Do not check string size for printf()'s format string

[yzhao1012]

And create String with its original size, without truncation.

This allows having longer format string in printf() statement,
and does not affect existing functionality.

Checklist

• Language changes are updated in docs/reference_guide.md
• User-visible and non-trivial changes updated in CHANGELOG.md
• The new behaviour is covered by tests

[yzhao1012]

Not a language change.

Need help with where to add the tests.

[fbs]

Bit of a shame we cannot use is_compiel_time_func here. I've created #1539 to make that possible.

[fbs]

Thanks!

Need help with where to add the tests.

You generally want to add a test for the pass you modified. So in this case in tests/semantic_analyser.cpp you can extend TEST(semantic_analyser, printf) with a case for this. And please add a runtime test too.

Could you also run clang format and squash all the commits together?

[yzhao1012]

Thanks!

Need help with where to add the tests.

You generally want to add a test for the pass you modified. So in this case in tests/semantic_analyser.cpp you can extend TEST(semantic_analyser, printf) with a case for this. And please add a runtime test too.

Could you also run clang format and squash all the commits together?

Fixed clang-format issue.

Working on test now.

[fbs]

@yzhao1012, can I help you with the tests? This would be good to get this in :)

[yzhao1012]

@yzhao1012, can I help you with the tests? This would be good to get this in :)

It would be great if you can shoulder the task of writing tests.

I am not sure what form of collaboration is the best here. It's totally OK to me if you can just copy or rewrite this PR in a new one that you create from scratch.

Or you were thinking to give specific instructions on writing tests?

[fbs]

I was thinking simple something like this

TEST(semantic_analyser, call_printf)
{
  std::stringstream prog;

  prog << "i:ms:100 { printf(\"" << std::string("a", 200) << " %d\\n\", 1); }"
  test(prog, 0);
}

[yzhao1012]

Thanks!

Need help with where to add the tests.

You generally want to add a test for the pass you modified. So in this case in tests/semantic_analyser.cpp you can extend TEST(semantic_analyser, printf) with a case for this. And please add a runtime test too.
Could you also run clang format and squash all the commits together?

Fixed clang-format issue.

Working on test now.

How could I run semantic_analyser.cpp?

I was reading https://github.com/iovisor/bpftrace/tree/master/tests but could not find the exact instructions on how to run an individual test.

[fbs]

if you want an individual test you can do ./tests/bpftrace_test --gtest_filter="semantic_analyser.call_printf" but you can just run the whole testsuite.

[fbs]

@yzhao1012 if you don't mind I'll steal this, rebase and add the tests and then get it merged :). Its nice to have