Make moc obey the preprocessor environment variable for include paths

C preprocessors augment their standard list of include paths from the
environment: Unix preprocessors use $C_INCLUDE_PATH (for C) and
$CPLUS_INCLUDE_PATH (for C++), plus CPATH for both, whereas MSVC uses
the an environment variable simply called "INCLUDE". Handling this for
MSVC is particularly important because the VCVARSALL.BAT script sets the
necessary #include paths in the environment for important things.
Without that being parsed, moc won't find some #defines, like
WINAPI_DESKTOP_FAMILY.

[ChangeLog][moc] qmake and moc now cooperate to use the Visual Studio
environment variables (set by the VCVARSALL.BAT script) to find system
include files. A possible consequence is that moc parses application
headers slightly differently, depending on #if conditions that depended
on macros that previous versions had not seen #define'd. Implementers of
other buildsystems are advised to pass the --compiler-flavor=msvc option
to moc.

Change-Id: I7e06274214d1939b0124e5b4bf169cceaef9ca46
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>

1 files changed, 48 insertions, 0 deletions

diff --git a/tests/auto/tools/moc/tst_moc.cpp b/tests/auto/tools/moc/tst_moc.cpp
index 1cf6f94720..ab15f81939 100644
--- a/tests/auto/tools/moc/tst_moc.cpp
+++ b/tests/auto/tools/moc/tst_moc.cpp
@@ -577,6 +577,8 @@ private slots:
     void defineMacroViaCmdline();
     void defineMacroViaForcedInclude();
     void defineMacroViaForcedIncludeRelative();
+    void environmentIncludePaths_data();
+    void environmentIncludePaths();
     void specifyMetaTagsFromCmdline();
     void invokable();
     void singleFunctionKeywordSignalAndSlot();
@@ -1295,6 +1297,52 @@ void tst_Moc::defineMacroViaForcedIncludeRelative()
 #endif
 }
 
+
+void tst_Moc::environmentIncludePaths_data()
+{
+#if defined(Q_OS_LINUX) && defined(Q_CC_GNU) && !defined(QT_NO_PROCESS)
+    QTest::addColumn<QString>("cmdline");
+    QTest::addColumn<QString>("varname");
+
+    QTest::newRow("INCLUDE") << "--compiler-flavor=msvc" << "INCLUDE";
+    QTest::newRow("CPATH1") << QString() << "CPATH";
+    QTest::newRow("CPATH2") << "--compiler-flavor=unix" << "CPATH";
+    QTest::newRow("CPLUS_INCLUDE_PATH1") << QString() << "CPLUS_INCLUDE_PATH";
+    QTest::newRow("CPLUS_INCLUDE_PATH2") << "--compiler-flavor=unix" << "CPLUS_INCLUDE_PATH";
+#endif
+}
+
+void tst_Moc::environmentIncludePaths()
+{
+#if defined(Q_OS_LINUX) && defined(Q_CC_GNU) && !defined(QT_NO_PROCESS)
+    QFETCH(QString, cmdline);
+    QFETCH(QString, varname);
+
+    QStringList args;
+    if (!cmdline.isEmpty())
+        args << cmdline;
+    args << "--include" << QStringLiteral("extradefines.h")
+         << m_sourceDirectory + QStringLiteral("/macro-on-cmdline.h");
+
+    QProcessEnvironment env = QProcessEnvironment::systemEnvironment();
+    env.remove("INCLUDE");
+    env.remove("CPATH");
+    env.remove("CPLUS_INCLUDE_PATH");
+    env.insert(varname, m_sourceDirectory + "/subdir");
+
+    QProcess proc;
+    proc.setProcessEnvironment(env);
+    proc.start(m_moc, args);
+    QVERIFY(proc.waitForFinished());
+    QCOMPARE(proc.exitCode(), 0);
+    QCOMPARE(proc.readAllStandardError(), QByteArray());
+    QByteArray mocOut = proc.readAllStandardOutput();
+    QVERIFY(!mocOut.isEmpty());
+#else
+    QSKIP("Only tested on linux/gcc");
+#endif
+}
+
 // tst_Moc::specifyMetaTagsFromCmdline()
 // plugin_metadata.h contains a plugin which we register here. Since we're not building this
 // application as a plugin, we need top copy some of the initializer code found in qplugin.h: