[PATCH 0/7 v2] RUNTIME_PREFIX

[PATCH 0/7 v2] RUNTIME_PREFIX

[Steffen Prohaska]

This series is a replacement for

   http://article.gmane.org/gmane.comp.version-control.git/105109

improved according to the comments by Dscho and Hannes.

        Steffen


Steffen Prohaska (6):
  Move computation of absolute paths from Makefile to runtime (in
    preparation for RUNTIME_PREFIX)
  git_extract_argv0_path(): Move check for valid argv0 from caller to
    callee
  Add calls to git_extract_argv0_path() in programs that call
    git_config_*
  Modify setup_path() to only add git_exec_path() to PATH
  Compute prefix at runtime if RUNTIME_PREFIX is set
  Windows: Revert to default paths and convert them by RUNTIME_PREFIX

Steve Haslam (1):
  Refactor git_set_argv0_path() to git_extract_argv0_path()

 Makefile             |   49 +++++++++++++++++++------------
 builtin-help.c       |    4 +-
 daemon.c             |    2 +
 exec_cmd.c           |   77 ++++++++++++++++++++++++++++++++++++++++++++------
 exec_cmd.h           |    2 +-
 fast-import.c        |    3 ++
 git.c                |   18 ++---------
 hash-object.c        |    3 ++
 http-push.c          |    2 +
 imap-send.c          |    3 ++
 index-pack.c         |    3 ++
 merge-index.c        |    3 ++
 merge-tree.c         |    3 ++
 mktag.c              |    3 ++
 mktree.c             |    3 ++
 pack-redundant.c     |    3 ++
 patch-id.c           |    3 ++
 unpack-file.c        |    3 ++
 update-server-info.c |    3 ++
 upload-pack.c        |    2 +
 var.c                |    3 ++
 21 files changed, 150 insertions(+), 45 deletions(-)

[PATCH 1/7 v2] Move computation of absolute paths from Makefile to runtime (in preparation for RUNTIME_PREFIX)

[Steffen Prohaska]

This commit prepares the Makefile for relocatable binaries (called
RUNTIME_PREFIX).  Such binaries will be able to be moved together
with the system configuration files to a different directory,
requiring to compute the prefix at runtime.

In a first step, we make all paths relative in the Makefile and
teach system_path() to add the prefix instead.  We used to compute
absolute paths in the Makefile and passed them to C as defines.  We
now pass relative paths to C and call system_path() to add the
prefix at runtime.

Signed-off-by: Steffen Prohaska <prohaska@zib.de>
---
 Makefile       |   42 ++++++++++++++++++++++++++----------------
 builtin-help.c |    4 ++--
 exec_cmd.c     |   12 ++++++++----
 3 files changed, 36 insertions(+), 22 deletions(-)

diff --git a/Makefile b/Makefile
index 2b873fa..1d2060a 100644
--- a/Makefile
+++ b/Makefile
@@ -179,28 +179,32 @@ STRIP ?= strip
 # Among the variables below, these:
 #   gitexecdir
 #   template_dir
+#   mandir
+#   infodir
 #   htmldir
 #   ETC_GITCONFIG (but not sysconfdir)
-# can be specified as a relative path ../some/where/else (which must begin
-# with ../); this is interpreted as relative to $(bindir) and "git" at
+# can be specified as a relative path some/where/else;
+# this is interpreted as relative to $(prefix) and "git" at
 # runtime figures out where they are based on the path to the executable.
 # This can help installing the suite in a relocatable way.
 
 prefix = $(HOME)
-bindir = $(prefix)/bin
-mandir = $(prefix)/share/man
-infodir = $(prefix)/share/info
-gitexecdir = $(prefix)/libexec/git-core
+bindir_relative = bin
+bindir = $(prefix)/$(bindir_relative)
+mandir = share/man
+infodir = share/info
+gitexecdir = libexec/git-core
 sharedir = $(prefix)/share
-template_dir = $(sharedir)/git-core/templates
-htmldir=$(sharedir)/doc/git-doc
+template_dir = share/git-core/templates
+htmldir = share/doc/git-doc
 ifeq ($(prefix),/usr)
 sysconfdir = /etc
+ETC_GITCONFIG = $(sysconfdir)/gitconfig
 else
 sysconfdir = $(prefix)/etc
+ETC_GITCONFIG = etc/gitconfig
 endif
 lib = lib
-ETC_GITCONFIG = $(sysconfdir)/gitconfig
 # DESTDIR=
 
