Build warning in zle_keymap.c

Build warning in zle_keymap.c

[Bart Schaefer]

I just recompiled from a complete "make clean; rm config.modules;
./configure" for the first time in several months and:

zle_keymap.c: In function ‘getkeymapcmd’:
zle_keymap.c:1656:27: warning: ‘startcsi’ may be used uninitialized in
this function [-Wmaybe-uninitialized]
 1656 |       lastlen <= startcsi + 2) {
      |                  ~~~~~~~~~^~~

Re: Build warning in zle_keymap.c

[Oliver Kiddle]

Bart Schaefer wrote:
> I just recompiled from a complete "make clean; rm config.modules;
> ./configure" for the first time in several months and:
>
> zle_keymap.c: In function ‘getkeymapcmd’:
> zle_keymap.c:1656:27: warning: ‘startcsi’ may be used uninitialized in
> this function [-Wmaybe-uninitialized]
>  1656 |       lastlen <= startcsi + 2) {
>       |                  ~~~~~~~~~^~~

If you follow the logic, it isn't actually possible so the warning is
wrong.

Where csi is false, the value of startcsi is irrelevant so we can
replace both with just one variable, either by using -1 as the false
value or changing the startcsi offset (it can be zero). The patch below
takes the latter approach. csi is now either 0 (meaning false/not
in a CSI sequence) or points to the offset in keybuf to the first
character after \e[ (which can't be zero). That isn't the start of the
CSI sequence so I kept csi and dropped startcsi.
Does this silence the compiler?

Oliver

diff --git a/Src/Zle/zle_keymap.c b/Src/Zle/zle_keymap.c
index ec8dd031e..a31ab22d7 100644
--- a/Src/Zle/zle_keymap.c
+++ b/Src/Zle/zle_keymap.c
@@ -1586,7 +1586,7 @@ getkeymapcmd(Keymap km, Thingy *funcp, char **strp)
     Thingy func = t_undefinedkey;
     char *str = NULL;
     int lastlen = 0, lastc = lastchar;
-    int timeout = 0, csi = 0, startcsi;
+    int timeout = 0, csi = 0;
 
     keybuflen = 0;
     keybuf[0] = 0;
@@ -1640,22 +1640,23 @@ getkeymapcmd(Keymap km, Thingy *funcp, char **strp)
 	/* CSI key sequences have a well defined structure so if we currently
 	 * have an incomplete one, loop so the rest of it will be included in
 	 * the key sequence if that arrives within the timeout. */
-	if (keybuflen >= 3 && !csi) {
-	    startcsi = keybuflen - 3;
-	    csi = keybuf[startcsi] == '\033' && keybuf[keybuflen - 2] == '[';
-	}
+	if (!csi && keybuflen >= 3 && keybuf[keybuflen - 3] == '\033' &&
+		keybuf[keybuflen - 2] == '[')
+	    csi = keybuflen - 1;
 	if (csi) {
-	    csi = keybuf[keybuflen - 2] != Meta && keybuf[keybuflen - 1] >= 0x20
-		&& keybuf[keybuflen - 1] <= 0x3f;
+	    if (keybuf[keybuflen - 2] == Meta || keybuf[keybuflen - 1] < 0x20
+		   || keybuf[keybuflen - 1] > 0x3f) {
 	    /* If we reach the end of a valid CSI sequence and the matched key
 	     * binding is for part of the CSI introduction, select instead the
 	     * undefined-key widget and consume the full sequence from the
 	     * input buffer. */
-	    if (!csi && keybuf[keybuflen - 1] >= 0x40 &&
-		    keybuf[keybuflen - 1] <= 0x7e && lastlen > startcsi &&
-		    lastlen <= startcsi + 2) {
-		func = t_undefinedkey;
-		lastlen = keybuflen;
+		if (keybuf[keybuflen - 1] >= 0x40 &&
+			keybuf[keybuflen - 1] <= 0x7e && lastlen > csi - 2 &&
+			lastlen <= csi) {
+		    func = t_undefinedkey;
+		    lastlen = keybuflen;
+		}
+		csi = 0;
 	    }
 	}
 

Re: Build warning in zle_keymap.c

[Bart Schaefer]

On Thu, Feb 16, 2023 at 3:36 PM Oliver Kiddle <opk@zsh.org> wrote:
>
> Does this silence the compiler?

It does.