From ae6471f1c94f51df540d95edc09c7749002f44e8 Mon Sep 17 00:00:00 2001
From: Peter Mikkelsen <peter@pmikkelsen.com>
Date: Tue, 22 Feb 2022 20:41:56 +0000
Subject: Implement some form of error guards. It may not be perfect yet

---
 error.c | 49 +++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 45 insertions(+), 4 deletions(-)

(limited to 'error.c')

diff --git a/error.c b/error.c
index 47837a9..2a59553 100644
--- a/error.c
+++ b/error.c
@@ -5,7 +5,7 @@
 
 #include "apl9.h"
 
-ErrorHandler globalerror;
+ErrorGuard *globalerrorguard;
 
 Rune *errorstrs[] = {
 	[ESyntax] = L"SYNTAX ERROR",
@@ -20,11 +20,52 @@ Rune *errorstrs[] = {
 	[ENotImplemented] = L"NOT IMPLEMENTED",
 };
 
+ErrorGuard *
+newerrorguard(Array *codes, Statement *guard)
+{
+	DfnFrame *fr = getcurrentdfn();
+	ErrorGuard *eg = emallocz(sizeof(ErrorGuard), 1);
+	eg->active = 1;
+	eg->guard = guard;
+
+	if(fr == nil)
+		globalerrorguard = eg;
+	else{
+		eg->next = fr->errorguards;
+		fr->errorguards = eg;
+		eg->frame = dupdfnframe(fr);
+	}
+
+	for(int i = 0; i < GetSize(codes); i++)
+		eg->code |= (1<<codes->intdata[i]);
+
+	return eg;
+}
+
 void
 throwerror(Rune *msg, int err)
 {
-	free(globalerror.msg);
-	globalerror.msg = msg ? runestrdup(msg) : nil;
-	longjmp(globalerror.jmp, err);
+	ErrorGuard *matching = globalerrorguard;
+	DfnFrame *frame = getcurrentdfn();
+	ThreadData *td = getthreaddata();
+	td->lasterror = err;
+	if(td->lasterrormsg)
+		free(td->lasterrormsg);
+	td->lasterrormsg = msg;
+
+	while(frame != nil){
+		for(ErrorGuard *eg = frame->errorguards; eg != nil; eg = eg->next){
+			if(!eg->active)
+				continue;
+			if(((1<<err) & eg->code) || (eg->code == 1)){
+				matching = eg;
+				goto match;
+			}
+		}
+		frame = frame->prev;
+		popdfnframe();
+	}
+match:
+	longjmp(matching->jmp, 1);
 }
 
-- 
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