 # default configuration for gitweb
@@ -1086,6 +1090,7 @@ ETC_GITCONFIG_SQ = $(subst ','\'',$(ETC_GITCONFIG))
 
 DESTDIR_SQ = $(subst ','\'',$(DESTDIR))
 bindir_SQ = $(subst ','\'',$(bindir))
+bindir_relative_SQ = $(subst ','\'',$(bindir_relative))
 mandir_SQ = $(subst ','\'',$(mandir))
 infodir_SQ = $(subst ','\'',$(infodir))
 gitexecdir_SQ = $(subst ','\'',$(gitexecdir))
@@ -1251,7 +1256,12 @@ git.o git.spec \
 	$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) $<
 
 exec_cmd.o: exec_cmd.c GIT-CFLAGS
-	$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) '-DGIT_EXEC_PATH="$(gitexecdir_SQ)"' $<
+	$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) \
+		'-DGIT_EXEC_PATH="$(gitexecdir_SQ)"' \
+		'-DBINDIR="$(bindir_relative_SQ)"' \
+		'-DPREFIX="$(prefix_SQ)"' \
+		$<
+
 builtin-init-db.o: builtin-init-db.c GIT-CFLAGS
 	$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) -DDEFAULT_GIT_TEMPLATE_DIR='"$(template_dir_SQ)"' $<
 
@@ -1407,17 +1417,17 @@ remove-dashes:
 
 ### Installation rules
 
-ifeq ($(firstword $(subst /, ,$(template_dir))),..)
-template_instdir = $(bindir)/$(template_dir)
-else
+ifeq ($(abspath $(template_dir)),$(template_dir))
 template_instdir = $(template_dir)
+else
+template_instdir = $(prefix)/$(template_dir)
 endif
 export template_instdir
 
-ifeq ($(firstword $(subst /, ,$(gitexecdir))),..)
-gitexec_instdir = $(bindir)/$(gitexecdir)
-else
+ifeq ($(abspath $(gitexecdir)),$(gitexecdir))
 gitexec_instdir = $(gitexecdir)
+else
+gitexec_instdir = $(prefix)/$(gitexecdir)
 endif
 gitexec_instdir_SQ = $(subst ','\'',$(gitexec_instdir))
 export gitexec_instdir
diff --git a/builtin-help.c b/builtin-help.c
index f076efa..9b57a74 100644
--- a/builtin-help.c
+++ b/builtin-help.c
@@ -329,7 +329,7 @@ static void setup_man_path(void)
 	 * old_path, the ':' at the end will let 'man' to try
 	 * system-wide paths after ours to find the manual page. If
 	 * there is old_path, we need ':' as delimiter. */
-	strbuf_addstr(&new_path, GIT_MAN_PATH);
+	strbuf_addstr(&new_path, system_path(GIT_MAN_PATH));
 	strbuf_addch(&new_path, ':');
 	if (old_path)
 		strbuf_addstr(&new_path, old_path);
@@ -375,7 +375,7 @@ static void show_man_page(const char *git_cmd)
 static void show_info_page(const char *git_cmd)
 {
 	const char *page = cmd_to_page(git_cmd);
-	setenv("INFOPATH", GIT_INFO_PATH, 1);
+	setenv("INFOPATH", system_path(GIT_INFO_PATH), 1);
 	execlp("info", "info", "gitman", page, NULL);
 }
 
diff --git a/exec_cmd.c b/exec_cmd.c
index cdd35f9..b7e7b60 100644
--- a/exec_cmd.c
+++ b/exec_cmd.c
@@ -9,11 +9,15 @@ static const char *argv0_path;
 
 const char *system_path(const char *path)
 {
-	if (!is_absolute_path(path) && argv0_path) {
-		struct strbuf d = STRBUF_INIT;
-		strbuf_addf(&d, "%s/%s", argv0_path, path);
-		path = strbuf_detach(&d, NULL);
+	static const char *prefix = PREFIX;
+
+	if (is_absolute_path(path)) {
+		return path;
 	}
+
+	struct strbuf d = STRBUF_INIT;
+	strbuf_addf(&d, "%s/%s", prefix, path);
+	path = strbuf_detach(&d, NULL);
 	return path;
 }
 
-- 
1.6.1.87.g15624

[PATCH 2/7 v2] Refactor git_set_argv0_path() to git_extract_argv0_path()

[Steffen Prohaska]

From: Steve Haslam <shaslam@lastminute.com>

This commit moves the code that computes the dirname of argv[0]
from git.c's main() to git_set_argv0_path() and renames the function
to git_extract_argv0_path().  This makes the code in git.c's main
less cluttered, and we can use the dirname computation from other
main() functions too.

