new loplugin unusedenumvalues

Change-Id: I03d684fc35238a45a6d99855e5ee6d3a5e33740d

2 files changed, 356 insertions, 0 deletions

diff --git a/compilerplugins/clang/unusedenumconstants.cxx b/compilerplugins/clang/unusedenumconstants.cxx
new file mode 100644
index 000000000000..c26589493f23
--- /dev/null
+++ b/compilerplugins/clang/unusedenumconstants.cxx
@@ -0,0 +1,198 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <cassert>
+#include <string>
+#include <iostream>
+#include <fstream>
+#include <set>
+#include "plugin.hxx"
+#include "compat.hxx"
+
+/**
+This looks for unused enum constants
+
+We search for 3 things
+(a) constants that are declared but never used
+(b) constants only used in a "read" fashion i.e. we compare stuff against them, but we never store a value anywhere
+(c) constants only used in a "write" fashion i.e. we store a value, but never check for that value
+
+(a) is fairly reliable but (b) and (c) will need some checking before acting on.
+
+Be warned that it produces around 5G of log file.
+
+The process goes something like this:
+  $ make check
+  $ make FORCE_COMPILE_ALL=1 COMPILER_PLUGIN_TOOL='unusedenumconstants' check
+  $ ./compilerplugins/clang/unusedenumconstants.py
+
+Note that the actual process may involve a fair amount of undoing, hand editing, and general messing around
+to get it to work :-)
+
+*/
+
+namespace {
+
+struct MyFieldInfo
+{
+    std::string parentClass;
+    std::string fieldName;
+    std::string sourceLocation;
+};
+bool operator < (const MyFieldInfo &lhs, const MyFieldInfo &rhs)
+{
+    return std::tie(lhs.parentClass, lhs.fieldName)
+         < std::tie(rhs.parentClass, rhs.fieldName);
+}
+
+
+// try to limit the voluminous output a little
+static std::set<MyFieldInfo> definitionSet;
+static std::set<MyFieldInfo> writeSet;
+static std::set<MyFieldInfo> readSet;
+
+
+class UnusedEnumConstants:
+    public RecursiveASTVisitor<UnusedEnumConstants>, public loplugin::Plugin
+{
+public:
+    explicit UnusedEnumConstants(InstantiationData const & data): Plugin(data) {}
+
+    virtual void run() override
+    {
+        TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
+
+        // dump all our output in one write call - this is to try and limit IO "crosstalk" between multiple processes
+        // writing to the same logfile
+        std::string output;
+        for (const MyFieldInfo & s : definitionSet)
+            output += "definition:\t" + s.parentClass + "\t" + s.fieldName + "\t" + s.sourceLocation + "\n";
+        for (const MyFieldInfo & s : writeSet)
+            output += "write:\t" + s.parentClass + "\t" + s.fieldName + "\n";
+        for (const MyFieldInfo & s : readSet)
+            output += "read:\t" + s.parentClass + "\t" + s.fieldName + "\n";
+        ofstream myfile;
+        myfile.open( SRCDIR "/loplugin.unusedenumconstants.log", ios::app | ios::out);
+        myfile << output;
+        myfile.close();
+    }
+
+    bool shouldVisitTemplateInstantiations () const { return true; }
+    bool shouldVisitImplicitCode() const { return true; }
+
+    bool VisitEnumConstantDecl( const EnumConstantDecl * );
+    bool VisitDeclRefExpr( const DeclRefExpr * );
+private:
+    MyFieldInfo niceName(const EnumConstantDecl*);
+};
+
+MyFieldInfo UnusedEnumConstants::niceName(const EnumConstantDecl* enumConstantDecl)
+{
+    MyFieldInfo aInfo;
+
+    aInfo.parentClass = enumConstantDecl->getType().getAsString();
+    aInfo.fieldName = enumConstantDecl->getNameAsString();
+
+    SourceLocation expansionLoc = compiler.getSourceManager().getExpansionLoc( enumConstantDecl->getLocation() );
+    StringRef name = compiler.getSourceManager().getFilename(expansionLoc);
+    aInfo.sourceLocation = std::string(name.substr(strlen(SRCDIR)+1)) + ":" + std::to_string(compiler.getSourceManager().getSpellingLineNumber(expansionLoc));
+    normalizeDotDotInFilePath(aInfo.sourceLocation);
+
+    return aInfo;
+}
+
+bool UnusedEnumConstants::VisitEnumConstantDecl( const EnumConstantDecl* enumConstantDecl )
+{
+    enumConstantDecl = enumConstantDecl->getCanonicalDecl();
+    if (ignoreLocation( enumConstantDecl )) {
+        return true;
+    }
+    // ignore stuff that forms part of the stable URE interface
+    if (isInUnoIncludeFile(compiler.getSourceManager().getSpellingLoc(enumConstantDecl->getLocation()))) {
+        return true;
+    }
+
+    definitionSet.insert(niceName(enumConstantDecl));
+    return true;
+}
+
+bool UnusedEnumConstants::VisitDeclRefExpr( const DeclRefExpr* declRefExpr )
+{
+    auto enumConstantDecl = dyn_cast<EnumConstantDecl>(declRefExpr->getDecl());
+    if (!enumConstantDecl) {
+        return true;
+    }
+    enumConstantDecl = enumConstantDecl->getCanonicalDecl();
+    if (ignoreLocation(enumConstantDecl)) {
+        return true;
+    }
+    // ignore stuff that forms part of the stable URE interface
+    if (isInUnoIncludeFile(compiler.getSourceManager().getSpellingLoc(enumConstantDecl->getLocation()))) {
+        return true;
+    }
+
+    const Stmt * parent = declRefExpr;
+try_again:
+    parent = parentStmt(parent);
+    bool bWrite = false;
+    bool bRead = false;
+    bool bDump = false;
+    if (!parent)
+    {
+        // Could probably do better here.
