ProjectExplorer: Collect and remember non-functional toolchains

It's not unusual for the toolchain auto-detection procedure to encounter
binaries that turn out not to be valid toolchains only after running
them, either because they are genuinely broken or because their names
match a compiler name pattern, but they are not actually compilers.
Until now, we would re-run such executables on every start of Qt
Creator, potentially delaying start-up unnecessarily.
Now we store them in the settings and do not try to run them again.
For now, the collection of bad toolchains is done for GCC only. Follow-
up patches will add support for more toolchain types.

Change-Id: Icfa28de523737bdd88af3a2bfa8b947326c1bc70
Reviewed-by: hjk <hjk@qt.io>

src/plugins/projectexplorer/toolchain.cpp

@@ -39,6 +39,8 @@
 #include <QFileInfo>
 #include <QUuid>
 
+#include <utility>
+
 using namespace Utils;
 
 static const char ID_KEY[] = "ProjectExplorer.ToolChain.Id";
@@ -652,4 +654,62 @@ ToolchainDetector::ToolchainDetector(const Toolchains &alreadyKnown, const IDevi
     : alreadyKnown(alreadyKnown), device(device)
 {}
 
+BadToolchain::BadToolchain(const Utils::FilePath &filePath)
+    : BadToolchain(filePath, filePath.symLinkTarget(), filePath.lastModified())
+{}
+
+BadToolchain::BadToolchain(const Utils::FilePath &filePath, const Utils::FilePath &symlinkTarget,
+                           const QDateTime &timestamp)
+    : filePath(filePath), symlinkTarget(symlinkTarget), timestamp(timestamp)
+{}
+
+
+static QString badToolchainFilePathKey() { return {"FilePath"}; }
+static QString badToolchainSymlinkTargetKey() { return {"TargetFilePath"}; }
+static QString badToolchainTimestampKey() { return {"Timestamp"}; }
+
+QVariantMap BadToolchain::toMap() const
+{
+    return {
+        std::make_pair(badToolchainFilePathKey(), filePath.toVariant()),
+        std::make_pair(badToolchainSymlinkTargetKey(), symlinkTarget.toVariant()),
+        std::make_pair(badToolchainTimestampKey(), timestamp.toMSecsSinceEpoch()),
+    };
+}
+
+BadToolchain BadToolchain::fromMap(const QVariantMap &map)
+{
+    return {
+        FilePath::fromVariant(map.value(badToolchainFilePathKey())),
+        FilePath::fromVariant(map.value(badToolchainSymlinkTargetKey())),
+        QDateTime::fromMSecsSinceEpoch(map.value(badToolchainTimestampKey()).toLongLong())
+    };
+}
+
+BadToolchains::BadToolchains(const QList<BadToolchain> &toolchains)
+    : toolchains(Utils::filtered(toolchains, [](const BadToolchain &badTc) {
+          return badTc.filePath.lastModified() == badTc.timestamp
+                  && badTc.filePath.symLinkTarget() == badTc.symlinkTarget;
+      }))
+{}
+
+bool BadToolchains::isBadToolchain(const FilePath &toolchain) const
+{
+    return Utils::contains(toolchains, [toolchain](const BadToolchain &badTc) {
+        return badTc.filePath == toolchain.absoluteFilePath()
+                || badTc.symlinkTarget == toolchain.absoluteFilePath();
+    });
+}
+
+QVariant BadToolchains::toVariant() const
+{
+    return Utils::transform<QVariantList>(toolchains, &BadToolchain::toMap);
+}
+
+BadToolchains BadToolchains::fromVariant(const QVariant &v)
+{
+    return Utils::transform<QList<BadToolchain>>(v.toList(),
+            [](const QVariant &e) { return BadToolchain::fromMap(e.toMap()); });
+}
+
 } // namespace ProjectExplorer