From: Denis Mukhin <dmukhin@ford.com> 

There can be multiple test harnesses per one test target. Fix that by
iterating over all prerequisites in emit-harness-nested-rule().

Signed-off-by: Denis Mukhin <dmukhin@ford.com>
---
 tools/tests/domid/Makefile | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/tools/tests/domid/Makefile b/tools/tests/domid/Makefile
index 753129029ed9..1a2129d20655 100644
--- a/tools/tests/domid/Makefile
+++ b/tools/tests/domid/Makefile
@@ -14,16 +14,18 @@ $(shell sed -n \
     's/^[ \t]*# *include[ \t]*[<"]\([^">]*\)[">].*/\1/p' $(1) 2>/dev/null)
 endef
 
-# NB: $1 cannot be a list
+# $1 target
+# $2 list of test harnesses
 define emit-harness-nested-rule
-$(1): $(CURDIR)/harness.h
-	mkdir -p $$(@D);
-	ln -sf $$< $$@;
+$(1): $(2)
+	mkdir -p $$(@D); \
+	for i in $$<; do ln -sf $$$$i $$@; done
 
 endef
 
 define emit-harness-rules
-$(foreach x,$(2),$(call emit-harness-nested-rule,$(CURDIR)/generated/$(x)))
+$(foreach x,$(2),$(call \
+    emit-harness-nested-rule,$(CURDIR)/generated/$(x),$(CURDIR)/harness.h))
 $(1:.c=.o): $(addprefix $(CURDIR)/generated/,$(2))
 endef
 
-- 
2.52.0

On Thu, Dec 04, 2025 at 04:37:11AM -0800, dmukhin@xen.org wrote:
> diff --git a/tools/tests/domid/Makefile b/tools/tests/domid/Makefile
> index 753129029ed9..1a2129d20655 100644
> --- a/tools/tests/domid/Makefile
> +++ b/tools/tests/domid/Makefile
> @@ -14,16 +14,18 @@ $(shell sed -n \
>      's/^[ \t]*# *include[ \t]*[<"]\([^">]*\)[">].*/\1/p' $(1) 2>/dev/null)
>  endef
>  
> -# NB: $1 cannot be a list
> +# $1 target
> +# $2 list of test harnesses
>  define emit-harness-nested-rule
> -$(1): $(CURDIR)/harness.h
> -	mkdir -p $$(@D);
> -	ln -sf $$< $$@;
> +$(1): $(2)
> +	mkdir -p $$(@D); \
> +	for i in $$<; do ln -sf $$$$i $$@; done

This doesn't work.

First, on the first line, the introduction of the backslash mean that
error from `mkdir` are ignored, Make will execute both line in the same
shell instead of 2 separate shell. You would need to add `set -e` if
executing all lines of the recipe in the same shell is useful.

Second, $< only refer to the first prerequisite. So only a single
symlink is created, even if $(2) list multiple files.

Third, if we fix to loop through all the dependencies, the loop will
still only create a single symlink, the last iteration will overwrite
the previous one.

Thanks,

-- 
Anthony PERARD

On 04.12.2025 13:37, dmukhin@xen.org wrote:
> From: Denis Mukhin <dmukhin@ford.com> 
> 
> There can be multiple test harnesses per one test target. Fix that by
> iterating over all prerequisites in emit-harness-nested-rule().

This reads as if previously there was no iterating, and you add some.
What you do it further parameterize the existing macro. That anomaly
actually looks to reflect itself ...

> Signed-off-by: Denis Mukhin <dmukhin@ford.com>
> ---
>  tools/tests/domid/Makefile | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/tools/tests/domid/Makefile b/tools/tests/domid/Makefile
> index 753129029ed9..1a2129d20655 100644
> --- a/tools/tests/domid/Makefile
> +++ b/tools/tests/domid/Makefile
> @@ -14,16 +14,18 @@ $(shell sed -n \
>      's/^[ \t]*# *include[ \t]*[<"]\([^">]*\)[">].*/\1/p' $(1) 2>/dev/null)
>  endef
>  
> -# NB: $1 cannot be a list
> +# $1 target
> +# $2 list of test harnesses

... in this comment. According to ...

>  define emit-harness-nested-rule
> -$(1): $(CURDIR)/harness.h
> -	mkdir -p $$(@D);
> -	ln -sf $$< $$@;
> +$(1): $(2)

... the use of the parameter, this is the list of dependencies.

And then, how does this make any difference at all when ...

> +	mkdir -p $$(@D); \
> +	for i in $$<; do ln -sf $$$$i $$@; done
>  
>  endef
>  
>  define emit-harness-rules
> -$(foreach x,$(2),$(call emit-harness-nested-rule,$(CURDIR)/generated/$(x)))
> +$(foreach x,$(2),$(call \
> +    emit-harness-nested-rule,$(CURDIR)/generated/$(x),$(CURDIR)/harness.h))

... you still hardcode the exact same file here?

As an aside, imo this would better be wrapped as

$(foreach x,$(2),$(call emit-harness-nested-rule, \
                        $(CURDIR)/generated/$(x),$(CURDIR)/harness.h))

or even

$(foreach x,$(2),$(call emit-harness-nested-rule, \
                        $(CURDIR)/generated/$(x), \
                        $(CURDIR)/harness.h))

Jan