[cfe-dev] Analysing a file with AST matcher tool takes significant more time than just compile the same file

[Han Wang]

Hi Manuel,

After using -O2 the speed is 30% faster from 10min to 7min. If I use clang
to just compile this source file, it takes 40sec.

Best regards,
Han

On Thu, Jul 16, 2015 at 11:33 AM, Manuel Klimek <klimek at google.com> wrote:

> You'll want to use Lexer::getSourceText instead of trying to write your
> own (trust me, it's hard ;), but otherwise your code looks innocent enough.
> Are you compiling with at least -O2 and NDEBUG enabled?
>
> On Thu, Jul 16, 2015 at 11:26 AM Han Wang <wanghan02 at gmail.com> wrote:
>
>> #include <stdio.h>
>> #include <string>
>> #include <vector>
>> #include <system_error>
>> #include <type_traits>
>> #include "clang/AST/AST.h"
>> #include "clang/Frontend/TextDiagnosticPrinter.h"
>> #include "clang/Tooling/CommonOptionsParser.h"
>> #include "clang/ASTMatchers/ASTMatchers.h"
>> #include "clang/ASTMatchers/ASTMatchFinder.h"
>> #include "clang/Basic/SourceManager.h"
>> #include "clang/Frontend/FrontendActions.h"
>> #include "clang/Lex/Lexer.h"
>> #include "clang/Tooling/CompilationDatabase.h"
>> #include "clang/Tooling/Refactoring.h"
>> #include "clang/Tooling/Tooling.h"
>> #include "llvm/ADT/Twine.h"
>> #include "llvm/Support/CommandLine.h"
>> #include "llvm/Support/MemoryBuffer.h"
>> #include "llvm/Support/Path.h"
>> #include "llvm/Support/Signals.h"
>> #include "llvm/Support/raw_ostream.h"
>> #include "llvm/Support/TargetSelect.h"
>>
>> using namespace llvm;
>> using clang::tooling::newFrontendActionFactory;
>> using clang::tooling::Replacement;
>> using clang::tooling::CompilationDatabase;
>> using namespace clang;
>> using namespace clang::ast_matchers;
>> using namespace clang::driver;
>> using namespace clang::tooling;
>>
>> static llvm::cl::OptionCategory ToolingSampleCategory("IsEmpty");
>>
>>
>> // Returns the text that makes up 'node' in the source.
>> // Returns an empty string if the text cannot be found.
>> template <typename T>
>> static std::string getText(const SourceManager &SourceManager, const T
>> &Node) {
>>   SourceLocation StartSpellingLocation =
>>       SourceManager.getSpellingLoc(Node.getLocStart());
>>   SourceLocation EndSpellingLocation =
>>       SourceManager.getSpellingLoc(Node.getLocEnd());
>>   if (!StartSpellingLocation.isValid() || !EndSpellingLocation.isValid())
>> {
>>     return std::string();
>>   }
>>   bool Invalid = true;
>>   const char *Text =
>>       SourceManager.getCharacterData(StartSpellingLocation, &Invalid);
>>   if (Invalid) {
>>     return std::string();
>>   }
>>   std::pair<FileID, unsigned> Start =
>>       SourceManager.getDecomposedLoc(StartSpellingLocation);
>>   std::pair<FileID, unsigned> End =
>>       SourceManager.getDecomposedLoc(Lexer::getLocForEndOfToken(
>>           EndSpellingLocation, 0, SourceManager, LangOptions()));
>>   if (Start.first != End.first) {
>>     // Start and end are in different files.
>>     return std::string();
>>   }
>>   if (End.second < Start.second) {
>>     // Shuffling text with macros may cause this.
>>     return std::string();
>>   }
>>   return std::string(Text, End.second - Start.second);
>> }
>>
>> class ColIsEmptyHandler: public MatchFinder::MatchCallback {
