new loplugin inlineablemethods

look for methods that are:

(*) non-virtual
(*) only called once
(*) only called from inside their own class
(*) small i.e. < 40 characters

which are candidates for just having their code inlined

Change-Id: I0e9e8125d140282cdcdd2a77374059b17b2fcd7d

2 files changed, 480 insertions, 0 deletions

diff --git a/compilerplugins/clang/inlineablemethods.cxx b/compilerplugins/clang/inlineablemethods.cxx
new file mode 100644
index 000000000000..3dd58d352c45
--- /dev/null
+++ b/compilerplugins/clang/inlineablemethods.cxx
@@ -0,0 +1,332 @@
+/* -*- 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 <unordered_map>
+
+
+#include "clang/AST/Attr.h"
+
+#include "plugin.hxx"
+#include "compat.hxx"
+
+/**
+ Methods that are only called from inside their own class, and are only called from one spot
+
+
+ TODO if a method has only one call-site, and that call site is inside a constructor
+     then it's probably worth inlining, since it's probably an old method that was intended to be shared amongst
+     multiple constructors
+*/
+
+namespace {
+
+struct MyFuncInfo
+{
+    std::string access;
+    std::string returnType;
+    std::string nameAndParams;
+    std::string sourceLocation;
+
+};
+bool operator < (const MyFuncInfo &lhs, const MyFuncInfo &rhs)
+{
+    return std::tie(lhs.returnType, lhs.nameAndParams)
+         < std::tie(rhs.returnType, rhs.nameAndParams);
+}
+
+// try to limit the voluminous output a little
+
+static std::unordered_map<std::string, MyFuncInfo> calledFromMap;
+static std::set<MyFuncInfo> definitionSet;
+static std::set<MyFuncInfo> calledFromOutsideSet;
+static std::set<MyFuncInfo> largeFunctionSet;
+static std::set<MyFuncInfo> addressOfSet;
+
+
+class InlineableMethods:
+    public RecursiveASTVisitor<InlineableMethods>, public loplugin::Plugin
+{
+public:
+    explicit InlineableMethods(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 MyFuncInfo & s : definitionSet)
+            output += "definition:\t" + s.access + "\t" + s.returnType + "\t" + s.nameAndParams + "\t" + s.sourceLocation + "\n";
+        for (const MyFuncInfo & s : calledFromOutsideSet)
+            output += "outside:\t" + s.returnType + "\t" + s.nameAndParams + "\n";
+        for (const std::pair<std::string,MyFuncInfo> & s : calledFromMap)
+            output += "calledFrom:\t" + s.first
+                       + "\t" + s.second.returnType + "\t" + s.second.nameAndParams + "\n";
+        for (const MyFuncInfo & s : largeFunctionSet)
+            output += "large:\t" + s.returnType + "\t" + s.nameAndParams + "\n";
+        for (const MyFuncInfo & s : addressOfSet)
+            output += "addrof:\t" + s.returnType + "\t" + s.nameAndParams + "\n";
+        ofstream myfile;
+        myfile.open( SRCDIR "/loplugin.inlineablemethods.log", ios::app | ios::out);
+        myfile << output;
+        myfile.close();
+    }
+
+    bool shouldVisitTemplateInstantiations () const { return true; }
+    bool shouldVisitImplicitCode() const { return true; }
+
+    bool VisitFunctionDecl( const FunctionDecl* );
+    bool VisitDeclRefExpr( const DeclRefExpr* );
+    bool VisitMemberExpr( const MemberExpr* );
+    // interception methods for FunctionDecl and all its subclasses
+    bool TraverseFunctionDecl( FunctionDecl* );
+    bool TraverseCXXMethodDecl( CXXMethodDecl* );
+    bool TraverseCXXConstructorDecl( CXXConstructorDecl* );
+    bool TraverseCXXConversionDecl( CXXConversionDecl* );
+    bool TraverseCXXDestructorDecl( CXXDestructorDecl* );
+
+private:
+    MyFuncInfo niceName(const FunctionDecl* functionDecl);
+    std::string toString(SourceLocation loc);
+    void functionTouchedFromExpr( const FunctionDecl* calleeFunctionDecl, const Expr* expr );
+    bool isCalleeFunctionInteresting( const FunctionDecl* );
+    void logCalledFrom(SourceLocation calleeSite, const FunctionDecl* functionDecl);
+
+    // I use traverse and a member variable because I cannot find a reliable way of walking back up the AST tree using the parentStmt() stuff
+    // TODO doesn't cope with nested functions
+    const FunctionDecl* mpTraversingFunction = nullptr;
+};
+
+MyFuncInfo InlineableMethods::niceName(const FunctionDecl* functionDecl)
+{
+    if (functionDecl->getInstantiatedFromMemberFunction())
+        functionDecl = functionDecl->getInstantiatedFromMemberFunction();
+    else if (functionDecl->getClassScopeSpecializationPattern())
+        functionDecl = functionDecl->getClassScopeSpecializationPattern();
+// workaround clang-3.5 issue
+#if CLANG_VERSION >= 30600
+    else if (functionDecl->getTemplateInstantiationPattern())
+        functionDecl = functionDecl->getTemplateInstantiationPattern();
+#endif
+
+    MyFuncInfo aInfo;
+    switch (functionDecl->getAccess())
+    {
+    case AS_public: aInfo.access = "public"; break;
+    case AS_private: aInfo.access = "private"; break;
+    case AS_protected: aInfo.access = "protected"; break;
+    default: aInfo.access = "unknown"; break;
+    }
+    if (!isa<CXXConstructorDecl>(functionDecl)) {
+        aInfo.returnType = compat::getReturnType(*functionDecl).getCanonicalType().getAsString();
+    } else {
+        aInfo.returnType = "";
+    }
+
+    if (isa<CXXMethodDecl>(functionDecl)) {
+        const CXXRecordDecl* recordDecl = dyn_cast<CXXMethodDecl>(functionDecl)->getParent();
+        aInfo.nameAndParams += recordDecl->getQualifiedNameAsString();
+        aInfo.nameAndParams += "::";
+    }
+    aInfo.nameAndParams += functionDecl->getNameAsString() + "(";
+    bool bFirst = true;
+    for (const ParmVarDecl *pParmVarDecl : compat::parameters(*functionDecl)) {
+        if (bFirst)
+            bFirst = false;
+        else
+            aInfo.nameAndParams += ",";
+        aInfo.nameAndParams += pParmVarDecl->getType().getCanonicalType().getAsString();
+    }
+    aInfo.nameAndParams += ")";
+    if (isa<CXXMethodDecl>(functionDecl) && dyn_cast<CXXMethodDecl>(functionDecl)->isConst()) {
+        aInfo.nameAndParams += " const";
+    }
+
+    aInfo.sourceLocation = toString( functionDecl->getLocation() );
+
+    return aInfo;
+}
+
+std::string InlineableMethods::toString(SourceLocation loc)
+{
+    SourceLocation expansionLoc = compiler.getSourceManager().getExpansionLoc( loc );
+    StringRef name = compiler.getSourceManager().getFilename(expansionLoc);
+    std::string sourceLocation = std::string(name.substr(strlen(SRCDIR)+1)) + ":" + std::to_string(compiler.getSourceManager().getSpellingLineNumber(expansionLoc));
+    normalizeDotDotInFilePath(sourceLocation);
+    return sourceLocation;
+}
+
+bool InlineableMethods::VisitFunctionDecl( const FunctionDecl* functionDecl )
+{
+    const FunctionDecl* canonicalFunctionDecl = functionDecl->getCanonicalDecl();
+    if (!isCalleeFunctionInteresting(canonicalFunctionDecl)) {
+        return true;
+    }
+    definitionSet.insert(niceName(canonicalFunctionDecl));
+
+    if (functionDecl->doesThisDeclarationHaveABody()) {
+        bool bLargeFunction = false;
+        if (const CompoundStmt* compoundStmt = dyn_cast<CompoundStmt>(functionDecl->getBody())) {
+            if (compoundStmt->size() > 1) {
+                bLargeFunction = true;
+            }
+            if (!bLargeFunction) {
+                 auto s1 = compiler.getSourceManager().getCharacterData(compoundStmt->getLBracLoc());
+                 auto s2 = compiler.getSourceManager().getCharacterData(compoundStmt->getRBracLoc());
+                 bLargeFunction = (s2 - s1) > 40;
+                 // any function that uses a parameter more than once
+                 if (!bLargeFunction) {
+                     StringRef bodyText(s1, s2-s1);
