Improve support for catch2

[federico]

Hello, I want to report a bug.

cppcheck currently has issue parsing the macros of the catch2 project, a test suite for c++

A minimal example for reproducing the issue looks like following

main.cpp

#define CATCH_CONFIG_MAIN
#include "catch_amalgamated.hpp"
int factorial( int number ) {
    return number <= 1 ? number : factorial(number-1) * number;     
}
TEST_CASE( "Factorials are computed" ) {
        REQUIRE_THROWS_AS(factorial(1), int);
}

then download catch_amalgamated.cpp and catch_amalgamated.hpp from the catch project (https://github.com/catchorg/Catch2) in the same directory (issue is also reproducible with the non-amalgamated library

the project can be compiled and executed with "g++ main.cpp catch_amalgamated.cpp && ./a.out"

compile_command.json

[
{
  "directory": "/home/debianuser/cppcheck-test",
  "command": "g++ main.cpp catch_amalgamated.cpp",
  "file": "main.cpp",
  "output": "a.out"
}
]

"cppcheck main.cpp" reports as error

main.cpp:11:3: error: There is an unknown macro here somewhere. Configuration is required. If _catch_sr is a macro then please configure it. [unknownMacro]
  REQUIRE_THROWS_AS(factorial(1), int);

and the issue persists when using a compile_command.json project file

[
{
  "directory": "<path to current directory>",
  "command": "g++ main.cpp catch_amalgamated.cpp",
  "file": "main.cpp",
  "output": "a.out"
}
]

Note that _catch_sr is not a macro, but is concatenated to a macro, for example

#define CATCH_REQUIRE_THROWS_AS( expr, exceptionType ) INTERNAL_CATCH_THROWS_AS( "CATCH_REQUIRE_THROWS_AS", exceptionType, Catch::ResultDisposition::Normal, expr )


#define INTERNAL_CATCH_THROWS_AS( macroName, exceptionType, resultDisposition, expr ) \
    do { \
        Catch::AssertionHandler catchAssertionHandler( macroName##_catch_sr, CATCH_INTERNAL_LINEINFO, CATCH_INTERNAL_STRINGIFY(expr) ", " CATCH_INTERNAL_STRINGIFY(exceptionType), resultDisposition ); \
        if( catchAssertionHandler.allowThrows() ) \

[CHR]

It's probably best to create a library configuration for Catch2 (similar to e.g. googletest.cfg that we already have) and not make headers like catch_amalgamated.hppvisible to cppcheck.

[federico]

It would be better if cppcheck is able to handle such construct too, but having a short-term solution is fine too, as it makes possible to use cppcheck on the test suite too

catch headers should all match the pattern "catch_.*\.hpp"