centralize/unify/sanitize INCLUDEPATH "enrichment"

instead of having each generator do its own magic (little surprisingly,
with different outcomes), add "stuff" to the search path in one place
used by all generators. this has several consequences:
- (unless disabled via CONFIG+=no_include_pwd) $$PWD is now consistently
  prepended by all generators. most notably, this was entirely missing
  from the MSVC generators (both nmake and VS) - despite them needing it
  most. this also affects Xcode projects.
- $$OUT_PWD (if different from $$PWD) is now added right after $$PWD,
  not at the end. this precedence clarification only makes sense, given
  that qmake tries to make shadow builds as transparent as possible.
- the qmakespec's dir is now consistently appended. the UNIX and PBX
  generators prepended it, while the rest already appended. few files
  actually include qplatformdefs.h, so having it late in the search path
  seems reasonable.
- the effect of CONFIG+=depend_includepath is now fully consistent with
  the actual include path.

Change-Id: I5f7570183351ade29342ea74fef706a0738842bf
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

qmake/generators/mac/pbuilder_pbx.cpp

@@ -739,11 +739,7 @@ ProjectBuilderMakefileGenerator::writeMakeParts(QTextStream &t)
             mkt << "DEFINES       = "
                 << varGlue("PRL_EXPORT_DEFINES","-D"," -D"," ")
                 << varGlue("DEFINES","-D"," -D","") << endl;
-            mkt << "INCPATH       = -I" << specdir();
-            if(!project->isActiveConfig("no_include_pwd")) {
-                QString pwd = escapeFilePath(fileFixify(qmake_getpwd()));
-                mkt << " -I" << pwd;
-            }
+            mkt << "INCPATH       =";
             {
                 const ProStringList &incs = project->values("INCLUDEPATH");
                 for (ProStringList::ConstIterator incit = incs.begin(); incit != incs.end(); ++incit)
@@ -1495,7 +1491,7 @@ ProjectBuilderMakefileGenerator::writeMakeParts(QTextStream &t)
                     t << "\t\t\t\t" << writeSettings("GCC_PRECOMPILE_PREFIX_HEADER", "YES") << ";\n"
                     << "\t\t\t\t" << writeSettings("GCC_PREFIX_HEADER", escapeFilePath(project->first("PRECOMPILED_HEADER"))) << ";\n";
                 }
-                t << "\t\t\t\t" << writeSettings("HEADER_SEARCH_PATHS", fixListForOutput("INCLUDEPATH") + ProStringList(fixForOutput(specdir())), SettingsAsList, 5) << ";\n"
+                t << "\t\t\t\t" << writeSettings("HEADER_SEARCH_PATHS", fixListForOutput("INCLUDEPATH"), SettingsAsList, 5) << ";\n"
                   << "\t\t\t\t" << writeSettings("LIBRARY_SEARCH_PATHS", fixListForOutput("QMAKE_PBX_LIBPATHS"), SettingsAsList, 5) << ";\n"
                   << "\t\t\t\t" << writeSettings("FRAMEWORK_SEARCH_PATHS", fixListForOutput("QMAKE_FRAMEWORKPATH"),
                         !project->values("QMAKE_FRAMEWORKPATH").isEmpty() ? SettingsAsList : 0, 5) << ";\n";

qmake/generators/makefile.cpp

@@ -444,6 +444,25 @@ MakefileGenerator::init()
 
     setSystemIncludes(v["QMAKE_DEFAULT_INCDIRS"]);
 
