cmd/compile: error points to nonexistent file

[rsc]

The x.go:0: here does not make much sense given that x.go does not exist.
It seems like it should be omitted, no?

$ go tool compile x.go
x.go:0: open x.go: no such file or directory

/cc @griesemer

[griesemer]

Agreed.

[tandr]

Curious - how many scripts/tools that parse compiler output and rely on the line start being file:linenumber will need to be modified?
There is no way to get structured output from the compiler (say, for example --json, that would produce all errors and warnings in a nicely parseable structured format). So tools are relying on compiler output parsing.

[beoran]

FWIW, Geany has no problems with either the current behavior or the proposed x.go: open x.go: no such file or directory message. There's no file to open anyway. So I guess most other editors will be ok if they have smart enough compiler output parsers.

[gopherbot]

Change https://golang.org/cl/229357 mentions this issue: cmd/compile: omit non-existent file in error column prefix

[gopherbot]

Change https://golang.org/cl/230941 mentions this issue: cmd/compile: omit file:pos for non-existent errors