+                     for (const ParmVarDecl* param : compat::parameters(*functionDecl)) {
+                         StringRef name = param->getName();
+                         if (name.empty())
+                             continue;
+                         size_t idx = bodyText.find(name);
+                         if (idx != StringRef::npos && bodyText.find(name, idx+1) != StringRef::npos) {
+                             bLargeFunction = true;
+                             break;
+                         }
+                     }
+                 }
+            }
+        }
+        if (bLargeFunction) {
+            largeFunctionSet.insert(niceName(canonicalFunctionDecl));
+        }
+    }
+    return true;
+}
+
+bool InlineableMethods::TraverseFunctionDecl( FunctionDecl* p )
+{
+    mpTraversingFunction = p;
+    bool ret = RecursiveASTVisitor::TraverseFunctionDecl(p);
+    mpTraversingFunction = nullptr;
+    return ret;
+}
+bool InlineableMethods::TraverseCXXMethodDecl( CXXMethodDecl* p )
+{
+    mpTraversingFunction = p;
+    bool ret = RecursiveASTVisitor::TraverseCXXMethodDecl(p);
+    mpTraversingFunction = nullptr;
+    return ret;
+}
+bool InlineableMethods::TraverseCXXConstructorDecl( CXXConstructorDecl* p )
+{
+    mpTraversingFunction = p;
+    bool ret = RecursiveASTVisitor::TraverseCXXConstructorDecl(p);
+    mpTraversingFunction = nullptr;
+    return ret;
+}
+bool InlineableMethods::TraverseCXXConversionDecl( CXXConversionDecl* p )
+{
+    mpTraversingFunction = p;
+    bool ret = RecursiveASTVisitor::TraverseCXXConversionDecl(p);
+    mpTraversingFunction = nullptr;
+    return ret;
+}
+bool InlineableMethods::TraverseCXXDestructorDecl( CXXDestructorDecl* p )
+{
+    mpTraversingFunction = p;
+    bool ret = RecursiveASTVisitor::TraverseCXXDestructorDecl(p);
+    mpTraversingFunction = nullptr;
+    return ret;
+}
+
+bool InlineableMethods::VisitMemberExpr( const MemberExpr* memberExpr )
+{
+    const FunctionDecl* functionDecl = dyn_cast<FunctionDecl>(memberExpr->getMemberDecl());
+    if (functionDecl) {
+        functionTouchedFromExpr(functionDecl, memberExpr);
+    }
+    return true;
+}
+
+bool InlineableMethods::VisitDeclRefExpr( const DeclRefExpr* declRefExpr )
+{
+    const FunctionDecl* functionDecl = dyn_cast<FunctionDecl>(declRefExpr->getDecl());
+    if (functionDecl) {
+        functionTouchedFromExpr(functionDecl, declRefExpr);
+    }
+    return true;
+}
+
+void InlineableMethods::functionTouchedFromExpr( const FunctionDecl* calleeFunctionDecl, const Expr* expr )
+{
+    if (!mpTraversingFunction) {
+        return;
+    }
+    const FunctionDecl* canonicalFunctionDecl = calleeFunctionDecl->getCanonicalDecl();
+    if (!isCalleeFunctionInteresting(canonicalFunctionDecl)) {
+        return;
+    }
+
+    logCalledFrom(expr->getLocStart(), canonicalFunctionDecl);
+
+    if (const UnaryOperator* unaryOp = dyn_cast_or_null<UnaryOperator>(parentStmt(expr))) {
+        if (unaryOp->getOpcode() == UO_AddrOf) {
+            addressOfSet.insert(niceName(canonicalFunctionDecl));
+        }
+    }
+
+    const CXXMethodDecl* calleeMethodDecl = dyn_cast<CXXMethodDecl>(calleeFunctionDecl);
+    const CXXMethodDecl* callsiteParentMethodDecl = dyn_cast<CXXMethodDecl>(mpTraversingFunction);
+    if (!callsiteParentMethodDecl
+        || calleeMethodDecl->getParent() != callsiteParentMethodDecl->getParent())
+    {
+        calledFromOutsideSet.insert(niceName(canonicalFunctionDecl));
+    }
+}
+
+void InlineableMethods::logCalledFrom(SourceLocation calleeLoc, const FunctionDecl* functionDecl)
+{
+    functionDecl = functionDecl->getCanonicalDecl();
+    while (functionDecl->getTemplateInstantiationPattern())
+        functionDecl = functionDecl->getTemplateInstantiationPattern();
+    calledFromMap.emplace(toString(calleeLoc), niceName(functionDecl));
+}
+
