Artifact normalization

1. A computer-implemented method comprising:

receiving a request to perform an analysis of a collection of source code files, wherein each source code file in the collection of source code files has a respective associated original file path;

determining that a first original file path of a first source code file of the collection of source code files includes a plurality of symbolic links;

generating a resolved file path for the first original file path of the first source code file, including evaluating each symbolic link of the plurality of symbolic links in the first original file path according to one or more resolution criteria, wherein the one or more resolution criteria specify when to resolve a symbolic link in an original file path, including:

determining whether the symbolic link in the first original file path satisfies the one or more resolution criteria,

whenever the symbolic link in the first original file path satisfies any of the one or more resolution criteria, resolving the symbolic link and updating a resolved file path for the first source code file with a resolved path component corresponding to the symbolic link, and

whenever the symbolic link in the first original file path does not satisfy any of the one or more resolution criteria, leaving the symbolic link in the resolved file path for the first source code file,

wherein the resolved file path for the first original file path includes resolved path components for one or more but fewer than all of the plurality of symbolic links in the first original file path;

applying a file path transformation function to the resolved file path for the first source code file to generate a normalized file path for the first source code file; and

generating one or more normalized analysis artifacts for the first source code file, wherein each reference, in the one or more normalized analysis artifacts, to the first source code file, uses the normalized file path for the first source code file instead of the original file path for the first source code file.

2. The method of claim 1 , wherein after evaluating each symbolic link of the plurality of symbolic links in the first original file path, the resolved file path for the first source code file includes at least one of the plurality of symbolic links.

3. The method of claim 1 , wherein evaluating each symbolic link of the plurality of symbolic links in the first original file path comprises evaluating the symbolic links in order from a filename component of the original file path to each parent component of the filename component of the original file path.

4. The method of claim 1 , wherein determining whether the symbolic link satisfies the one or more resolution criteria comprises determining that one or more of the resolution criteria are satisfied because a particular symbolic link of the first original file path does not identify a file having a computer-generated name in a content-addressable file system.

5. The method of claim 1 , wherein determining whether the symbolic link satisfies the one or more resolution criteria comprises determining that one or more of the resolution criteria are satisfied because a particular symbolic link of the first original file path is a symbolic link to a directory and not to a file.

6. The method of claim 1 , wherein determining whether the symbolic link satisfies the one or more resolution criteria comprises determining that one or more of the resolution criteria are satisfied because the symbolic link is a link to a location within a user-specified directory tree.

7. The method of claim 1 , wherein determining whether the symbolic link satisfies the one or more resolution criteria comprises determining that one or more of the resolution criteria are satisfied because a particular symbolic link of the first original file path identifies a file path that matches a portion of a checkout root directory.

8. The method of claim 1 , further comprising computing, from the one or more normalized analysis artifacts, respective values of one or more source code attributes for one or more of the source code files in response to the request.

9. The method of claim 8 , wherein at least two source code files, in the collection of source code files, that have different respective original parent directories according to respective original file paths of the two source code files have a same normalized parent directory according to respective normalized file paths of the two source code files.

10. The method of claim 9 , wherein the two source code files have different original file paths and a same normalized file path, and

wherein computing, from the one or more normalized analysis artifacts, respective values of one or more source code attributes for one or more of the source code files comprises computing a single respective value of each source code attribute for the normalized file path of the two source code files.

11. A system comprising:

one or more computers and one or more storage devices storing instructions that are operable, when executed by the one or more computers, to cause the one or more computers to perform operations comprising:

receiving a request to perform an analysis of a collection of source code files, wherein each source code file in the collection of source code files has a respective associated original file path;

determining that a first original file path of a first source code file of the collection of source code files includes a plurality of symbolic links;

generating a resolved file path for the first original file path of the first source code file, including evaluating each symbolic link of the plurality of symbolic links in the first original file path according to one or more resolution criteria, wherein the one or more resolution criteria specify when to resolve a symbolic link in an original file path, including:

determining whether the symbolic link in the first original file path satisfies the one or more resolution criteria,

