improve unusedfields loplugin to find constructor-only fields

ie. fields that are only touched in the constructor

Change-Id: Ia714cbfed9710e47e69ca9f0eb0eac4f7e8b8a86
Reviewed-on: https://gerrit.libreoffice.org/54412
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

compilerplugins/clang/unusedfields.cxx

@@ -67,6 +67,7 @@ bool operator < (const MyFieldInfo &lhs, const MyFieldInfo &rhs)
 // try to limit the voluminous output a little
 static std::set<MyFieldInfo> touchedFromInsideSet;
 static std::set<MyFieldInfo> touchedFromOutsideSet;
+static std::set<MyFieldInfo> touchedFromOutsideConstructorSet;
 static std::set<MyFieldInfo> readFromSet;
 static std::set<MyFieldInfo> writeToSet;
 static std::set<MyFieldInfo> definitionSet;
@@ -186,6 +187,8 @@ void UnusedFields::run()
             output += "inside:\t" + s.parentClass + "\t" + s.fieldName + "\n";
         for (const MyFieldInfo & s : touchedFromOutsideSet)
             output += "outside:\t" + s.parentClass + "\t" + s.fieldName + "\n";
+        for (const MyFieldInfo & s : touchedFromOutsideConstructorSet)
+            output += "outside-constructor:\t" + s.parentClass + "\t" + s.fieldName + "\n";
         for (const MyFieldInfo & s : readFromSet)
             output += "read:\t" + s.parentClass + "\t" + s.fieldName + "\n";
         for (const MyFieldInfo & s : writeToSet)
@@ -989,6 +992,8 @@ void UnusedFields::checkTouchedFromOutside(const FieldDecl* fieldDecl, const Exp
     } else {
         if (memberExprParentFunction->getParent() == fieldDecl->getParent()) {
             touchedFromInsideSet.insert(fieldInfo);
+            if (!constructorDecl)
+                touchedFromOutsideConstructorSet.insert(fieldInfo);
         } else {
             touchedFromOutsideSet.insert(fieldInfo);
         }

compilerplugins/clang/unusedfields.py

@@ -9,10 +9,11 @@ protectedAndPublicDefinitionSet = set() # set of tuple(type, name)
 definitionToSourceLocationMap = dict()
 definitionToTypeMap = dict()
 touchedFromInsideSet = set()
+touchedFromOutsideSet = set()
+touchedFromOutsideConstructorSet = set()
 readFromSet = set()
 writeToSet = set()
 sourceLocationSet = set()
-touchedFromOutsideSet = set()
 
 # clang does not always use exactly the same numbers in the type-parameter vars it generates
 # so I need to substitute them to ensure we can match correctly.
@@ -48,6 +49,8 @@ with io.open("workdir/loplugin.unusedfields.log", "rb", buffering=1024*1024) as
             touchedFromInsideSet.add(parseFieldInfo(tokens))
         elif tokens[0] == "outside:":
             touchedFromOutsideSet.add(parseFieldInfo(tokens))
+        elif tokens[0] == "outside-constructor:":
+            touchedFromOutsideConstructorSet.add(parseFieldInfo(tokens))
         elif tokens[0] == "read:":
             readFromSet.add(parseFieldInfo(tokens))
         elif tokens[0] == "write:":
@@ -67,7 +70,7 @@ for k, definitions in sourceLocationToDefinitionMap.iteritems():
         for d in definitions:
             definitionSet.remove(d)
 
-# Calculate untouched or untouched-except-for-in-constructor
+# Calculate untouched
 untouchedSet = set()
 untouchedSetD = set()
 for d in definitionSet:
@@ -103,6 +106,41 @@ for d in definitionSet:
     untouchedSet.add((d[0] + " " + d[1] + " " + fieldType, srcLoc))
     untouchedSetD.add(d)
 
+# Calculate only-touched-in-constructor set
+onlyUsedInConstructorSet = set()
+for d in definitionSet:
+    if d in touchedFromOutsideSet or d in touchedFromOutsideConstructorSet:
+        continue
+    srcLoc = definitionToSourceLocationMap[d];
+    # this is all representations of on-disk data structures
+    if (srcLoc.startswith("sc/source/filter/inc/scflt.hxx")
+        or srcLoc.startswith("sw/source/filter/ww8/")
+        or srcLoc.startswith("vcl/source/filter/sgvmain.hxx")
+        or srcLoc.startswith("vcl/source/filter/sgfbram.hxx")
+        or srcLoc.startswith("vcl/inc/unx/XIM.h")
+        or srcLoc.startswith("vcl/inc/unx/gtk/gloactiongroup.h")
+        or srcLoc.startswith("include/svl/svdde.hxx")
+        or srcLoc.startswith("lotuswordpro/source/filter/lwpsdwdrawheader.hxx")
+        or srcLoc.startswith("hwpfilter/")
+        or srcLoc.startswith("embeddedobj/source/inc/")
+        or srcLoc.startswith("svtools/source/dialogs/insdlg.cxx")
+        or srcLoc.startswith("bridges/")):
+        continue
+    fieldType = definitionToTypeMap[d]
+    if "std::unique_ptr" in fieldType:
+        continue
+    if "std::shared_ptr" in fieldType:
+        continue
+    if "Reference<" in fieldType:
+        continue
+    if "VclPtr<" in fieldType:
+        continue
+    if "osl::Mutex" in fieldType:
+        continue
+    if "::sfx2::sidebar::ControllerItem" in fieldType:
+        continue
+    onlyUsedInConstructorSet.add((d[0] + " " + d[1] + " " + fieldType, srcLoc))
+
 writeonlySet = set()
 for d in definitionSet:
     parentClazz = d[0];
@@ -196,6 +234,7 @@ tmp1list = sorted(untouchedSet, key=lambda v: natural_sort_key(v[1]))
 tmp2list = sorted(writeonlySet, key=lambda v: natural_sort_key(v[1]))
 tmp3list = sorted(canBePrivateSet, key=lambda v: natural_sort_key(v[1]))
 tmp4list = sorted(readonlySet, key=lambda v: natural_sort_key(v[1]))
+tmp5list = sorted(onlyUsedInConstructorSet, key=lambda v: natural_sort_key(v[1]))
 
 # print out the results
 with open("compilerplugins/clang/unusedfields.untouched.results", "wt") as f:
@@ -215,5 +254,9 @@ with open("compilerplugins/clang/unusedfields.readonly.results", "wt") as f:
     for t in tmp4list:
         f.write( t[1] + "\n" )
         f.write( "    " + t[0] + "\n" )
+with open("compilerplugins/clang/unusedfields.only-used-in-constructor.results", "wt") as f:
+    for t in tmp5list:
+        f.write( t[1] + "\n" )
+        f.write( "    " + t[0] + "\n" )