From 595660fb847df00d2d5290bb5fb5cfec5b67bd06 Mon Sep 17 00:00:00 2001
From: Norman Feske <norman.feske@genode-labs.com>
Date: Wed, 5 Apr 2023 12:17:49 +0200
Subject: [PATCH] tool/depot: sanity check for presence of port hash

If a content.mk file wrongly refers to a non-existing directory in a
call of the 'port_dir' function, the 'content_env_missing_ports.mk' gets
stuck while invoking 'cat' without argument, which makes such mistakes
difficult to diagnose. This patch adds a sanity check for the existence
of the port hash file at the specified location before attempting to
'cat' the hash-file content.
---
 tool/depot/mk/content_env_missing_ports.mk | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/tool/depot/mk/content_env_missing_ports.mk b/tool/depot/mk/content_env_missing_ports.mk
index c09b3a8d19..f96436cb87 100644
--- a/tool/depot/mk/content_env_missing_ports.mk
+++ b/tool/depot/mk/content_env_missing_ports.mk
@@ -25,6 +25,18 @@ disable_shell = $(eval SHELL:=true)
 #
 $(disable_shell)
 
+#
+# Check for the existance of a port's hash file
+#
+# \param $1  path to hash file
+#
+# This check may fail whenever a 'port_dir' call in a content.mk file refers to
+# a wrong repository.
+#
+_assert_hash_exists = $(if $(wildcard $1).hash,,\
+                         $(error missing hash file for port '$(notdir $1)'\
+                         (expected at $1)))
+
 #
 # If a port is missing, append its name to the missing ports file
 #
@@ -37,7 +49,7 @@ _assert = $(if $1,$1,$(shell echo $2 >> $(MISSING_PORTS_FILE)))
 #
 #   $(call port_dir,$(GENODE_DIR)/repos/libports/ports/libpng)
 #
-_port_hash = $(shell cat $(call _assert,$(wildcard $1.hash),$(notdir $1)))
+_port_hash = $(_assert_hash_exists)$(shell cat $(call _assert,$(wildcard $1.hash),$(notdir $1)))
 _port_dir  = $(wildcard $(CONTRIB_DIR)/$(notdir $1)-$(call _port_hash,$1))
 port_dir   = $(call enable_shell)$(call _assert,$(call _port_dir,$1),$(notdir $1))$(call disable_shell)