Merge #969

969: Add builtin macros framework r=CohenArthur a=CohenArthur

This PR adds bases to define new builtin macro functions.

Since we operate at the `insert_macro_def` level, this requires builtin macros to be defined, as is the case in the rust standard library:

```rust
    macro_rules! assert {
        ($cond:expr $(,)?) => {{ /* compiler built-in */ }};
        ($cond:expr, $($arg:tt)+) => {{ /* compiler built-in */ }};
    }
```

Co-authored-by: Arthur Cohen <arthur.cohen@embecosm.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/gcc/rust/util/rust-hir-map.cc b/gcc/rust/util/rust-hir-map.cc
index 1348e29..1c0e8fc 100644
--- a/gcc/rust/util/rust-hir-map.cc
+++ b/gcc/rust/util/rust-hir-map.cc
@@ -19,6 +19,7 @@
 #include "rust-hir-map.h"
 #include "rust-ast-full.h"
 #include "rust-hir-full.h"
+#include "rust-macro-builtins.h"
 
 namespace Rust {
 namespace Analysis {
@@ -741,6 +742,16 @@ Mappings::iterate_trait_items (
 void
 Mappings::insert_macro_def (AST::MacroRulesDefinition *macro)
 {
+  static std::map<std::string, std::function<AST::ASTFragment (
+				 Location, AST::MacroInvocData &)>>
+    builtin_macros = {
+      {"assert", MacroBuiltin::assert},
+    };
+
+  auto builtin = builtin_macros.find (macro->get_rule_name ());
+  if (builtin != builtin_macros.end ())
+    macro->set_builtin_transcriber (builtin->second);
+
   auto it = macroMappings.find (macro->get_node_id ());
   rust_assert (it == macroMappings.end ());