simplify api: recursive="heuristic" by default

lib/spack/llnl/util/filesystem.py

@@ -2108,9 +2108,8 @@ def add_macro(self, macro):
 def find_headers(
     headers: Union[List[str], str],
     root: str,
-    recursive: bool = False,
+    recursive: Union[bool, str] = "heuristic",
     *,
-    heuristic: bool = True,
     max_depth: Optional[int] = None,
 ) -> HeaderList:
     """Returns an iterable object containing a list of full paths to
@@ -2130,10 +2129,8 @@ def find_headers(
     Parameters:
         headers: Header name(s) to search for
         root: The root directory to start searching from
-        recursive: if False (default) search only root folder, if True recurse from the root. Note
+        recursive: if False search only root folder, if True recurse from the root. Defaults to
-            that recursive search does not imply exhaustive search if heuristic is True.
+            "heuristic", which uses a non-exhaustive, faster search.
-        heuristic: if True (default), use a non-exhaustive, faster search. Has no effect
-            if recursive is False.
         max_depth: if set, don't search below this depth. Cannot be set if recursive is False.
 
     Returns:
@@ -2147,6 +2144,9 @@ def find_headers(
             f"first argument [got {type(headers)} instead]"
         )
 
+    if recursive is False and max_depth is not None:
+        raise ValueError(f"max_depth ({max_depth}) cannot be set if recursive is False")
+
     # Construct the right suffix for the headers
     suffixes = [
         # C
@@ -2167,8 +2167,8 @@ def find_headers(
     # List of headers we are searching with suffixes
     headers = [f"{header}.{suffix}" for header in headers for suffix in suffixes]
 
-    if not recursive or not heuristic:
+    if isinstance(recursive, bool):
-        return HeaderList(find(root, headers, recursive=recursive))
+        return HeaderList(find(root, headers, recursive=recursive, max_depth=max_depth))
 
     # The heuristic here is simpler than the one for libraries: restrict search to <root>/include
     # (if root isn't an include directory itself) and limit search depth so that headers are found
@@ -2351,9 +2351,9 @@ def find_libraries(
     libraries: Union[List[str], str],
     root: str,
     shared: bool = True,
-    recursive: bool = False,
+    recursive: Union[bool, str] = "heuristic",
     runtime: bool = True,
-    heuristic: bool = True,
+    *,
     max_depth: Optional[int] = None,
 ) -> LibraryList:
     """Find libraries in the specified root directory.
@@ -2373,12 +2373,10 @@ def find_libraries(
         libraries: library name(s) to search for
         root: the root directory to start searching from
         shared: if True searches for shared libraries, otherwise for static. Defaults to True.
-        recursive: if False (default) search only root folder, if True recurse from the root. Note
+        recursive: if False search only root folder, if True recurse from the root. Defaults to
-            that recursive search does not imply exhaustive search if heuristic is True.
+            "heuristic", which uses a non-exhaustive, faster search.
         runtime: Windows only option, no-op elsewhere. If True (default), search for runtime shared
             libs (.DLL), otherwise, search for .Lib files. If shared is False, this has no meaning.
-        heuristic: if True (default), use a non-exhaustive, faster search. Has no effect if
-            recursive is False.
         max_depth: if set, don't search below this depth. Cannot be set if recursive is False.
 
     Returns:
@@ -2393,7 +2391,7 @@ def find_libraries(
             f"first argument [got {type(libraries)} instead]"
         )
 
-    if not recursive and max_depth is not None:
+    if recursive is False and max_depth is not None:
         raise ValueError(f"max_depth ({max_depth}) cannot be set if recursive is False")
 
     if sys.platform == "win32":
@@ -2419,10 +2417,8 @@ def find_libraries(
     # List of libraries we are searching with suffixes
     libraries = [f"{lib}.{suffix}" for lib in libraries for suffix in suffixes]
 
-    if not recursive:
+    if isinstance(recursive, bool):
-        return LibraryList(find(root, libraries, recursive=False))
+        return LibraryList(find(root, libraries, recursive=recursive, max_depth=max_depth))
-    elif not heuristic:
-        return LibraryList(find(root, libraries, recursive=True, max_depth=max_depth))
 
     # Heuristic search: a form of non-exhaustive iterative deepening, in order to return early if
     # libraries are found in their usual locations. This is the default behavior for recursive

lib/spack/spack/spec.py

@@ -1109,7 +1109,7 @@ def _headers_default_handler(spec: "Spec"):
         NoHeadersError: If no headers are found
     """
     home = getattr(spec.package, "home")
-    headers = fs.find_headers("*", root=home, recursive=True, heuristic=True)
+    headers = fs.find_headers("*", root=home)
 
     if headers:
         return headers
@@ -1159,9 +1159,7 @@ def _libs_default_handler(spec: "Spec"):
     for shared in search_shared:
         # Since we are searching for link libraries, on Windows search only for
         # ".Lib" extensions by default as those represent import libraries for implicit links.
-        libs = fs.find_libraries(
+        libs = fs.find_libraries(name, home, shared=shared, runtime=False)
-            name, home, shared=shared, recursive=True, runtime=False, heuristic=True
-        )
         if libs:
             return libs