Clang LibTooling - How to use DependencyCollector - c++

Question

I'm trying to use the DependencyCollector class of Clang in my Tool to list all the dependencies in a file, lets say test.cpp
Here is my program:
#include "stdafx.h"
#include <iostream>
#include "clang/Frontend/FrontendActions.h"
#include "clang/Tooling/CommonOptionsParser.h"
#include "clang/Tooling/Tooling.h"
#include "llvm/Support/CommandLine.h"
#include "clang/Lex/PPCallbacks.h"
#include "clang/Frontend/CompilerInstance.h"
#include "clang/Frontend/Utils.h"
using namespace std;
using namespace clang::tooling;
using namespace clang;
using namespace llvm;
static cl::OptionCategory MyToolCategory("my-tool options");
static cl::extrahelp CommonHelp(CommonOptionsParser::HelpMessage);
static cl::extrahelp MoreHelp("\nMore help text...");
class myDependencyCollector : public DependencyCollector {
private:
public:
bool sawDependency(StringRef Filename, bool FromModule, bool IsSystem, bool IsModuleFile, bool IsMissing) {
if (Filename == "stdafx.h" || IsSystem) {
return false;
} else {
return true;
}
}
bool needSystemDependencies() {
return false;
}
};
class DependencyAction : public PreprocessOnlyAction {
private:
myDependencyCollector *col;
public:
virtual bool usesPreprocessOnly() const {
return true;
}
bool BeginSourceFileAction(CompilerInstance &ci) {
Preprocessor &pp = ci.getPreprocessor();
col = new myDependencyCollector();
col->attachToPreprocessor(pp);
return true;
}
void ExecuteAction() {
}
virtual void EndSourceFileAction() {
llvm::ArrayRef<string> arr = col->getDependencies();
int size = arr.size();
for (int i = 0; i < size; i = i+1) {
cout << arr[i] << endl;
}
}
};
int main(int argc, const char **argv)
{
CommonOptionsParser OptionsParser(argc, argv, MyToolCategory);
ClangTool Tool(OptionsParser.getCompilations(), OptionsParser.getSourcePathList());
int result = Tool.run(newFrontendActionFactory<DependencyAction>().get());
return result;
}
Now, if I run the program on, for example the file test.cpp:
#include <iostream>
#include "test.h"
void do_math(int *x) {
*x += 5;
}
int main(void) {
int result = -1, val = 4;
do_math(&val);
return result;
}
The program doesn't find any includes.
It would be great if anybody could help me because I have not been able to find an answer after hours of searching on the internet.

Answer 1

The problem is that you overwrite the ExecuteAction() method from class PreprocessOnlyAction with an empty body.
If you delete the line:
void ExecuteAction() {}
everything works as expected.