Fix moc stumbling over gcc __attribute__ extensions

Reported by David Faure.

In KDE a DEPRECATED macro gets defined in a header file created by cmake.
The define is not guarded with #if Q_CC_GNU or similar because at cmake
time the compiler is determined. Therefore moc suddenly sees this gcc
specific token and stumbles over it.

This patch simply defines an empty __attribute__ macro that will expand
to nothing and thus become invisible to moc's "C++ parser" after the
pre-processing.

Change-Id: I4448b9ac3f72b6334e32b27484401fb0fca23a0c
Reviewed-by: David Faure <faure@kde.org>
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/src/tools/moc/main.cpp b/src/tools/moc/main.cpp
index e87c742632..ccdae64738 100644
--- a/src/tools/moc/main.cpp
+++ b/src/tools/moc/main.cpp
@@ -170,6 +170,14 @@ int runMoc(int _argc, char **_argv)
     Moc moc;
     pp.macros["Q_MOC_RUN"];
     pp.macros["__cplusplus"];
+
+    // Don't stumble over GCC extensions
+    Macro dummyVariadicFunctionMacro;
+    dummyVariadicFunctionMacro.isFunction = true;
+    dummyVariadicFunctionMacro.isVariadic = true;
+    dummyVariadicFunctionMacro.arguments += Symbol(0, PP_IDENTIFIER, "__VA_ARGS__");
+    pp.macros["__attribute__"] = dummyVariadicFunctionMacro;
+
     QByteArray filename;
     QByteArray output;
     FILE *in = 0;