2019 LLVM Developers’ Meeting: S. Haastregt & A. Stulova “An overview of Clang ”

llvm.org/devmtg/2019-10/
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An overview of Clang - Sven van Haastregt, Anastasia Stulova
Slides: Coming soon
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This tutorial will give an overview of Clang. We will cover the distinction between the Clang compiler driver and the Clang language frontend, with an emphasis on the latter. We will examine the different Clang components that a C program goes through when being compiled, i.e., lexing, parsing, semantic analysis, and LLVM IR generation. This includes some of the Clang Abstract Syntax Tree (AST), Type, and the Diagnostics infrastructure. We will conclude by explaining the various ways in which Clang is tested.
The tutorial is aimed at newcomers who have a basic understanding of compiler concepts and wish to learn about the architecture of Clang or start contributing to Clang.
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Videos Filmed & Edited by Bash Films: www.BashFilms.com

[@malharjajoo7393]

10:22 - Core components of Clang Front end
12:49 - Lexer & Preprocessor
17:33 - Parser
22:46 - Sema (Semantic Analyzer)
26:33 - Diagnostics subsystem
29:40 - AST
34:50 - Codegen
38:26 - working on Clang source
- 41:47- Testing Clang
50:21 - some useful links

[@MarcosScheeren]

This round of 101, introductions and overviews from the 2019 dev meeting it's really great. Listening from people deep into the LLVM's projects gives valuable insights on what really matters on the various LLVM pipelines.

[@aleksay2142]

Nice talk. It is great to see the separate track for the talks like this. Also, It would be great to add this information to the docs.

[@UberOcelot]

For those watching things in 2021 or later. The question about Clang modes that help with error explosion, this is more or less referring to template errors. Concepts which can be used to constrain templates in the same vein as Rust Trait-bounds, will greatly improve the readability of templates. The issue with templates lies in the stage in which they are processes and the lack of type information, in many ways templates act like a structured version of C macros. While Rust generics are processed in AST with type bound checking to reject errors early, C++ will instead generate heaps of bad code that will only be rejected at a later stage. Concepts in C++20 rectifies some of these shortcomings, and we can see that in it's better error reporting.

[@vxanica]

Nice talk~! Anastasia Stulova is a really good speaker. I learned a lot about clang.

[@gauravbhokare]

Only true dragon-borns come here !

[@vxanica]

th-cam.com/video/5kkMpJpIGYU/w-d-xo.html for the last question. Why not use parser generator to write the parser? I suppose that, for C++, it is just not possible since some parsing process needs to be decided after some little semantic check. for C++ it is not possible I think.