+bool InlineableMethods::isCalleeFunctionInteresting(const FunctionDecl* functionDecl)
+{
+    // ignore stuff that forms part of the stable URE interface
+    if (isInUnoIncludeFile(compiler.getSourceManager().getSpellingLoc(
+                              functionDecl->getNameInfo().getLoc()))) {
+        return false;
+    }
+    if (isa<CXXDestructorDecl>(functionDecl)) {
+        return false;
+    }
+    if (functionDecl->isDeleted() || functionDecl->isDefaulted()) {
+        return false;
+    }
+    if (isa<CXXConstructorDecl>(functionDecl) && dyn_cast<CXXConstructorDecl>(functionDecl)->isCopyConstructor()) {
+        return false;
+    }
+    if (!functionDecl->getLocation().isValid() || ignoreLocation(functionDecl)) {
+        return false;
+    }
+    const CXXMethodDecl* methodDecl = dyn_cast<CXXMethodDecl>(functionDecl);
+    if (!methodDecl || methodDecl->isVirtual()) {
+        return false;
+    }
+    return true;
+}
+
+loplugin::Plugin::Registration< InlineableMethods > X("inlineablemethods", true);
+
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/compilerplugins/clang/inlineablemethods.py b/compilerplugins/clang/inlineablemethods.py
new file mode 100755
index 000000000000..a9b75472b3a9
--- /dev/null
+++ b/compilerplugins/clang/inlineablemethods.py
@@ -0,0 +1,148 @@
+#!/usr/bin/python
+
+import sys
+import re
+import io
+
+# --------------------------------------------------------------------------------------------
+# globals
+# --------------------------------------------------------------------------------------------
+
+definitionSet = set() # set of tuple(return_type, name_and_params)
+definitionToSourceLocationMap = dict()
+calledFromDict = dict()
+calledFromOutsideSet = set()
+largeFunctionSet = set() # set of tuple(return_type, name_and_params)
+addressOfSet = set() # set of tuple(return_type, name_and_params)
+
+# 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)
+
+# --------------------------------------------------------------------------------------------
+# primary input loop
+# --------------------------------------------------------------------------------------------
+
+# 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.inlineablemethods.log", "rb", buffering=1024*1024) as txt:
+    for line in txt:
+        tokens = line.strip().split("\t")
+        if tokens[0] == "definition:":
+            access = tokens[1]
+            returnType = tokens[2]
+            nameAndParams = tokens[3]
+            sourceLocation = tokens[4]
+            funcInfo = (normalizeTypeParams(returnType), normalizeTypeParams(nameAndParams))
+            definitionSet.add(funcInfo)
+            definitionToSourceLocationMap[funcInfo] = sourceLocation
+        elif tokens[0] == "calledFrom:":
+            calleeLocation = tokens[1]
+            returnType = tokens[2]
+            nameAndParams = tokens[3]
+            funcInfo = (normalizeTypeParams(returnType), normalizeTypeParams(nameAndParams))
+            if not funcInfo in calledFromDict:
+                calledFromDict[funcInfo] = set()
+            calledFromDict[funcInfo].add(calleeLocation)
+        elif tokens[0] == "outside:":
+            returnType = tokens[1]
+            nameAndParams = tokens[2]
+            calledFromOutsideSet.add((normalizeTypeParams(returnType), normalizeTypeParams(nameAndParams)))
+        elif tokens[0] == "large:":
+            returnType = tokens[1]
+            nameAndParams = tokens[2]
+            largeFunctionSet.add((normalizeTypeParams(returnType), normalizeTypeParams(nameAndParams)))
+        elif tokens[0] == "addrof:":
+            returnType = tokens[1]
+            nameAndParams = tokens[2]
+            addressOfSet.add((normalizeTypeParams(returnType), normalizeTypeParams(nameAndParams)))
+        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 it.
