[hackers] [scc] [cc1] Fix pre increment/decrement for pointers || Roberto E. Vargas Caballero

From: <git_AT_suckless.org>
Date: Tue, 27 Sep 2016 10:29:05 +0200 (CEST)

commit 56b94fe84a71df35ca1cbdd299985b2fe480c3ba
Author: Roberto E. Vargas Caballero <k0ga_AT_shike2.com>
AuthorDate: Tue Sep 27 10:26:04 2016 +0200
Commit: Roberto E. Vargas Caballero <k0ga_AT_shike2.com>
CommitDate: Tue Sep 27 10:26:04 2016 +0200

    [cc1] Fix pre increment/decrement for pointers
    
    Pre increment/decrement for pointers was broken, mainly
    because pointers are not arithmetic types, and the size
    of the pointers were calculated in two different places.
    Another problem was related to the fact that post inc/dec
    generates an op but pre inc/dec generates another one,
    and the tests were checking only against the values
    generated for post operators.

diff --git a/cc1/expr.c b/cc1/expr.c
index 0f17ec3..c4ebc09 100644
--- a/cc1/expr.c
+++ b/cc1/expr.c
_AT_@ -321,7 +321,7 @@ parithmetic(char op, Node *lp, Node *rp)
         rp = simplify(OMUL, sizettype, rp, size);
         rp = convert(rp, tp, 1);
 
- return simplify(OADD, tp, lp, rp);
+ return simplify(op, tp, lp, rp);
 
 incomplete:
         errorp("invalid use of undefined type");
_AT_@ -339,13 +339,19 @@ arithmetic(char op, Node *lp, Node *rp)
 
         if ((ltp->prop & TARITH) && (rtp->prop & TARITH)) {
                 arithconv(&lp, &rp);
- } else if ((ltp->op == PTR || rtp->op == PTR) &&
- (op == OADD || op == OSUB)) {
- return parithmetic(op, rp, lp);
- } else if (op != OINC && op != ODEC) {
- errorp("incorrect arithmetic operands");
+ return simplify(op, lp->type, lp, rp);
+ } else if ((ltp->op == PTR || rtp->op == PTR)) {
+ switch (op) {
+ case OADD:
+ case OSUB:
+ case OA_ADD:
+ case OA_SUB:
+ case OINC:
+ case ODEC:
+ return parithmetic(op, rp, lp);
+ }
         }
- return simplify(op, lp->type, lp, rp);
+ errorp("incorrect arithmetic operands");
 }
 
 static Node *
_AT_@ -563,12 +569,10 @@ incdec(Node *np, char op)
                 return np;
         } else if (tp->op == PTR && !(tp->type->prop & TDEFINED)) {
                 errorp("%s of pointer to an incomplete type",
- (op == OINC) ? "increment" : "decrement");
+ (op == OINC || op == OA_ADD) ? "increment" : "decrement");
                 return np;
- } else if (tp->prop & TARITH) {
+ } else if (tp->op == PTR || (tp->prop & TARITH)) {
                 inc = constnode(one);
- } else if (tp->op == PTR) {
- inc = sizeofnode(tp->type);
         } else {
                 errorp("wrong type argument to increment or decrement");
                 return np;
diff --git a/cc1/tests/test036.c b/cc1/tests/test036.c
index 707cc42..d09bfc0 100644
--- a/cc1/tests/test036.c
+++ b/cc1/tests/test036.c
_AT_@ -19,28 +19,28 @@ R7 I "n
 L9
         e
 L10
- R1 _AT_I R2 #N2 :iP @I :I
+ R1 _AT_I R2 #P2 :iP @I :I
         v L12 #I7
 L12
- R1 _AT_I R2 #N2 :iP @I :I
+ R1 _AT_I R2 #P2 :iP @I :I
         v L13 #I6
 L13
- R1 _AT_I R2 #N2 :iP @I :I
+ R1 _AT_I R2 #P2 :iP @I :I
         v L14 #I5
 L14
- R1 _AT_I R2 #N2 :iP @I :I
+ R1 _AT_I R2 #P2 :iP @I :I
         v L15 #I4
 L15
- R1 _AT_I R2 #N2 :iP @I :I
+ R1 _AT_I R2 #P2 :iP @I :I
         v L16 #I3
 L16
- R1 _AT_I R2 #N2 :iP @I :I
+ R1 _AT_I R2 #P2 :iP @I :I
         v L17 #I2
 L17
- R1 _AT_I R2 #N2 :iP @I :I
+ R1 _AT_I R2 #P2 :iP @I :I
         v L18 #I1
 L18
- R1 _AT_I R2 #N2 :iP @I :I
+ R1 _AT_I R2 #P2 :iP @I :I
         y L10 R7 #I1 :-I #I0 >I
         b
 L11
diff --git a/cc1/tests/test065.c b/cc1/tests/test065.c
index c7b6e65..b5de713 100644
--- a/cc1/tests/test065.c
+++ b/cc1/tests/test065.c
_AT_@ -4,7 +4,7 @@
 name: TEST065
 description: Test decay mixed with * operators
 error:
-test065.c:65: error: decrement of pointer to an incomplete type
+test065.c:65: error: increment of pointer to an incomplete type
 test065.c:65: error: invalid use of undefined type
 test065.c:66: warning: 'argv' defined but not used
 output:
Received on Tue Sep 27 2016 - 10:29:05 CEST