[PATCH v1 0/1] Fix rpath handling in OCaml's Makefile.rules

[PATCH v1 0/1] Fix rpath handling in OCaml's Makefile.rules

[Andrii Sultanov]

As reported by Nix's Xen team, OCaml stub libs would embed an absolute
rpath in the binaries, which was picked up on by patchelf. This is a
symptom of improper handling of -rpath-link in the first place, so
correct that and get rid of the issue.

Andrii Sultanov (1):
  tools/ocaml: Specify rpath correctly for ocamlmklib

 tools/ocaml/Makefile.rules | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

-- 
2.39.5

[PATCH v1 1/1] tools/ocaml: Specify rpath correctly for ocamlmklib

[Andrii Sultanov]

ocamlmklib has special handling for C-like '-Wl,-rpath' option, but does
not know how to handle '-Wl,-rpath-link', as evidenced by warnings like:
"Unknown option
-Wl,-rpath-link=$HOME/xen/tools/ocaml/libs/eventchn/../../../../tools/libs/toollog"
Pass this option directly to the compiler with -ccopt instead.

This prevents embedding absolute paths from buildtime into binary's RPATH.

Fixes: f7b4e4558b42 ("tools/ocaml: Fix OCaml libs rules")
Signed-off-by: Andrii Sultanov <andrii.sultanov@cloud.com>
---
 tools/ocaml/Makefile.rules | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/ocaml/Makefile.rules b/tools/ocaml/Makefile.rules
index b9d4b51f0a..055725d910 100644
--- a/tools/ocaml/Makefile.rules
+++ b/tools/ocaml/Makefile.rules
@@ -63,7 +63,7 @@ mk-caml-lib-bytecode = $(call quiet-command, $(OCAMLC) $(OCAMLCFLAGS) -a -o $1 $
 
 mk-caml-stubs = $(call quiet-command, $(OCAMLMKLIB) -o `basename $1 .a` $2,MKLIB,$1)
 mk-caml-lib-stubs = \
-	$(call quiet-command, $(OCAMLMKLIB) -o `basename $1 .a | sed -e 's/^lib//'` $2 $3,MKLIB,$1)
+	$(call quiet-command, $(OCAMLMKLIB) -o `basename $1 .a | sed -e 's/^lib//'` $2 `echo $3 | sed -e 's/-ccopt \(-l\|-L\)/\1/g'`,MKLIB,$1)
 
 # define a library target <name>.cmxa and <name>.cma
 define OCAML_LIBRARY_template
@@ -74,7 +74,7 @@ define OCAML_LIBRARY_template
  $(1)_stubs.a: $(foreach obj,$$($(1)_C_OBJS),$(obj).o)
 	$(call mk-caml-stubs,$$@, $$+)
  lib$(1)_stubs.a: $(foreach obj,$($(1)_C_OBJS),$(obj).o)
-	$(call mk-caml-lib-stubs,$$@, $$+, $(foreach lib,$(LIBS_$(1)),$(lib)))
+	$(call mk-caml-lib-stubs,$$@, $$+, $(foreach lib,$(LIBS_$(1)),-ccopt $(lib)))
 endef
 
 # Dynamically linked OCaml libraries ("plugins" in Dynlink parlance)
-- 
2.39.5

Re: [PATCH v1 0/1] Fix rpath handling in OCaml's Makefile.rules

[Christian Lindig]

> On 9 Dec 2024, at 15:16, Andrii Sultanov <andrii.sultanov@cloud.com> wrote:
> 
> As reported by Nix's Xen team, OCaml stub libs would embed an absolute
> rpath in the binaries, which was picked up on by patchelf. This is a
> symptom of improper handling of -rpath-link in the first place, so
> correct that and get rid of the issue.
> 
> Andrii Sultanov (1):
>  tools/ocaml: Specify rpath correctly for ocamlmklib
> 
> tools/ocaml/Makefile.rules | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
> 
> -- 
> 2.39.5
> 

Acked-by: Christian Lindig <christian.lindig@cloud.com>

Re: [PATCH v1 0/1] Fix rpath handling in OCaml's Makefile.rules

[Andrii Sultanov]

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DO NOT COMMIT - this patch is not correct, and I will send an updated
version later.

On Mon, Dec 9, 2024 at 3:16 PM Andrii Sultanov <andrii.sultanov@cloud.com>
wrote:

> As reported by Nix's Xen team, OCaml stub libs would embed an absolute
> rpath in the binaries, which was picked up on by patchelf. This is a
> symptom of improper handling of -rpath-link in the first place, so
> correct that and get rid of the issue.
>
> Andrii Sultanov (1):
>   tools/ocaml: Specify rpath correctly for ocamlmklib
>
>  tools/ocaml/Makefile.rules | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> --
> 2.39.5
>
>

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