Method toPosition

inference/primitive.go:272–297

toPosition returns the correct position information for the given pos, removing sandbox prefix if any.

(pos token.Pos)

// toPosition returns the correct position information for the given pos, removing sandbox prefix
// if any.
func (p *primitivizer) toPosition(pos token.Pos) token.Position {
	// Generated files contain "//line" directives that point back to the original source file
	// for better error reporting, and PositionFor supports reading that information and adjust
	// the position accordingly (i.e., returning a position that points back to the original source
	// file). However, since we are using the precise position information for correctly
	// identifying upstream objects in our cross-package inference, such adjustment will break it
	// the inference (downstream analysis knows nothing about the "original source file").
	// Therefore, here we explicitly disable the adjustment.
	position := p.pass.Fset.PositionFor(pos, false /* adjusted */)

	// For build systems that employ sandboxing (e.g., bazel), the file names in the `Fset` may
	// contain a random prefix. For example:
	//   <SANDBOX_PREFIX>/<WORKSPACE_UUID>/src/mypkg/mysrc1.go
	//   <SANDBOX_PREFIX>/<WORKSPACE_UUID>/src/mypkg/mysrc2.go
	//   src/upstream/mysrc1.go
	//   src/upstream/mysrc2.go
	// Notice that the upstream files do not have this prefix, since this information is loaded
	// from archive file (that stores the symbol information etc.), but not from the sandbox.
	// So, we trim the `<SANDBOX_PREFIX>/<WORKSPACE_UUID>/` here, which is CWD set by bazel build.
	// For other drivers (standard or golangci-lint), we won't even have this prefix prepended,
	// since the file paths will always be in the form of the relative paths (e.g.,
	// `src/mypkg/mysrc1.go`). Trimming the prefixes here for them is simply a no-op.
	position.Filename = tokenhelper.RelToCwd(position.Filename)

	return position
}