musl's ldd - don't exit immidately even if some libraries was not found

musl's ldd - don't exit immidately even if some libraries was not found

[orc]

[-- Attachment #1: Type: text/plain, Size: 70 bytes --]

Patch to make ldd not to exit immidately after unsolved dependencies.

[-- Attachment #2: musl-0.9.1-ldd-dontfail.patch --]
[-- Type: application/octet-stream, Size: 998 bytes --]

diff -Naur musl-0.9.1.o/src/ldso/dynlink.c musl-0.9.1/src/ldso/dynlink.c
--- musl-0.9.1.o/src/ldso/dynlink.c	2012-06-04 04:32:05.000000000 +0800
+++ musl-0.9.1/src/ldso/dynlink.c	2012-06-20 00:32:52.332607400 +0800
@@ -430,12 +430,16 @@
 			if (p->dynv[i] != DT_NEEDED) continue;
 			dep = load_library(p->strings + p->dynv[i+1]);
 			if (!dep) {
-				snprintf(errbuf, sizeof errbuf,
-					"Error loading shared library %s: %m (needed by %s)",
-					p->strings + p->dynv[i+1], p->name);
-				if (runtime) longjmp(rtld_fail, 1);
-				dprintf(2, "%s\n", errbuf);
-				_exit(127);
+				if (!ldd_mode) {
+					snprintf(errbuf, sizeof errbuf,
+						"Error loading shared library %s: %m (needed by %s)",
+						p->strings + p->dynv[i+1], p->name);
+					if (runtime) longjmp(rtld_fail, 1);
+					dprintf(2, "%s\n", errbuf);
+					_exit(127);
+				}
+				else
+					dprintf(1, "\t%s => not found\n", p->strings + p->dynv[i+1]);
 			}
 			if (runtime) {
 				tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));

Re: musl's ldd - don't exit immidately even if some libraries was not found

[Isaac Dunham]

On Wed, 20 Jun 2012 00:42:10 +0800
orc <orc@sibserver.ru> wrote:

> Patch to make ldd not to exit immidately after unsolved dependencies.

Out of curiosity, 
1-what practical use is this, and

2-is there any other system that behaves the same? 

(well, I can think of HXRT with one environment variable set...but
that's Windows emulation for DOS, so I can see them having odd behavior)

(Note, I'm not saying it's the wrong thing to do, just wondering where
you could use it without expecting SIGSEGV)

Re: musl's ldd - don't exit immidately even if some libraries was not found

[Rich Felker]

On Tue, Jun 19, 2012 at 05:53:16PM -0700, Isaac Dunham wrote:
> On Wed, 20 Jun 2012 00:42:10 +0800
> orc <orc@sibserver.ru> wrote:
> 
> > Patch to make ldd not to exit immidately after unsolved dependencies.
> 
> Out of curiosity, 
> 1-what practical use is this, and
> 
> 2-is there any other system that behaves the same? 
> 
> (well, I can think of HXRT with one environment variable set...but
> that's Windows emulation for DOS, so I can see them having odd behavior)
> 
> (Note, I'm not saying it's the wrong thing to do, just wondering where
> you could use it without expecting SIGSEGV)

My guess is that the practical use is to get a list of ALL missing
library dependencies rather than just the first one.

Rich

Re: musl's ldd - don't exit immidately even if some libraries was not found

[orc]

On Tue, 19 Jun 2012 21:17:36 -0400
Rich Felker <dalias@aerifal.cx> wrote:

> On Tue, Jun 19, 2012 at 05:53:16PM -0700, Isaac Dunham wrote:
> > On Wed, 20 Jun 2012 00:42:10 +0800
> > orc <orc@sibserver.ru> wrote:
> > 
> > > Patch to make ldd not to exit immidately after unsolved
> > > dependencies.
> > 
> > Out of curiosity, 
> > 1-what practical use is this, and
> > 
> > 2-is there any other system that behaves the same? 
> > 
> > (well, I can think of HXRT with one environment variable set...but
> > that's Windows emulation for DOS, so I can see them having odd
> > behavior)
> > 
> > (Note, I'm not saying it's the wrong thing to do, just wondering
> > where you could use it without expecting SIGSEGV)
> 
> My guess is that the practical use is to get a list of ALL missing
> library dependencies rather than just the first one.
> 
> Rich

Yes, in ldd mode dynamic linker will not exit immediately after missing
library. That what this patch does.
In environments where everything is built from source and no missing
libraries this patch is useless I think, but just to be sure.

Sorry for my English mistakes and message without [PATCH] tag.