hphp/hack/src/parser/mode_parser.rs

   1 // Copyright (c) 2019, Facebook, Inc.
   2 // All rights reserved.
   3 //
   4 // This source code is licensed under the MIT license found in the
   5 // LICENSE file in the "hack" directory of this source tree.
   6
   7 use bumpalo::Bump;
   8 use parser_core_types::parser_env::ParserEnv;
   9 use parser_core_types::source_text::SourceText;
  10 use parser_core_types::syntax_by_ref::syntax::Syntax;
  11 use parser_core_types::syntax_by_ref::syntax_variant_generated::SyntaxVariant;
  12 use parser_core_types::syntax_by_ref::syntax_variant_generated::{self as syntax};
  13 use parser_core_types::syntax_tree::FileMode;
  14
  15 pub enum Language {
  16     Hack,
  17     PHP,
  18 }
  19
  20 // Returns Language::PHP if text is a PHP file (has .php extension and starts
  21 // with anything other than <?hh). Correctly recognizing PHP files is important
  22 // for open-source projects, which may need Hack and PHP files to coexist in the
  23 // same directory.
  24 pub fn parse_mode(text: &SourceText<'_>) -> (Language, Option<FileMode>) {
  25     let bump = Bump::new();
  26     if let Some(header) =
  27         positioned_by_ref_parser::parse_header_only(ParserEnv::default(), &bump, text)
  28     {
  29         match header.children {
  30             SyntaxVariant::MarkupSection(section_children) => {
  31                 match section_children {
  32                     syntax::MarkupSectionChildren {
  33                         suffix:
  34                             Syntax {
  35                                 children: SyntaxVariant::MarkupSuffix(suffix_children),
  36                                 ..
  37                             },
  38                         ..
  39                     } => {
  40                         let syntax::MarkupSuffixChildren { name, .. } = *suffix_children;
  41                         match &name.children {
  42                             // <?, <?php or <?anything_else except <?hh
  43                             SyntaxVariant::Missing => (Language::PHP, None),
  44                             // <?hh
  45                             _ => {
  46                                 if text.file_path().has_extension("hhi") {
  47                                     (Language::Hack, Some(FileMode::Hhi))
  48                                 } else {
  49                                     (Language::Hack, Some(FileMode::Strict))
  50                                 }
  51                             }
  52                         }
  53                     }
  54                     _ => {
  55                         // unreachable (parser either returns a value that matches
  56                         // the above expressions, or None)
  57                         (Language::Hack, Some(FileMode::Strict))
  58                     }
  59                 }
  60             }
  61             // unreachable (parser either returns a value that matches
  62             // the above expression, or None)
  63             _ => (Language::Hack, Some(FileMode::Strict)),
  64         }
  65     } else {
  66         (Language::Hack, Some(FileMode::Strict))
  67     }
  68 }