cuelang.org/go@v0.10.1/cue/load/loader.go (about)

     1  // Copyright 2018 The CUE Authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package load
    16  
    17  // Files in this package are to a large extent based on Go files from the following
    18  // Go packages:
    19  //    - cmd/go/internal/load
    20  //    - go/build
    21  
    22  import (
    23  	"path/filepath"
    24  
    25  	"cuelang.org/go/cue/build"
    26  	"cuelang.org/go/cue/errors"
    27  	"cuelang.org/go/cue/token"
    28  	"cuelang.org/go/internal/mod/modpkgload"
    29  
    30  	// Trigger the unconditional loading of all core builtin packages if load
    31  	// is used. This was deemed the simplest way to avoid having to import
    32  	// this line explicitly, and thus breaking existing code, for the majority
    33  	// of cases, while not introducing an import cycle.
    34  	_ "cuelang.org/go/pkg"
    35  )
    36  
    37  type loader struct {
    38  	cfg    *Config
    39  	tagger *tagger
    40  	stk    importStack
    41  	pkgs   *modpkgload.Packages
    42  
    43  	// dirCachedBuildFiles caches the work involved when reading a
    44  	// directory. It is keyed by directory name. When we descend into
    45  	// subdirectories to load patterns such as ./... we often end up
    46  	// loading parent directories many times over; this cache
    47  	// amortizes that work.
    48  	dirCachedBuildFiles map[string]cachedDirFiles
    49  }
    50  
    51  type cachedDirFiles struct {
    52  	err       errors.Error
    53  	filenames []string
    54  }
    55  
    56  func newLoader(c *Config, tg *tagger, pkgs *modpkgload.Packages) *loader {
    57  	return &loader{
    58  		cfg:                 c,
    59  		tagger:              tg,
    60  		pkgs:                pkgs,
    61  		dirCachedBuildFiles: make(map[string]cachedDirFiles),
    62  	}
    63  }
    64  
    65  func (l *loader) abs(filename string) string {
    66  	if !isLocalImport(filename) {
    67  		return filename
    68  	}
    69  	return filepath.Join(l.cfg.Dir, filename)
    70  }
    71  
    72  func (l *loader) errPkgf(importPos []token.Pos, format string, args ...interface{}) *PackageError {
    73  	err := &PackageError{
    74  		ImportStack: l.stk.Copy(),
    75  		Message:     errors.NewMessagef(format, args...),
    76  	}
    77  	err.fillPos(l.cfg.Dir, importPos)
    78  	return err
    79  }
    80  
    81  // cueFilesPackage creates a package for building a collection of CUE files
    82  // (typically named on the command line).
    83  func (l *loader) cueFilesPackage(files []*build.File) *build.Instance {
    84  	// ModInit() // TODO: support modules
    85  	pkg := l.cfg.Context.NewInstance(l.cfg.Dir, l.loadFunc())
    86  
    87  	for _, bf := range files {
    88  		f := bf.Filename
    89  		if f == "-" {
    90  			continue
    91  		}
    92  		if !filepath.IsAbs(f) {
    93  			f = filepath.Join(l.cfg.Dir, f)
    94  		}
    95  		fi, err := l.cfg.fileSystem.stat(f)
    96  		if err != nil {
    97  			return l.cfg.newErrInstance(errors.Wrapf(err, token.NoPos, "could not find file %v", f))
    98  		}
    99  		if fi.IsDir() {
   100  			return l.cfg.newErrInstance(errors.Newf(token.NoPos, "file is a directory %v", f))
   101  		}
   102  	}
   103  
   104  	fp := newFileProcessor(l.cfg, pkg, l.tagger)
   105  	if l.cfg.Package == "*" {
   106  		fp.allPackages = true
   107  		pkg.PkgName = "_"
   108  	}
   109  	for _, bf := range files {
   110  		fp.add(l.cfg.Dir, bf, allowAnonymous|allowExcludedFiles)
   111  	}
   112  
   113  	// TODO: ModImportFromFiles(files)
   114  	pkg.Dir = l.cfg.Dir
   115  	rewriteFiles(pkg, pkg.Dir, true)
   116  	for _, err := range errors.Errors(fp.finalize(pkg)) { // ImportDir(&ctxt, dir, 0)
   117  		var x *NoFilesError
   118  		if len(pkg.OrphanedFiles) == 0 || !errors.As(err, &x) {
   119  			pkg.ReportError(err)
   120  		}
   121  	}
   122  	// TODO: Support module importing.
   123  	// if ModDirImportPath != nil {
   124  	// 	// Use the effective import path of the directory
   125  	// 	// for deciding visibility during pkg.load.
   126  	// 	bp.ImportPath = ModDirImportPath(dir)
   127  	// }
   128  
   129  	pkg.User = true
   130  	l.addFiles(pkg)
   131  
   132  	_ = pkg.Complete()
   133  	pkg.DisplayPath = "command-line-arguments"
   134  
   135  	return pkg
   136  }
   137  
   138  // addFiles populates p.Files by reading CUE syntax from p.BuildFiles.
   139  func (l *loader) addFiles(p *build.Instance) {
   140  	for _, bf := range p.BuildFiles {
   141  		f, err := l.cfg.fileSystem.getCUESyntax(bf)
   142  		if err != nil {
   143  			p.ReportError(errors.Promote(err, "load"))
   144  		}
   145  		_ = p.AddSyntax(f)
   146  	}
   147  }