Is there an elegant way to traverse Clang AST Statements? - c++

Question

I am trying to traverse all function definitions and extract information from them. I have to iterate over all statements in the function body, and depending on the type, execute a specific function.
For the moment I have an ugly if-else block. Is there a more elegant way to do this?
void FunctionMatcher::processStatement(const clang::Stmt *statement) {
string type = statement->getStmtClassName();
if (type == "ReturnStmt") {
auto rs = dyn_cast<const ReturnStmt *>(statement);
processReturnStmt(rs);
} else if (type == "WhileStmt") {
auto ws = dyn_cast<WhileStmt>(statement);
processWhileStmt(ws);
} else if (type == "ForStmt") {
auto fs = dyn_cast<const ForStmt *>(statement);
processForStmt(fs);
} else if (type == "IfStmt") {
auto is = dyn_cast<const IfStmt *>(statement);
processIfStmt(is);
} else if (type == "SwitchStmt") {
auto ss = dyn_cast<const SwitchStmt *>(statement);
processSwitchStmt(ss);
} else if (type == "CompoundStmt") {
auto cs = dyn_cast<const CompoundStmt *>(statement);
for (auto child : cs->children())
processStatement(child);
} else {
// ...
}

Answer 1

By navigating through the code of clang::TextNodeDumper, I found a solution.
Apparently Clang has its own visitors for statements, declarations etc...
Simple example:
class StatementVisitor : public ConstStmtVisitor<StatementVisitor> {
public:
StatementVisitor();
void Visit(const Stmt *Node) {
ConstStmtVisitor<StatementVisitor>::Visit(Node);
}
void VisitIfStmt(const IfStmt *Node) {
llvm::outs() << " An if statement yay!\n";
}
void VisitWhileStmt(const WhileStmt *Node) {
llvm::outs() << " A While statement yay!\n";
}
};

Answer 2

you can use RecursiveASTVisitor
its traverse all statement in given code, recursively
class MyASTVisitor : public RecursiveASTVisitor<MyASTVisitor>
{
public:
bool VisitFunctionDecl(FunctionDecl* f)
{
...
}
bool VisitIfStmt(IfStmt* IF)
{
...
}
bool VisitForStmt(ForStmt* FS)
{
...
}
bool VisitWhileStmt(WhileStmt* WS)
{
...
}
}