+        // Sometimes this is a constructor-initialiser-expression, so just make a pessimistic assumption.
+        bWrite = true;
+    } else if (isa<CallExpr>(parent) || isa<InitListExpr>(parent) || isa<ArraySubscriptExpr>(parent)
+                || isa<ReturnStmt>(parent) || isa<DeclStmt>(parent)
+                || isa<CXXConstructExpr>(parent)
+                || isa<CXXThrowExpr>(parent))
+    {
+        bWrite = true;
+    } else if (isa<CaseStmt>(parent) || isa<SwitchStmt>(parent))
+    {
+        bRead = true;
+    } else if (const BinaryOperator * binaryOp = dyn_cast<BinaryOperator>(parent))
+    {
+        if (BinaryOperator::isAssignmentOp(binaryOp->getOpcode())) {
+            bWrite = true;
+        } else {
+            bRead = true;
+        }
+    } else if (isa<CastExpr>(parent) || isa<UnaryOperator>(parent)
+                || isa<ConditionalOperator>(parent) || isa<ParenExpr>(parent)
+                || isa<MaterializeTemporaryExpr>(parent)
+                || isa<ExprWithCleanups>(parent))
+    {
+        goto try_again;
+    } else {
+        bDump = true;
+    }
+
+    // to let me know if I missed something
+    if (bDump) {
+        parent->dump();
+        report( DiagnosticsEngine::Warning,
+                "unhandled clang AST node type",
+                parent->getLocStart());
+    }
+
+    if (bWrite) {
+        writeSet.insert(niceName(enumConstantDecl));
+    }
+    if (bRead) {
+        readSet.insert(niceName(enumConstantDecl));
+    }
+    return true;
+}
+
+loplugin::Plugin::Registration< UnusedEnumConstants > X("unusedenumconstants", true);
+
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/compilerplugins/clang/unusedenumconstants.py b/compilerplugins/clang/unusedenumconstants.py
new file mode 100755
index 000000000000..5a9fe362edb2
--- /dev/null
+++ b/compilerplugins/clang/unusedenumconstants.py
@@ -0,0 +1,158 @@
+#!/usr/bin/python
+
+import sys
+import re
+import io
+
+definitionSet = set()
+definitionToSourceLocationMap = dict()
+readSet = set()
+writeSet = set()
+sourceLocationSet = 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.
+normalizeTypeParamsRegex = re.compile(r"type-parameter-\d+-\d+")
+def normalizeTypeParams( line ):
+    return normalizeTypeParamsRegex.sub("type-parameter-?-?", line)
+
+def parseFieldInfo( tokens ):
+    if len(tokens) == 3:
+        return (normalizeTypeParams(tokens[1]), tokens[2])
+    else:
+        return (normalizeTypeParams(tokens[1]), "")
+
+# The parsing here is designed to avoid grabbing stuff which is mixed in from gbuild.
+# I have not yet found a way of suppressing the gbuild output.
