ProjectExplorer: Fix msvc toolschain abi compatibility

According to MSDN: "You can mix binaries built by different versions of
the v140, v141, and v142 toolsets. However, you must link by using a
toolset at least as recent as the most recent binary in your app. Here's
an example: you can link an app compiled using any 2017 toolset (v141,
versions 15.0 through 15.9) to a static library compiled using, say,
Visual Studio 2019 version 16.2 (v142), if they're linked using a
version 16.2 or later toolset. You can link a version 16.2 library to a
version 16.4 app as long as you use a 16.4 or later toolset."

https://docs.microsoft.com/en-us/cpp/porting/binary-compat-2015-2017?
view=msvc-160

So don't try to assign an older msvc toolchain to a kit that contains a
Qt build with a newer version of msvc.

Fixes: QTCREATORBUG-25618
Change-Id: If58676da5f61add1eed7e786862ee475e180b7dc
Reviewed-by: Robert Löhning <robert.loehning@qt.io>
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>

src/plugins/projectexplorer/abi.cpp

@@ -726,14 +726,6 @@ bool Abi::isCompatibleWith(const Abi &other) const
     return isCompat;
 }
 
-bool Abi::isFullyCompatibleWith(const Abi &other) const
-{
-    return *this == other
-            || (wordWidth() == other.wordWidth()
-                && architecture() == other.architecture()
-                && compatibleMSVCFlavors(osFlavor(), other.osFlavor()));
-}
-
 bool Abi::isValid() const
 {
     return m_architecture != UnknownArchitecture

src/plugins/projectexplorer/abi.h

@@ -148,7 +148,6 @@ public:
     bool operator != (const Abi &other) const;
     bool operator == (const Abi &other) const;
     bool isCompatibleWith(const Abi &other) const;
-    bool isFullyCompatibleWith(const Abi &other) const;
 
     bool isValid() const;
     bool isNull() const;

src/plugins/projectexplorer/msvctoolchain.cpp

@@ -908,6 +908,33 @@ QStringList MsvcToolChain::suggestedMkspecList() const
     return {};
 }
 
+Abis MsvcToolChain::supportedAbis() const
+{
+    Abi abi = targetAbi();
+    Abis abis = {abi};
+    switch (abi.osFlavor()) {
+    case Abi::WindowsMsvc2019Flavor:
+        abis << Abi(abi.architecture(),
+                    abi.os(),
+                    Abi::WindowsMsvc2017Flavor,
+                    abi.binaryFormat(),
+                    abi.wordWidth(),
+                    abi.param());
+        Q_FALLTHROUGH();
+    case Abi::WindowsMsvc2017Flavor:
+        abis << Abi(abi.architecture(),
+                    abi.os(),
+                    Abi::WindowsMsvc2015Flavor,
+                    abi.binaryFormat(),
+                    abi.wordWidth(),
+                    abi.param());
+        break;
+    default:
+        break;
+    }
+    return abis;
+}
+
 QVariantMap MsvcToolChain::toMap() const
 {
     QVariantMap data = ToolChain::toMap();

src/plugins/projectexplorer/msvctoolchain.h

@@ -67,6 +67,7 @@ public:
     QString originalTargetTriple() const override;
 
     QStringList suggestedMkspecList() const override;
+    Abis supportedAbis() const override;
 
     QVariantMap toMap() const override;
     bool fromMap(const QVariantMap &data) override;

src/plugins/qtsupport/baseqtversion.cpp

@@ -516,6 +516,7 @@ Tasks BaseQtVersion::validateKit(const Kit *k)
 
     if (ToolChain *tc = ToolChainKitAspect::cxxToolChain(k)) {
         Abi targetAbi = tc->targetAbi();
+        Abis supportedAbis = tc->supportedAbis();
         bool fuzzyMatch = false;
         bool fullMatch = false;
 
@@ -526,9 +527,12 @@ Tasks BaseQtVersion::validateKit(const Kit *k)
             qtAbiString.append(qtAbi.toString());
 
             if (!fullMatch)
-                fullMatch = targetAbi.isFullyCompatibleWith(qtAbi);
+                fullMatch = supportedAbis.contains(qtAbi);
-            if (!fuzzyMatch)
+            if (!fuzzyMatch && !fullMatch) {
-                fuzzyMatch = targetAbi.isCompatibleWith(qtAbi);
+                fuzzyMatch = Utils::anyOf(supportedAbis, [&](const Abi &abi) {
+                    return qtAbi.isCompatibleWith(abi);
+                });
+            }
         }
 
         QString message;

src/plugins/qtsupport/qtkitinformation.cpp

@@ -222,11 +222,10 @@ void QtKitAspect::fix(Kit *k)
 
     const QString spec = version->mkspec();
     QList<ToolChain *> possibleTcs = ToolChainManager::toolChains([version](const ToolChain *t) {
-        return t->isValid()
+        if (!t->isValid() || t->language() != ProjectExplorer::Constants::CXX_LANGUAGE_ID)
-                && t->language() == ProjectExplorer::Constants::CXX_LANGUAGE_ID
+            return false;
-                && contains(version->qtAbis(), [t](const Abi &qtAbi) {
+        return Utils::anyOf(version->qtAbis(),
-                       return qtAbi.isFullyCompatibleWith(t->targetAbi());
+                            [t](const Abi &qtAbi) { return t->supportedAbis().contains(qtAbi); });
-                   });
     });
     if (!possibleTcs.isEmpty()) {
         // Prefer exact matches.