diff options
| author | Thomas E. Dickey <dickey@invisible-island.net> | 2024-03-03 18:51:46 -0500 |
|---|---|---|
| committer | Thomas E. Dickey <dickey@invisible-island.net> | 2024-03-04 03:53:29 -0500 |
| commit | fd4b2ce63feae01744a850fa6f1809ff15361a8b (patch) | |
| tree | 1b3c1e374bcc7a70e621a3327e6eb8d37bd55521 | |
| parent | d33708e30f102f6ab278d6f809eeaa18e65d0716 (diff) | |
fix clang/gcc warnings for undefined behavior, also fix a bug
XtConvertAndStore may update the XrmValue value, changing its size.
clang and gcc warn about undefined behavior in the case-statement
following the call (which uses the size), but do not explain what
the problem is. Since this code is not intended to handle changes
of the size, simply reject that case. That quiets the gcc warnings
and is actually all that is needed for correctness. clang still
complains (neither knows what the call does), but can be quieted
by initializing the variable before calling the function.
The code happens to work without the fix as long as it is not
used to convert between resource types which would increase the
size.
Signed-off-by: Thomas E. Dickey <dickey@invisible-island.net>
| -rw-r--r-- | src/Actions.c | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/src/Actions.c b/src/Actions.c index 8f0cead..abb61ef 100644 --- a/src/Actions.c +++ b/src/Actions.c @@ -413,6 +413,7 @@ XawSetValuesAction(Widget w, XEvent *event, #ifdef LONG64 long c_8; #endif + unsigned use_size; if (!(*num_params & 1)) { @@ -444,13 +445,14 @@ XawSetValuesAction(Widget w, XEvent *event, from.size = (Cardinal) strlen(value) + 1; from.addr = (char *)value; to.size = resource->size; - switch (to.size) + use_size = resource->size; + switch (use_size) { - case 1: to.addr = (XPointer)&c_1; break; - case 2: to.addr = (XPointer)&c_2; break; - case 4: to.addr = (XPointer)&c_4; break; + case 1: to.addr = (XPointer)&c_1; c_1 = 0; break; + case 2: to.addr = (XPointer)&c_2; c_2 = 0; break; + case 4: to.addr = (XPointer)&c_4; c_4 = 0; break; #ifdef LONG64 - case 8: to.addr = (XPointer)&c_8; break; + case 8: to.addr = (XPointer)&c_8; c_8 = 0; break; #endif default: { @@ -470,10 +472,11 @@ XawSetValuesAction(Widget w, XEvent *event, c_4 = (int)from.addr; #endif else if (!XtConvertAndStore(w, XtRString, &from, - XrmQuarkToString(resource->qtype), &to)) + XrmQuarkToString(resource->qtype), &to) + || to.size != use_size) continue; - switch (to.size) + switch (use_size) { case 1: XtSetArg(arglist[num_args], XrmQuarkToString(resource->qname), c_1); |