From: bones_was_here <bones_was_here@xonotic.au>
Date: Thu, 4 Jan 2024 14:41:43 +0000 (+1000)
Subject: sys: write significant engine and QC errors to stderr
X-Git-Url: https://git.xonotic.org/?p=xonotic%2Fdarkplaces.git;a=commitdiff_plain;h=a678225e4d3c0c44488efd0bc597325c2de7ef18;ds=sidebyside

sys: write significant engine and QC errors to stderr

A server configured with -nostdout or sys_stdout 0 will now be able to
report bugs.

Retrieves stdio stream FDs instead of assuming they're always 0,1,2.
Fixes some comment!=code discrepancies.

Signed-off-by: bones_was_here <bones_was_here@xonotic.au>
---

diff --git a/host.c b/host.c
index 424b0729..2bfd6912 100644
--- a/host.c
+++ b/host.c
@@ -89,6 +89,10 @@ void Host_Error (const char *error, ...)
 	static char hosterrorstring2[MAX_INPUTLINE]; // THREAD UNSAFE
 	static qbool hosterror = false;
 	va_list argptr;
+	int outfd = sys.outfd;
+
+	// set output to stderr
+	sys.outfd = fileno(stderr);
 
 	// turn off rcon redirect if it was active when the crash occurred
 	// to prevent loops when it is a networking problem
@@ -141,6 +145,9 @@ void Host_Error (const char *error, ...)
 
 	hosterror = false;
 
+	// restore configured outfd
+	sys.outfd = outfd;
+
 	Host_AbortCurrentFrame();
 }
 
diff --git a/prvm_cmds.c b/prvm_cmds.c
index 0d281e62..2812f2c2 100644
--- a/prvm_cmds.c
+++ b/prvm_cmds.c
@@ -27,6 +27,10 @@ void VM_Warning(prvm_prog_t *prog, const char *fmt, ...)
 	va_list argptr;
 	char msg[MAX_INPUTLINE];
 	static double recursive = -1;
+	int outfd = sys.outfd;
+
+	// set output to stderr
+	sys.outfd = fileno(stderr);
 
 	va_start(argptr,fmt);
 	dpvsnprintf(msg,sizeof(msg),fmt,argptr);
@@ -41,6 +45,9 @@ void VM_Warning(prvm_prog_t *prog, const char *fmt, ...)
 		PRVM_PrintState(prog, 0);
 		recursive = -1;
 	}
+
+	// restore configured outfd
+	sys.outfd = outfd;
 }
 
 
diff --git a/prvm_exec.c b/prvm_exec.c
index fd0ff40b..af71b302 100644
--- a/prvm_exec.c
+++ b/prvm_exec.c
@@ -715,6 +715,7 @@ extern cvar_t prvm_errordump;
 void PRVM_Crash(prvm_prog_t *prog)
 {
 	char vabuf[1024];
+	int outfd = sys.outfd;
 
 	cl.csqc_loaded = false;
 
@@ -723,6 +724,9 @@ void PRVM_Crash(prvm_prog_t *prog)
 	if (!prog->loaded)
 		return;
 
+	// set output to stderr
+	sys.outfd = fileno(stderr);
+
 	PRVM_serverfunction(SV_Shutdown) = 0; // don't call SV_Shutdown on crash
 
 	if( prog->depth > 0 )
@@ -746,6 +750,9 @@ void PRVM_Crash(prvm_prog_t *prog)
 
 	// reset the prog pointer
 	prog = NULL;
+
+	// restore configured outfd
+	sys.outfd = outfd;
 }
 
 /*
diff --git a/sys_shared.c b/sys_shared.c
index 78bb56e3..6cfe9213 100644
--- a/sys_shared.c
+++ b/sys_shared.c
@@ -71,10 +71,13 @@ void Sys_Quit (int returnvalue)
 #ifdef __ANDROID__
 	Sys_AllowProfiling(false);
 #endif
+
 #ifndef WIN32
-	fcntl (0, F_SETFL, fcntl (0, F_GETFL, 0) & ~O_NONBLOCK);
+	fcntl(fileno(stdout), F_SETFL, fcntl(fileno(stdout), F_GETFL, 0) & ~O_NONBLOCK);
+	fcntl(fileno(stderr), F_SETFL, fcntl(fileno(stderr), F_GETFL, 0) & ~O_NONBLOCK);
 #endif
 	fflush(stdout);
+	fflush(stderr);
 
 	exit(returnvalue);
 }
@@ -700,9 +703,10 @@ void Sys_Error (const char *error, ...)
 	va_list argptr;
 	char string[MAX_INPUTLINE];
 
-// change stdin to non blocking
+	// set output to blocking stderr
+	sys.outfd = fileno(stderr);
 #ifndef WIN32
-	fcntl (0, F_SETFL, fcntl (0, F_GETFL, 0) & ~O_NONBLOCK);
+	fcntl(sys.outfd, F_SETFL, fcntl(sys.outfd, F_GETFL, 0) & ~O_NONBLOCK);
 #endif
 
 	va_start (argptr,error);
@@ -716,6 +720,8 @@ void Sys_Error (const char *error, ...)
 
 	Sys_SDL_Dialog("Engine Error", string);
 
+	fflush(stderr);
+
 	exit (1);
 }
 
@@ -941,10 +947,16 @@ static void Sys_HandleCrash(int sig)
 		default:      sigdesc = "Yo dawg, we hit a bug while hitting a bug";
 	}
 
+	// set output to blocking stderr
+	sys.outfd = fileno(stderr);
+#ifndef WIN32
+	fcntl(sys.outfd, F_SETFL, fcntl(sys.outfd, F_GETFL, 0) & ~O_NONBLOCK);
+#endif
+
 	fprintf(stderr, "\n\n\e[1;37;41m    Engine Crash: %s (%d)    \e[m\n", sigdesc, sig);
 #if __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 1
 	// the first two addresses will be in this function and in signal() in libc
-	backtrace_symbols_fd(stackframes + 2, framecount - 2, fileno(stderr));
+	backtrace_symbols_fd(stackframes + 2, framecount - 2, sys.outfd);
 #endif
 	fprintf(stderr, "\e[1m%s\e[m\n", engineversion);
 
@@ -956,6 +968,8 @@ static void Sys_HandleCrash(int sig)
 
 	Sys_SDL_Dialog("Engine Crash", sigdesc);
 
+	fflush(stderr);
+
 	exit (sig);
 }