Rename LocalInternedString and more

[nnethercote]

This PR renames LocalInternedString as SymbolStr, removes an unnecessary impl from it, improves comments, and cleans up some SymbolStr uses.

r? @estebank

[eddyb]

I mentioned elsewhere my suggestion of SymbolContents (another one could be SymbolData), and I feel like SymbolStr isn't clear enough of a name.
But it's really just a bikeshed, and not that important.

[Centril]

Should these be sym::s?

[eddyb]

We can probably replace most string literals with valid literals in them, in the compiler, with sym::s.

I'd try this if I was in front of my laptop:

rg '"[_a-zA-Z][_a-zA-Z0-9]*"' src/lib*

[nnethercote]

rust_eh_personality already is a symbol. We could add the other two. For all potential static symbols there is a decision about whether the identifier is hot enough or frequently used enough for it to be worthwhile, and that decision is not always clear-cut.

"Intern all the static strings" is a possibility, but it would add a lot more due to functions like this one:

rust/src/librustdoc/clean/cfg.rs

Lines 337 to 402 in 10a52c2

	let n = &*name.as_str();
	let human_readable = match(n, value){
	("unix",None) => "Unix",
	("windows",None) => "Windows",
	("debug_assertions",None) => "debug-assertions enabled",
	("target_os",Some(os)) => match&*os.as_str(){
	"android" => "Android",
	"dragonfly" => "DragonFly BSD",
	"emscripten" => "Emscripten",
	"freebsd" => "FreeBSD",
	"fuchsia" => "Fuchsia",
	"haiku" => "Haiku",
	"ios" => "iOS",
	"l4re" => "L4Re",
	"linux" => "Linux",
	"macos" => "macOS",
	"netbsd" => "NetBSD",
	"openbsd" => "OpenBSD",
	"redox" => "Redox",
	"solaris" => "Solaris",
	"windows" => "Windows",
	_ => "",
	},
	("target_arch",Some(arch)) => match&*arch.as_str(){
	"aarch64" => "AArch64",
	"arm" => "ARM",
	"asmjs" => "JavaScript",
	"mips" => "MIPS",
	"mips64" => "MIPS-64",
	"msp430" => "MSP430",
	"powerpc" => "PowerPC",
	"powerpc64" => "PowerPC-64",
	"s390x" => "s390x",
	"sparc64" => "SPARC64",
	"wasm32" => "WebAssembly",
	"x86" => "x86",
	"x86_64" => "x86-64",
	_ => "",
	},
	("target_vendor",Some(vendor)) => match&*vendor.as_str(){
	"apple" => "Apple",
	"pc" => "PC",
	"rumprun" => "Rumprun",
	"sun" => "Sun",
	"fortanix" => "Fortanix",
	_ => ""
	},
	("target_env",Some(env)) => match&*env.as_str(){
	"gnu" => "GNU",
	"msvc" => "MSVC",
	"musl" => "musl",
	"newlib" => "Newlib",
	"uclibc" => "uClibc",
	"sgx" => "SGX",
	_ => "",
	},
	("target_endian",Some(endian)) => returnwrite!(fmt,"{}-endian", endian),
	("target_pointer_width",Some(bits)) => returnwrite!(fmt,"{}-bit", bits),
	("target_feature",Some(feat)) =>
	ifself.1{
	returnwrite!(fmt,"<code>{}</code>", feat);
	}else{
	returnwrite!(fmt,"target feature <code>{}</code>", feat);
	},
	_ => "",
	};

[nnethercote]

(I should add: I have already converted all the static identifiers that I though were worth converting. Other people may reasonably think that more should be converted.)

[eddyb]

cc @Manishearth could elsa have a FrozenIndexSet that is also thread-safe without a lock?
In this case, just a SyncFrozenVec might be enough.

[nnethercote]

What's the status here? It's not clear to me if @eddyb or @Centril is the reviewer. There are some comments but none of them seem like show-stoppers.

[Centril]

Can I please not be the reviewer? =D

It appears @estebank is. :)

[nnethercote]

Indeed, I mixed up GitHub's "assignees" and "reviewers" fields. @estebank is the reviewer.

[estebank]

@bors r+ rollup=never

[bors]

📌 Commit 7a466f070585c2f399b3980e1fe6b7e0c721c989 has been approved by estebank

[bors]

☔ The latest upstream changes (presumably #65718) made this pull request unmergeable. Please resolve the merge conflicts.