[ spr:
 - split Steve's original commit and wrote new commit message.
 - Integrated Johannes Schindelin's
   cca1704897e7fdb182f68d4c48a437c5d7bc5203 while rebasing onto master.
]

Signed-off-by: Steve Haslam <shaslam@lastminute.com>
Signed-off-by: Steffen Prohaska <prohaska@zib.de>
---
 exec_cmd.c |   14 ++++++++++++--
 exec_cmd.h |    2 +-
 git.c      |   19 +++++--------------
 3 files changed, 18 insertions(+), 17 deletions(-)

diff --git a/exec_cmd.c b/exec_cmd.c
index b7e7b60..23a52cf 100644
--- a/exec_cmd.c
+++ b/exec_cmd.c
@@ -21,9 +21,19 @@ const char *system_path(const char *path)
 	return path;
 }
 
-void git_set_argv0_path(const char *path)
+const char *git_extract_argv0_path(const char *argv0)
 {
-	argv0_path = path;
+	const char *slash = argv0 + strlen(argv0);
+
+	while (argv0 <= slash && !is_dir_sep(*slash))
+		slash--;
+
+	if (slash >= argv0) {
+		argv0_path = xstrndup(argv0, slash - argv0);
+		return slash + 1;
+	}
+
+	return argv0;
 }
 
 void git_set_argv_exec_path(const char *exec_path)
diff --git a/exec_cmd.h b/exec_cmd.h
index 594f961..392e903 100644
--- a/exec_cmd.h
+++ b/exec_cmd.h
@@ -2,7 +2,7 @@
 #define GIT_EXEC_CMD_H
 
 extern void git_set_argv_exec_path(const char *exec_path);
-extern void git_set_argv0_path(const char *path);
+extern const char* git_extract_argv0_path(const char *path);
 extern const char* git_exec_path(void);
 extern void setup_path(void);
 extern const char **prepare_git_cmd(const char **argv);
diff --git a/git.c b/git.c
index a53e24f..b99b1b2 100644
--- a/git.c
+++ b/git.c
@@ -419,22 +419,13 @@ static void execv_dashed_external(const char **argv)
 
 int main(int argc, const char **argv)
 {
-	const char *cmd = argv[0] && *argv[0] ? argv[0] : "git-help";
-	char *slash = (char *)cmd + strlen(cmd);
+	const char *cmd;
 	int done_alias = 0;
 
-	/*
-	 * Take the basename of argv[0] as the command
-	 * name, and the dirname as the default exec_path
-	 * if we don't have anything better.
-	 */
-	while (cmd <= slash && !is_dir_sep(*slash))
-		slash--;
-	if (cmd <= slash) {
-		*slash++ = 0;
-		git_set_argv0_path(cmd);
-		cmd = slash;
-	}
+	if (argv[0] && *argv[0])
+		cmd = git_extract_argv0_path(argv[0]);
+	else
+		cmd = "git-help";
 
 	/*
 	 * "git-xxxx" is the same as "git xxxx", but we obviously:
-- 
1.6.1.87.g15624

[PATCH 3/7 v2] git_extract_argv0_path(): Move check for valid argv0 from caller to callee

[Steffen Prohaska]

This simplifies the calling code.

Signed-off-by: Steffen Prohaska <prohaska@zib.de>
---
 exec_cmd.c |    3 +++
 git.c      |    5 ++---
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/exec_cmd.c b/exec_cmd.c
index 23a52cf..89931e4 100644
--- a/exec_cmd.c
+++ b/exec_cmd.c
@@ -23,6 +23,9 @@ const char *system_path(const char *path)
 
 const char *git_extract_argv0_path(const char *argv0)
 {
+	if (!argv0 || !*argv0)
+		return 0;
+
 	const char *slash = argv0 + strlen(argv0);
 
 	while (argv0 <= slash && !is_dir_sep(*slash))
diff --git a/git.c b/git.c
index b99b1b2..9c8da93 100644
--- a/git.c
+++ b/git.c
@@ -422,9 +422,8 @@ int main(int argc, const char **argv)
 	const char *cmd;
 	int done_alias = 0;
 
-	if (argv[0] && *argv[0])
-		cmd = git_extract_argv0_path(argv[0]);
-	else
+	cmd = git_extract_argv0_path(argv[0]);
+	if (!cmd)
 		cmd = "git-help";
 
 	/*
-- 
1.6.1.87.g15624

[PATCH 4/7 v2] Add calls to git_extract_argv0_path() in programs that call git_config_*

[Steffen Prohaska]

Programs that use git_config need to find the global configuration.
When runtime prefix computation is enabled, this requires that
git_extract_argv0_path() is called early in the program's main().

This commit adds the necessary calls.

