Cannot build TypeScript: "gulp local" hangs

[kpreisser]

Hi,
since yesterday, I seem to not be able to build TypeScript on a Windows machine because "gulp local" hangs after printing "Requiring external module ts-node/register".

I just run the following steps on a clean Windows 10 x64 Version 1511 machine:

1. Install Git for Windows 2.9.2 (x64), TortoiseGit 2.2.0.0 (x64), Node.js v4.4.7 LTS (x64).
2. Clone https://github.com/Microsoft/TypeScript.git.
3. In the TypeScript directory, run npm install -g gulp and npm install as written in the readme.
4. In the TypeScript directory, run gulp local.

However, the console window now looks like this since 10 mins, and there is no harddisk or network activity (however there is 100% usage for 1 CPU core):

Any idea what could be causing this?
Thanks!

[Artazor]

Exactly the same!

[Artazor]

Even gulp clean hangs with the same symptoms

[Artazor]

Looks that it is not a Windows specific problem - I'm on OSX 10.11.5

[Artazor]

Something strange happens, when loading tsconfig (which is absent for the TypeScript project itself, ts-node scans all the files in TypeScript/tests/baselines/reference/project and does it extremely slow. Investigating further.

[Artazor]

getFileMatcherPatterns produces extremely inefficient RegEx for includeFilePattern.
It hangs (actually takes very long time) on long file names.
the culprit:

/^((\/Users\/Artazor\/repo\/TypeScript(\/[^\/.][^\/]*)*?\/([^.\/]([^.\/]*(\.(?!min\.js$))?)*)?))$/.test(
"/Users/Artazor/repo/TypeScript/tests/baselines/reference/project/declarationsImportedUseInFunction/amd/useModule.d.ts")

Will investigate further and probably make a PR with fix

UPD updated the culprit regexp

[mhegazy]

@weswigham can u take a look

[Artazor]

/^(((\/[^\/.][^\/]*)*?\/([^.\/]([^.\/]*(\.(?!min\.js$))?)*)?))$/ - has a catastrophic backtracking

[Artazor]

The problematic regexp is built right here: https://github.com/Microsoft/TypeScript/blob/8b2ea398ffc54f96018e40091d1827cb81d5ee39/src/compiler/core.ts#L944

[Artazor]

The problem was introduced (I suspect) by the commit 8325565

[Artazor]

the problem is not caught by tests because fileName values used in tests are too short. performance problems start to be observable starting from 130 characters (on my machine) and quickly grow with the length.