package/pkg-generic.mk: factor out patch directories

The .stamp_patched rule currently uses shell loops and conditions to
iterate over the patches in the package directory and
BR2_GLOBAL_PATCH_DIRS and to select between the versioned and
unversioned directory.

We want to add the patch list to show-info as well, so we need a way to
do this entirely in Make functions.

Introduce the function pkg-patches-dirs in pkg-utils which copies this
functionality in make syntax, and use it in the .stamp_patched rule.
As an extra simplification, only consider the version directory if
PKG_VERSION actually exists. Otherwise, we would use the directory with
a slash appended for packages without version. Why this does work, it
just looks weird for no reason.

Furthermore, introduce the function pkg-patch-hash-dirs which simply
enumerates the package directory and the package subdirectories of
BR2_GLOBAL_PATCH_DIRS. This function is used for _HASH_FILES as well.

Ideally, we should be able to factor our the handling of the version
subdirectory between the patches and hashes as well. Unfortunately, they
are treated subtly different: patches don't use the base directory if
the version directory exists, while hashes do use the base directory. We
don't want to change this behaviour.

Signed-off-by: Thomas Perale <thomas.perale@mind.be>
Co-authored-by: Matthias Swiggers <matthias.swiggers@mind.be>
[Arnout:
 - split into a separate patch;
 - don't fully factor with _HASH_FILES because version is treaded
   differently;
 - introduce pkg-patch-hash-dirs;
 - retain the RAWNAME comment, but move it to pkg-patch-hash-dirs;
 - use foreach instead of shell loop, and $(seq) instead of exit 1;
 - rewrite to retain original behaviour of only using versioned dir.
]
Signed-off-by: Arnout Vandecappelle <arnout@mind.be>

package/pkg-generic.mk

@@ -231,29 +231,13 @@ $(BUILD_DIR)/%/.stamp_rsynced:
 	$(Q)touch $@
 
 # Patch
-#
-# The RAWNAME variable is the lowercased package name, which allows to
-# find the package directory (typically package/<pkgname>) and the
-# prefix of the patches
-#
-# For BR2_GLOBAL_PATCH_DIR, only generate if it is defined
-$(BUILD_DIR)/%/.stamp_patched: PATCH_BASE_DIRS =  $(PKGDIR)
-$(BUILD_DIR)/%/.stamp_patched: PATCH_BASE_DIRS += $(addsuffix /$(RAWNAME),$(call qstrip,$(BR2_GLOBAL_PATCH_DIR)))
 $(BUILD_DIR)/%/.stamp_patched:
 	@$(call step_start,patch)
 	@$(call MESSAGE,"Patching")
 	$(foreach hook,$($(PKG)_PRE_PATCH_HOOKS),$(call $(hook))$(sep))
 	$(foreach p,$($(PKG)_PATCH),$(APPLY_PATCHES) $(@D) $($(PKG)_DL_DIR) $(notdir $(p))$(sep))
-	$(Q)( \
-	for D in $(PATCH_BASE_DIRS); do \
-	  if test -d $${D}; then \
-	    if test -d $${D}/$($(PKG)_VERSION); then \
-	      $(APPLY_PATCHES) $(@D) $${D}/$($(PKG)_VERSION) \*.patch || exit 1; \
-	    else \
-	      $(APPLY_PATCHES) $(@D) $${D} \*.patch || exit 1; \
-	    fi; \
-	  fi; \
-	done; \
+	$(foreach dir,$(call pkg-patches-dirs,$(PKG)),\
+		$(Q)$(APPLY_PATCHES) $(@D) $(dir) \*.patch$(sep)\
 	)
 	$(foreach hook,$($(PKG)_POST_PATCH_HOOKS),$(call $(hook))$(sep))
 	@$(call step_end,patch)
@@ -517,7 +501,7 @@ $(2)_VERSION := $$(call sanitize,$$($(2)_DL_VERSION))
 
 $(2)_HASH_FILES = \
 	$$(strip \
-		$$(foreach d, $$($(2)_PKGDIR) $$(addsuffix /$$($(2)_RAWNAME), $$(call qstrip,$$(BR2_GLOBAL_PATCH_DIR))),\
+		$$(foreach d, $$(call pkg-patch-hash-dirs,$(2)),\
 			$$(if $$(wildcard $$(d)/$$($(2)_VERSION)/$$($(2)_RAWNAME).hash),\
 				$$(d)/$$($(2)_VERSION)/$$($(2)_RAWNAME).hash,\
 				$$(d)/$$($(2)_RAWNAME).hash\

package/pkg-utils.mk

@@ -156,6 +156,18 @@ define _json-info-pkg
 	)
 endef
 
+# The RAWNAME variable is the lowercased package name, which allows to
+# find the package directory (typically package/<pkgname>) and the
+# prefix of the patches
+pkg-patch-hash-dirs = \
+	$($(1)_PKGDIR) $(addsuffix /$($(1)_RAWNAME),$(call qstrip,$(BR2_GLOBAL_PATCH_DIR)))
+
+pkg-patches-dirs = \
+	$(foreach dir, $(call pkg-patch-hash-dirs,$(1)),\
+		$(wildcard $(if $($(1)_VERSION),\
+			$(or $(wildcard $(dir)/$($(1)_VERSION)),$(dir)),\
+			$(dir))))
+
 define _json-info-pkg-details
 	"version": $(call mk-json-str,$($(1)_DL_VERSION)),
 	"licenses": $(call mk-json-str,$($(1)_LICENSE)),