From 3f7bf07497cf854e655b17ee0849924a82aa9839 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Deuc=D0=B5?= <shurd@sasktel.net>
Date: Sun, 5 Jan 2025 06:25:07 -0500
Subject: [PATCH] Define and use a new IGNORE_RESULT() macro
Historically, casting to void would suppress warnings about things
being unused. However, an attribute was created for functions like
realloc() where not using the result is always a bug, so when the
attribute is used, you must actually use the return value and can't
cast to void to avoid a warning.
Given this attribute, the glibc authors decided to apply it to all
the functions that usually should have their return value checked
(chdir(), write(), etc) when _FORTIFY_SOURCE is defined because if
you care about correctness enough to define _FORTIFY_SOURCE, you'll
always do something useful with these return values.
Extending the hilarity, some distros define _FORTIFY_SOURCE by
default.
The result is functions that occasionally can safely be called
regardless of the return value will throw a warning if you don't
"do something" with that return value.
Of course, you can just turn off the warnings completely with a
compiler flag, but then you lose the excellent warning about things
like realloc() that always make sense and were the original reason
for the option.
---
src/conio/x_events.c | 30 +++++++++---------------------
src/syncterm/telnets.c | 4 ++--
src/xpdev/genwrap.h | 12 ++++++++++++
3 files changed, 23 insertions(+), 23 deletions(-)
diff --git a/src/conio/x_events.c b/src/conio/x_events.c
index 71d69ae57b..75e11644ea 100644
--- a/src/conio/x_events.c
+++ b/src/conio/x_events.c
@@ -1665,17 +1665,17 @@ handle_bios_key(uint32_t *bios_key, bool *bios_key_parsing, bool *zero_first)
if (ch == 0)
x11.XBell(dpy, 100);
else {
- write(key_pipe[1], &ch, 1);
+ IGNORE_RESULT(write(key_pipe[1], &ch, 1));
if (ch == 0xe0)
- write(key_pipe[1], &ch, 1);
+ IGNORE_RESULT(write(key_pipe[1], &ch, 1));
}
}
else {
// Codepage character
ch = *bios_key;
- write(key_pipe[1], &ch, 1);
+ IGNORE_RESULT(write(key_pipe[1], &ch, 1));
if (ch == 0xe0)
- write(key_pipe[1], &ch, 1);
+ IGNORE_RESULT(write(key_pipe[1], &ch, 1));
}
}
*bios_key = 0;
@@ -1701,11 +1701,7 @@ x11_event(XEvent *ev)
case ClientMessage:
if (ev->xclient.format == 32 && ev->xclient.data.l[0] == A(WM_DELETE_WINDOW) && A(WM_DELETE_WINDOW) != None) {
uint16_t key=CIO_KEY_QUIT;
- // Bow to GCC
- if (write(key_pipe[1], &key, 2) == EXIT_FAILURE)
- return;
- else
- return;
+ IGNORE_RESULT(write(key_pipe[1], &key, 2));
}
else if(ev->xclient.format == 32 && ev->xclient.data.l[0] == A(_NET_WM_PING) && A(_NET_WM_PING) != None) {
ev->xclient.window = root;
@@ -2078,14 +2074,10 @@ x11_event(XEvent *ev)
else
ch = cpchar_from_unicode_cpoint(getcodepage(), wbuf[i], 0);
if (ch) {
- // Bow to GCC
if (ch == 0xe0) // Double-up 0xe0
- if (write(key_pipe[1], &ch, 1) == -1)
- return;
- if (write(key_pipe[1], &ch, 1) == EXIT_SUCCESS)
- return;
- else
- return;
+ IGNORE_RESULT(write(key_pipe[1], &ch, 1));
+ IGNORE_RESULT(write(key_pipe[1], &ch, 1));
+ return;
}
}
break;
@@ -2296,13 +2288,9 @@ x11_event(XEvent *ev)
uint16_t key=scan;
if (key < 128)
key = cpchar_from_unicode_cpoint(getcodepage(), key, key);
- // Bow to GCC
if (key == 0xe0)
key = CIO_KEY_LITERAL_E0;
- if (write(key_pipe[1], &key, (scan & 0xff) ? 1 : 2) != EXIT_SUCCESS)
- return;
- else
- return;
+ IGNORE_RESULT(write(key_pipe[1], &key, (scan & 0xff) ? 1 : 2));
}
break;
}
diff --git a/src/syncterm/telnets.c b/src/syncterm/telnets.c
index 0e0f4e89c4..8e74b30706 100644
--- a/src/syncterm/telnets.c
+++ b/src/syncterm/telnets.c
@@ -41,7 +41,7 @@ telnets_input_thread(void *args)
if (!socket_readable(telnets_sock, 100))
continue;
pthread_mutex_lock(&telnets_mutex);
- cryptFlushData(telnets_session);
+ IGNORE_RESULT(cryptFlushData(telnets_session));
status = cryptPopData(telnets_session, conn_api.rd_buf, conn_api.rd_buf_size, &rd);
pthread_mutex_unlock(&telnets_mutex);
// Handle case where there was socket activity without readable data (ie: rekey)
@@ -101,7 +101,7 @@ telnets_output_thread(void *args)
}
if (sent) {
pthread_mutex_lock(&telnets_mutex);
- cryptFlushData(telnets_session);
+ IGNORE_RESULT(cryptFlushData(telnets_session));
pthread_mutex_unlock(&telnets_mutex);
}
}
diff --git a/src/xpdev/genwrap.h b/src/xpdev/genwrap.h
index d8dd96cfe9..57ba788198 100644
--- a/src/xpdev/genwrap.h
+++ b/src/xpdev/genwrap.h
@@ -48,6 +48,18 @@
#endif
#endif
+#if defined(REALLY_GCC)
+ #define IGNORE_RESULT(x) do { \
+ _Pragma("GCC diagnostic push") \
+ _Pragma("GCC diagnostic ignored \"-Wunused-result\"") \
+ (void)x; \
+ _Pragma("GCC diagnostic pop") \
+ } while(0)
+
+#else
+ #define IGNORE_RESULT(x) ((void)(x))
+#endif
+
#if !defined(_WIN32)
/* Simple Win32 function equivalents */
#define GetCurrentProcessId() getpid()
--
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