1f1ad77303a89026caa686b37d4199a62c94bf43
kent
  Tue Feb 1 12:38:07 2011 -0800
Making it so that track html description is fetched for hgc and hgTrackUi.  To do this had to get a way to fetch a text file from a URL without putting up any warning messages if it was not there, which ended up requiring a new warning handler.
diff --git src/lib/errabort.c src/lib/errabort.c
index f91385a..70eb78d 100644
--- src/lib/errabort.c
+++ src/lib/errabort.c
@@ -1,244 +1,257 @@
 /* ErrAbort.c - our error handler.
  *
  * This maintains two stacks - a warning message printer
  * stack, and a "abort handler" stack.
  *
  * By default the warnings will go to stderr, and
  * aborts will exit the program.  You can push a
  * function on to the appropriate stack to change
  * this behavior.  The top function on the stack
  * gets called.
  *
  * This file is copyright 2002 Jim Kent, but license is hereby
  * granted for all use - public, private or commercial. */
 
 // developer: this include is for an occasionally useful means of getting stack info without crashing
 // however, it is not supported on cygwin.  Conditionally compile this in when desired.
 //#define BACKTRACE_EXISTS
 #ifdef BACKTRACE_EXISTS
 #include <execinfo.h>
 #endif///def BACKTRACE_EXISTS
 #include "common.h"
 #include "dystring.h"
 #include "errabort.h"
 
 static char const rcsid[] = "$Id: errabort.c,v 1.16 2010/01/12 18:16:27 markd Exp $";
 
 static boolean debugPushPopErr = FALSE; // generate stack dump on push/pop error
 boolean errAbortInProgress = FALSE;  /* Flag to indicate that an error abort is in progress.
                                       * Needed so that a warn handler can tell if it's really
                                       * being called because of a warning or an error. */
 
 static void defaultVaWarn(char *format, va_list args)
 /* Default error message handler. */
 {
 if (format != NULL) {
     fflush(stdout);
     vfprintf(stderr, format, args);
     fprintf(stderr, "\n");
     }
 }
 
+static void silentVaWarn(char *format, va_list args)
+/* Warning handler that just hides it.  Useful sometimes when high level code
+ * expects low level code may fail (as in finding a file on the net) but doesn't
+ * want user to be bothered about it. */
+{
+}
+
 #define maxWarnHandlers 20
 static WarnHandler warnArray[maxWarnHandlers] = {defaultVaWarn,};
 static int warnIx = 0;
 
 void vaWarn(char *format, va_list args)
 /* Call top of warning stack to issue warning. */
 {
 warnArray[warnIx](format, args);
 }
 
 void warn(char *format, ...)
 /* Issue a warning message. */
 {
 va_list args;
 va_start(args, format);
 vaWarn(format, args);
 va_end(args);
 }
 
 void warnWithBackTrace(char *format, ...)
 /* Issue a warning message and append backtrace. */
 {
 va_list args;
 va_start(args, format);
 struct dyString *dy = newDyString(255);
 dyStringAppend(dy, format);
 
 #define STACK_LIMIT 20
 char **strings = NULL;
 int count = 0;
 
 // developer: this is an occasionally useful means of getting stack info without crashing
 // however, it is not supported on cygwin.  Conditionally compile this in when desired.
 // The define is at top to include execinfo.h
 #ifdef BACKTRACE_EXISTS
 void *buffer[STACK_LIMIT];
 count = backtrace(buffer, STACK_LIMIT);
 strings = backtrace_symbols(buffer, count);
 #endif///def BACKTRACE_EXISTS
 
 if (strings == NULL)
     dyStringAppend(dy,"\nno backtrace_symbols available in errabort::warnWithBackTrace().");
 else
     {
     dyStringAppend(dy,"\nBACKTRACE [can use 'addr2line -Cfise {exe} addr addr ...']:");
     int ix;
     for (ix = 1; ix < count && strings[ix] != NULL; ix++)
         dyStringPrintf(dy,"\n%s", strings[ix]);
 
