commit 8f037db88552b5171807d4a9f8be6e8942aab8a1 (tree)
parent 1f4a097117a75b053d620658df4cb4e81c40fe1a
Author: Veikka Tuominen <git@vexu.eu>
Date: Mon, 7 Mar 2022 20:41:48 +0200
stage2: correct constness of allocs
Diffstat:
5 files changed, 26 insertions(+), 3 deletions(-)
diff --git a/src/AstGen.zig b/src/AstGen.zig
@@ -2138,6 +2138,7 @@ fn unusedResultExpr(gz: *GenZir, scope: *Scope, statement: Ast.Node.Index) Inner
.alloc_inferred_mut,
.alloc_inferred_comptime,
.alloc_inferred_comptime_mut,
+ .make_ptr_const,
.array_cat,
.array_mul,
.array_type,
@@ -2754,12 +2755,13 @@ fn varDecl(
if (resolve_inferred_alloc != .none) {
_ = try gz.addUnNode(.resolve_inferred_alloc, resolve_inferred_alloc, node);
}
+ const const_ptr = try gz.addUnNode(.make_ptr_const, init_scope.rl_ptr, node);
const sub_scope = try block_arena.create(Scope.LocalPtr);
sub_scope.* = .{
.parent = scope,
.gen_zir = gz,
.name = ident_name,
- .ptr = init_scope.rl_ptr,
+ .ptr = const_ptr,
.token_src = name_token,
.maybe_comptime = true,
.id_cat = .@"local constant",
diff --git a/src/Sema.zig b/src/Sema.zig
@@ -607,6 +607,7 @@ fn analyzeBodyInner(
.alloc_inferred_comptime_mut => try sema.zirAllocInferredComptime(inst, Type.initTag(.inferred_alloc_mut)),
.alloc_mut => try sema.zirAllocMut(block, inst),
.alloc_comptime_mut => try sema.zirAllocComptime(block, inst),
+ .make_ptr_const => try sema.zirMakePtrConst(block, inst),
.anyframe_type => try sema.zirAnyframeType(block, inst),
.array_cat => try sema.zirArrayCat(block, inst),
.array_mul => try sema.zirArrayMul(block, inst),
@@ -2409,6 +2410,21 @@ fn zirAllocComptime(sema: *Sema, block: *Block, inst: Zir.Inst.Index) CompileErr
return sema.analyzeComptimeAlloc(block, var_ty, 0, ty_src);
}
+fn zirMakePtrConst(sema: *Sema, block: *Block, inst: Zir.Inst.Index) CompileError!Air.Inst.Ref {
+ const inst_data = sema.code.instructions.items(.data)[inst].un_node;
+ const ptr = sema.resolveInst(inst_data.operand);
+ const ptr_ty = sema.typeOf(ptr);
+ var ptr_info = ptr_ty.ptrInfo().data;
+ ptr_info.mutable = false;
+ const const_ptr_ty = try Type.ptr(sema.arena, sema.mod.getTarget(), ptr_info);
+
+ if (try sema.resolveMaybeUndefVal(block, inst_data.src(), ptr)) |val| {
+ return sema.addConstant(const_ptr_ty, val);
+ }
+ try sema.requireRuntimeBlock(block, inst_data.src());
+ return block.addBitCast(const_ptr_ty, ptr);
+}
+
fn zirAllocInferredComptime(
sema: *Sema,
inst: Zir.Inst.Index,
diff --git a/src/Zir.zig b/src/Zir.zig
@@ -954,6 +954,10 @@ 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
+ /// `Extended.alloc` into a constant version of the same pointer.
+ /// Uses the `un_node` union field.
+ make_ptr_const,
/// Implements `resume` syntax. Uses `un_node` field.
@"resume",
@@ -993,6 +997,7 @@ pub const Inst = struct {
.alloc_inferred_mut,
.alloc_inferred_comptime,
.alloc_inferred_comptime_mut,
+ .make_ptr_const,
.array_cat,
.array_mul,
.array_type,
@@ -1496,6 +1501,7 @@ pub const Inst = struct {
.alloc_inferred_comptime = .node,
.alloc_inferred_comptime_mut = .node,
.resolve_inferred_alloc = .un_node,
+ .make_ptr_const = .un_node,
.@"resume" = .un_node,
.@"await" = .un_node,
diff --git a/src/print_zir.zig b/src/print_zir.zig
@@ -238,6 +238,7 @@ const Writer = struct {
.field_base_ptr,
.validate_array_init_ty,
.validate_struct_init_ty,
+ .make_ptr_const,
=> try self.writeUnNode(stream, inst),
.ref,
diff --git a/test/behavior/bugs/5474.zig b/test/behavior/bugs/5474.zig
@@ -54,8 +54,6 @@ test "pointer-to-array constness for zero-size elements, var" {
}
test "pointer-to-array constness for zero-size elements, const" {
- if (builtin.zig_backend != .stage1) return error.SkipZigTest; // TODO
-
try constant();
comptime try constant();
}
