[analyzer][docs][NFC] Document the ento namespace in the llvm/Lexicon

[steakhal]

Summary

Document the ento namespace in the Lexicon according to @nicolas17 on the mailing list.

---

The analyzer lived at different namespaces at different times.
Originally lived at the GR aka. (Graph Reachability) namespace [7], later it moved under the ento namespace [9].

The Static Analyzer's code lived at many other places as well:
Analysis -[2]-> Checker -[5]-> GR -[10]> entoSA -[11]-> StaticAnalyzer

The relevant code motion, refactor commits, cfe-dev mailing in chronological order:

1. 2008-03-15 Make a major restructuring of the clang tree: introduce a top-level
2. 2010-01-25 Split libAnalysis into two libraries: libAnalysis and libChecker
3. 2010-12-21 Reorganization of Checker files
4. 2010-12-22 Refactoring: include/clang/Checker -> include/clang/GR
5. 2010-12-22 Refactoring: lib/Checker -> lib/GR
6. 2010-12-22 Refactoring: Move checkers into lib/GR/Checkers and their own library, libclangGRCheckers
7. 2010-12-22 Refactoring: Move stuff into namespace 'GR'
8. 2010-12-22 Refactoring: Drop the 'GR' prefix.
9. 2010-12-23 Rename static analyzer namespace 'GR' to 'ento'
10. 2010-12-23 Rename headers: 'clang/GR' 'clang/EntoSA' and update Makefile
11. 2010-12-23 Chris Lattner has strong opinions about directory
12. 2010-12-24 Remove the EntoSA directories.

[martong]

LG!

[Szelethus]

What a legacy.

[xazax.hun]

LGTM with a nit.

llvm/docs/Lexicon.rst

99

I'd link the homepage of the static analyzer.

[steakhal]

Add link to the static analyzer llvm page.

llvm/docs/Lexicon.rst

99

Good idea.
However, I would link to the https://clang.llvm.org/docs/ClangStaticAnalyzer.html instead.
There is already a link to the Official Tool Page.

[rnkovacs]

llvm/docs/Lexicon.rst

101

I think it is the other way around, i.e. 'entomology' is abbreviated to 'ento'. You could write that 'it is an abbreviation of entomology'.

[whisperity]

llvm/docs/Lexicon.rst

99

100

This lexicon is for the entirety of LLVM, not just Clang, so maybe we should write "Clang Static Analyser" proper.

101

Why is the mobile version (m.wikipedia) linked? Also, you can Wikipedia shortlink in the following format. The shortlink will automatically properly redirect the user to the proper site based on their device configuration, but if a desktop user opens m.wikipedia there isn't any "reverse redirect" for the proper desktop site...

I've also incorporated @rnkovacs's suggestion.

[steakhal]

• Rephrase paragraph
• Use desktop site wikipedia link

Thank you all for the valuable comments. Awesome.

[ASDenysPetrov]

LGTM!

llvm/docs/Lexicon.rst

103

It's good idea to spell out this abbreviation. One thing I'd add is why exactly Entomology.
Use this http://clang-developers.42468.n3.nabble.com/analyzer-Spell-out-ENTO-in-clang-ento-td4068268.html

[steakhal]

llvm/docs/Lexicon.rst

103

In fact, that mailing thread inspired this patch.
What do you think I should elaborate on?

[whisperity]

llvm/docs/Lexicon.rst

103

Use this http://clang-developers.42468.n3.nabble.com/analyzer-Spell-out-ENTO-in-clang-ento-td4068268.html

That site is so damn horrendous especially with the bug they seem to have of not showing the author of the mails proper, but repeating the same name... I'd rather then link the official mailing list page: https://lists.llvm.org/pipermail/cfe-dev/2020-May/065569.html

But also not link anything, maybe mention the joke on this page.

[whisperity]

llvm/docs/Lexicon.rst

103

Because it finds bugs. 😂 (Or at least wants to.) I think that's the joke and that's the reason.

[steakhal]

• Mentioned the previous namespaces as well (GR, entoGR)
• Slightly rephrased previous sentences
• Updated the summary, to give a deeper dive into the history of the Clang Static Analyzer - for git blame

[whisperity]

One minor "typo", otherwise I think we are saying everything that could be and needs to be said. Also, @steakhal, that must have been one massive blame.

llvm/docs/Lexicon.rst

100

Eh, it seems people are too fond of AmE, and the name is written in BrE, but the URL is in AmE. I think the official name of the tool is also the AmE spelling.

[steakhal]

• Fixed typo in the link Clang Static Analyser -> Clang Static Analyzer

---

In D86446#2259072, @whisperity wrote:

One minor "typo", otherwise I think we are saying everything that could be and needs to be said. Also, @steakhal, that must have been one massive blame.

Thank you for the note.
It took me some time to decipher the AmE and BrE xD. Nice catch though.

llvm/docs/Lexicon.rst

**Derived Pointer**
     any `safe point`_. This term is used in opposition to `object pointer`_.
 
 **DSA**
     Data Structure Analysis
 
 **DSE**
     Dead Store Elimination
 
+E
+-
+
+**ento**
+    This namespace houses the
+    `Clang Static Analyzer <https://clang.llvm.org/docs/ClangStaticAnalyzer.html>`_.
+    It is an abbreviaton of `entomology <https://en.wikipedia.org/wiki/Entomology>`_.
+
+      *"Entomology is the scientific study of insects."*
+
+    In the past, this namespace had not only the name `GR` (aka. Graph Reachability)
+    but also `entoSA`.
+
 F
 -
 
 **FCA**
     First Class Aggregate
 
 **FDE**
     Frame Description Entry. A kind of CFI used to describe the stack frame of