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author | bors[bot] <26634292+bors[bot]@users.noreply.github.com> | 2019-12-05 20:00:20 +0000 |
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committer | GitHub <[email protected]> | 2019-12-05 20:00:20 +0000 |
commit | 6e10a9f57815ad865a570816436adfdf0de1cdf0 (patch) | |
tree | 410c416bfe9daa05743ce8c49418c20df28dd625 /crates/ra_hir_expand/src/name.rs | |
parent | 217a6fa4a387dbfe6ac725b6dba2f15d6532679f (diff) | |
parent | 10697041c1c72ddbe27c41912e691656be6ccce4 (diff) |
Merge #2479
2479: Add expansion infrastructure for derive macros r=matklad a=flodiebold
I thought I'd experiment a bit with attribute macro/derive expansion, and here's what I've got so far. It has dummy implementations of the Copy / Clone derives, to show that the approach works; it doesn't add any attribute macro support, but I think that fits into the architecture.
Basically, during raw item collection, we look at the attributes and generate macro calls for them if necessary. Currently I only do this for derives, and just add the derive macro calls as separate calls next to the item. I think for derives, it's important that they don't obscure the actual item, since they can't actually change it (e.g. sending the item token tree through macro expansion unnecessarily might make completion within it more complicated).
Attribute macros would have to be recognized at that stage and replace the item (i.e., the raw item collector will just emit an attribute macro call, and not the item). I think when we implement this, we should try to recognize known inert attributes, so that we don't do macro expansion unnecessarily; anything that isn't known needs to be treated as a possible attribute macro call (since the raw item collector can't resolve the macro yet).
There's basically no name resolution for attribute macros implemented, I just hardcoded the built-in derives. In the future, the built-ins should work within the normal name resolution infrastructure; the problem there is that the builtin stubs in `std` use macros 2.0, which we don't support yet (and adding support is outside the scope of this).
One aspect that I don't really have a solution for, but I don't know how important it is, is removing the attribute itself from its input. I'm pretty sure rustc leaves out the attribute macro from the input, but to do that, we'd have to create a completely new syntax node. I guess we could do it when / after converting to a token tree.
Co-authored-by: Florian Diebold <[email protected]>
Diffstat (limited to 'crates/ra_hir_expand/src/name.rs')
-rw-r--r-- | crates/ra_hir_expand/src/name.rs | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/crates/ra_hir_expand/src/name.rs b/crates/ra_hir_expand/src/name.rs index 05ba37070..c5a191160 100644 --- a/crates/ra_hir_expand/src/name.rs +++ b/crates/ra_hir_expand/src/name.rs | |||
@@ -83,6 +83,12 @@ impl AsName for ast::Name { | |||
83 | } | 83 | } |
84 | } | 84 | } |
85 | 85 | ||
86 | impl AsName for tt::Ident { | ||
87 | fn as_name(&self) -> Name { | ||
88 | Name::resolve(&self.text) | ||
89 | } | ||
90 | } | ||
91 | |||
86 | impl AsName for ast::FieldKind { | 92 | impl AsName for ast::FieldKind { |
87 | fn as_name(&self) -> Name { | 93 | fn as_name(&self) -> Name { |
88 | match self { | 94 | match self { |
@@ -153,3 +159,14 @@ pub const COLUMN_MACRO: Name = Name::new_inline_ascii(6, b"column"); | |||
153 | pub const COMPILE_ERROR_MACRO: Name = Name::new_inline_ascii(13, b"compile_error"); | 159 | pub const COMPILE_ERROR_MACRO: Name = Name::new_inline_ascii(13, b"compile_error"); |
154 | pub const LINE_MACRO: Name = Name::new_inline_ascii(4, b"line"); | 160 | pub const LINE_MACRO: Name = Name::new_inline_ascii(4, b"line"); |
155 | pub const STRINGIFY_MACRO: Name = Name::new_inline_ascii(9, b"stringify"); | 161 | pub const STRINGIFY_MACRO: Name = Name::new_inline_ascii(9, b"stringify"); |
162 | |||
163 | // Builtin derives | ||
164 | pub const COPY_TRAIT: Name = Name::new_inline_ascii(4, b"Copy"); | ||
165 | pub const CLONE_TRAIT: Name = Name::new_inline_ascii(5, b"Clone"); | ||
166 | pub const DEFAULT_TRAIT: Name = Name::new_inline_ascii(7, b"Default"); | ||
167 | pub const DEBUG_TRAIT: Name = Name::new_inline_ascii(5, b"Debug"); | ||
168 | pub const HASH_TRAIT: Name = Name::new_inline_ascii(4, b"Hash"); | ||
169 | pub const ORD_TRAIT: Name = Name::new_inline_ascii(3, b"Ord"); | ||
170 | pub const PARTIAL_ORD_TRAIT: Name = Name::new_inline_ascii(10, b"PartialOrd"); | ||
171 | pub const EQ_TRAIT: Name = Name::new_inline_ascii(2, b"Eq"); | ||
172 | pub const PARTIAL_EQ_TRAIT: Name = Name::new_inline_ascii(9, b"PartialEq"); | ||