Signed-off-by: Steffen Prohaska <prohaska@zib.de>
---
 daemon.c             |    2 ++
 fast-import.c        |    3 +++
 hash-object.c        |    3 +++
 http-push.c          |    2 ++
 imap-send.c          |    3 +++
 index-pack.c         |    3 +++
 merge-index.c        |    3 +++
 merge-tree.c         |    3 +++
 mktag.c              |    3 +++
 mktree.c             |    3 +++
 pack-redundant.c     |    3 +++
 patch-id.c           |    3 +++
 unpack-file.c        |    3 +++
 update-server-info.c |    3 +++
 upload-pack.c        |    2 ++
 var.c                |    3 +++
 16 files changed, 45 insertions(+), 0 deletions(-)

diff --git a/daemon.c b/daemon.c
index 540700e..d93cf96 100644
--- a/daemon.c
+++ b/daemon.c
@@ -937,6 +937,8 @@ int main(int argc, char **argv)
 	gid_t gid = 0;
 	int i;
 
+	git_extract_argv0_path(argv[0]);
+
 	for (i = 1; i < argc; i++) {
 		char *arg = argv[i];
 
diff --git a/fast-import.c b/fast-import.c
index f0e08ac..1935206 100644
--- a/fast-import.c
+++ b/fast-import.c
@@ -150,6 +150,7 @@ Format of STDIN stream:
 #include "refs.h"
 #include "csum-file.h"
 #include "quote.h"
+#include "exec_cmd.h"
 
 #define PACK_ID_BITS 16
 #define MAX_PACK_ID ((1<<PACK_ID_BITS)-1)
@@ -2406,6 +2407,8 @@ int main(int argc, const char **argv)
 {
 	unsigned int i, show_stats = 1;
 
+	git_extract_argv0_path(argv[0]);
+
 	setup_git_directory();
 	git_config(git_pack_config, NULL);
 	if (!pack_compression_seen && core_compression_seen)
diff --git a/hash-object.c b/hash-object.c
index 846e91a..37e6677 100644
--- a/hash-object.c
+++ b/hash-object.c
@@ -8,6 +8,7 @@
 #include "blob.h"
 #include "quote.h"
 #include "parse-options.h"
+#include "exec_cmd.h"
 
 static void hash_fd(int fd, const char *type, int write_object, const char *path)
 {
@@ -81,6 +82,8 @@ int main(int argc, const char **argv)
 
 	type = blob_type;
 
+	git_extract_argv0_path(argv[0]);
+
 	git_config(git_default_config, NULL);
 
 	argc = parse_options(argc, argv, hash_object_options, hash_object_usage, 0);
diff --git a/http-push.c b/http-push.c
index a4b7d08..09caede 100644
--- a/http-push.c
+++ b/http-push.c
@@ -2179,6 +2179,8 @@ int main(int argc, char **argv)
 	struct ref *ref;
 	char *rewritten_url = NULL;
 
+	git_extract_argv0_path(argv[0]);
+
 	setup_git_directory();
 
 	remote = xcalloc(sizeof(*remote), 1);
diff --git a/imap-send.c b/imap-send.c
index c3fa0df..f91293c 100644
--- a/imap-send.c
+++ b/imap-send.c
@@ -23,6 +23,7 @@
  */
 
 #include "cache.h"
+#include "exec_cmd.h"
 #ifdef NO_OPENSSL
 typedef void *SSL;
 #endif
@@ -1389,6 +1390,8 @@ int main(int argc, char **argv)
 	int total, n = 0;
 	int nongit_ok;
 
+	git_extract_argv0_path(argv[0]);
+
 	/* init the random number generator */
 	arc4_init();
 
diff --git a/index-pack.c b/index-pack.c
index 2931511..72c41fd 100644
--- a/index-pack.c
+++ b/index-pack.c
@@ -8,6 +8,7 @@
 #include "tree.h"
 #include "progress.h"
 #include "fsck.h"
+#include "exec_cmd.h"
 
 static const char index_pack_usage[] =
 "git index-pack [-v] [-o <index-file>] [{ ---keep | --keep=<msg> }] [--strict] { <pack-file> | --stdin [--fix-thin] [<pack-file>] }";
@@ -880,6 +881,8 @@ int main(int argc, char **argv)
 	struct pack_idx_entry **idx_objects;
 	unsigned char pack_sha1[20];
 
+	git_extract_argv0_path(argv[0]);
+
 	/*
 	 * We wish to read the repository's config file if any, and
 	 * for that it is necessary to call setup_git_directory_gently().
diff --git a/merge-index.c b/merge-index.c
index 7827e87..c00a2b3 100644
--- a/merge-index.c
+++ b/merge-index.c
@@ -1,5 +1,6 @@
 #include "cache.h"
 #include "run-command.h"
+#include "exec_cmd.h"
 
 static const char *pgm;
 static const char *arguments[9];
@@ -93,6 +94,8 @@ int main(int argc, char **argv)
 	if (argc < 3)
 		usage("git-merge-index [-o] [-q] <merge-program> (-a | [--] <filename>*)");
 
+	git_extract_argv0_path(argv[0]);
+
 	setup_git_directory();
 	read_cache();
 
diff --git a/merge-tree.c b/merge-tree.c
index 2d1413e..f18201a 100644
--- a/merge-tree.c
+++ b/merge-tree.c
@@ -2,6 +2,7 @@
 #include "tree-walk.h"
 #include "xdiff-interface.h"
 #include "blob.h"
+#include "exec_cmd.h"
 
 static const char merge_tree_usage[] = "git-merge-tree <base-tree> <branch1> <branch2>";
 static int resolve_directories = 1;
@@ -344,6 +345,8 @@ int main(int argc, char **argv)
 	if (argc != 4)
 		usage(merge_tree_usage);
 
+	git_extract_argv0_path(argv[0]);
+
 	setup_git_directory();
 
 	buf1 = get_tree_descriptor(t+0, argv[1]);
diff --git a/mktag.c b/mktag.c
index ba3d495..6d5083e 100644
--- a/mktag.c
+++ b/mktag.c
@@ -1,5 +1,6 @@
 #include "cache.h"
 #include "tag.h"
+#include "exec_cmd.h"
 
 /*
  * A signature file has a very simple fixed format: four lines
@@ -159,6 +160,8 @@ int main(int argc, char **argv)
 	if (argc != 1)
 		usage("git-mktag < signaturefile");
 
+	git_extract_argv0_path(argv[0]);
+
 	setup_git_directory();
 
 	if (strbuf_read(&buf, 0, 4096) < 0) {
diff --git a/mktree.c b/mktree.c
index 514fd9b..6283bc3 100644
--- a/mktree.c
+++ b/mktree.c
@@ -6,6 +6,7 @@
 #include "cache.h"
 #include "quote.h"
 #include "tree.h"
+#include "exec_cmd.h"
 
 static struct treeent {
 	unsigned mode;
@@ -70,6 +71,8 @@ int main(int ac, char **av)
 	unsigned char sha1[20];
 	int line_termination = '\n';
 
+	git_extract_argv0_path(av[0]);
+
 	setup_git_directory();
 
 	while ((1 < ac) && av[1][0] == '-') {
diff --git a/pack-redundant.c b/pack-redundant.c
index e93eb96..48a12bc 100644
--- a/pack-redundant.c
+++ b/pack-redundant.c
@@ -7,6 +7,7 @@
 */
 
 #include "cache.h"
+#include "exec_cmd.h"
 
 #define BLKSIZE 512
 
@@ -601,6 +602,8 @@ int main(int argc, char **argv)
 	unsigned char *sha1;
 	char buf[42]; /* 40 byte sha1 + \n + \0 */
 
+	git_extract_argv0_path(argv[0]);
+
 	setup_git_directory();
 
 	for (i = 1; i < argc; i++) {
diff --git a/patch-id.c b/patch-id.c
index 871f1d2..3660ad4 100644
--- a/patch-id.c
+++ b/patch-id.c
@@ -1,4 +1,5 @@
 #include "cache.h"
+#include "exec_cmd.h"
 
 static void flush_current_id(int patchlen, unsigned char *id, git_SHA_CTX *c)
 {
@@ -79,6 +80,8 @@ int main(int argc, char **argv)
 	if (argc != 1)
 		usage(patch_id_usage);
 
+	git_extract_argv0_path(argv[0]);
+
 	generate_id_list();
 	return 0;
 }
diff --git a/unpack-file.c b/unpack-file.c
index bcdc8bb..6dd8ad0 100644
--- a/unpack-file.c
+++ b/unpack-file.c
@@ -1,5 +1,6 @@
 #include "cache.h"
 #include "blob.h"
+#include "exec_cmd.h"
 
 static char *create_temp_file(unsigned char *sha1)
 {
@@ -25,6 +26,8 @@ int main(int argc, char **argv)
 {
 	unsigned char sha1[20];
 
+	git_extract_argv0_path(argv[0]);
+
 	if (argc != 2)
 		usage("git-unpack-file <sha1>");
 	if (get_sha1(argv[1], sha1))
diff --git a/update-server-info.c b/update-server-info.c
index 7e8209e..7b38fd8 100644
--- a/update-server-info.c
+++ b/update-server-info.c
@@ -1,4 +1,5 @@
 #include "cache.h"
+#include "exec_cmd.h"
 
 static const char update_server_info_usage[] =
 "git update-server-info [--force]";
@@ -19,6 +20,8 @@ int main(int ac, char **av)
 	if (i != ac)
 		usage(update_server_info_usage);
 
+	git_extract_argv0_path(av[0]);
+
 	setup_git_directory();
 
 	return !!update_server_info(force);
diff --git a/upload-pack.c b/upload-pack.c
index e5adbc0..5db6f93 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -616,6 +616,8 @@ int main(int argc, char **argv)
 	int i;
 	int strict = 0;
 
