AuroraMiddleware/qt5base-lts
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Doc: fix null pointer passing to fprintf

Browse Source 
When these docs were written, the context.file and context.function
pointers were never null. But in commit d78fb442d7
(Qt 5.4), we made the logging pass null pointers in release builds. The
C standard does not say that passing null pointers is permitted. In
fact, it says "If no l length modifier is present, the argument shall be
a pointer to the initial element of an array of character type." and
that's pretty explicit that it needs to point to the initial element of
a string.

Fixes: QTBUG-72478
Change-Id: I4ac1156702324f0fb814fffd156f624ffefa1445
Reviewed-by: Topi Reiniö <topi.reinio@qt.io>
This commit is contained in:
Thiago Macieira 2018-12-11 12:48:12 -08:00
parent 3c3a2eb3ce
commit 3e4f8aa8f4
1 changed files with 7 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
src/corelib/doc/snippets/code/src_corelib_global_qglobal.cpp
View File

@ -279,21 +279,23 @@ const TInputType &myMin(const TInputType &value1, const TInputType &value2)
void myMessageOutput(QtMsgType type, const QMessageLogContext &context, const QString &msg) void myMessageOutput(QtMsgType type, const QMessageLogContext &context, const QString &msg)
{ {
QByteArray localMsg = msg.toLocal8Bit(); QByteArray localMsg = msg.toLocal8Bit();
const char *file = context.file ? context.file : "";
const char *function = context.function ? context.function : "";
switch (type) { switch (type) {
case QtDebugMsg: case QtDebugMsg:
fprintf(stderr, "Debug: %s (%s:%u, %s)\n", localMsg.constData(), context.file, context.line, context.function); fprintf(stderr, "Debug: %s (%s:%u, %s)\n", localMsg.constData(), file, context.line, function);
break; break;
case QtInfoMsg: case QtInfoMsg:
fprintf(stderr, "Info: %s (%s:%u, %s)\n", localMsg.constData(), context.file, context.line, context.function); fprintf(stderr, "Info: %s (%s:%u, %s)\n", localMsg.constData(), file, context.line, function);
break; break;
case QtWarningMsg: case QtWarningMsg:
fprintf(stderr, "Warning: %s (%s:%u, %s)\n", localMsg.constData(), context.file, context.line, context.function); fprintf(stderr, "Warning: %s (%s:%u, %s)\n", localMsg.constData(), file, context.line, function);
break; break;
case QtCriticalMsg: case QtCriticalMsg:
fprintf(stderr, "Critical: %s (%s:%u, %s)\n", localMsg.constData(), context.file, context.line, context.function); fprintf(stderr, "Critical: %s (%s:%u, %s)\n", localMsg.constData(), file, context.line, function);
break; break;
case QtFatalMsg: case QtFatalMsg:
fprintf(stderr, "Fatal: %s (%s:%u, %s)\n", localMsg.constData(), context.file, context.line, context.function); fprintf(stderr, "Fatal: %s (%s:%u, %s)\n", localMsg.constData(), file, context.line, function);
break; break;
} }
} }