Add ability to search up the directory hierarchy for the system directory.

Do by specifying ".../" with '-m' or MAKESYSPATH (new) environment variable.

Reviewed by:	<sjg@NetBSD.org>
Obtained from:	NetBSD (+ embellishment by me, sent back to NetBSD)

4 files changed, 158 insertions, 11 deletions

diff --git a/usr.bin/make/dir.c b/usr.bin/make/dir.c
index 9b529ea..7cee3d4 100644
--- a/usr.bin/make/dir.c
+++ b/usr.bin/make/dir.c
@@ -61,6 +61,10 @@ __FBSDID("$FreeBSD$");
  *			If it exists, the entire path is returned.
  *			Otherwise NULL is returned.
  *
+ *	Dir_FindHereOrAbove Search for a path in the current directory and
+ *			then all the directories above it in turn until
+ *			the path is found or we reach the root ("/").
+ *
  *	Dir_MTime	Return the modification time of a node. The file
  *			is searched for along the default search path.
  *			The path and mtime fields of the node are filled in.
@@ -83,7 +87,7 @@ __FBSDID("$FreeBSD$");
  *	Dir_PrintDirectories	Print stats about the directory cache.
  */
 
-#include <sys/types.h>
+#include <sys/param.h>
 #include <sys/stat.h>
 #include <dirent.h>
 #include <err.h>
@@ -851,6 +855,83 @@ Path_FindFile(char *name, struct Path *path)
 
 /*-
  *-----------------------------------------------------------------------
+ * Dir_FindHereOrAbove  --
+ *	search for a path starting at a given directory and then working
+ *	our way up towards the root.
+ *
+ * Input:
+ *	here		starting directory
+ *	search_path	the path we are looking for
+ *	result		the result of a successful search is placed here
+ *	rlen		the length of the result buffer
+ *			(typically MAXPATHLEN + 1)
+ *
+ * Results:
+ *	0 on failure, 1 on success [in which case the found path is put
+ *	in the result buffer].
+ *
+ * Side Effects:
+ *-----------------------------------------------------------------------
+ */
+int
+Dir_FindHereOrAbove(char *here, char *search_path, char *result, int rlen)
+{
+	struct stat st;
+	char dirbase[MAXPATHLEN + 1], *db_end;
+	char try[MAXPATHLEN + 1], *try_end;
+
+	/* copy out our starting point */
+	snprintf(dirbase, sizeof(dirbase), "%s", here);
+	db_end = dirbase + strlen(dirbase);
+
+	/* loop until we determine a result */
+	while (1) {
+		/* try and stat(2) it ... */
+		snprintf(try, sizeof(try), "%s/%s", dirbase, search_path);
+		if (stat(try, &st) != -1) {
+			/*
+			 * Success!  If we found a file, chop off
+			 * the filename so we return a directory.
+			 */
+			if ((st.st_mode & S_IFMT) != S_IFDIR) {
+				try_end = try + strlen(try);
+				while (try_end > try && *try_end != '/')
+					try_end--;
+				if (try_end > try)
+					*try_end = 0;	/* chop! */
+			}
+
+			/*
+			 * Done!
+			 */
+			snprintf(result, rlen, "%s", try);
+			return(1);
+		}
+
+		/*
+		 * Nope, we didn't find it.  If we used up dirbase we've
+		 * reached the root and failed.
+		 */
+		if (db_end == dirbase)
+			break;		/* Failed! */
+
+		/*
+		 * truncate dirbase from the end to move up a dir
+		 */
+		while (db_end > dirbase && *db_end != '/')
+			db_end--;
+		*db_end = 0;		/* chop! */
+
+	} /* while (1) */
+
+	/*
+	 * We failed...
+	 */
+	return(0);
+}
+
+/*-
+ *-----------------------------------------------------------------------
  * Dir_MTime  --
  *	Find the modification time of the file described by gn along the
  *	search path dirSearchPath.
diff --git a/usr.bin/make/dir.h b/usr.bin/make/dir.h
index 03481b8..1ae89ae 100644
--- a/usr.bin/make/dir.h
+++ b/usr.bin/make/dir.h
@@ -56,6 +56,7 @@ TAILQ_HEAD(Path, PathElement);
 void Dir_Init(void);
 void Dir_InitDot(void);
 Boolean Dir_HasWildcards(const char *);
+int Dir_FindHereOrAbove(char *, char *, char *, int);
 int Dir_MTime(struct GNode *);
 void Dir_PrintDirectories(void);
 
diff --git a/usr.bin/make/main.c b/usr.bin/make/main.c
index eec6bbf..91638d4 100644
--- a/usr.bin/make/main.c
+++ b/usr.bin/make/main.c
@@ -368,6 +368,7 @@ MainParseArgs(int argc, char **argv)
 {
 	int c;
 	Boolean	found_dd = FALSE;
+	char found_dir[MAXPATHLEN + 1];	/* for searching for sys.mk */
 
