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authorBen Gamari <ben@smart-cactus.org>2021-04-02 11:52:47 -0400
committerMarge Bot <ben+marge-bot@smart-cactus.org>2021-05-05 05:42:38 -0400
commit7ffbdc3fa603c6411249ba9b758cf8f109c5fb30 (patch)
tree8a05d6e03ce2790e6e59651c824e569fee088d33 /m4/fp_prog_context_diff.m4
parent6acadb79afe685c635fd255f90551a0fbfcbe3dc (diff)
downloadhaskell-7ffbdc3fa603c6411249ba9b758cf8f109c5fb30.tar.gz
Break up aclocal.m4
Diffstat (limited to 'm4/fp_prog_context_diff.m4')
-rw-r--r--m4/fp_prog_context_diff.m423
1 files changed, 23 insertions, 0 deletions
diff --git a/m4/fp_prog_context_diff.m4 b/m4/fp_prog_context_diff.m4
new file mode 100644
index 0000000000..886f73ce4c
--- /dev/null
+++ b/m4/fp_prog_context_diff.m4
@@ -0,0 +1,23 @@
+# FP_PROG_CONTEXT_DIFF
+# --------------------
+# Figure out how to do context diffs. Sets the output variable ContextDiffCmd.
+#
+# Note: NeXTStep thinks diff'ing a file against itself is "trouble".
+AC_DEFUN([FP_PROG_CONTEXT_DIFF],
+[AC_CACHE_CHECK([for a working context diff], [fp_cv_context_diff],
+[echo foo > conftest1
+echo foo > conftest2
+fp_cv_context_diff=no
+for fp_var in '-U 1' '-u1' '-C 1' '-c1'
+do
+ if diff $fp_var conftest1 conftest2 > /dev/null 2>&1; then
+ fp_cv_context_diff="diff $fp_var"
+ break
+ fi
+done])
+if test x"$fp_cv_context_diff" = xno; then
+ AC_MSG_ERROR([cannot figure out how to do context diffs])
+fi
+AC_SUBST(ContextDiffCmd, [$fp_cv_context_diff])
+])# FP_PROG_CONTEXT_DIFF
+