C++: Add support for clang on Windows

This is about clang in "mingw mode", not clang-cl.
When targeting Windows, clang is a lot like mingw, so factor out the
common parts into a new base module.
Testing uncovered a number of invalid assumptions in our autotests,
which are also fixed in this patch. In addition, minor adjustments had
to be made to the Qt.core module and to the qbscore lib.

Change-Id: I73085dc62a65e2a9d0397cf234c8641989246f22
Reviewed-by: Ivan Komissarov <ABBAPOH@gmail.com>
Reviewed-by: Jörg Bornemann <joerg.bornemann@qt.io>

1 files changed, 38 insertions, 0 deletions

diff --git a/src/app/qbs-setup-toolchains/gccprobe.cpp b/src/app/qbs-setup-toolchains/gccprobe.cpp
index e979acf59..a8482f8d0 100644
--- a/src/app/qbs-setup-toolchains/gccprobe.cpp
+++ b/src/app/qbs-setup-toolchains/gccprobe.cpp
@@ -46,11 +46,14 @@
 
 #include <tools/hostosinfo.h>
 #include <tools/profile.h>
+#include <tools/settings.h>
 #include <tools/toolchains.h>
 
 #include <QtCore/qdir.h>
 #include <QtCore/qprocess.h>
 
+#include <algorithm>
+
 using namespace qbs;
 using Internal::HostOsInfo;
 using Internal::Tr;
@@ -395,6 +398,31 @@ Profile createGccProfile(const QFileInfo &compiler, Settings *settings,
 
     setCommonProperties(profile, compiler, toolchainTypes, details);
 
+    if (HostOsInfo::isWindowsHost() && toolchainTypes.contains(QLatin1String("clang"))) {
+        const QStringList profileNames = settings->profiles();
+        bool foundMingw = false;
+        for (const QString &profileName : profileNames) {
+            const Profile otherProfile(profileName, settings);
+            if (otherProfile.value(QLatin1String("qbs.toolchainType")).toString()
+                    == QLatin1String("mingw")
+                    || otherProfile.value(QLatin1String("qbs.toolchain"))
+                    .toStringList().contains(QLatin1String("mingw"))) {
+                const QFileInfo tcDir(otherProfile.value(QLatin1String("cpp.toolchainInstallPath"))
+                        .toString());
+                if (!tcDir.fileName().isEmpty() && tcDir.exists()) {
+                    profile.setValue(QLatin1String("qbs.sysroot"), tcDir.path());
+                    foundMingw = true;
+                    break;
+                }
+            }
+        }
+        if (!foundMingw) {
+            qbsWarning() << Tr::tr("Using clang on Windows requires a mingw installation. "
+                                   "Please set qbs.sysroot accordingly for profile '%1'.")
+                            .arg(profile.name());
+        }
+    }
+
     if (!toolchainTypes.contains(QLatin1String("clang"))) {
         // Check whether auxiliary tools reside within the toolchain's install path.
         // This might not be the case when using icecc or another compiler wrapper.
@@ -466,6 +494,16 @@ void gccProbe(Settings *settings, QList<Profile> &profiles, const QString &compi
         return;
     }
 
+    // Sort candidates so that mingw comes first. Information from mingw profiles is potentially
+    // used for setting up clang profiles.
+    if (HostOsInfo::isWindowsHost()) {
+        std::sort(candidates.begin(), candidates.end(),
+                  [](const QFileInfo &fi1, const QFileInfo &fi2) {
+            return fi1.absoluteFilePath().contains(QLatin1String("mingw"))
+                    && !fi2.absoluteFilePath().contains(QLatin1String("mingw"));
+        });
+    }
+
     for (const auto &candidate : qAsConst(candidates)) {
         const QStringList toolchainTypes = toolchainTypeFromCompilerName(
                     candidate.baseName());