+	git_extract_argv0_path(argv[0]);
+
 	for (i = 1; i < argc; i++) {
 		char *arg = argv[i];
 
diff --git a/var.c b/var.c
index f1eb314..7362ed8 100644
--- a/var.c
+++ b/var.c
@@ -4,6 +4,7 @@
  * Copyright (C) Eric Biederman, 2005
  */
 #include "cache.h"
+#include "exec_cmd.h"
 
 static const char var_usage[] = "git var [-l | <variable>]";
 
@@ -56,6 +57,8 @@ int main(int argc, char **argv)
 		usage(var_usage);
 	}
 
+	git_extract_argv0_path(argv[0]);
+
 	setup_git_directory_gently(&nongit);
 	val = NULL;
 
-- 
1.6.1.87.g15624

[PATCH 5/7 v2] Modify setup_path() to only add git_exec_path() to PATH

[Steffen Prohaska]

Searching git programs only in the highest priority location is
sufficient.  It does not make sense that some of the required
programs are located at the highest priority location but other
programs are picked up from a lower priority exec-path.  If
exec-path is overridden a complete set of commands should be
provided, otherwise several different versions could get mixed,
which is likely to cause confusion.

If a user explicitly overrides the default location (by --exec-path
or GIT_EXEC_PATH), we now expect that all the required programs are
found there.  Instead of adding the directories "argv_exec_path",
"getenv(EXEC_PATH_ENVIRONMENT)", and "system_path(GIT_EXEC_PATH)"
to PATH, we now rely on git_exec_path(), which implements the same
order, but only returns the highest priority location to search for
executables.

Accessing only the location with highest priority is also required
for testing executables built with RUNTIME_PREFIX.  The call to
system_path() should be avoided if RUNTIME_PREFIX is set and the
executable is not installed at its final destination.  Because we
test before installing, we want to avoid calling system_path()
during tests.  The modifications in this commit avoid calling
system_path(GIT_EXEC_PATH) if a higher-priority location is
provided, which is the case when running the tests.

Signed-off-by: Steffen Prohaska <prohaska@zib.de>
---
 exec_cmd.c |    4 +---
 1 files changed, 1 insertions(+), 3 deletions(-)

diff --git a/exec_cmd.c b/exec_cmd.c
index 89931e4..d9408db 100644
--- a/exec_cmd.c
+++ b/exec_cmd.c
@@ -78,9 +78,7 @@ void setup_path(void)
 	const char *old_path = getenv("PATH");
 	struct strbuf new_path = STRBUF_INIT;
 
-	add_path(&new_path, argv_exec_path);
-	add_path(&new_path, getenv(EXEC_PATH_ENVIRONMENT));
-	add_path(&new_path, system_path(GIT_EXEC_PATH));
+	add_path(&new_path, git_exec_path());
 	add_path(&new_path, argv0_path);
 
 	if (old_path)
-- 
1.6.1.87.g15624

[PATCH 6/7 v2] Compute prefix at runtime if RUNTIME_PREFIX is set

[Steffen Prohaska]

This commit adds support for relocatable binaries (called
RUNTIME_PREFIX).  Such binaries can be moved together with the
system configuration files to a different directory, as long as the
relative paths from the binary to the configuration files is
preserved.  This functionality is essential on Windows where we
deliver git binaries with an installer that allows to freely choose
the installation location.

If RUNTIME_PREFIX is unset we use the static prefix.  This will be
the default on Unix.  Thus, the behavior on Unix will remain
identical to the old implementation, which used to add the prefix
in the Makefile.

If RUNTIME_PREFIX is set the prefix is computed from the location
of the executable.  In this case, system_path() tries to strip
known directories that executables can be located in from the path
of the executable.  If the path is successfully stripped it is used
as the prefix.  For example, if the executable is
"/msysgit/bin/git" and BINDIR is "bin", then the prefix computed is
"/msysgit".

If the runtime prefix computation fails, we fall back to the static
prefix specified in the makefile.  This can be the case if the
executable is not installed at a known location.  Note that our
test system sets GIT_CONFIG_NOSYSTEM to tell git to ignore global
configuration files during testing.  Hence testing does not trigger
the fall back.

Note that RUNTIME_PREFIX only works on Windows, though adding
support on Unix should not be too hard.  The implementation
requires argv0_path to be set to an absolute path.  argv0_path must
point to the directory of the executable.  We use assert() to
verify this in debug builds.  On Windows, the wrapper for main()
(see compat/mingw.h) guarantees that argv0_path is correctly
initialized.  On Unix, further work is required before
RUNTIME_PREFIX can be enabled.