     free(strings);
     }
 vaWarn(dyStringCannibalize(&dy), args);
 va_end(args);
 }
 
 
 void errnoWarn(char *format, ...)
 /* Prints error message from UNIX errno first, then does rest of warning. */
 {
 char fbuf[512];
 va_list args;
 va_start(args, format);
 sprintf(fbuf, "%s\n%s", strerror(errno), format);
 vaWarn(fbuf, args);
 va_end(args);
 }
 
 
 void pushWarnHandler(WarnHandler handler)
 /* Set abort handler */
 {
 if (warnIx >= maxWarnHandlers-1)
     {
     if (debugPushPopErr)
         dumpStack("pushWarnHandler overflow");
     errAbort("Too many pushWarnHandlers, can only handle %d\n", maxWarnHandlers-1);
     }
 warnArray[++warnIx] = handler;
 }
 
 void popWarnHandler()
 /* Revert to old warn handler. */
 {
 if (warnIx <= 0)
     {
     if (debugPushPopErr)
         dumpStack("popWarnHandler underflow");
     errAbort("Too many popWarnHandlers\n");
     }
 --warnIx;
 }
 
 static void defaultAbort()
 /* Default error handler exits program. */
 {
 if ((getenv("ERRASSERT") != NULL) || (getenv("ERRABORT") != NULL))
     abort();
 else
     exit(-1);
 }
 
 #define maxAbortHandlers 12
 static AbortHandler abortArray[maxAbortHandlers] = {defaultAbort,};
 static int abortIx = 0;
 
 void noWarnAbort()
 /* Abort without message. */
 {
 abortArray[abortIx]();
 exit(-1);		/* This is just to make compiler happy.
                          * We have already exited or longjmped by now. */
 }
 
 void vaErrAbort(char *format, va_list args)
 /* Abort function, with optional (vprintf formatted) error message. */
 {
 /* flag is needed because both errAbort and warn generate message
  * using the warn handler, however sometimes one needed to know
  * (like when logging), if it's an error or a warning.  This is far from
  * perfect, as this isn't cleared if the error handler continues,
  * as with an exception mechanism. */
 errAbortInProgress = TRUE;
 vaWarn(format, args);
 noWarnAbort();
 }
 
 void errAbort(char *format, ...)
 /* Abort function, with optional (printf formatted) error message. */
 {
 va_list args;
 va_start(args, format);
 vaErrAbort(format, args);
 va_end(args);
 }
 
 void errnoAbort(char *format, ...)
 /* Prints error message from UNIX errno first, then does errAbort. */
 {
 char fbuf[512];
 va_list args;
 va_start(args, format);
 sprintf(fbuf, "%s\n%s", strerror(errno), format);
 vaErrAbort(fbuf, args);
 va_end(args);
 }
 
 void pushAbortHandler(AbortHandler handler)
 /* Set abort handler */
 {
 if (abortIx >= maxAbortHandlers-1)
     {
     if (debugPushPopErr)
         dumpStack("pushAbortHandler overflow");
     errAbort("Too many pushAbortHandlers, can only handle %d\n", maxAbortHandlers-1);
     }
 abortArray[++abortIx] = handler;
 }
 
 void popAbortHandler()
 /* Revert to old abort handler. */
 {
 if (abortIx <= 0)
     {
     if (debugPushPopErr)
         dumpStack("popAbortHandler underflow");
     errAbort("Too many popAbortHandlers\n");
     }
 --abortIx;
 }
 
 static void debugAbort()
 /* Call the debugger. */
 {
 fflush(stdout);
 assert(FALSE);
 defaultAbort();
 }
 
 void pushDebugAbort()
 /* Push abort handler that will invoke debugger. */
 {
 pushAbortHandler(debugAbort);
 }
 
 static void warnAbortHandler(char *format, va_list args)
 /* warn handler that also aborts. */
 {
 defaultVaWarn(format, args);
 noWarnAbort();
 }
 
 void pushWarnAbort()
 /* Push handler that will abort on warnings. */
 {
 pushWarnHandler(warnAbortHandler);
 }
 
+void pushSilentWarnHandler()
+/* Set warning handler to be quiet.  Do a popWarnHandler to restore. */
+{
+pushWarnHandler(silentVaWarn);
+}
+
 void errAbortDebugnPushPopErr()
 /*  generate stack dump if there is a error in the push/pop functions */
 {
 debugPushPopErr = TRUE;
 }