self-hosted: remove allocateDeclIndexes from the public link.File API

src/Module.zig

@@ -4585,7 +4585,6 @@ fn semaDecl(mod: *Module, decl_index: Decl.Index) !bool {
                 // We don't fully codegen the decl until later, but we do need to reserve a global
                 // offset table index for it. This allows us to codegen decls out of dependency
                 // order, increasing how many computations can be done in parallel.
-                try mod.comp.bin_file.allocateDeclIndexes(decl_index);
                 try mod.comp.work_queue.writeItem(.{ .codegen_func = func });
                 if (type_changed and mod.emit_h != null) {
                     try mod.comp.work_queue.writeItem(.{ .emit_h_decl = decl_index });
@@ -4697,7 +4696,6 @@ fn semaDecl(mod: *Module, decl_index: Decl.Index) !bool {
         // codegen backend wants full access to the Decl Type.
         try sema.resolveTypeFully(decl.ty);
 
-        try mod.comp.bin_file.allocateDeclIndexes(decl_index);
         try mod.comp.work_queue.writeItem(.{ .codegen_decl = decl_index });
 
         if (type_changed and mod.emit_h != null) {
@@ -5315,29 +5313,6 @@ pub fn deleteUnusedDecl(mod: *Module, decl_index: Decl.Index) void {
     const decl = mod.declPtr(decl_index);
     log.debug("deleteUnusedDecl {d} ({s})", .{ decl_index, decl.name });
 
-    // TODO: remove `allocateDeclIndexes` and make the API that the linker backends
-    // are required to notice the first time `updateDecl` happens and keep track
-    // of it themselves. However they can rely on getting a `freeDecl` call if any
-    // `updateDecl` or `updateFunc` calls happen. This will allow us to avoid any call
-    // into the linker backend here, since the linker backend will never have been told
-    // about the Decl in the first place.
-    // Until then, we did call `allocateDeclIndexes` on this anonymous Decl and so we
-    // must call `freeDecl` in the linker backend now.
-    switch (mod.comp.bin_file.tag) {
-        .coff,
-        .elf,
-        .macho,
-        .c,
-        .wasm,
-        => {}, // this linker backend has already migrated to the new API
-
-        else => if (decl.has_tv) {
-            if (decl.ty.isFnOrHasRuntimeBits()) {
-                mod.comp.bin_file.freeDecl(decl_index);
-            }
-        },
-    }
-
     assert(!mod.declIsRoot(decl_index));
     assert(decl.src_namespace.anon_decls.swapRemove(decl_index));
 
@@ -5822,7 +5797,6 @@ pub fn initNewAnonDecl(
     // the Decl will be garbage collected by the `codegen_decl` task instead of sent
     // to the linker.
     if (typed_value.ty.isFnOrHasRuntimeBits()) {
-        try mod.comp.bin_file.allocateDeclIndexes(new_decl_index);
         try mod.comp.anon_work_queue.writeItem(.{ .codegen_decl = new_decl_index });
     }
 }

src/Sema.zig

@@ -7510,7 +7510,6 @@ fn resolveGenericInstantiationType(
     // Queue up a `codegen_func` work item for the new Fn. The `comptime_args` field
     // will be populated, ensuring it will have `analyzeBody` called with the ZIR
     // parameters mapped appropriately.
-    try mod.comp.bin_file.allocateDeclIndexes(new_decl_index);
     try mod.comp.work_queue.writeItem(.{ .codegen_func = new_func });
     return new_func;
 }

src/link.zig

@@ -533,8 +533,7 @@ pub const File = struct {
         }
     }
 
-    /// May be called before or after updateDeclExports but must be called
-    /// after allocateDeclIndexes for any given Decl.
+    /// May be called before or after updateDeclExports for any given Decl.
     pub fn updateDecl(base: *File, module: *Module, decl_index: Module.Decl.Index) UpdateDeclError!void {
         const decl = module.declPtr(decl_index);
         log.debug("updateDecl {*} ({s}), type={}", .{ decl, decl.name, decl.ty.fmtDebug() });
@@ -557,8 +556,7 @@ pub const File = struct {
         }
     }
 
-    /// May be called before or after updateDeclExports but must be called
-    /// after allocateDeclIndexes for any given Decl.
+    /// May be called before or after updateDeclExports for any given Decl.
     pub fn updateFunc(base: *File, module: *Module, func: *Module.Fn, air: Air, liveness: Liveness) UpdateDeclError!void {
         const owner_decl = module.declPtr(func.owner_decl);
         log.debug("updateFunc {*} ({s}), type={}", .{
@@ -602,32 +600,6 @@ pub const File = struct {
         }
     }
 
-    /// Must be called before any call to updateDecl or updateDeclExports for
-    /// any given Decl.
-    /// TODO we're transitioning to deleting this function and instead having
-    /// each linker backend notice the first time updateDecl or updateFunc is called, or
-    /// a callee referenced from AIR.
-    pub fn allocateDeclIndexes(base: *File, decl_index: Module.Decl.Index) error{OutOfMemory}!void {
-        const decl = base.options.module.?.declPtr(decl_index);
-        log.debug("allocateDeclIndexes {*} ({s})", .{ decl, decl.name });
-        if (build_options.only_c) {
-            assert(base.tag == .c);
-            return;
-        }
-        switch (base.tag) {
-            .plan9 => return @fieldParentPtr(Plan9, "base", base).allocateDeclIndexes(decl_index),
-
-            .coff,
-            .elf,
-            .macho,
-            .c,
-            .spirv,
-            .nvptx,
-            .wasm,
-            => {},
-        }
-    }
-
     pub fn releaseLock(self: *File) void {
         if (self.lock) |*lock| {
             lock.release();
@@ -878,8 +850,7 @@ pub const File = struct {
         AnalysisFail,
     };
 
-    /// May be called before or after updateDecl, but must be called after
-    /// allocateDeclIndexes for any given Decl.
+    /// May be called before or after updateDecl for any given Decl.
     pub fn updateDeclExports(
         base: *File,
         module: *Module,

src/link/Plan9.zig

@@ -424,7 +424,7 @@ fn updateFinish(self: *Plan9, decl: *Module.Decl) !void {
     // write the internal linker metadata
     decl.link.plan9.type = sym_t;
     // write the symbol
-    // we already have the got index because that got allocated in allocateDeclIndexes
+    // we already have the got index
     const sym: aout.Sym = .{
         .value = undefined, // the value of stuff gets filled in in flushModule
         .type = decl.link.plan9.type,
@@ -737,7 +737,7 @@ fn addDeclExports(
 
 pub fn freeDecl(self: *Plan9, decl_index: Module.Decl.Index) void {
     // TODO audit the lifetimes of decls table entries. It's possible to get
-    // allocateDeclIndexes and then freeDecl without any updateDecl in between.
+    // freeDecl without any updateDecl in between.
     // However that is planned to change, see the TODO comment in Module.zig
     // in the deleteUnusedDecl function.
     const mod = self.base.options.module.?;
@@ -959,11 +959,6 @@ pub fn writeSyms(self: *Plan9, buf: *std.ArrayList(u8)) !void {
     }
 }
 
-/// this will be removed, moved to updateFinish
-pub fn allocateDeclIndexes(self: *Plan9, decl_index: Module.Decl.Index) !void {
-    _ = self;
-    _ = decl_index;
-}
 /// Must be called only after a successful call to `updateDecl`.
 pub fn updateDeclLineNumber(self: *Plan9, mod: *Module, decl: *const Module.Decl) !void {
     _ = self;