QtSupport: Try harder to ensure that Qt kits have a toolchain

If we encounter a kit with a Qt version, but no toolchain, try to find a
matching toolchain and set it on the kit.
This is helpful if the user forgets to set the toolchain or a toolchain
gets removed.

Fixes: QTCREATORBUG-23564
Change-Id: I2b29ece81502b10d2a64a431a0edbcd43b1ec3a6
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>

1 files changed, 39 insertions, 3 deletions

diff --git a/src/plugins/qtsupport/qtkitinformation.cpp b/src/plugins/qtsupport/qtkitinformation.cpp
index 7d8ada64803..1e4037c4477 100644
--- a/src/plugins/qtsupport/qtkitinformation.cpp
+++ b/src/plugins/qtsupport/qtkitinformation.cpp
@@ -35,6 +35,8 @@
 #include <coreplugin/icore.h>
 #include <projectexplorer/projectexplorerconstants.h>
 #include <projectexplorer/task.h>
+#include <projectexplorer/toolchain.h>
+#include <projectexplorer/toolchainmanager.h>
 #include <utils/algorithm.h>
 #include <utils/buildablehelperlibrary.h>
 #include <utils/macroexpander.h>
@@ -207,9 +209,43 @@ void QtKitAspect::fix(ProjectExplorer::Kit *k)
 {
     QTC_ASSERT(QtVersionManager::isLoaded(), return);
     BaseQtVersion *version = qtVersion(k);
-    if (!version && qtVersionId(k) >= 0) {
-        qWarning("Qt version is no longer known, removing from kit \"%s\".", qPrintable(k->displayName()));
-        setQtVersionId(k, -1);
+    if (!version) {
+        if (qtVersionId(k) >= 0) {
+            qWarning("Qt version is no longer known, removing from kit \"%s\".",
+                     qPrintable(k->displayName()));
+            setQtVersionId(k, -1);
+        }
+        return;
+    }
+
+    // Set a matching toolchain if we don't have one.
+    if (ToolChainKitAspect::toolChain(k, ProjectExplorer::Constants::CXX_LANGUAGE_ID))
+        return;
+    const QString spec = version->mkspec();
+    const QList<ToolChain *> possibleTcs = ToolChainManager::toolChains(
+                [version](const ToolChain *t) {
+        return t->isValid()
+                && t->language() == Core::Id(ProjectExplorer::Constants::CXX_LANGUAGE_ID)
+                && version->qtAbis().contains(t->targetAbi());
+    });
+    if (!possibleTcs.isEmpty()) {
+        const QList<ToolChain *> goodTcs = Utils::filtered(possibleTcs,
+                                                           [&spec](const ToolChain *t) {
+            return t->suggestedMkspecList().contains(spec);
+        });
+        // Hack to prefer a tool chain from PATH (e.g. autodetected) over other matches.
+        // This improves the situation a bit if a cross-compilation tool chain has the
+        // same ABI as the host.
+        const Environment systemEnvironment = Environment::systemEnvironment();
+        ToolChain *bestTc = Utils::findOrDefault(goodTcs,
+                                                 [&systemEnvironment](const ToolChain *t) {
+            return systemEnvironment.path().contains(t->compilerCommand().parentDir());
+        });
+        if (!bestTc) {
+            bestTc = goodTcs.isEmpty() ? possibleTcs.last() : goodTcs.last();
+        }
+        if (bestTc)
+            ToolChainKitAspect::setAllToolChainsToMatch(k, bestTc);
     }
 }