Auto merge of #86676 - cjgillot:localexpn, r=petrochenkov

Make expansions stable for incr. comp.

This PR aims to make expansions stable for incr. comp. by using the same architecture as definitions:
- the interned identifier `ExpnId` contains a `CrateNum` and a crate-local id;
- bidirectional maps `ExpnHash <-> ExpnId` are setup;
- incr. comp. on-disk cache saves and reconstructs expansions using their `ExpnHash`.

I tried to use as many `LocalExpnId` as I could in the resolver code, but I may have missed a few opportunities.

All this will allow to use an `ExpnId` as a query key, and to force this query without recomputing caller queries. For instance, this will be used to implement #85999.

r? `@petrochenkov`

4 files changed, 39 insertions, 39 deletions

diff --git a/src/test/ui/hygiene/unpretty-debug.stdout b/src/test/ui/hygiene/unpretty-debug.stdout
index 84ca046212d..ffb9f9eed41 100644
--- a/src/test/ui/hygiene/unpretty-debug.stdout
+++ b/src/test/ui/hygiene/unpretty-debug.stdout
@@ -19,10 +19,10 @@ fn y /* 0#0 */() { }
 
 /*
 Expansions:
-0: parent: ExpnId(0), call_site_ctxt: #0, def_site_ctxt: #0, kind: Root
-1: parent: ExpnId(0), call_site_ctxt: #0, def_site_ctxt: #0, kind: Macro(Bang, "foo")
+crate0::{{expn0}}: parent: crate0::{{expn0}}, call_site_ctxt: #0, def_site_ctxt: #0, kind: Root
+crate0::{{expn1}}: parent: crate0::{{expn0}}, call_site_ctxt: #0, def_site_ctxt: #0, kind: Macro(Bang, "foo")
 
 SyntaxContexts:
-#0: parent: #0, outer_mark: (ExpnId(0), Opaque)
-#1: parent: #0, outer_mark: (ExpnId(1), SemiTransparent)
+#0: parent: #0, outer_mark: (crate0::{{expn0}}, Opaque)
+#1: parent: #0, outer_mark: (crate0::{{expn1}}, SemiTransparent)
 */
diff --git a/src/test/ui/proc-macro/meta-macro-hygiene.stdout b/src/test/ui/proc-macro/meta-macro-hygiene.stdout
index dc63d014451..2524d8273b7 100644
--- a/src/test/ui/proc-macro/meta-macro-hygiene.stdout
+++ b/src/test/ui/proc-macro/meta-macro-hygiene.stdout
@@ -43,23 +43,23 @@ fn main /* 0#0 */() { ; }
 
 /*
 Expansions:
-0: parent: ExpnId(0), call_site_ctxt: #0, def_site_ctxt: #0, kind: Root
-1: parent: ExpnId(0), call_site_ctxt: #0, def_site_ctxt: #0, kind: AstPass(StdImports)
-2: parent: ExpnId(0), call_site_ctxt: #0, def_site_ctxt: #0, kind: Macro(Bang, "produce_it")
-3: parent: ExpnId(0), call_site_ctxt: #0, def_site_ctxt: #0, kind: AstPass(StdImports)
-4: parent: ExpnId(2), call_site_ctxt: #4, def_site_ctxt: #0, kind: Macro(Bang, "meta_macro::print_def_site")
-5: parent: ExpnId(4), call_site_ctxt: #5, def_site_ctxt: #0, kind: Macro(Bang, "$crate::dummy")
+crate0::{{expn0}}: parent: crate0::{{expn0}}, call_site_ctxt: #0, def_site_ctxt: #0, kind: Root
+crate0::{{expn1}}: parent: crate0::{{expn0}}, call_site_ctxt: #0, def_site_ctxt: #0, kind: AstPass(StdImports)
+crate0::{{expn2}}: parent: crate0::{{expn0}}, call_site_ctxt: #0, def_site_ctxt: #0, kind: Macro(Bang, "produce_it")
+crate0::{{expn3}}: parent: crate0::{{expn2}}, call_site_ctxt: #4, def_site_ctxt: #0, kind: Macro(Bang, "meta_macro::print_def_site")
+crate0::{{expn4}}: parent: crate0::{{expn3}}, call_site_ctxt: #5, def_site_ctxt: #0, kind: Macro(Bang, "$crate::dummy")
+crate2::{{expn1}}: parent: crate0::{{expn0}}, call_site_ctxt: #0, def_site_ctxt: #0, kind: AstPass(StdImports)
 
 SyntaxContexts:
-#0: parent: #0, outer_mark: (ExpnId(0), Opaque)
-#1: parent: #0, outer_mark: (ExpnId(1), Opaque)
-#2: parent: #0, outer_mark: (ExpnId(1), Transparent)
-#3: parent: #0, outer_mark: (ExpnId(3), Opaque)
-#4: parent: #0, outer_mark: (ExpnId(2), SemiTransparent)
-#5: parent: #0, outer_mark: (ExpnId(4), Opaque)
-#6: parent: #4, outer_mark: (ExpnId(4), Transparent)
-#7: parent: #0, outer_mark: (ExpnId(4), SemiTransparent)
-#8: parent: #0, outer_mark: (ExpnId(5), Opaque)
-#9: parent: #5, outer_mark: (ExpnId(5), Transparent)
-#10: parent: #5, outer_mark: (ExpnId(5), SemiTransparent)
+#0: parent: #0, outer_mark: (crate0::{{expn0}}, Opaque)
+#1: parent: #0, outer_mark: (crate0::{{expn1}}, Opaque)
+#2: parent: #0, outer_mark: (crate0::{{expn1}}, Transparent)
+#3: parent: #0, outer_mark: (crate2::{{expn1}}, Opaque)
+#4: parent: #0, outer_mark: (crate0::{{expn2}}, SemiTransparent)
+#5: parent: #0, outer_mark: (crate0::{{expn3}}, Opaque)
+#6: parent: #4, outer_mark: (crate0::{{expn3}}, Transparent)
+#7: parent: #0, outer_mark: (crate0::{{expn3}}, SemiTransparent)
+#8: parent: #0, outer_mark: (crate0::{{expn4}}, Opaque)
+#9: parent: #5, outer_mark: (crate0::{{expn4}}, Transparent)
+#10: parent: #5, outer_mark: (crate0::{{expn4}}, SemiTransparent)
 */
diff --git a/src/test/ui/proc-macro/nonterminal-token-hygiene.stdout b/src/test/ui/proc-macro/nonterminal-token-hygiene.stdout
index 75e6a49b314..b5ab82737e9 100644
--- a/src/test/ui/proc-macro/nonterminal-token-hygiene.stdout
+++ b/src/test/ui/proc-macro/nonterminal-token-hygiene.stdout
@@ -67,22 +67,22 @@ fn main /* 0#0 */() { }
 
