qmake: use the manifest embedding feature of the MSVC linker

Since VS 2012 the linker supports the /MANIFEST:embed option, which can
be used to embed the automatically generated manifest without calling
mt.exe. Using this feature simplifies our generated makefiles, esp. in
the case of incremental linking.

Task-number: QTBUG-37363
Change-Id: I2c2d8d2abf36c1b9e7b41bc15244344aab8f5b6e
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>

2 files changed, 23 insertions, 6 deletions

diff --git a/qmake/generators/win32/msvc_nmake.cpp b/qmake/generators/win32/msvc_nmake.cpp
index b8a564968d..52511b2008 100644
--- a/qmake/generators/win32/msvc_nmake.cpp
+++ b/qmake/generators/win32/msvc_nmake.cpp
@@ -514,18 +514,23 @@ void NmakeMakefileGenerator::writeBuildRulesPart(QTextStream &t)
             const QString target = var("DEST_TARGET");
             QString manifest = project->first("QMAKE_MANIFEST").toQString();
             QString extraLFlags;
+            const bool linkerSupportsEmbedding = (msvcVersion() >= 1200);
             if (manifest.isEmpty()) {
                 generateManifest = true;
-                manifest = escapeFilePath(target + ".embed.manifest");
-                extraLFlags = "/MANIFEST /MANIFESTFILE:" + manifest;
-                project->values("QMAKE_CLEAN") << manifest;
+                if (linkerSupportsEmbedding) {
+                    extraLFlags = "/MANIFEST:embed";
+                } else {
+                    manifest = escapeFilePath(target + ".embed.manifest");
+                    extraLFlags += "/MANIFEST /MANIFESTFILE:" + manifest;
+                    project->values("QMAKE_CLEAN") << manifest;
+                }
             } else {
                 manifest = escapeFilePath(fileFixify(manifest));
             }
 
             const QString resourceId = (templateName == "app") ? "1" : "2";
             const bool incrementalLinking = project->values("QMAKE_LFLAGS").toQStringList().filter(QRegExp("(/|-)INCREMENTAL:NO")).isEmpty();
-            if (incrementalLinking) {
+            if (incrementalLinking && !linkerSupportsEmbedding) {
                 // Link a resource that contains the manifest without modifying the exe/dll after linking.
 
                 QString manifest_rc = escapeFilePath(target +  "_manifest.rc");
@@ -558,8 +563,10 @@ void NmakeMakefileGenerator::writeBuildRulesPart(QTextStream &t)
                 // directly embed the manifest in the executable after linking
                 t << "\n\t";
                 writeLinkCommand(t, extraLFlags);
-                t << "\n\tmt.exe /nologo /manifest " << manifest
-                  << " /outputresource:$(DESTDIR_TARGET);" << resourceId;
+                if (!linkerSupportsEmbedding) {
+                    t << "\n\tmt.exe /nologo /manifest " << manifest
+                      << " /outputresource:$(DESTDIR_TARGET);" << resourceId;
+                }
             }
         }  else {
             t << "\n\t";
@@ -590,4 +597,13 @@ void NmakeMakefileGenerator::writeLinkCommand(QTextStream &t, const QString &ext
     t << "\n<<";
 }
 
+int NmakeMakefileGenerator::msvcVersion() const
+{
+    const int fallbackVersion = 800;    // Visual Studio 2005
+    const QString ver = project->first(ProKey("MSVC_VER")).toQString();
+    bool ok;
+    float f = ver.toFloat(&ok);
+    return ok ? int(f * 100) : fallbackVersion;
+}
+
 QT_END_NAMESPACE
diff --git a/qmake/generators/win32/msvc_nmake.h b/qmake/generators/win32/msvc_nmake.h
index 4d3c69bdd6..8d8f5360e0 100644
--- a/qmake/generators/win32/msvc_nmake.h
+++ b/qmake/generators/win32/msvc_nmake.h
@@ -54,6 +54,7 @@ class NmakeMakefileGenerator : public Win32MakefileGenerator
     void writeImplicitRulesPart(QTextStream &t);
     void writeBuildRulesPart(QTextStream &t);
     void writeLinkCommand(QTextStream &t, const QString &extraFlags = QString(), const QString &extraInlineFileContent = QString());
+    int msvcVersion() const;
     void init();
 
 protected: