buildsys: embed the current git commit id(or tag) to ctags binary

If configure is used for building and building is done in
a git repository, git commit id is embedded to ctags
executable (as before). The id can be seen in the output
of `ctags --version' or in __TAG_PROGRAM_VERSION pseudo tag
in a tags file.

If ctags built on a platform where configure is not used,
the id is set to 0. If ctags at the outside of a git repository,
the id is set to 0.

This feature will be used in regression test I'm designing now.

For tagged version, embed the tag instead of commit id.
Suggested by @k-takata.

Signed-off-by: Masatake YAMATO <[email protected]>

.gitignore

@@ -46,6 +46,7 @@ mkinstalldirs
 perf.data*
 readtags
 readtags.exe
+repoinfo.h
 respmvc
 stamp-h1
 STDERR.*

Makefile.am

@@ -25,13 +25,28 @@ ctags_CPPFLAGS = -I. -I$(srcdir) -I$(srcdir)/main
 ctags_CPPFLAGS+= $(DEBUG_CPPFLAGS)
 ctags_CPPFLAGS+= $(FNMATCH_CPPFLAGS)
 ctags_CPPFLAGS+= $(REGCOMP_CPPFLAGS)
+ctags_CPPFLAGS+= -DHAVE_REPOINFO_H
 
 ctags_CFLAGS   = -g -O2
 ctags_CFLAGS  += $(EXTRA_CFLAGS)
 ctags_CFLAGS  += $(WARNING_CFLAGS)
 ctags_CFLAGS  += $(COVERAGE_CFLAGS)
 ctags_CFLAGS  += $(CGCC_CFLAGS)
 
+nodist_ctags_SOURCES = $(REPOINFO_HEADS)
+BUILT_SOURCES = $(REPOINFO_HEADS)
+CLEANFILES = $(REPOINFO_HEADS)
+$(REPOINFO_OBJS): $(REPOINFO_SRCS) $(REPOINFO_HEADS)
+if BUILD_IN_GIT_REPO
+GEN_REPOINFO = $(srcdir)/misc/gen-repoinfo
+$(REPOINFO_HEADS): $(srcdir)/.git/*
+	$(GEN_REPOINFO) > $@
+endif
+if !BUILD_IN_GIT_REPO
+$(REPOINFO_HEADS):
+	echo 0 > $@
+endif
+
 OPTLIB2C = $(srcdir)/misc/optlib2c
 .ctags.c: $(OPTLIB2C)
 	$(OPTLIB2C) $< > $@

configure.ac

@@ -298,6 +298,19 @@ fi
 
 # Checks for operating environment
 # --------------------------------
+in_git_repo=no
+AC_MSG_CHECKING(building in a git repository)
+if test -f "${srcdir}/.git/HEAD"; then
+	in_git_repo=yes
+fi
+AC_MSG_RESULT(${in_git_repo})
+
+AC_CHECK_PROGS([GIT], [git])
+if ! test "${GIT+set}" = "set"; then
+	in_git_repo=no
+fi
+AM_CONDITIONAL([BUILD_IN_GIT_REPO], [test "x${in_git_repo}" = "xyes"])
+
 
 # Check for temporary directory
 AC_MSG_CHECKING(directory to use for temporary files)

main/ctags.h

@@ -20,6 +20,11 @@
 #define PROGRAM_COPYRIGHT "Copyright (C) 2015"
 #define AUTHOR_NAME       "Universal Ctags Team"
 
+/*
+ * Constant
+ */
+extern const char* ctags_repoinfo;
+
 #endif	/* CTAGS_MAIN_CTAGS_H */
 
 /* vi:set tabstop=4 shiftwidth=4: */

main/entry.c

@@ -168,7 +168,7 @@ static void addPseudoTags (void)
 	{
 		char format [11];
 		const char *formatComment = "unknown format";
-		char commit_id [8] = "";
+		const char* repoinfo;
 
 		sprintf (format, "%u", Option.tagFileFormat);
 
