Matcher working in clang-query, but not in LibTooling

Clang Frontend
1

Hello everyone,

Why is it that the following matcher

cxxRecordDecl(has(unless(cxxRecordDecl())))

works in clang-query, but when copied to to a .cpp file, it won’t compile the matcher:

…/lib/UsingAnalysis.cpp:46:29: error: no matching function for call to object of type ‘const internal::ArgumentAdaptingMatcherFuncinternal::HasMatcher’
auto m = cxxRecordDecl(has(unless(cxxRecordDecl())));
^~~
/usr/local/include/clang/ASTMatchers/ASTMatchersInternal.h:1183:3: note: candidate template ignored: could not match ‘Matcher’ against ‘VariadicOperatorMatcher’
operator()(const Matcher &InnerMatcher) const {

Tried on macOS 10.13 & Ubuntu 20.04 with LLVM 11.0.0.

Best,
Siegfried

2

A minimal code sample to trigger the error:

#include “clang/ASTMatchers/ASTMatchers.h”

using namespace clang::ast_matchers;

int main(int argc, char** argv){
auto m = cxxRecordDecl(has(unless(cxxRecordDecl())));
return 0;

}

Best, Siegfried

3

clang-query parsing is less strict than the c++ language, so there are probably a few of these differences.

I assume you realize that you should instead use either

unless(has())

or

has(decl(unless(cxxRecordDecl())))

depending on what you are trying to achieve?

4

Hi, thanks for your answer!
Your second matcher proposal captures the right behavior: I want to match
declarations that are of any kind but that specific one.
On the internet I read to use clang-query to prototype matchers, so I was pretty surprised
that it didn’t work when I copied it over.
Best,
Siegfried