Re: build from RO source tree?

Geert Uytterhoeven (geert@linux-m68k.org)
Wed, 2 Jul 2003 16:15:51 +0200 (MEST)


On 2 Jul 2003, david nicol wrote:
> Is there a make option for building from a read-only kernel source,
> possibly by doing a pre-pass to create a mess of symlinks?
>
> Something like
>
> (chdir $readonly_sourceroot && find . -type d ) \
> | xargs -n5 mkdir
> (chdir $readonly_sourceroot && find . -type f ) \
> | xargs -i ln -s $readonly_sourceroot/{} {}
> make
>
>
> but as a configure option of some kind.

Date: Fri, 23 May 2003 15:49:45 +0200 (MEST)
From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Linux Kernel Development <linux-kernel@vger.kernel.org>
Subject: [PATCH] touchless dependencies for 2.4.x

Hi,

The 2.4.x dependency system depends on being able to `touch' include files in
case of recursive dependencies. This fails when using a revision control
system (e.g. ClearCase) where non-checked out files are read-only and cannot be
touch'ed.

The patch below solves this by making object files depend on (recursive) lists,
containing the list of dependencies for each header file.

Example:
- Dependencies:
o file.c includes header.h
o header.h includes header2.h

- Old way:

o .depend:

file.o: file.c header.h

o .hdepend:

header.h: header2.h
touch header.h

- New way:

o .depend:

file.o: file.c header.h $(dep_header.h)

o .hdepend:

dep_header.h += header2.h $(dep_header2.h)

Is this OK? So far I didn't notice any regressions.

--- linux-2.4.x/scripts/mkdep.c.orig Tue Apr 1 17:04:24 2003
+++ linux-2.4.x/scripts/mkdep.c Wed Apr 2 17:39:59 2003
@@ -45,8 +45,7 @@



-char __depname[512] = "\n\t@touch ";
-#define depname (__depname+9)
+char depname[512];
int hasdep;

struct path_struct {
@@ -75,9 +74,14 @@
{
if (!hasdep) {
hasdep = 1;
- printf("%s:", depname);
- if (g_filename)
+ if (g_filename) {
+ /* Source file (*.[cS]) */
+ printf("%s:", depname);
printf(" %s", g_filename);
+ } else {
+ /* header file (*.h) */
+ printf("dep_%s +=", depname);
+ }
}
}

@@ -203,7 +207,8 @@
path->buffer[path->len+len] = '\0';
if (access(path->buffer, F_OK) == 0) {
do_depname();
- printf(" \\\n %s", path->buffer);
+ printf(" \\\n %s $(dep_%s)", path->buffer,
+ path->buffer);
return;
}
}
@@ -520,7 +525,7 @@
/*
* Generate dependencies for one file.
*/
-void do_depend(const char * filename, const char * command)
+void do_depend(const char * filename)
{
int mapsize;
int pagesizem1 = getpagesize()-1;
@@ -559,9 +564,7 @@
clear_config();
state_machine(map, map+st.st_size);
if (hasdep) {
- puts(command);
- if (*command)
- define_precious(filename);
+ puts("");
}

munmap(map, mapsize);
@@ -607,7 +610,6 @@

while (--argc > 0) {
const char * filename = *++argv;
- const char * command = __depname;
g_filename = 0;
len = strlen(filename);
memcpy(depname, filename, len+1);
@@ -615,10 +617,9 @@
if (filename[len-1] == 'c' || filename[len-1] == 'S') {
depname[len-1] = 'o';
g_filename = filename;
- command = "";
}
}
- do_depend(filename, command);
+ do_depend(filename);
}
if (len_precious) {
*(str_precious+len_precious) = '\0';

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds

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