From 6b04276193b6c1277c3c9e3c7b13e55be4647579 Mon Sep 17 00:00:00 2001
From: Dominic Orchard <dom.orchard@gmail.com>
Date: Wed, 11 Dec 2024 16:36:23 +0000
Subject: [PATCH 1/2] report bad boz

---
 src/Language/Fortran/AST/Literal/Boz.hs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Language/Fortran/AST/Literal/Boz.hs b/src/Language/Fortran/AST/Literal/Boz.hs
index 34113786..fa68d794 100644
--- a/src/Language/Fortran/AST/Literal/Boz.hs
+++ b/src/Language/Fortran/AST/Literal/Boz.hs
@@ -95,7 +95,7 @@ parseBoz s =
       | p' == 'x' = Just $ BozPrefixZ Nonconforming
       | otherwise = Nothing
       where p' = Char.toLower p
-    errInvalid = error "Language.Fortran.AST.BOZ.parseBoz: invalid BOZ string"
+    errInvalid = error ("Language.Fortran.AST.BOZ.parseBoz: invalid BOZ string: " <> show s)
     -- | Remove the first and last elements in a list.
     shave = tail . init
 

From fba734fa7d3e31c6a54d97531e3a1bf2405b6032 Mon Sep 17 00:00:00 2001
From: Dominic Orchard <dom.orchard@gmail.com>
Date: Wed, 11 Dec 2024 17:24:15 +0000
Subject: [PATCH 2/2] bypass parsing boz for cpp pragmas

---
 src/Language/Fortran/Parser/Free/Lexer.x | 36 +++++++++++++++---------
 1 file changed, 22 insertions(+), 14 deletions(-)

diff --git a/src/Language/Fortran/Parser/Free/Lexer.x b/src/Language/Fortran/Parser/Free/Lexer.x
index 51f6cbb5..a8f263ed 100644
--- a/src/Language/Fortran/Parser/Free/Lexer.x
+++ b/src/Language/Fortran/Parser/Free/Lexer.x
@@ -1105,20 +1105,28 @@ advance move position =
 
 processLinePragma :: String -> AlexInput -> AlexInput
 processLinePragma m ai =
-  case dropWhile ((`elem` ["#", "line", "#line"]) . map toLower) (words m) of
-    -- 'line' pragma - rewrite the current line and filename
-    lineStr:otherWords
-      | line <- readIntOrBoz lineStr -> do
-        let revdropWNQ = reverse . drop 1 . dropWhile (flip notElem "'\"")
-        let file       = revdropWNQ . revdropWNQ $ unwords otherWords
-        -- if a newline is present, then the aiPosition is already on the next line
-        let maybe1 | elem '\n' m = 0 | otherwise = 1
-        -- lineOffs is the difference between the given line and the current next line
-        let lineOffs   = fromIntegral line - (posLine (aiPosition ai) + maybe1)
-        let newP       = (aiPosition ai) { posPragmaOffset = Just (lineOffs, file)
-                                         , posColumn = 1 }
-        ai { aiPosition = newP }
-    _ -> ai
+  let wordsm = words m
+      isLinePragma x = x `elem` ["#", "line", "#line"]
+  in -- If this is a line pragma then process this
+     if length wordsm > 0 && isLinePragma (head wordsm)
+     || (length wordsm > 1 && isLinePragma (head (tail wordsm)))
+     then
+        case dropWhile ((`elem` ["#", "line", "#line"]) . map toLower) wordsm of
+          -- 'line' pragma - rewrite the current line and filename
+          lineStr:otherWords
+            | line <- readIntOrBoz lineStr -> do
+              let revdropWNQ = reverse . drop 1 . dropWhile (flip notElem "'\"")
+              let file       = revdropWNQ . revdropWNQ $ unwords otherWords
+              -- if a newline is present, then the aiPosition is already on the next line
+              let maybe1 | elem '\n' m = 0 | otherwise = 1
+              -- lineOffs is the difference between the given line and the current next line
+              let lineOffs   = fromIntegral line - (posLine (aiPosition ai) + maybe1)
+              let newP       = (aiPosition ai) { posPragmaOffset = Just (lineOffs, file)
+                                              , posColumn = 1 }
+              ai { aiPosition = newP }
+          _ -> ai
+     -- Otherwise this is probably a CPP directive or some other pragma so ignore
+     else ai
 
 -- Handle pragmas that begin with #
 lexHash :: LexAction (Maybe Token)