Signed-off-by: Steffen Prohaska <prohaska@zib.de>
---
 Makefile   |    3 +++
 exec_cmd.c |   44 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+), 0 deletions(-)

diff --git a/Makefile b/Makefile
index 1d2060a..fbe52c9 100644
--- a/Makefile
+++ b/Makefile
@@ -1031,6 +1031,9 @@ ifdef INTERNAL_QSORT
 	COMPAT_CFLAGS += -DINTERNAL_QSORT
 	COMPAT_OBJS += compat/qsort.o
 endif
+ifdef RUNTIME_PREFIX
+	COMPAT_CFLAGS += -DRUNTIME_PREFIX
+endif
 
 ifdef NO_PTHREADS
 	THREADED_DELTA_SEARCH =
diff --git a/exec_cmd.c b/exec_cmd.c
index d9408db..5f59880 100644
--- a/exec_cmd.c
+++ b/exec_cmd.c
@@ -9,12 +9,56 @@ static const char *argv0_path;
 
 const char *system_path(const char *path)
 {
+#ifdef RUNTIME_PREFIX
+	static const char *prefix = 0;
+#else
 	static const char *prefix = PREFIX;
+#endif
 
 	if (is_absolute_path(path)) {
 		return path;
 	}
 
+#ifdef RUNTIME_PREFIX
+	assert(argv0_path);
+	assert(is_absolute_path(argv0_path));
+
+	if (!prefix) {
+		const char *strip[] = {
+			GIT_EXEC_PATH,
+			BINDIR,
+			0
+		};
+		const char **s;
+
+		for (s = strip; *s; s++) {
+			const char *sargv = argv0_path + strlen(argv0_path);
+			const char *ss = *s + strlen(*s);
+			while (argv0_path < sargv && *s < ss
+				&& (*sargv == *ss ||
+				    (is_dir_sep(*sargv) && is_dir_sep(*ss)))) {
+				sargv--;
+				ss--;
+			}
+			if (*s == ss) {
+				struct strbuf d = STRBUF_INIT;
+				/* We also skip the trailing directory separator. */
+				assert(sargv - argv0_path - 1 >= 0);
+				strbuf_add(&d, argv0_path, sargv - argv0_path - 1);
+				prefix = strbuf_detach(&d, NULL);
+				break;
+			}
+		}
+	}
+
+	if (!prefix) {
+		prefix = PREFIX;
+		fprintf(stderr, "RUNTIME_PREFIX requested, "
+				"but prefix computation failed.  "
+				"Using static fallback '%s'.\n", prefix);
+	}
+#endif
+
 	struct strbuf d = STRBUF_INIT;
 	strbuf_addf(&d, "%s/%s", prefix, path);
 	path = strbuf_detach(&d, NULL);
-- 
1.6.1.87.g15624

[PATCH 7/7 v2] Windows: Revert to default paths and convert them by RUNTIME_PREFIX

[Steffen Prohaska]

The RUNTIME_PREFIX mechanism allows us to use the default paths on
Windows too.  Defining RUNTIME_PREFIX explicitly requests for
translation of paths relative to the executable at runtime.

Signed-off-by: Steffen Prohaska <prohaska@zib.de>
---
 Makefile |    4 +---
 1 files changed, 1 insertions(+), 3 deletions(-)

diff --git a/Makefile b/Makefile
index fbe52c9..74ecd77 100644
--- a/Makefile
+++ b/Makefile
@@ -789,6 +789,7 @@ ifneq (,$(findstring MINGW,$(uname_S)))
 	SNPRINTF_RETURNS_BOGUS = YesPlease
 	NO_SVN_TESTS = YesPlease
 	NO_PERL_MAKEMAKER = YesPlease
+	RUNTIME_PREFIX = YesPlease
 	NO_POSIX_ONLY_PROGRAMS = YesPlease
 	NO_ST_BLOCKS_IN_STRUCT_STAT = YesPlease
 	COMPAT_CFLAGS += -D__USE_MINGW_ACCESS -DNOGDI -Icompat -Icompat/regex -Icompat/fnmatch
@@ -797,9 +798,6 @@ ifneq (,$(findstring MINGW,$(uname_S)))
 	COMPAT_OBJS += compat/mingw.o compat/fnmatch/fnmatch.o compat/regex/regex.o compat/winansi.o
 	EXTLIBS += -lws2_32
 	X = .exe
-	gitexecdir = ../libexec/git-core
-	template_dir = ../share/git-core/templates/
-	ETC_GITCONFIG = ../etc/gitconfig
 endif
 ifneq (,$(findstring arm,$(uname_M)))
 	ARM_SHA1 = YesPlease
-- 
1.6.1.87.g15624

Re: [PATCH 6/7 v2] Compute prefix at runtime if RUNTIME_PREFIX is set

[Johannes Schindelin]

Hi,

On Sun, 18 Jan 2009, Steffen Prohaska wrote:

> +	if (!prefix) {
> +		const char *strip[] = {
> +			GIT_EXEC_PATH,
> +			BINDIR,
> +			0
> +		};
> +		const char **s;
> +
> +		for (s = strip; *s; s++) {
> +			const char *sargv = argv0_path + strlen(argv0_path);

This does not need to be recomputed all the time, right?

