scripts: make demo_common.sh usable on its own

When looking for $root_dir, do not try to guess if the root path is
Mbed TLS or TF-PSA-Crypto one, but simply look for
"scripts/project_name.txt" file without reading it. In this way the
initial part of the script does not need "project_detection.sh".

Once the root path is found, we can easily:
- source "project_detection.sh";
- check if query_compile_time_config is available or not.

This commit also updates "dlopen_demo.sh" so that it simply sources
"demo_common.sh" and not "project_detection.sh" (not directly at least).

Signed-off-by: Valerio Setti <vsetti@baylibre.com>
Signed-off-by: Ronald Cron <ronald.cron@arm.com>

scripts/demo_common.sh

@@ -16,14 +16,13 @@
 
 set -e -u
 
-DEMO_COMMON_NEED_QUERY_COMPILE_TIME_CONFIG=${DEMO_COMMON_NEED_QUERY_COMPILE_TIME_CONFIG:-1}
-
-need_query_compile_time_config () {
-  if [ $DEMO_COMMON_NEED_QUERY_COMPILE_TIME_CONFIG -eq 1 ]; then
-    return 0;
-  else
+# Check if the provided path ($1) can be a valid root for Mbed TLS or TF-PSA-Crypto.
+# This is based on the fact that "scripts/project_name.txt" exists.
+is_valid_root () {
+  if ! [ -f "$1/scripts/project_name.txt" ]; then
     return 1;
   fi
+  return 0;
 }
 
 ## At the end of the while loop below $root_dir will point to the root directory
@@ -35,21 +34,15 @@ root_dir="${0%/*}"
 ##
 ## The code works no matter where the demo script is relative to the current
 ## directory, even if it is called with a relative path.
-n=5
+n=4
 while true; do
   # If we went up too many folders, then give up and return a failure.
   if [ $n -eq 0 ]; then
     echo >&2 "This doesn't seem to be an Mbed TLS source tree."
     exit 125
   fi
-  # If we reached the Mbed TLS root folder then we're done.
-  if is_mbedtls_root "$root_dir"; then
-    break;
-  fi
-  # If we reached the TF-PSA-Crypto root folder and the script that sourced
-  # this file does not need query_compile_time_config (which is only available
-  # in Mbed TLS repo) then we're done.
-  if is_tf_psa_crypto_root "$root_dir" && ! need_query_compile_time_config; then
+
+  if is_valid_root "$root_dir"; then
     break;
   fi
 
@@ -63,6 +56,9 @@ while true; do
   esac
 done
 
+# Now that we have a root path we can source the "project_detection.sh" script.
+. "$root_dir/framework/scripts/project_detection.sh"
+
 ## msg LINE...
 ## msg <TEXT_ORIGIN
 ## Display an informational message.
@@ -101,28 +97,44 @@ run_bad () {
   not "$@"
 }
 
-## $programs_dir is the directory containing the sample programs.
-## Assume an in-tree build.
-programs_dir="$root_dir/programs"
+## This check is temporary and it's due to the fact that we currently build
+## query_compile_time_config only in Mbed TLS repo and not in the TF-PSA-Crypto
+## one. Once we'll have in both repos this check can be removed.
+has_query_compile_time_config () {
+  if ! [ -f "$1/programs/test/query_compile_time_config" ]; then
+    return 1;
+  fi
+  return 0;
+}
+
+if has_query_compile_time_config "$root_dir"; then
+  query_compile_time_config_dir="$root_dir/programs/test"
+elif is_valid_root "$root_dir/.." && has_query_compile_time_config "$root_dir/.."; then
+  query_compile_time_config_dir="$root_dir/../programs/test"
+else
+  query_compile_time_config_dir=""
+fi
 
 ## config_has SYMBOL...
 ## Succeeds if the library configuration has all SYMBOLs set.
 ##
-## Note: "query_compile_time_config" is only available when in Mbed TLS project,
-## so "config_has" is not available in TF-PSA-Crypto one. If this function is
-## called from the latter we fail immediately.
+## Note: depending on the above check query_compile_time_config_dir might be
+##       intentionally set to "". In this case the following function will fail.
 config_has () {
-  if ! is_mbedtls_root "$root_dir"; then
-    return 1;
-  fi
   for x in "$@"; do
-    "$programs_dir/test/query_compile_time_config" "$x"
+    # This function is commonly called in an if condition, where "set -e"
+    # has no effect, so make sure to stop explicitly on error.
+    "$query_compile_time_config_dir/query_compile_time_config" "$x" || return $?
   done
 }
 
 ## depends_on SYMBOL...
 ## Exit if the library configuration does not have all SYMBOLs set.
 depends_on () {
+  if ! [ -f "$query_compile_time_config_dir/query_compile_time_config" ]; then
+    echo "query_compile_time_config is missing"
+    exit 127
+  fi
   m=
   for x in "$@"; do
     if ! config_has "$x"; then

tests/programs/dlopen_demo.sh

@@ -6,20 +6,16 @@
 # Copyright The Mbed TLS Contributors
 # SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
 
-DEMO_COMMON_NEED_QUERY_COMPILE_TIME_CONFIG=0
-
 SCRIPT_DIR=$(dirname "$0")
-. "${SCRIPT_DIR}/../../scripts/project_detection.sh"
 . "${SCRIPT_DIR}/../../scripts/demo_common.sh"
 
 msg "Test the dynamic loading of libmbed*"
 
-# Once demo_common.sh is sourced we'll have the following variables set:
-# - $root_dir points to the root path of Mbed TLS or TF-PSA-Crypto;
-# - $programs_dir points to "$root_dir/programs" folder.
+# Once demo_common.sh is sourced we'll have $root_dir pointing to the root
+# path of Mbed TLS or TF-PSA-Crypto.
 if is_mbedtls_root $root_dir; then
     msg "Running in Mbed TLS repo"
-    program="$programs_dir/test/dlopen"
+    program="$root_dir/programs/test/dlopen"
     library_dir="$root_dir/library"
 else
     msg "Running in TF-PSA-Crypto repo"