+with io.open("loplugin.unusedenumconstants.log", "rb", buffering=1024*1024) as txt:
+    for line in txt:
+        tokens = line.strip().split("\t")
+        if tokens[0] == "definition:":
+            fieldInfo = (normalizeTypeParams(tokens[1]), tokens[2])
+            srcLoc = tokens[3]
+            # ignore external source code
+            if (srcLoc.startswith("external/")):
+                continue
+            # ignore build folder
+            if (srcLoc.startswith("workdir/")):
+                continue
+            definitionSet.add(fieldInfo)
+            definitionToSourceLocationMap[fieldInfo] = srcLoc
+        elif tokens[0] == "read:":
+            readSet.add(parseFieldInfo(tokens))
+        elif tokens[0] == "write:":
+            writeSet.add(parseFieldInfo(tokens))
+        else:
+            print( "unknown line: " + line)
+
+# Invert the definitionToSourceLocationMap
+# If we see more than one method at the same sourceLocation, it's being autogenerated as part of a template
+# and we should just ignore
+sourceLocationToDefinitionMap = {}
+for k, v in definitionToSourceLocationMap.iteritems():
+    sourceLocationToDefinitionMap[v] = sourceLocationToDefinitionMap.get(v, [])
+    sourceLocationToDefinitionMap[v].append(k)
+for k, definitions in sourceLocationToDefinitionMap.iteritems():
+    if len(definitions) > 1:
+        for d in definitions:
+            definitionSet.remove(d)
+
+def startswith_one_of( srcLoc, fileSet ):
+    for f in fileSet:
+        if srcLoc.startswith(f):
+            return True;
+    return False;
+
+untouchedSet = set()
+for d in definitionSet:
+    if d in readSet or d in writeSet:
+        continue
+    srcLoc = definitionToSourceLocationMap[d];
+    if startswith_one_of(srcLoc,
+        [
+        # this is all representations of on-disk or external data structures
+         "basic/source/inc/filefmt.hxx",
+         "basic/source/sbx/sbxscan.cxx",
+         "cppcanvas/source/mtfrenderer/emfpbrush.hxx",
+         "filter/source/graphicfilter/ipcd/ipcd.cxx",
+         "filter/source/t602/t602filter.hxx",
+         "include/filter/msfilter/escherex.hxx",
+         "include/filter/msfilter/svdfppt.hxx",
+         "hwpfilter/",
+         "include/registry/types.hxx",
+         "lotuswordpro/",
+         "include/sot/formats.hxx",
+         "include/svx/msdffdef.hxx",
+         "sc/source/filter/inc/xlconst.hxx",
+         "include/unotools/saveopt.hxx",
+         "sw/inc/fldbas.hxx",
+         "sw/source/filter/inc/wwstyles.hxx",
+         "sw/source/filter/ww8/fields.hxx",
+         "vcl/source/fontsubset/cff.cxx",
+        # unit test code
+         "cppu/source/uno/check.cxx",
+        # general weird nonsense going on
+         "framework/inc/helper/mischelper.hxx"
+         "include/sfx2/shell.hxx",
+        # Windows or OSX only
+         "include/canvas/rendering/icolorbuffer.hxx",
+         "include/vcl/commandevent.hxx",
+        # must match some other enum
+         "include/editeng/bulletitem.hxx",
+         "include/editeng/svxenum.hxx",
+         "include/formula/opcode.hxx",
+         "include/i18nutil/paper.hxx",
+         "include/oox/drawingml/shapepropertymap.hxx",
+         "include/svl/nfkeytab.hx",
+         "include/svl/zforlist.hxx",
+        # represents constants from an external API
+         "opencl/inc/opencl_device_selection.h",
+         "vcl/inc/sft.hxx",
+         "vcl/inc/unx/XIM.h",
+         "vcl/unx/gtk/xid_fullscreen_on_all_monitors.c",
+         ]):
+        continue
+
+    if d[1] == "UNKNOWN" or d[1].endswith("NONE") or d[1].endswith("None") or d[1].endswith("EQUAL_SIZE"): continue
+
+    untouchedSet.add((d[0] + " " + d[1], srcLoc))
+
+writeonlySet = set()
+for d in writeSet:
+    if d in readSet:
+        continue
+    srcLoc = definitionToSourceLocationMap[d];
+    writeonlySet.add((d[0] + " " + d[1], srcLoc))
+
+readonlySet = set()
+for d in readSet:
+    if d in writeSet:
+        continue
+    srcLoc = definitionToSourceLocationMap[d];
+    readonlySet.add((d[0] + " " + d[1], srcLoc))
+
+# sort the results using a "natural order" so sequences like [item1,item2,item10] sort nicely
+def natural_sort_key(s, _nsre=re.compile('([0-9]+)')):
+    return [int(text) if text.isdigit() else text.lower()
+            for text in re.split(_nsre, s)]
+
+# sort results by name and line number
+tmp1list = sorted(untouchedSet, key=lambda v: natural_sort_key(v[1]))
+tmp2list = sorted(writeonlySet, key=lambda v: natural_sort_key(v[1]))
+tmp3list = sorted(readonlySet, key=lambda v: natural_sort_key(v[1]))
+
+# print out the results
+with open("loplugin.unusedenumconstants.report-untouched", "wt") as f:
+    for t in tmp1list:
+        f.write( t[1] + "\n" )
+        f.write( "    " + t[0] + "\n" )
+with open("loplugin.unusedenumconstants.report-writeonly", "wt") as f:
+    for t in tmp2list:
+        f.write( t[1] + "\n" )
+        f.write( "    " + t[0] + "\n" )
+with open("loplugin.unusedenumconstants.report-readonly", "wt") as f:
+    for t in tmp3list:
+        f.write( t[1] + "\n" )
+        f.write( "    " + t[0] + "\n" )
+
+