From 64281801b2c9e3cd46e7754a3ef567a38c92101c Mon Sep 17 00:00:00 2001
From: Jeremy Penner <jeremy@sporktania.com>
Date: Wed, 18 Aug 2021 22:19:57 -0400
Subject: [PATCH] Show LINE NUMBERS in compiler errors!!

---
 ssc/iigs/toolbox.fnl |  2 +-
 ssc/init.fnl         | 38 +++++++++++++++++++++++---------------
 ssc/macros.fnl       | 15 +++++++++++----
 3 files changed, 35 insertions(+), 20 deletions(-)

diff --git a/ssc/iigs/toolbox.fnl b/ssc/iigs/toolbox.fnl
index 45fdf21..dc812d3 100644
--- a/ssc/iigs/toolbox.fnl
+++ b/ssc/iigs/toolbox.fnl
@@ -440,7 +440,7 @@
   (def-toolbox 0x9a04 SetTextFace (textFace) void)
   (def-toolbox 0x9c04 SetTextMode (textMode) void)
   (def-toolbox 0xd204 SetTextSize (textSize) void)
-  (def-toolbox 0x4604 SetUserFIeld ((long userFieldValue)) void)
+  (def-toolbox 0x4604 SetUserField ((long userFieldValue)) void)
   (def-toolbox 0xc804 SetVisHandle ((long rgnHandle)) void)
   (def-toolbox 0xb404 SetVisRgn ((long rgnHandle)) void)
   (def-toolbox 0x9104 ShowCursor () void)
diff --git a/ssc/init.fnl b/ssc/init.fnl
index 478e48b..927af61 100644
--- a/ssc/init.fnl
+++ b/ssc/init.fnl
@@ -441,22 +441,30 @@
         post (icollect [_ (countiter (length args))] (self:drop))]
     (values (lume.concat [:block] pre [[:jsr f.name]] post) f.type)))
 
+(fn Ssc.enter-expr [self expr]
+  (let [m (getmetatable expr)]
+    (when (and m m.filename) (set self.expr-metadata m))))
+
 (fn Ssc.expr-poly [self expr]
-;   (pp expr)
-  (match expr
-    (where lit (?. (self:opgen lit) :hi)) (let [{: lo : hi} (self:opgen lit)]
-      (values [:block (lo :lda) [:sta self.LONG_LO] (hi :lda) [:sta self.LONG_HI]] :long))
-    (where lit (?. (self:opgen lit) :lo)) (let [{: lo} (self:opgen lit)] (values (lo :lda) :word))
-    (where getter (= (type getter) :string) (. self.getters getter))
-      (self:compile-function-call (. self.getters getter) [])
-    (where [func & args] (= (?. self.functions func :arity) (length args)))
-      (self:compile-function-call (. self.functions func) args)
-    (where [form & args] (. self.forms form))
-      (let [f (. self.forms form)
-            (cexpr etype) (f self (table.unpack args))]
-        (values cexpr (or etype :word)))
-    nil (values [:block] :void)
-    _ (error (.. "Unrecognized expression " (fv expr)))))
+  (self:enter-expr expr)
+  (let [(success c-expr etype)
+        (pcall #(match expr
+                  (where lit (?. (self:opgen lit) :hi)) (let [{: lo : hi} (self:opgen lit)]
+                    (values [:block (lo :lda) [:sta self.LONG_LO] (hi :lda) [:sta self.LONG_HI]] :long))
+                  (where lit (?. (self:opgen lit) :lo)) (let [{: lo} (self:opgen lit)] (values (lo :lda) :word))
+                  (where getter (= (type getter) :string) (. self.getters getter))
+                    (self:compile-function-call (. self.getters getter) [])
+                  (where [func & args] (= (?. self.functions func :arity) (length args)))
+                    (self:compile-function-call (. self.functions func) args)
+                  (where [form & args] (. self.forms form))
+                    (let [f (. self.forms form)
+                          (cexpr etype) (f self (table.unpack args))]
+                      (values cexpr (or etype :word)))
+                  nil (values [:block] :void)
+                  _ (error (.. "Unrecognized expression"))))]
+    (if success (values c-expr etype)
+      (let [{: filename : line} (or self.expr-metadata {:filename "<unknown>" :line "??"})]
+        (error (.. filename "@" line ": " (fv expr) "\n" c-expr))))))
 
 (fn Ssc.expr-word [self expr]
   (let [(c etype) (self:expr-poly expr)]
diff --git a/ssc/macros.fnl b/ssc/macros.fnl
index b87c41d..880bb4e 100644
--- a/ssc/macros.fnl
+++ b/ssc/macros.fnl
@@ -7,11 +7,18 @@
 ;    (form mymacro [(fn [ssc] (ssc:compile-expr [:+ 1 2]))])
 ; => [:form :mymacro (fn [ssc] (ssc:compile-expr [:+ 1 2]))]
 
+(fn attach-metadata [form result]
+  (if (list? form)
+      (let [{: filename : line : bytestart : byteend} form]
+        `(setmetatable ,result ,{: filename : line : bytestart : byteend}))
+    result))
+
 (fn form-to-fnl [form]
-  (if (sym? form)      (tostring form)
-      (sequence? form) (. form 1) ; escape
-      (list? form)     (icollect [_ inner-form (ipairs form)] (form-to-fnl inner-form))
-    form))
+  (attach-metadata form
+    (if (sym? form)      (tostring form)
+        (sequence? form) (. form 1) ; escape
+        (list? form)     (icollect [_ inner-form (ipairs form)] (form-to-fnl inner-form))
+      form)))
 
 (fn sss [...]
   (let [result `(values)]