qmake: link qt libraries by full path

this avoids the scenario where the linker would pick up the wrong qt
libraries for LIBS_PRIVATE because LIBS added the "wrong" path first.
this is also consistent with configure-supplied dependencies as of
recently.

as a side effect, this also removes pretenses of lsb linker handling, as
it makes no sense after the change and is certainly obsolete anyway.

Fixes: QTBUG-50921
Change-Id: I84398c9143f393c2eefb3c69a31bd9f633669924
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>

mkspecs/features/qt.prf

@@ -145,12 +145,14 @@ import_plugins:qtConfig(static) {
         # the plugin path. Unknown plugins must rely on the default link path.
         plug_type = $$eval(QT_PLUGIN.$${plug}.TYPE)
         !isEmpty(plug_type) {
+            plug_name = $$QMAKE_PREFIX_STATICLIB$${plug}$$qtPlatformTargetSuffix().$$QMAKE_EXTENSION_STATICLIB
             plug_path = $$eval(QT_PLUGIN.$${plug}.PATH)
             isEmpty(plug_path): \
                 plug_path = $$[QT_INSTALL_PLUGINS/get]
-            LIBS += -L$$plug_path/$$plug_type
+            LIBS += $$plug_path/$$plug_type/$$plug_name
+        } else {
+            LIBS += -l$${plug}$$qtPlatformTargetSuffix()
         }
-        LIBS += -l$${plug}$$qtPlatformTargetSuffix()
     }
 }
 
@@ -195,8 +197,6 @@ for(ever) {
         qtProcessModuleFlags(DEFINES, QT.$${QTLIB}.DEFINES)
 
         MODULE_INCLUDES -= $$QMAKE_DEFAULT_INCDIRS
-        MODULE_LIBS_ADD = $$MODULE_LIBS
-        MODULE_LIBS_ADD -= $$QMAKE_DEFAULT_LIBDIRS
 
         # Frameworks shouldn't need include paths, but much code does not use
         # module-qualified #includes, so by default we add paths which point
@@ -209,23 +209,17 @@ for(ever) {
         !isEmpty(MODULE_MODULE) {
             contains(MODULE_CONFIG, lib_bundle) {
                 framework = $$MODULE_MODULE
+                # Linking frameworks by absolute path does not work.
                 LIBS$$var_sfx += -framework $$framework
             } else {
-                !isEmpty(MODULE_LIBS_ADD): \
-                    LIBS$$var_sfx += -L$$MODULE_LIBS_ADD
-
                 lib = $$MODULE_MODULE$$qtPlatformTargetSuffix()
-                LIBS$$var_sfx += -l$$lib
-
-                contains(MODULE_CONFIG, staticlib): \
-                    PRE_TARGETDEPS *= $$MODULE_LIBS/$${QMAKE_PREFIX_STATICLIB}$${lib}.$${QMAKE_EXTENSION_STATICLIB}
-
-                !isEmpty(QMAKE_LSB) {
-                    !isEmpty(MODULE_LIBS_ADD): \
-                        QMAKE_LFLAGS *= --lsb-libpath=$$MODULE_LIBS_ADD
-                    QMAKE_LFLAGS *= --lsb-shared-libs=$$lib
-                    QMAKE_LIBDIR *= /opt/lsb/lib
+                win32|contains(MODULE_CONFIG, staticlib) {
+                    lib = $$MODULE_LIBS/$$QMAKE_PREFIX_STATICLIB$${lib}.$$QMAKE_EXTENSION_STATICLIB
+                    PRE_TARGETDEPS += $$lib
+                } else {
+                    lib = $$MODULE_LIBS/$$QMAKE_PREFIX_SHLIB$${lib}.$$QMAKE_EXTENSION_SHLIB
                 }
+                LIBS$$var_sfx += $$lib
             }
         }
         QMAKE_USE$$var_sfx += $$MODULE_USES
@@ -295,7 +289,8 @@ contains(all_qt_module_deps, qml): \
         for (key, IMPORTS._KEYS_) {
             PATH = $$eval(IMPORTS.$${key}.path)
             PLUGIN = $$eval(IMPORTS.$${key}.plugin)
-            !isEmpty(PATH):!isEmpty(PLUGIN): LIBS *= -L$$PATH -l$${PLUGIN}$$qtPlatformTargetSuffix()
+            !isEmpty(PATH):!isEmpty(PLUGIN): \
+                LIBS += $$PATH/$$QMAKE_PREFIX_STATICLIB$${PLUGIN}$$qtPlatformTargetSuffix().$$QMAKE_EXTENSION_STATICLIB
         }
 
