Allow overriding the bc implementation used in run-bc

While base bc is great, it uses libcrypto's BIGNUM implementation.
This implies that the independent verification of the bn_test isn't
as independent as it should be.

With this commit, run-bc picks up bn-gh if it is installed. This appears
to work on amd64, arm64 and sparc64 (where gbc is busted). I will send
PRs to the regress maintainers once I will have tested this a bit more
thoroughly. Committing this early since I juggle way too many diffs
already.

1 files changed, 7 insertions, 2 deletions

diff --git a/src/regress/lib/libcrypto/bn/Makefile b/src/regress/lib/libcrypto/bn/Makefile
index 2ba1d396dd..9d9d77ae2d 100644
--- a/src/regress/lib/libcrypto/bn/Makefile
+++ b/src/regress/lib/libcrypto/bn/Makefile
@@ -1,4 +1,4 @@
-#       $OpenBSD: Makefile,v 1.30 2023/04/17 19:37:18 tb Exp $
+#       $OpenBSD: Makefile,v 1.31 2023/04/17 19:51:05 tb Exp $
 
 PROGS +=        bn_add_sub
 PROGS +=        bn_cmp
@@ -53,10 +53,15 @@ CLEANFILES += bn_isqrt_gen_tables.txt.tmp bn_isqrt_gen_tables.txt
 run-regress-bn_test bn_test.out: bn_test
         ./bn_test -out bn_test.out
 
+.if exists(/usr/local/bin/bc-gh)
+BC ?=   bc-gh
+.endif
+BC ?=   bc
+
 REGRESS_TARGETS +=      run-bc
 .PHONY:                 run-bc
 run-bc: bn_test.out
-        bc < $> | tee bc.out | grep -v '^0$$'
+        ${BC} < $> | tee bc.out | grep -v '^0$$'
         ! grep -v '^test ' <bc.out | grep -v '^0$$'
 
 CLEANFILES +=   bn_test.out bc.out