 /*
 Expansions:
-0: parent: ExpnId(0), call_site_ctxt: #0, def_site_ctxt: #0, kind: Root
-1: parent: ExpnId(0), call_site_ctxt: #0, def_site_ctxt: #0, kind: AstPass(StdImports)
-2: parent: ExpnId(0), call_site_ctxt: #0, def_site_ctxt: #0, kind: Macro(Bang, "outer")
-3: parent: ExpnId(0), call_site_ctxt: #0, def_site_ctxt: #0, kind: AstPass(StdImports)
-4: parent: ExpnId(2), call_site_ctxt: #4, def_site_ctxt: #4, kind: Macro(Bang, "inner")
-5: parent: ExpnId(4), call_site_ctxt: #6, def_site_ctxt: #0, kind: Macro(Bang, "print_bang")
+crate0::{{expn0}}: parent: crate0::{{expn0}}, call_site_ctxt: #0, def_site_ctxt: #0, kind: Root
+crate0::{{expn1}}: parent: crate0::{{expn0}}, call_site_ctxt: #0, def_site_ctxt: #0, kind: AstPass(StdImports)
+crate0::{{expn2}}: parent: crate0::{{expn0}}, call_site_ctxt: #0, def_site_ctxt: #0, kind: Macro(Bang, "outer")
+crate0::{{expn3}}: parent: crate0::{{expn2}}, call_site_ctxt: #4, def_site_ctxt: #4, kind: Macro(Bang, "inner")
+crate0::{{expn4}}: parent: crate0::{{expn3}}, call_site_ctxt: #6, def_site_ctxt: #0, kind: Macro(Bang, "print_bang")
+crate2::{{expn1}}: parent: crate0::{{expn0}}, call_site_ctxt: #0, def_site_ctxt: #0, kind: AstPass(StdImports)
 
 SyntaxContexts:
-#0: parent: #0, outer_mark: (ExpnId(0), Opaque)
-#1: parent: #0, outer_mark: (ExpnId(1), Opaque)
-#2: parent: #0, outer_mark: (ExpnId(1), Transparent)
-#3: parent: #0, outer_mark: (ExpnId(3), Opaque)
-#4: parent: #0, outer_mark: (ExpnId(2), SemiTransparent)
-#5: parent: #0, outer_mark: (ExpnId(4), Opaque)
-#6: parent: #4, outer_mark: (ExpnId(4), Opaque)
-#7: parent: #0, outer_mark: (ExpnId(5), Opaque)
-#8: parent: #6, outer_mark: (ExpnId(5), Transparent)
-#9: parent: #5, outer_mark: (ExpnId(5), SemiTransparent)
+#0: parent: #0, outer_mark: (crate0::{{expn0}}, Opaque)
+#1: parent: #0, outer_mark: (crate0::{{expn1}}, Opaque)
+#2: parent: #0, outer_mark: (crate0::{{expn1}}, Transparent)
+#3: parent: #0, outer_mark: (crate2::{{expn1}}, Opaque)
+#4: parent: #0, outer_mark: (crate0::{{expn2}}, SemiTransparent)
+#5: parent: #0, outer_mark: (crate0::{{expn3}}, Opaque)
+#6: parent: #4, outer_mark: (crate0::{{expn3}}, Opaque)
+#7: parent: #0, outer_mark: (crate0::{{expn4}}, Opaque)
+#8: parent: #6, outer_mark: (crate0::{{expn4}}, Transparent)
+#9: parent: #5, outer_mark: (crate0::{{expn4}}, SemiTransparent)
 */
diff --git a/src/tools/rustfmt/src/utils.rs b/src/tools/rustfmt/src/utils.rs
index d3c349fb701..614cda5f911 100644
--- a/src/tools/rustfmt/src/utils.rs
+++ b/src/tools/rustfmt/src/utils.rs
@@ -6,7 +6,7 @@ use rustc_ast::ast::{
 };
 use rustc_ast::ptr;
 use rustc_ast_pretty::pprust;
-use rustc_span::{sym, symbol, BytePos, ExpnId, Span, Symbol, SyntaxContext};
+use rustc_span::{sym, symbol, BytePos, LocalExpnId, Span, Symbol, SyntaxContext};
 use unicode_width::UnicodeWidthStr;
 
 use crate::comment::{filter_normal_code, CharClasses, FullCodeCharKind, LineClasses};
@@ -675,7 +675,7 @@ pub(crate) trait NodeIdExt {
 
 impl NodeIdExt for NodeId {
     fn root() -> NodeId {
-        NodeId::placeholder_from_expn_id(ExpnId::root())
+        NodeId::placeholder_from_expn_id(LocalExpnId::ROOT)
     }
 }