> +			const char *ss = *s + strlen(*s);
> +			while (argv0_path < sargv && *s < ss
> +				&& (*sargv == *ss ||
> +				    (is_dir_sep(*sargv) && is_dir_sep(*ss)))) {
> +				sargv--;
> +				ss--;
> +			}
> +			if (*s == ss) {
> +				struct strbuf d = STRBUF_INIT;
> +				/* We also skip the trailing directory separator. */
> +				assert(sargv - argv0_path - 1 >= 0);
> +				strbuf_add(&d, argv0_path, sargv - argv0_path - 1);
> +				prefix = strbuf_detach(&d, NULL);
> +				break;
> +			}
> +		}
> +	}

I have a definite feeling that this code would be easier to read if it 
resembled this:

/* sets prefix if the suffix matches (modulo separator changes) */
static int strip_path_suffix(const char *path, const char *suffix,
	char **prefix)
{
	int path_len = strlen(path), suffix_len = strlen(suffix);

	while (suffix_len) {
		if (!path_len)
			return 1;

		path_len--; suffix_len--;
		/* strip arbitrary amount of directory separators */
		if (is_dir_sep(path[path_len]) && 
				is_dir_sep(suffix[suffix_len])) {
			while (path_len && is_dir_sep(path[path_len]))
				path_len--;
			while (suffix_len && is_dir_sep(suffix[suffix_len]))
				suffix_len--;
		}
		else if (path[path_len] != suffix[suffix_len])
			return 1;
	}

	while (path_len && is_dir_sep(path[path_len - 1]))
		path_len--;

	prefix = xstrndup(path, path_len);
	return 0;
}

...

	if (!prefix && strip_path_suffix(argv0_path, GIT_EXEC_PATH) &&
			strip_path_suffix(argv0_path, BINDIR)) {
		prefix = PREFIX;
		...

Note: this function could be exported in path.c, as it also handles the 
"a//bin" vs "a/bin" case.

Ciao,
Dscho

Re: [PATCH 3/7 v2] git_extract_argv0_path(): Move check for valid argv0 from caller to callee

[Johannes Sixt]

On Sonntag, 18. Januar 2009, Steffen Prohaska wrote:
> This simplifies the calling code.

But it could really be squashed into the previous patch, after fixing...

> @@ -23,6 +23,9 @@ const char *system_path(const char *path)
>
>  const char *git_extract_argv0_path(const char *argv0)
>  {
> +	if (!argv0 || !*argv0)
> +		return 0;
> +
>  	const char *slash = argv0 + strlen(argv0);

... this declaration after statement.

-- Hannes

Re: [PATCH 3/7 v2] git_extract_argv0_path(): Move check for valid argv0 from caller to callee

[Johannes Sixt]

On Sonntag, 18. Januar 2009, Johannes Sixt wrote:
> On Sonntag, 18. Januar 2009, Steffen Prohaska wrote:
> > This simplifies the calling code.
>
> But it could really be squashed into the previous patch, after fixing...
>
> > @@ -23,6 +23,9 @@ const char *system_path(const char *path)
> >
> >  const char *git_extract_argv0_path(const char *argv0)
> >  {
> > +	if (!argv0 || !*argv0)
> > +		return 0;
> > +
> >  	const char *slash = argv0 + strlen(argv0);
>
> ... this declaration after statement.

And we prefer NULL over 0 for the null pointer.

The series is nicely done, thank you! I am using it (the previous round) 
without problems so far. I hope we can get this in RSN.

-- Hannes

Re: [PATCH 3/7 v2] git_extract_argv0_path(): Move check for valid argv0 from caller to callee

[Junio C Hamano]

Johannes Sixt <j6t@kdbg.org> writes:

> On Sonntag, 18. Januar 2009, Johannes Sixt wrote:
>> On Sonntag, 18. Januar 2009, Steffen Prohaska wrote:
>> > This simplifies the calling code.
>>
>> But it could really be squashed into the previous patch, after fixing...
>>
>> > @@ -23,6 +23,9 @@ const char *system_path(const char *path)
>> >
>> >  const char *git_extract_argv0_path(const char *argv0)
>> >  {
>> > +	if (!argv0 || !*argv0)
>> > +		return 0;
>> > +
>> >  	const char *slash = argv0 + strlen(argv0);
>>
>> ... this declaration after statement.
>
> And we prefer NULL over 0 for the null pointer.
>
> The series is nicely done, thank you! I am using it (the previous round) 
> without problems so far. I hope we can get this in RSN.

Thanks, both.  I take that as your Ack to the whole series.

I've rebased the series to master, squashed in fixes like the above (there
were others) so that each step can compile.  Will queue the result.