whenever the symbolic link in the first original file path satisfies any of the one or more resolution criteria, resolving the symbolic link and updating a resolved file path for the first source code file with a resolved path component corresponding to the symbolic link, and

whenever the symbolic link in the first original file path does not satisfy any of the one or more resolution criteria, leaving the symbolic link in the resolved file path for the first source code file,

wherein the resolved file path for the first original file path includes resolved path components for one or more but fewer than all of the plurality of symbolic links in the first original file path;

applying a file path transformation function to the resolved file path for the first source code file to generate a normalized file path for the first source code file; and

generating one or more normalized analysis artifacts for the first source code file, wherein each reference, in the one or more normalized analysis artifacts, to the first source code file, uses the normalized file path for the first source code file instead of the original file path for the first source code file.

12. The system of claim 11 , wherein after evaluating each symbolic link of the plurality of symbolic links in the first original file path, the resolved file path for the first source code file includes at least one of the plurality of symbolic links.

13. The system of claim 11 , wherein evaluating each symbolic link of the plurality of symbolic links in the first original file path comprises evaluating the symbolic links in order from a filename component of the original file path to each parent component of the filename component of the original file path.

14. The system of claim 11 , wherein determining whether the symbolic link satisfies the one or more resolution criteria comprises determining that one or more of the resolution criteria are satisfied because a particular symbolic link of the first original file path does not identify a file having a computer-generated name in a content-addressable file system.

15. The system of claim 11 , wherein determining whether the symbolic link satisfies the one or more resolution criteria comprises determining that one or more of the resolution criteria are satisfied because a particular symbolic link of the first original file path is a symbolic link to a directory and not to a file.

16. The system of claim 11 , wherein determining whether the symbolic link satisfies the one or more resolution criteria comprises determining that one or more of the resolution criteria are satisfied because the symbolic link is a link to a location within a user-specified directory tree.

17. The system of claim 11 , wherein determining whether the symbolic link satisfies the one or more resolution criteria comprises determining that one or more of the resolution criteria are satisfied because a particular symbolic link of the first original file path identifies a file path that matches a portion of a checkout root directory.

18. The system of claim 11 , wherein the operations further comprise computing, from the one or more normalized analysis artifacts, respective values of one or more source code attributes for one or more of the source code files in response to the request.

19. The system of claim 11 , wherein at least two source code files, in the collection of source code files, that have different respective original parent directories according to respective original file paths of the two source code files have a same normalized parent directory according to respective normalized file paths of the two source code files.

20. The system of claim 19 , wherein the two source code files have different original file paths and a same normalized file path, and

wherein computing, from the one or more normalized analysis artifacts, respective values of one or more source code attributes for one or more of the source code files comprises computing a single respective value of each source code attribute for the normalized file path of the two source code files.

21. A computer program product, encoded on one or more non-transitory computer storage media, comprising instructions that when executed by one or more computers cause the one or more computers to perform operations comprising:

receiving a request to perform an analysis of a collection of source code files, wherein each source code file in the collection of source code files has a respective associated original file path;

determining that a first original file path of a first source code file of the collection of source code files includes a plurality of symbolic links;

generating a resolved file path for the first original file path of the first source code file, including evaluating each symbolic link of the plurality of symbolic links in the first original file path according to one or more resolution criteria, wherein the one or more resolution criteria specify when to resolve a symbolic link in an original file path, including:

determining whether the symbolic link in the first original file path satisfies the one or more resolution criteria,

whenever the symbolic link in the first original file path satisfies any of the one or more resolution criteria, resolving the symbolic link and updating a resolved file path for the first source code file with a resolved path component corresponding to the symbolic link, and

whenever the symbolic link in the first original file path does not satisfy any of the one or more resolution criteria, leaving the symbolic link in the resolved file path for the first source code file,

wherein the resolved file path for the first original file path includes resolved path components for one or more but fewer than all of the plurality of symbolic links in the first original file path;

applying a file path transformation function to the resolved file path for the first source code file to generate a normalized file path for the first source code file; and

generating one or more normalized analysis artifacts for the first source code file, wherein each reference, in the one or more normalized analysis artifacts, to the first source code file, uses the normalized file path for the first source code file instead of the original file path for the first source code file.