+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 isOtherConstness( d, callSet ):
+    method = d[0] + " " + d[1]
+    # if this method is const, and there is a non-const variant of it, and the non-const variant is in use, then leave it alone
+    if d[0].startswith("const ") and d[1].endswith(" const"):
+        if ((d[0][6:],d[1][:-6]) in callSet):
+           return True
+    elif method.endswith(" const"):
+        method2 = method[:len(method)-6] # strip off " const"
+        if ((d[0],method2) in callSet):
+           return True
+    if method.endswith(" const") and ("::iterator" in method):
+        method2 = method[:len(method)-6] # strip off " const"
+        method2 = method2.replace("::const_iterator", "::iterator")
+        if ((d[0],method2) in callSet):
+           return True
+    # if this method is non-const, and there is a const variant of it, and the const variant is in use, then leave it alone
+    if (not method.endswith(" const")) and ((d[0],"const " + method + " const") in callSet):
+           return True
+    if (not method.endswith(" const")) and ("::iterator" in method):
+        method2 = method.replace("::iterator", "::const_iterator") + " const"
+        if ((d[0],method2) in callSet):
+           return True
+    return False
+
+# 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)]
+def sort_set_by_natural_key(s):
+    return sorted(s, key=lambda v: natural_sort_key(v[1]))
+
+    
+# --------------------------------------------------------------------------------------------
+# Methods that are only called from inside their own class, and are only called from one spot
+# --------------------------------------------------------------------------------------------
+
+tmp4set = set()
+for d in definitionSet:
+    if d in calledFromOutsideSet:
+        continue
+    if isOtherConstness(d, calledFromOutsideSet):
+        continue
+    if d not in definitionToSourceLocationMap:
+        print("warning, method has no location: " + d[0] + " " + d[1])
+        continue
+    # ignore external code
+    if definitionToSourceLocationMap[d].startswith("external/"):
+       continue
+    # ignore constructors, calledFromOutsideSet does not provide accurate info for them
+    tokens = d[1].split("(")[0].split("::")
+    if len(tokens)>1 and tokens[-2] == tokens[-1]:
+        continue
+    # ignore large methods, which make the code clearer by being out of line
+    if d in largeFunctionSet:
+        continue
+    # ignore methods whose address we take
+    if d in addressOfSet:
+        continue
+    # ignore unused methods, leave them to the dedicated analysis
+    if d not in calledFromDict:
+        continue
+    # ignore methods called from more than one site
+    if len(calledFromDict[d]) > 1:
+        continue
+
+    method = d[0] + " " + d[1]
+    tmp4set.add((method, definitionToSourceLocationMap[d]))
+
+# print output, sorted by name and line number
+with open("loplugin.inlineablemethods.report", "wt") as f:
+    for t in sort_set_by_natural_key(tmp4set):
+        f.write(t[1] + "\n")
+        f.write("    " + t[0] + "\n")