+    ProStringList &incs = project->values("INCLUDEPATH");
+    if (!project->isActiveConfig("no_include_pwd")) {
+        if (Option::output_dir != qmake_getpwd()) {
+            // Pretend that the build dir is the source dir for #include purposes,
+            // consistently with the "transparent shadow builds" strategy. This is
+            // also consistent with #include "foo.h" falling back to #include <foo.h>
+            // behavior if it doesn't find the file in the source dir.
+            incs.prepend(Option::output_dir);
+        }
+        // This makes #include <foo.h> work if the header lives in the source dir.
+        // The benefit of that is questionable, as generally the user should use the
+        // correct include style, and extra compilers that put stuff in the source dir
+        // should add the dir themselves.
+        // More importantly, it makes #include "foo.h" work with MSVC when shadow-building,
+        // as this compiler looks files up relative to %CD%, not the source file's parent.
+        incs.prepend(qmake_getpwd());
+    }
+    incs.append(project->specDir());
+
     const char * const cacheKeys[] = { "_QMAKE_STASH_", "_QMAKE_SUPER_CACHE_", 0 };
     for (int i = 0; cacheKeys[i]; ++i) {
         if (v[cacheKeys[i]].isEmpty())
@@ -793,10 +812,6 @@ MakefileGenerator::init()
         ProStringList incDirs = v["DEPENDPATH"] + v["QMAKE_ABSOLUTE_SOURCE_PATH"];
         if(project->isActiveConfig("depend_includepath"))
             incDirs += v["INCLUDEPATH"];
-        if(!project->isActiveConfig("no_include_pwd")) {
-            QString pwd = qmake_getpwd();
-            incDirs += pwd;
-        }
         QList<QMakeLocalFileName> deplist;
         for (ProStringList::Iterator it = incDirs.begin(); it != incDirs.end(); ++it)
             deplist.append(QMakeLocalFileName(unescapeFilePath((*it).toQString())));
@@ -848,11 +863,6 @@ MakefileGenerator::init()
             (*it) = Option::fixPathToLocalOS((*it).toQString());
     }
 
-    if(!project->isActiveConfig("no_include_pwd")) { //get the output_dir into the pwd
-        if(Option::output_dir != qmake_getpwd())
-            project->values("INCLUDEPATH").append(".");
-    }
-
     //fix up the target deps
     static const char * const fixpaths[] = { "PRE_TARGETDEPS", "POST_TARGETDEPS", 0 };
     for (int path = 0; fixpaths[path]; path++) {

qmake/generators/unix/unixmake2.cpp

@@ -184,11 +184,7 @@ UnixMakefileGenerator::writeMakeParts(QTextStream &t)
       << varGlue("DEFINES","-D"," -D","") << endl;
     t << "CFLAGS        = " << var("QMAKE_CFLAGS") << " $(DEFINES)\n";
     t << "CXXFLAGS      = " << var("QMAKE_CXXFLAGS") << " $(DEFINES)\n";
-    t << "INCPATH       = -I" << specdir();
-    if(!project->isActiveConfig("no_include_pwd")) {
-        QString pwd = escapeFilePath(fileFixify(qmake_getpwd()));
-        t << " -I" << pwd;
-    }
+    t << "INCPATH       =";
     {
         QString isystem = var("QMAKE_CFLAGS_ISYSTEM");
         const ProStringList &incs = project->values("INCLUDEPATH");

qmake/generators/win32/mingw_make.cpp

@@ -306,11 +306,6 @@ void MingwMakefileGenerator::writeIncPart(QTextStream &t)
 {
     t << "INCPATH       = ";
 
-    if (!project->isActiveConfig("no_include_pwd")) {
-        QString pwd = escapeFilePath(fileFixify(qmake_getpwd()));
-        t << "-I" << pwd << " ";
-    }
-
     QString isystem = var("QMAKE_CFLAGS_ISYSTEM");
     const ProStringList &incs = project->values("INCLUDEPATH");
     for (ProStringList::ConstIterator incit = incs.begin(); incit != incs.end(); ++incit) {
@@ -324,8 +319,7 @@ void MingwMakefileGenerator::writeIncPart(QTextStream &t)
             t << "-I";
         t << quote << inc << quote << " ";
     }
-    t << "-I" << quote << specdir() << quote
-      << endl;
+    t << endl;
 }
 
 void MingwMakefileGenerator::writeLibsPart(QTextStream &t)

qmake/generators/win32/msvc_vcproj.cpp

@@ -1688,7 +1688,6 @@ void VcprojGenerator::initOld()
             inc = QString("\"%1\"").arg(inc); // Quote all paths if not quoted already
         project->values("MSVCPROJ_INCPATH").append("-I" + inc);
     }
-    project->values("MSVCPROJ_INCPATH").append("-I" + specdir());
 
     QString dest = Option::fixPathToTargetOS(project->first("TARGET").toQString()) + project->first("TARGET_EXT");
     project->values("MSVCPROJ_TARGET") = ProStringList(dest);

qmake/generators/win32/winmakefile.cpp

@@ -606,8 +606,7 @@ void Win32MakefileGenerator::writeIncPart(QTextStream &t)
         if(!inc.isEmpty())
             t << "-I\"" << inc << "\" ";
     }
-    t << "-I\"" << specdir() << "\""
-      << endl;
+    t << endl;
 }
 
 void Win32MakefileGenerator::writeStandardParts(QTextStream &t)