duskos

commit bc5c151262fcbb75a95019eef5c2093cd9a821ca
parent 3fbb95310a2d46eb0f623cd411ba299fcc2da313
Author: Virgil Dupras <hsoft@hardcoded.net>
Date:   Mon,  5 Dec 2022 21:06:49 -0500

comp/c: implement typecasting

Maybe it doesn't cover all possible legitimate uses of typecasting, but it
covers my immediate one in uxntal.

Diffstat:
M
fs/comp/c/pgen.fs
 | 
2
+-
M
fs/comp/c/vm/commonhi.fs
 | 
8
++++++++
M
fs/comp/c/vm/forth.fs
 | 
1
+
M
fs/comp/c/vm/i386.fs
 | 
1
+
M
fs/tests/comp/c/cc.fs
 | 
1
+
M
fs/tests/comp/c/test.c
 | 
5
+++++

6 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/fs/comp/c/pgen.fs b/fs/comp/c/pgen.fs
@@ -275,7 +275,7 @@ MAXLITSZ Stack :new structbind Stack _list
       \ can be an expression or a typecast
       nextt dup parseType if ( tok type )
         \ TODO: actually process the typecast
-        nip parseDeclarator drop read) nextt parseFactor
+        nip parseDeclarator read) nextt parseFactor vmop :typecast
         else ( tok ) parseExpression read) parsePostfixOp then
     endof
     '"' of isChar?^ MAXLITSZ _litarena :[
diff --git a/fs/comp/c/vm/commonhi.fs b/fs/comp/c/vm/commonhi.fs
@@ -13,6 +13,14 @@ struct+[ VMOp
     dup :isconst? if tuck arg swap / swap to arg else VMOp :/n then
     else 2drop then ;
   : :+n over if dup :isconst? if to+ arg else VMOp :+n then else 2drop then ;
+  : :&n dup :isconst? if tuck arg and swap to arg else VMOp :&n then ;
+
+  : :typecast ( type self -- )
+    2dup to type swap typesize case ( self )
+      1 of = $ff swap :&n endof
+      2 of = $ffff swap :&n endof
+      drop
+    endcase ;
 ]struct
 
 UNOPCNT wordtbl constops ( n -- n )
diff --git a/fs/comp/c/vm/forth.fs b/fs/comp/c/vm/forth.fs
@@ -41,6 +41,7 @@ struct+[ VMOp
   : :*n ( n self -- ) tuck :compile litn compile * :>reg ;
   : :/n ( n self -- ) tuck :compile litn compile / :>reg ;
   : :+n ( n self -- ) tuck :compile litn compile + :>reg ;
+  : :&n ( n self -- ) tuck :compile litn compile and :>reg ;
   : :>res dup :compile :>reg ;
 ]struct
 
diff --git a/fs/comp/c/vm/i386.fs b/fs/comp/c/vm/i386.fs
@@ -111,6 +111,7 @@ struct+[ VMOp
   : :>res dup :>reg :>simple ;
 
   : :+n ( n self -- ) dup :>res :compile i) add, ;
+  : :&n ( n self -- ) dup :>res :compile i) and, ;
 
 ]struct
 
diff --git a/fs/tests/comp/c/cc.fs b/fs/tests/comp/c/cc.fs
@@ -61,6 +61,7 @@ S" foobar" 2 get8b 'o' #eq
 S" foobar" 4 get8b 'b' #eq
 S" foobar" dup 2 'X' set8b S" fXobar" #s=
 S" foobar" dup 6 'X' set8b S" foobaX" #s=
+typecast 1 #eq
 5 whilesum 15 #eq
 5 dowhilesum 15 #eq
 create mydata 42 , $12345678 , $23456789 ,
diff --git a/fs/tests/comp/c/test.c b/fs/tests/comp/c/test.c
@@ -229,6 +229,11 @@ char get8b(char *s, int i) {
 void set8b(char *s, int i, char c) {
     s[i] = c;
 }
+int typecast() {
+	char x = $ff;
+	int y = 1;
+	return x == (char)(y-2);
+}
 void whilesum(int n) {
     int res = 0;
     while (n) {