Resolve "rst_update_prelude.py needs to work"

Author: frank-at-adacore

contrib/rst_update_prelude.py

@@ -1,3 +1,34 @@
+"""
+Currently, every module needs to contain a 'prelude' that
+is expected to have the same content across every module.
+This script is designed to "fix" the prelude when
+a required content is updated / added.
+
+To better organize this content, the default prelude
+file uses RST containers to indicate where each specific
+content begins. These sections are as follows:
+   BEGIN - any beginning matter
+   ROLES - common RST roles
+   SYMBOLS - common symbol replacements
+   REQUIRES - module-specific content
+   PROVIDES - module-specific content
+   END - end of prelude (contains the rest of the module).
+In addition, anything appearing before BEGIN will be
+saved as well.
+
+The general process is to use 'split' to break
+the module into sections and use the prelude section
+name as the key. Anything appearing before BEGIN
+will use FIRST_KEY as the key. We then compare the
+actual to expected content only for BEGIN, SYMBOLS,
+and ROLES). If there is a difference, the actual
+content is updated. (The remaining sections are considered
+module-specific).
+After comparison, the sections are written out in the
+same order they were read in (either to stdout or
+back to the original file).
+"""
+
 import os
 import sys
 import argparse
@@ -6,15 +37,84 @@
 
 CWD = Path(sys.argv[0]).resolve().parents[1]
 
+"""
+Flag used to split file into pieces
+"""
+PRELUDE_FLAG = "container:: PRELUDE "
+
+FIRST_KEY = "000"
+
+"""
+Dictionary used to store expected prelude pieces
+"""
+EXPECTED = {}
+
+
+"""
+Populate the expected values from the predefined prelude
+"""
+
+
+def load_prelude(filename):
+    global EXPECTED
+
+    with open(filename, "rt") as file:
+        content = file.read()
+        pieces = content.split(PRELUDE_FLAG)
+        EXPECTED[FIRST_KEY] = pieces[0]
+        for section in pieces[1:]:
+            name, content = section.split("\n", 1)
+            EXPECTED[name] = content
 
-def section_start(l):
-    # Section/Chapter/Slide separator
-    if len(l) > 2 and l[0] == l[1] and l[1] == l[2] and l[0] in "*-=+":
-        return True
-    # include another file
-    elif "include::" in l:
-        return True
-    return False
+
+"""
+Compare 'filename' contents to the expected contents.
+If no changes are necessary, the file is not modified
+"""
+
+
+def process_file(filename, in_place):
+
+    ACTUAL = {}
+    pieces = None
+    update_required = False
+
+    with open(filename, "rt") as file:
+        content = file.read()
+        pieces = content.split(PRELUDE_FLAG)
+        ACTUAL[FIRST_KEY] = pieces[0]
+        for section in pieces[1:]:
+            name, content = section.split("\n", 1)
+            ACTUAL[name] = content
+
+    for key in ACTUAL.keys():
+        if not key in EXPECTED.keys():
+            if in_place:
+                print("   removing " + key)
+            del ACTUAL[key]
+            update_required = True
+
+        elif key == "BEGIN" or key == "ROLES" or key == "SYMBOLS":
+            if ACTUAL[key] != EXPECTED[key]:
+                if in_place:
+                    print("   updating " + key)
+                ACTUAL[key] = EXPECTED[key]
+                update_required = True
+
+    for key in EXPECTED.keys():
+        if not key in ACTUAL.keys():
+            if in_place:
+                print("   adding " + key)
+            ACTUAL[key] = EXPECTED[key]
+            update_required = True
+
+    if update_required:
+        f_out = open(filename, "wt") if in_place else sys.stdout
+        for key in ACTUAL.keys():
+            if key == FIRST_KEY:
+                f_out.write(ACTUAL[key])
+            else:
+                f_out.write(PRELUDE_FLAG + key + "\n" + ACTUAL[key])
 
 
 if __name__ == "__main__":
@@ -24,39 +124,7 @@ def section_start(l):
     ap.add_argument("files", nargs="+")
     args = ap.parse_args()
 
-    with open(args.prelude, "rt") as pf:
-        prelude_content = pf.read()
-
-    if prelude_content.endswith(os.linesep):
-        prelude_content = prelude_content[:-1]
+    load_prelude(args.prelude)
 
     for f in args.files:
-        with open(f, "rt") as ff:
-            file_lines = ff.read().splitlines()
-
-        f_out = open(f, "wt") if args.in_place else sys.stdout
-
-        def print_out(*a, **kw):
-            kw.setdefault("file", f_out)
-            print(*a, **kw)
-
-        STATE_INIT, STATE_CHAPTER, STATE_END = 0, 1, 2
-        state = STATE_INIT
-        skip = 0
-        for l in file_lines:
-            if skip:
-                skip -= 1
-                print_out(l)
-            elif state == STATE_INIT:
-                if section_start(l):
-                    state = STATE_CHAPTER
-                    skip = 3
-                    print_out(l)
-            elif state == STATE_CHAPTER:
-                if section_start(l):
-                    print_out(prelude_content)
-                    print_out()
-                    print_out(l)
-                    state = STATE_END
-            elif state == STATE_END:
-                print_out(l)
+        process_file(f, args.in_place)