 rearg:
 	optind = 1;	/* since we're called more than once */
@@ -394,6 +395,8 @@ rearg:
 		case 'C':
 			if (chdir(optarg) == -1)
 				err(1, "chdir %s", optarg);
+			if (getcwd(curdir, MAXPATHLEN) == NULL)
+				err(2, NULL);
 			break;
 		case 'D':
 			Var_SetGlobal(optarg, "1");
@@ -492,7 +495,15 @@ rearg:
 			MFLAGS_append("-k", NULL);
 			break;
 		case 'm':
-			Path_AddDir(&sysIncPath, optarg);
+			/* look for magic parent directory search string */
+			if (strncmp(".../", optarg, 4) == 0) {
+				if (!Dir_FindHereOrAbove(curdir, optarg + 4,
+				    found_dir, sizeof(found_dir)))
+					break;		/* nothing doing */
+				Path_AddDir(&sysIncPath, found_dir);
+			} else {
+				Path_AddDir(&sysIncPath, optarg);
+			}
 			MFLAGS_append("-m", optarg);
 			break;
 		case 'n':
@@ -869,6 +880,7 @@ main(int argc, char **argv)
 	char mdpath[MAXPATHLEN];
 	char obpath[MAXPATHLEN];
 	char cdpath[MAXPATHLEN];
+	char found_dir[MAXPATHLEN + 1];	/* for searching for sys.mk */
 	char *cp = NULL, *start;
 
 	save_argv = argv;
@@ -1022,6 +1034,12 @@ main(int argc, char **argv)
 	Job_SetPrefix();
 
 	/*
+	 * Find where we are...
+	 */
+	if (getcwd(curdir, MAXPATHLEN) == NULL)
+		err(2, NULL);
+
+	/*
 	 * First snag things out of the MAKEFLAGS environment
 	 * variable.  Then parse the command line arguments.
 	 */
@@ -1030,11 +1048,8 @@ main(int argc, char **argv)
 	MainParseArgs(argc, argv);
 
 	/*
-	 * Find where we are...
+	 * Verify that cwd is sane (after -C may have changed it).
 	 */
-	if (getcwd(curdir, MAXPATHLEN) == NULL)
-		err(2, NULL);
-
 	{
 	struct stat sa;
 
@@ -1132,18 +1147,37 @@ main(int argc, char **argv)
 	 * as dir1:...:dirn) to the system include path.
 	 */
 	if (TAILQ_EMPTY(&sysIncPath)) {
-		char syspath[] = PATH_DEFSYSPATH;
+		char defsyspath[] = PATH_DEFSYSPATH;
+		char *syspath = getenv("MAKESYSPATH");
+
+		/*
+		 * If no user-supplied system path was given (thru -m option)
+		 * add the directories from the DEFSYSPATH (more than one may
+		 * be given as dir1:...:dirn) to the system include path.
+		 */
+		if (syspath == NULL || *syspath == '\0')
+			syspath = defsyspath;
+		else
+			syspath = estrdup(syspath);
 
 		for (start = syspath; *start != '\0'; start = cp) {
 			for (cp = start; *cp != '\0' && *cp != ':'; cp++)
 				continue;
-			if (*cp == '\0') {
-				Path_AddDir(&sysIncPath, start);
-			} else {
+			if (*cp == ':') {
 				*cp++ = '\0';
+			}
+			/* look for magic parent directory search string */
+			if (strncmp(".../", start, 4) == 0) {
+				if (Dir_FindHereOrAbove(curdir, start + 4,
+				    found_dir, sizeof(found_dir))) {
+					Path_AddDir(&sysIncPath, found_dir);
+				}
+			} else {
 				Path_AddDir(&sysIncPath, start);
 			}
 		}
+		if (syspath != defsyspath)
+			free(syspath);
 	}
 
 	/*
diff --git a/usr.bin/make/make.1 b/usr.bin/make/make.1
index a4e837c..2c478a3 100644
--- a/usr.bin/make/make.1
+++ b/usr.bin/make/make.1
@@ -240,6 +240,36 @@ The system include path will always be appended to the search path used
 for "..."-style inclusions and makefile searches (see the
 .Fl I
 option).
+.Pp
+If a file or directory name in the
+.Fl m
+argument (or the
+.Ev MAKESYSPATH
+environment variable) starts with the string
+.Qq \&.../
+then
+.Nm
+will search for the specified file or directory named in the remaining part
+of the argument string.
+The search starts with the current directory of the Makefile and then works
+upward towards the root of the filesystem.
+If the search is successful,
+then the resulting directory replaces the
+.Qq \&.../
+specification in the
+.Fl m
+argument.
+If used, this feature allows
+.Nm
+to easily search in the current source tree for customized sys.mk files
+(e.g. by using
+.Qq \&.../mk/sys.mk
+as an argument).
+Note that a
+.Fl C
+that are earlier on the command line affect where
+.Fl m Qq \&.../
+searches.
 .It Fl n
 Display the commands that would have been executed, but do not actually
 execute them.
@@ -1665,8 +1695,9 @@ utility uses the following environment variables, if they exist:
 .Ev MAKE ,
 .Ev MAKEFLAGS ,
 .Ev MAKEOBJDIR ,
+.Ev MAKEOBJDIRPREFIX ,
 and
-.Ev MAKEOBJDIRPREFIX .
+.Ev MAKESYSPATH .
 .Sh FILES
 .Bl -tag -width /usr/share/doc/psd/12.make -compact
 .It Pa .depend