qdoc: Let qdoc print better log messages

This change enables qdoc to print better log messages. A new logging
function is added to Location, where the qdoc error and warning
functions are located. The new function is logToStdErrAlways(msg).
It always formats msg for output to stderr by prepending the current
time and the word LOG. Several LOG messages are now sent to stderr.

Also, qdoc now always tells clang to output its parsing errors to
stderr during the building of the precompiled header in the prepare
phase. These clang parser errors are easily identified in the new
LOG.

When no include paths are passed to qdoc on the command line, which
is the case for QtPlatformHeaders, qdoc guesses some reasonable include
paths from the information available and passes them to clang. It works
ok for the QtPlatformHeaders module. However, clang gets lost in some
NSOpenGL headers and prints quite a lot of useless parse errors, so
we arbitrarily turn off clang's parse errors whenever qdoc has to guess
the include paths.

The guessed include paths are printed in the LOG, and a warning that
clang does not print parse errors when the include paths are guessed
is also printed in LOG.

Change-Id: I8e5bd0cc5b27463c4c85c9cdcc01b030ac03a1c1
Reviewed-by: Martin Smith <martin.smith@qt.io>
Reviewed-by: Paul Wicking <paul.wicking@qt.io>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/qdoc/clangcodeparser.h b/src/qdoc/clangcodeparser.h
index b70fcc0e8..b3497608d 100644
--- a/src/qdoc/clangcodeparser.h
+++ b/src/qdoc/clangcodeparser.h
@@ -69,6 +69,7 @@ public:
     void buildPCH();
 
 private:
+    int printParsingErrors_;
     QHash<QString, QString> allHeaders_; // file name->path
     QVector<QByteArray> includePaths_;
     QScopedPointer<QTemporaryDir> pchFileDir_;