configure: add hack to rename ccan's sha256 routines to avoid libwally clash

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

ccan_compat.h

@@ -0,0 +1,19 @@
+#ifndef LIGHTNING_CCAN_COMPAT_H
+#define LIGHTNING_CCAN_COMPAT_H
+/* Magical file included from config.h (ie. everywhere) which renames
+ * sha256 routines so they don't clash with libwally-core's internal ones */
+#define sha256(sha, p, size) ccan_sha256(sha, p, size)
+#define sha256_init(ctx) ccan_sha256_init(ctx)
+#define sha256_update(ctx, p, size) ccan_sha256_update(ctx, p, size)
+#define sha256_done(sha256, res) ccan_sha256_done(sha256, res)
+#define sha256_u8(ctx, v) ccan_sha256_u8(ctx, v)
+#define sha256_u16(ctx, v) ccan_sha256_u16(ctx, v)
+#define sha256_u32(ctx, v) ccan_sha256_u32(ctx, v)
+#define sha256_u64(ctx, v) ccan_sha256_u64(ctx, v)
+#define sha256_le16(ctx, v) ccan_sha256_le16(ctx, v)
+#define sha256_le32(ctx, v) ccan_sha256_le32(ctx, v)
+#define sha256_le64(ctx, v) ccan_sha256_le64(ctx, v)
+#define sha256_be16(ctx, v) ccan_sha256_be16(ctx, v)
+#define sha256_be32(ctx, v) ccan_sha256_be32(ctx, v)
+#define sha256_be64(ctx, v) ccan_sha256_be64(ctx, v)
+#endif /* LIGHTNING_CCAN_COMPAT_H */

configure

@@ -128,3 +128,7 @@ add_var VALGRIND "$VALGRIND"
 add_var DEVELOPER "$DEVELOPER" $CONFIG_HEADER
 add_var COMPAT "$COMPAT" $CONFIG_HEADER
 add_var PYTEST "$PYTEST"
+
+# Hack to avoid sha256 name clash with libwally: will be fixed when that
+# becomes a standalone shared lib.
+echo '#include "ccan_compat.h"' >> $CONFIG_HEADER