[nnethercote]

I rebased.

@bors r=estebank

[bors]

📌 Commit d0db290 has been approved by estebank

[bors]

⌛ Testing commit d0db290 with merge 0afc234c654c32d457d73f5c454b89455918dfaa...

[rust-highfive]

The job x86_64-gnu-tools of your PR failed (pretty log, raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

2019-11-03T07:10:04.2092474Z Caused By: "https://rust-lang.github.io/chalk/doc/chalk_parse/index.html" returned 404 Not Found
2019-11-03T07:10:04.2092993Z Caused By: "https://rust-lang.github.io/chalk/doc/chalk/index.html" returned 404 Not Found
2019-11-03T07:10:04.2093349Z Caused By: "https://rust-lang.github.io/chalk/doc/chalki/index.html" returned 404 Not Found
2019-11-03T07:10:04.2093753Z Caused By: "https://doc.rust-lang.org/nightly/nightly-rustc/syntax/parse/struct.ParseSess.html" returned 404 Not Found
2019-11-03T07:10:04.2093937Z Caused By: There was an error while fetching "http://www.cs.rice.edu/%7Eyguo/pubs/PID824943.pdf", http://www.cs.rice.edu/%7Eyguo/pubs/PID824943.pdf: timed out
2019-11-03T07:10:04.2094114Z 2019-11-03T07:10:04.2097005Z command did not execute successfully: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-tools-bin/rustbook" "linkcheck" "/checkout/src/doc/rustc-guide"
2019-11-03T07:10:04.2098340Z expected success, got: exit code: 101
2019-11-03T07:10:04.2098741Z ---
2019-11-03T07:16:38.3107307Z 2019-11-03T07:16:43.1579761Z error[E0277]: the trait bound `syntax_pos::symbol::SymbolStr: std::convert::AsRef<std::ffi::OsStr>` is not satisfied
2019-11-03T07:16:43.1581114Z --> src/tools/clippy/clippy_lints/src/path_buf_push_overwrite.rs:53:44
2019-11-03T07:16:43.1581796Z |
2019-11-03T07:16:43.1582827Z 53 | if let pushed_path = Path::new(&path_lit.as_str());
2019-11-03T07:16:43.1583837Z | ^^^^^^^^^^^^^^^^^^ the trait `std::convert::AsRef<std::ffi::OsStr>` is not implemented for `syntax_pos::symbol::SymbolStr`
2019-11-03T07:16:43.1585151Z ::: /checkout/src/libstd/path.rs:1814:19
2019-11-03T07:16:43.1585719Z |
2019-11-03T07:16:43.1585719Z |
2019-11-03T07:16:43.1586396Z 1814 | pub fn new<S: AsRef<OsStr> + ?Sized>(s: &S) -> &Path {
2019-11-03T07:16:43.1587769Z 2019-11-03T07:16:44.0585621Z error: aborting due to 5 previous errors
2019-11-03T07:16:44.0585803Z 2019-11-03T07:16:44.0592176Z Some errors have detailed explanations: E0277, E0432.
---
2019-11-03T07:55:01.6353394Z local time: Sun Nov 3 07:55:01 UTC 2019
2019-11-03T07:55:01.9051349Z network time: Sun, 03 Nov 2019 07:55:01 GMT
2019-11-03T07:55:01.9055246Z == end clock drift check ==
2019-11-03T07:55:02.9035817Z 2019-11-03T07:55:02.9162598Z ##[error]Bash exited with code '1'.
2019-11-03T07:55:02.9203954Z ##[section]Starting: Checkout
2019-11-03T07:55:02.9206104Z ==============================================================================
2019-11-03T07:55:02.9206207Z Task : Get sources
2019-11-03T07:55:02.9206319Z Description : Get sources from a repository. Supports Git, TfsVC, and SVN repositories.

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @TimNN. (Feature Requests)

[bors]

💔 Test failed - checks-azure

[nnethercote]

No Tools Breakage Week is over, or close enough that by the time this gets through the queue it will be.

@bors r=estebank

[bors]

💡 This pull request was already approved, no need to approve it again.

• This pull request previously failed. You should add more commits to fix the bug, or use retry to trigger a build again.
• There's another pull request that is currently being tested, blocking this pull request: Rollup of 8 pull requests #66121

[bors]

📌 Commit d0db290 has been approved by estebank

[Centril]

@bors rollup=maybe

[bors]

⌛ Testing commit d0db290 with merge e8b190a...