@@ -187,11 +187,8 @@ static void addPseudoTags (void)
 		writePseudoTag ("TAG_PROGRAM_AUTHOR",  AUTHOR_NAME,  "", NULL);
 		writePseudoTag ("TAG_PROGRAM_NAME",    PROGRAM_NAME, "Derived from Exuberant Ctags", NULL);
 		writePseudoTag ("TAG_PROGRAM_URL",     PROGRAM_URL,  "official site", NULL);
-
-#if defined(CTAGS_COMMIT_ID) && CTAGS_COMMIT_ID != 0
-			snprintf (commit_id, sizeof (commit_id), "%.7x", CTAGS_COMMIT_ID);
-#endif
-		writePseudoTag ("TAG_PROGRAM_VERSION", PROGRAM_VERSION, commit_id, NULL);
+		repoinfo = ctags_repoinfo? ctags_repoinfo: "";
+		writePseudoTag ("TAG_PROGRAM_VERSION", PROGRAM_VERSION, repoinfo, NULL);
 
 #ifdef HAVE_ICONV
 		if (Option.outputEncoding)

main/options.c

@@ -1188,15 +1188,14 @@ static void processListFieldsOption(const char *const option __unused__,
 
 static void printProgramIdentification (void)
 {
-	printf (
-#if defined(CTAGS_COMMIT_ID) && CTAGS_COMMIT_ID != 0
-		"%s %s(%.7x), %s %s\n",
-		PROGRAM_NAME, PROGRAM_VERSION, CTAGS_COMMIT_ID,
-#else
-		"%s %s, %s %s\n",
-		PROGRAM_NAME, PROGRAM_VERSION,
-#endif
-		PROGRAM_COPYRIGHT, AUTHOR_NAME);
+	if (ctags_repoinfo)
+		printf ("%s %s(%s), %s %s\n",
+			PROGRAM_NAME, PROGRAM_VERSION, ctags_repoinfo,
+			PROGRAM_COPYRIGHT, AUTHOR_NAME);
+	else
+		printf ("%s %s, %s %s\n",
+			PROGRAM_NAME, PROGRAM_VERSION,
+			PROGRAM_COPYRIGHT, AUTHOR_NAME);
 	printf ("Universal Ctags is derived from Exuberant Ctags.\n");
 	printf ("Exuberant Ctags 5.8, Copyright (C) 1996-2009 Darren Hiebert\n");
 

main/repoinfo.c

@@ -0,0 +1,8 @@
+#include "general.h"
+#include "ctags.h"
+#ifdef HAVE_REPOINFO_H
+#include "main/repoinfo.h"
+#else
+#define CTAGS_REPOINFO ((char*)0)
+#endif
+const char* ctags_repoinfo = CTAGS_REPOINFO;

misc/gen-repoinfo

@@ -0,0 +1,4 @@
+#!/bin/sh
+rinfo=`git describe --tag --exact-match HEAD 2> /dev/null || git rev-parse --short HEAD`
+echo "#define CTAGS_REPOINFO \"${rinfo}\""
+

source.mak

@@ -1,5 +1,13 @@
 # Shared macros
 
+# REPOINFO_HEADS is included from REPOINFO_SRCS
+# only when the building environment has ability
+# to generate the header file.
+# REPOINFO_OBJS is always linked to ctags executable.
+REPOINFO_HEADS = main/repoinfo.h
+REPOINFO_SRCS  = main/repoinfo.c
+REPOINFO_OBJS  = $(REPOINFO_SRCS:.c=.$(OBJEXT))
+
 MAIN_HEADS =			\
 	main/args.h		\
 	main/ctags.h		\
@@ -51,7 +59,11 @@ MAIN_SRCS =				\
 	main/sort.c			\
 	main/strlist.c			\
 	main/vstring.c			\
-	main/xtag.c
+	main/xtag.c			\
+	\
+	$(REPOINFO_SRCS) \
+	\
+	$(NULL)
 
 include makefiles/translator_input.mak
 TRANSLATED_SRCS = $(TRANSLATOR_INPUT:.ctags=.c)

win32/ctags_vs2013.vcxproj

@@ -153,6 +153,7 @@
       <WarningLevel Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">TurnOffAllWarnings</WarningLevel>
       <WarningLevel Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">TurnOffAllWarnings</WarningLevel>
     </ClCompile>
+    <ClCompile Include="..\main\repoinfo.c" />
     <ClCompile Include="..\parsers\rst.c" />
     <ClCompile Include="..\parsers\r.c" />
     <ClCompile Include="..\parsers\rexx.c" />

win32/ctags_vs2013.vcxproj.filters

@@ -262,6 +262,9 @@
     <ClCompile Include="..\main\xtag.c">
       <Filter>Source Files\Main</Filter>
     </ClCompile>
+    <ClCompile Include="..\main\repoinfo.c">
+      <Filter>Source Files\Main</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="..\main\e_msoft.h">