genman: guard against symbol hash collisions.

* genman.txr (process-ambiguities): Keep track of
calculated hashes and error out when there is a
duplicate. When the time comes, we will have to
resolve those somehow, and also change the doc
function to do it the same way.

1 files changed, 10 insertions, 6 deletions

diff --git a/genman.txr b/genman.txr
index d1593cfb..6ef0404b 100644
--- a/genman.txr
+++ b/genman.txr
@@ -42,12 +42,16 @@
      `TOC-@sec`)
 
    (defun process-ambiguities (hash)
-     (dohash (sym tags hash)
-       (let ((shash (fmt "S-~,08X" (crc32 sym))))
-         (set [hash sym] shash)
-         (if (null (cdr tags))
-           (push shash [direct (car tags)])
-           (set [disamb shash] (reverse tags)))))))
+     (let ((rhash (hash)))
+       (dohash (sym tags hash)
+         (let ((shash (fmt "S-~,08X" (crc32 sym))))
+           (if [rhash shash]
+             (error "~a ~a hash collision" sym [rhash shash])
+             (set [rhash shash] sym))
+           (set [hash sym] shash)
+           (if (null (cdr tags))
+             (push shash [direct (car tags)])
+             (set [disamb shash] (reverse tags))))))))
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 @(skip 15)
 <h1>TXR</h1>