 'CXX' g++
+      require_compiler c++
       ;;
     g++)
-      require_gnu_compiler 'CXX' g++
+      require_compiler --force-gnu c++
       ;;
     fortran)
-      require_compiler 'FC' gfortran
+      require_compiler f9x
       ;;
     fortran77)
-      # gfortran should be able to seamlessly compile Fortran 77 code
-      require_compiler 'F77' g77 gfortran
+      require_compiler f77
       ;;
     gfortran)
-      require_gnu_compiler 'FC' gfortran
+      require_compiler --force-gnu f9x
       # This ensures that gfortran and a fortran77 compiler can both be
       # required.
       case " $required " in
-- 
1.6.5