fbt: glob improvements (#3117)

* fbt: glob improvements, now treats entries with no special glob chars as files by default, not calling scons' globbing for them
* fbt: further fixes for glob
* fbt: less strict existence checks
* fbt: fixed frame_rate collection; typo fixes & comments

Co-authored-by: あく <alleteam@gmail.com>

scripts/fbt_tools/sconsrecursiveglob.py

@@ -1,6 +1,7 @@
 import SCons
 from fbt.util import GLOB_FILE_EXCLUSION
 from SCons.Script import Flatten
+from SCons.Node.FS import has_glob_magic
 
 
 def GlobRecursive(env, pattern, node=".", exclude=[]):
@@ -9,14 +10,20 @@ def GlobRecursive(env, pattern, node=".", exclude=[]):
     results = []
     if isinstance(node, str):
         node = env.Dir(node)
-    for f in node.glob("*", source=True, exclude=exclude):
-        if isinstance(f, SCons.Node.FS.Dir):
-            results += env.GlobRecursive(pattern, f, exclude)
-    results += node.glob(
-        pattern,
-        source=True,
-        exclude=exclude,
-    )
+    # Only initiate actual recursion if special symbols can be found in 'pattern'
+    if has_glob_magic(pattern):
+        for f in node.glob("*", source=True, exclude=exclude):
+            if isinstance(f, SCons.Node.FS.Dir):
+                results += env.GlobRecursive(pattern, f, exclude)
+        results += node.glob(
+            pattern,
+            source=True,
+            exclude=exclude,
+        )
+    # Otherwise, just check if that's an existing file path
+    # NB: still creates "virtual" nodes as part of existence check
+    elif (file_node := node.File(pattern)).exists() or file_node.rexists():
+        results.append(file_node)
     # print(f"Glob result for {pattern} from {node}: {results}")
     return results