BUILD: add a new file "version.c" to carry version updates

While testing fixes, it's sometimes confusing to rebuild only one C file
(e.g. a mux) and not to have the correct commit ID reported in "haproxy -v"
nor on the stats page.

This patch adds a new "version.c" file which is always rebuilt. It's
very small and contains only 3 variables derived from the various
version strings. These variables are used instead of the macros at the
few places showing the version. This way the output version of the
running code is always correct for the parts that were rebuilt.

Makefile

@@ -947,7 +947,7 @@ OBJS = src/proto_http.o src/cfgparse-listen.o src/proto_htx.o src/stream.o    \
        src/http.o src/hpack-dec.o src/action.o src/proto_udp.o src/http_acl.o \
        src/xxhash.o src/hpack-enc.o src/h2.o src/freq_ctr.o src/lru.o         \
        src/protocol.o src/arg.o src/hpack-huff.o src/hdr_idx.o src/base64.o   \
-       src/hash.o src/mailers.o src/activity.o src/http_msg.o
+       src/hash.o src/mailers.o src/activity.o src/http_msg.o src/version.o
 
 EBTREE_OBJS = $(EBTREE_DIR)/ebtree.o $(EBTREE_DIR)/eb32sctree.o \
               $(EBTREE_DIR)/eb32tree.o $(EBTREE_DIR)/eb64tree.o \
@@ -984,6 +984,9 @@ objsize: haproxy
 %.o:	%.c $(DEP)
 	$(cmd_CC) $(COPTS) -c -o $@ $<
 
+# rebuild it every time
+.PHONY: src/version.c
+
 src/trace.o: src/trace.c $(DEP)
 	$(cmd_CC) $(TRACE_COPTS) -c -o $@ $<
 

include/common/version.h

@@ -66,5 +66,9 @@
 #error "Must define CONFIG_HAPROXY_DATE"
 #endif
 
+extern const char *haproxy_version;
+extern const char *haproxy_date;
+extern const char *stats_version_string;
+
 #endif /* _COMMON_VERSION_H */
 

src/haproxy.c

@@ -370,7 +370,7 @@ void hap_register_per_thread_deinit(void (*fct)())
 
 static void display_version()
 {
-	printf("HA-Proxy version " HAPROXY_VERSION " " HAPROXY_DATE" - https://haproxy.org/\n");
+	printf("HA-Proxy version %s %s - https://haproxy.org/\n", haproxy_version, haproxy_date);
 }
 
 static void display_build_opts()

src/stats.c

@@ -2386,7 +2386,7 @@ static void stats_dump_html_info(struct stream_interface *si, struct uri_auth *u
 	              "<td align=\"left\" valign=\"top\" nowrap width=\"1%%\">"
 	              "<b>Display option:</b><ul style=\"margin-top: 0.25em;\">"
 	              "",
-	              (uri->flags & ST_HIDEVER) ? "" : (STATS_VERSION_STRING),
+	              (uri->flags & ST_HIDEVER) ? "" : (stats_version_string),
 	              pid, (uri->flags & ST_SHNODE) ? " on " : "",
 		      (uri->flags & ST_SHNODE) ? (uri->node ? uri->node : global.node) : "",
 	              (uri->flags & ST_SHDESC) ? ": " : "",
@@ -3558,8 +3558,8 @@ int stats_fill_info(struct field *info, int len)
 	memset(info, 0, sizeof(*info) * len);
 
 	info[INF_NAME]                           = mkf_str(FO_PRODUCT|FN_OUTPUT|FS_SERVICE, PRODUCT_NAME);
-	info[INF_VERSION]                        = mkf_str(FO_PRODUCT|FN_OUTPUT|FS_SERVICE, HAPROXY_VERSION);
-	info[INF_RELEASE_DATE]                   = mkf_str(FO_PRODUCT|FN_OUTPUT|FS_SERVICE, HAPROXY_DATE);
+	info[INF_VERSION]                        = mkf_str(FO_PRODUCT|FN_OUTPUT|FS_SERVICE, haproxy_version);
+	info[INF_RELEASE_DATE]                   = mkf_str(FO_PRODUCT|FN_OUTPUT|FS_SERVICE, haproxy_date);
 
 	info[INF_NBTHREAD]                       = mkf_u32(FO_CONFIG|FS_SERVICE, global.nbthread);
 	info[INF_NBPROC]                         = mkf_u32(FO_CONFIG|FS_SERVICE, global.nbproc);

src/version.c

@@ -0,0 +1,11 @@
+/*
+ * Version reporting : all user-visible version information should come from
+ * this file so that rebuilding only this one is enough to report the latest
+ * code version.
+ */
+
+#include <common/version.h>
+
+const char *haproxy_version      = HAPROXY_VERSION;
+const char *haproxy_date         = HAPROXY_DATE;
+const char *stats_version_string = STATS_VERSION_STRING;