         # create qml_plugin_import.cpp

mkspecs/features/win32/opengl.prf

@@ -1,13 +1,21 @@
 QT_FOR_CONFIG += gui
 
+defineTest(prependOpenGlLib) {
+    path = $$QT.core.libs/$$QMAKE_PREFIX_STATICLIB$$1
+    ext = .$$QMAKE_EXTENSION_STATICLIB
+    QMAKE_LIBS_OPENGL_ES2 = $${path}$${ext} $$QMAKE_LIBS_OPENGL_ES2
+    QMAKE_LIBS_OPENGL_ES2_DEBUG = $${path}d$${ext} $$QMAKE_LIBS_OPENGL_ES2_DEBUG
+    export(QMAKE_LIBS_OPENGL_ES2)
+    export(QMAKE_LIBS_OPENGL_ES2_DEBUG)
+}
+
 qtConfig(opengles2) {
     # Depending on the configuration we use libQtANGLE or libEGL and libGLESv2
     qtConfig(combined-angle-lib) {
-        QMAKE_LIBS_OPENGL_ES2 = -l$${LIBQTANGLE_NAME} $$QMAKE_LIBS_OPENGL_ES2
-        QMAKE_LIBS_OPENGL_ES2_DEBUG = -l$${LIBQTANGLE_NAME}d $$QMAKE_LIBS_OPENGL_ES2_DEBUG
+        prependOpenGlLib($$LIBQTANGLE_NAME)
     } else {
-        QMAKE_LIBS_OPENGL_ES2 = -l$${LIBEGL_NAME} -l$${LIBGLESV2_NAME} $$QMAKE_LIBS_OPENGL_ES2
-        QMAKE_LIBS_OPENGL_ES2_DEBUG = -l$${LIBEGL_NAME}d -l$${LIBGLESV2_NAME}d $$QMAKE_LIBS_OPENGL_ES2_DEBUG
+        prependOpenGlLib($$LIBGLESV2_NAME)
+        prependOpenGlLib($$LIBEGL_NAME)
     }
 #   For Desktop, use the ANGLE library location passed on from configure.
     INCLUDEPATH += $$QMAKE_INCDIR_OPENGL_ES2

mkspecs/features/win32/windows.prf

@@ -6,10 +6,9 @@ contains(TEMPLATE, ".*app") {
 
     qt:for(entryLib, $$list($$unique(QMAKE_LIBS_QT_ENTRY))) {
         isEqual(entryLib, -lqtmain) {
-            !contains(QMAKE_DEFAULT_LIBDIRS, $$QT.core.libs): \
-                QMAKE_LIBS += -L$$QT.core.libs
-            CONFIG(debug, debug|release): QMAKE_LIBS += $${entryLib}$${QT_LIBINFIX}d
-            else: QMAKE_LIBS += $${entryLib}$${QT_LIBINFIX}
+            lib = $$QT.core.libs/$${QMAKE_PREFIX_STATICLIB}qtmain$$QT_LIBINFIX$$qtPlatformTargetSuffix().$$QMAKE_EXTENSION_STATICLIB
+            PRE_TARGETDEPS += $$lib
+            QMAKE_LIBS += $$lib
         } else {
             QMAKE_LIBS += $${entryLib}
         }

mkspecs/linux-lsb-g++/qmake.conf

@@ -13,7 +13,6 @@ load(qt_config)
 
 QMAKE_LIBS_THREAD      += -lrt
 
-QMAKE_LSB               = 1
 QMAKE_CC                = lsbcc
 QMAKE_CXX               = lsbc++