src/libsyntax_ext/test_case.rs

   1 // http://rust-lang.org/COPYRIGHT.
   2 //
   3
   4 // #[test_case] is used by custom test authors to mark tests
   5 // When building for test, it needs to make the item public and gensym the name
   6 // Otherwise, we'll omit the item. This behavior means that any item annotated
   7 // with #[test_case] is never addressable.
   8 //
   9 // We mark item with an inert attribute "rustc_test_marker" which the test generation
  10 // logic will pick up on.
  11
  12 use syntax::ext::base::*;
  13 use syntax::ext::build::AstBuilder;
  14 use syntax::ext::hygiene::{self, Mark, SyntaxContext};
  15 use syntax::ast;
  16 use syntax::source_map::respan;
  17 use syntax::symbol::{Symbol, sym};
  18 use syntax_pos::{DUMMY_SP, Span};
  19 use syntax::source_map::{ExpnInfo, MacroAttribute};
  20 use syntax::feature_gate;
  21
  22 pub fn expand(
  23     ecx: &mut ExtCtxt<'_>,
  24     attr_sp: Span,
  25     _meta_item: &ast::MetaItem,
  26     anno_item: Annotatable
  27 ) -> Vec<Annotatable> {
  28     if !ecx.ecfg.enable_custom_test_frameworks() {
  29         feature_gate::emit_feature_err(&ecx.parse_sess,
  30                                        sym::custom_test_frameworks,
  31                                        attr_sp,
  32                                        feature_gate::GateIssue::Language,
  33                                        feature_gate::EXPLAIN_CUSTOM_TEST_FRAMEWORKS);
  34     }
  35
  36     if !ecx.ecfg.should_test { return vec![]; }
  37
  38     let sp = {
  39         let mark = Mark::fresh(Mark::root());
  40         mark.set_expn_info(ExpnInfo {
  41             call_site: DUMMY_SP,
  42             def_site: None,
  43             format: MacroAttribute(Symbol::intern("test_case")),
  44             allow_internal_unstable: Some(vec![
  45                 Symbol::intern("test"),
  46                 Symbol::intern("rustc_attrs"),
  47             ].into()),
  48             allow_internal_unsafe: false,
  49             local_inner_macros: false,
  50             edition: hygiene::default_edition(),
  51         });
  52         attr_sp.with_ctxt(SyntaxContext::empty().apply_mark(mark))
  53     };
  54
  55     let mut item = anno_item.expect_item();
  56
  57     item = item.map(|mut item| {
  58         item.vis = respan(item.vis.span, ast::VisibilityKind::Public);
  59         item.ident = item.ident.gensym();
  60         item.attrs.push(
  61             ecx.attribute(sp,
  62                 ecx.meta_word(sp, Symbol::intern("rustc_test_marker")))
  63         );
  64         item
  65     });
  66
  67     return vec![Annotatable::Item(item)]
  68 }