Commit dd402f6d83071535fffac055fabe72ebcb0db994 | zig

author	Matthew Lugg <mlugg@mlugg.co.uk> 2023-10-19 16:56:20-07:00
committer	Andrew Kelley <andrew@ziglang.org> 2023-10-21 21:38:41-04:00
log	dd402f6d83071535fffac055fabe72ebcb0db994
tree	4e3f74cec7d55c84c070a16dfd5b27502df969f9
parent	5e1db5e47800a8e9bb1d8d11f07b0023bd8e49ef

After the previous commit, these make_ptr_const ZIR instructions are
redundant.

2 files changed, 9 insertions(+), 6 deletions(-)

src/AstGen.zig+6-4

 @@ -3123,10 +3123,10 @@ fn varDecl(
             if (nodeMayAppendToErrorTrace(tree, var_decl.ast.init_node))
                 _ = try gz.addSaveErrRetIndex(.{ .if_of_error_type = init_inst });
-            if (resolve_inferred_alloc != .none) {
+            const const_ptr = if (resolve_inferred_alloc != .none) p: {
                 _ = try gz.addUnNode(.resolve_inferred_alloc, resolve_inferred_alloc, node);
-            }
+                break :p var_ptr;
-            const const_ptr = try gz.addUnNode(.make_ptr_const, var_ptr, node);
+            } else try gz.addUnNode(.make_ptr_const, var_ptr, node);
             try gz.addDbgVar(.dbg_var_ptr, ident_name, const_ptr);
 @@ -3533,7 +3533,9 @@ fn assignDestructureMaybeDecls(
             else => unreachable,
         };
         // If the alloc was const, make it const.
-        const var_ptr = if (is_const) make_const: {
+        const var_ptr = if (is_const and full.ast.type_node != 0) make_const: {
+            // Note that we don't do this if type_node == 0 since `resolve_inferred_alloc`
+            // handles it for us.
             break :make_const try gz.addUnNode(.make_ptr_const, raw_ptr, node);
         } else raw_ptr;
         const name_token = full.ast.mut_token + 1;

src/Zir.zig+3-2

 @@ -997,8 +997,9 @@ pub const Inst = struct {
         /// is the allocation that needs to have its type inferred.
         /// Uses the `un_node` field. The AST node is the var decl.
         resolve_inferred_alloc,
-        /// Turns a pointer coming from an `alloc`, `alloc_inferred`, `alloc_inferred_comptime` or
+        /// Turns a pointer coming from an `alloc` or `Extended.alloc` into a constant
-        /// `Extended.alloc` into a constant version of the same pointer.
+        /// version of the same pointer. For inferred allocations this is instead implicitly
+        /// handled by the `resolve_inferred_alloc` instruction.
         /// Uses the `un_node` union field.
         make_ptr_const,