>> public:
>>   ColIsEmptyHandler(Replacements *Replace): Replace(Replace) {};
>>   virtual void run(const MatchFinder::MatchResult &Result) {
>>     if (const CXXMemberCallExpr *callExpr =
>> Result.Nodes.getNodeAs<clang::CXXMemberCallExpr>("Col::IsEmptyExpr")) {
>>       const std::string text = getText(*(Result.SourceManager),
>> *callExpr);
>>       Replacement Rep(*(Result.SourceManager),
>> CharSourceRange::getTokenRange(SourceRange(callExpr->getCallee()->getExprLoc())),
>> "IsEmpty");
>>       Replace->insert(Rep);
>>     }
>>   }
>> private:
>>   Replacements *Replace;
>> };
>>
>> class ColIsEmptyInClassHandler: public MatchFinder::MatchCallback {
>> public:
>>   ColIsEmptyInClassHandler(Replacements *Replace): Replace(Replace) {};
>>   virtual void run(const MatchFinder::MatchResult &Result) {
>>     if (const CXXMethodDecl *decl =
>> Result.Nodes.getNodeAs<clang::CXXMethodDecl>("Col::IsEmptyInClass")) {
>>       const std::string text = getText(*(Result.SourceManager), *decl);
>>       Replacement Rep(*(Result.SourceManager),
>> CharSourceRange::getTokenRange(SourceRange(decl->getNameInfo().getLoc())),
>> "IsEmpty");
>>       Replace->insert(Rep);
>>     }
>>   }
>> private:
>>   Replacements *Replace;
>> };
>>
>> int main(int argc, const char **argv) {
>>   llvm::InitializeAllTargets();
>>   llvm::InitializeAllTargetMCs();
>>   llvm::InitializeAllAsmPrinters();
>>   llvm::InitializeAllAsmParsers();
>>   CommonOptionsParser op(argc, argv, ToolingSampleCategory);
>>   RefactoringTool Tool(op.getCompilations(), op.getSourcePathList());
>>   // Set up AST matcher callbacks.
>>   ColIsEmptyHandler HandlerForColIsEmpty(&Tool.getReplacements());
>>   ColIsEmptyInClassHandler
>> HandlerForColIsEmptyInClass(&Tool.getReplacements());
>>   MatchFinder Finder;
>>   Finder.addMatcher(memberCallExpr(hasDeclaration(methodDecl(
>>   hasName("Empty"),
>> ofClass(isSameOrDerivedFrom(hasName("Col")))))).bind("Col::IsEmptyExpr"),
>> &HandlerForColIsEmpty);
>>   Finder.addMatcher(methodDecl(hasName("Empty"),
>> ofClass(isSameOrDerivedFrom(hasName("Col")))).bind("Col::IsEmptyInClass"),
>> &HandlerForColIsEmptyInClass);
>>   // Run the tool and collect a list of replacements.
>>   if (int Result =
>> Tool.runAndSave(newFrontendActionFactory(&Finder).get())) {
>>     return Result;
>>   }
>>   llvm::outs() << "Replacements collected by the tool:\n";
>>   for (auto &r : Tool.getReplacements()) {
>>     llvm::outs() << r.toString() << "\n";
>>   }
>>   return 0;
>> }
>>
>> On Thu, Jul 16, 2015 at 11:11 AM, Manuel Klimek <klimek at google.com>
>> wrote:
>>
>>> Can you post the code for the matcher?
>>>
>>> On Thu, Jul 16, 2015 at 11:02 AM Han Wang <wanghan02 at gmail.com> wrote:
>>>
>>>> Hi,
>>>>
>>>> I'm using clang AST matcher tool on MAC to analyse complex files with
>>>> many many headers included. It turns out that it takes more than 10 times
>>>> longer than just compile the same file with clang. Is it normal or am I
>>>> doing something wrong? Thanks!
>>>>
>>>> Best regards,
>>>> Han
>>>> _______________________________________________
>>>> cfe-dev mailing list
>>>> cfe-dev at cs.uiuc.edu
>>>> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev
>>>>
>>>
>>
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