* interp/c-util.boot (stackAndThrow): Take an optional parameter.

	* interp/compiler.boot (compReturn): Robustify.
	(unknownTypeError): Likewise.
	* interp/info.boot (knownInfo): Likewise.

3 files changed, 13 insertions, 12 deletions

diff --git a/src/interp/c-util.boot b/src/interp/c-util.boot
index 65636852..05dd92c4 100644
--- a/src/interp/c-util.boot
+++ b/src/interp/c-util.boot
@@ -527,7 +527,9 @@ stackMessageIfNone msg ==
     [msg,:$compErrorMessageStack]
   nil
  
-stackAndThrow msg ==
+stackAndThrow(msg, args == nil) ==
+  if args ^= nil then
+    msg := buildMessage(msg,args)
   $compErrorMessageStack:= [msg,:$compErrorMessageStack]
   THROW("compOrCroak",nil)
  
diff --git a/src/interp/compiler.boot b/src/interp/compiler.boot
index 0f42b428..3fc3b462 100644
--- a/src/interp/compiler.boot
+++ b/src/interp/compiler.boot
@@ -920,7 +920,7 @@ compLeave(["leave",level,x],m,e) ==
 compReturn: (%Form,%Mode,%Env) -> %Maybe %Triple
 compReturn(["return",level,x],m,e) ==
   null $exitModeStack =>
-    stackSemanticError(["the return before","%b",x,"%d","is unneccessary"],nil)
+    stackAndThrow('"the return before %1b is unneccessary",[x])
     nil
   level^=1 => userError '"multi-level returns not supported"
   index:= MAX(0,#$exitModeStack-1)
@@ -1206,7 +1206,7 @@ unknownTypeError name ==
   name:=
     name is [op,:.] => op
     name
-  stackSemanticError(["%b",name,"%d","is not a known type"],nil)
+  stackAndThrow('"%1b is not a known type",[name])
 
 compPretend: (%Form,%Mode,%Env) -> %Maybe %Triple
 compPretend(["pretend",x,t],m,e) ==
diff --git a/src/interp/info.boot b/src/interp/info.boot
index 21bc44ba..68bf58e3 100644
--- a/src/interp/info.boot
+++ b/src/interp/info.boot
@@ -164,10 +164,10 @@ knownInfo pred ==
   pred is ["or",:l] => or/[knownInfo u for u in l]
   pred is ["and",:l] => and/[knownInfo u for u in l]
   pred is ["ATTRIBUTE",name,attr] =>
-    v:= compForMode(name,$EmptyMode,$e)
-    null v => stackSemanticError(["can't find category of ",name],nil)
-    [vv,.,.]:= compMakeCategoryObject(CADR v,$e)
-    null vv => stackSemanticError(["can't make category of ",name],nil)
+    v:= compForMode(name,$EmptyMode,$e) or return
+          stackAndThrow('"can't find category of %1pb",[name])
+    [vv,.,.]:= compMakeCategoryObject(CADR v,$e) or return
+                 stackAndThrow('"can't make category of %1pb",[name])
     member(attr,vv.2) => true
     x:= assoc(attr,vv.2) => knownInfo CADR x
           --format is a list of two elements: information, predicate
@@ -176,15 +176,14 @@ knownInfo pred ==
     cat is ["ATTRIBUTE",:a] => knownInfo ["ATTRIBUTE",name,:a]
     cat is ["SIGNATURE",:a] => knownInfo ["SIGNATURE",name,:a]
     name is ['Union,:.] => false
-    v:= compForMode(name,$EmptyMode,$e)
-    null v => stackSemanticError(["can't find category of ",name],nil)
+    v:= compForMode(name,$EmptyMode,$e) or return
+          stackAndThrow('"can't find category of %1pb",[name])
     vmode := CADR v
     cat = vmode => true
     vmode is ["Join",:l] and member(cat,l) => true
-    [vv,.,.]:= compMakeCategoryObject(vmode,$e)
+    [vv,.,.]:= compMakeCategoryObject(vmode,$e) or return
+                 stackAndThrow('"cannot find category %1pb",[vmode])
     catlist := vv.4
-    --catlist := SUBST(name,'$,vv.4)
-    null vv => stackSemanticError(["can't make category of ",name],nil)
     member(cat,first catlist) => true  --checks princ. ancestors
     (u:=assoc(cat,CADR catlist)) and knownInfo(CADR u) => true
     -- previous line checks fundamental anscestors, we should check their