Files
sx/src/backend/llvm/reflection.zig
agra 64f77e9779 fix(std): render integer formatter extremes — i64::MIN and unsigned all-ones [F0.8]
Resolves issue 0090. The `{}` integer formatter mis-rendered both ends of
the 64-bit range:

- `int_to_string` computed the magnitude as `0 - n`, which overflows for
  `s64::MIN` (its magnitude is unrepresentable as a positive s64) — the
  value stayed negative, the digit loop ran zero times, so only `-`
  printed. It now extracts digits straight from `n` (per-digit
  `|n % 10|`, `n` truncating toward zero), never negating MIN.

- `any_to_string`'s `case int:` formatted every integer as s64, so a u64
  all-ones value printed as `-1`. There was no `uint` type-category to
  distinguish signedness. Added an additive `type_is_unsigned(T)`
  reflection builtin (static fold + dynamic interp/LLVM paths, mirroring
  `type_name`), backed by the new `TypeTable.isUnsignedInt` predicate, and
  a `uint_to_string` formatter (unsigned decimal via long-division over
  four 16-bit limbs). `case int:` routes through `type_is_unsigned(type)`.

The 16-bit-limb split is factored into a shared `decompose_u16x4`, now
reused by `int_to_hex_string` (no second unsigned-math routine).

Regression: examples/0046-basic-int-formatter-extremes pins both extremes
plus a width spread; unit tests cover `isUnsignedInt`. Docs (specs.md
representation note, readme std API) updated for unsigned/extreme `{}`
behavior. IR snapshots refreshed for the two new std functions.
2026-06-05 09:05:37 +03:00

236 lines
12 KiB
Zig

const std = @import("std");
const llvm = @import("../../llvm_api.zig");
const c = llvm.c;
const errors = @import("../../errors.zig");
const emit = @import("../../ir/emit_llvm.zig");
const ir_inst = @import("../../ir/inst.zig");
const ir_types = @import("../../ir/types.zig");
const LLVMEmitter = emit.LLVMEmitter;
const Inst = ir_inst.Inst;
const TypeId = ir_types.TypeId;
const StringId = ir_types.StringId;
/// Reflection metadata + trace-frame emission (architecture phase A7.2),
/// extracted from `LLVMEmitter`. A backend `*LLVMEmitter` facade (field `e`):
/// the type/field/tag reflection NAME-ARRAY builders (memoized into
/// `type_name_array`/`field_name_arrays`/`tag_name_array` on `LLVMEmitter`) and
/// the error-trace `Frame` builders. Reads cached LLVM handles / the IR type
/// table / the module via `self.e.*`; the memoizing composite getters
/// (`getStringStructType`/`getFrameStructType`) + `emitFieldValueGet` stay on
/// `LLVMEmitter`. Entry points are reached via `self.reflection()`.
pub const Reflection = struct {
e: *LLVMEmitter,
/// Lazy global `[N x string]` indexed by `TypeId.index()`, holding each
/// type's display name. Built on the first dynamic `type_name(t)` call site.
pub fn getOrBuildTypeNameArray(self: Reflection) c.LLVMValueRef {
if (self.e.type_name_array) |g| return g;
const n: u32 = @intCast(self.e.ir_mod.types.infos.items.len);
const string_ty = self.e.getStringStructType();
var field_vals = std.ArrayList(c.LLVMValueRef).empty;
defer field_vals.deinit(self.e.alloc);
var i: u32 = 0;
while (i < n) : (i += 1) {
const tid = TypeId.fromIndex(i);
const name_str = self.e.ir_mod.types.formatTypeName(self.e.alloc, tid);
const str_z = self.e.alloc.dupeZ(u8, name_str) catch unreachable;
defer self.e.alloc.free(str_z);
const global_str = c.LLVMAddGlobal(self.e.llvm_module, c.LLVMArrayType(self.e.cached_i8, @intCast(name_str.len + 1)), "tn.str");
c.LLVMSetInitializer(global_str, c.LLVMConstStringInContext(self.e.context, str_z.ptr, @intCast(name_str.len + 1), 1));
c.LLVMSetGlobalConstant(global_str, 1);
c.LLVMSetLinkage(global_str, c.LLVMPrivateLinkage);
const len_val = c.LLVMConstInt(self.e.cached_i64, name_str.len, 0);
var struct_fields = [2]c.LLVMValueRef{ global_str, len_val };
const const_struct = c.LLVMConstStructInContext(self.e.context, &struct_fields, 2, 0);
field_vals.append(self.e.alloc, const_struct) catch unreachable;
}
const arr_ty = c.LLVMArrayType(string_ty, n);
const arr_init = c.LLVMConstArray(string_ty, field_vals.items.ptr, n);
const global = c.LLVMAddGlobal(self.e.llvm_module, arr_ty, "__sx_type_names");
c.LLVMSetInitializer(global, arr_init);
c.LLVMSetGlobalConstant(global, 1);
c.LLVMSetLinkage(global, c.LLVMPrivateLinkage);
self.e.type_name_array = global;
self.e.type_name_array_len = n;
return global;
}
/// Lazy global `[N x i1]` indexed by `TypeId.index()`: 1 where the type is
/// an unsigned integer. Built on the first dynamic `type_is_unsigned(t)`
/// call site; the runtime arm GEPs in at the boxed TypeId and loads the bit.
/// Derives every entry from `TypeTable.isUnsignedInt` — the single
/// signedness source-of-truth, so no per-index magic lives in the emitter.
pub fn getOrBuildTypeIsUnsignedArray(self: Reflection) c.LLVMValueRef {
if (self.e.type_is_unsigned_array) |g| return g;
const n: u32 = @intCast(self.e.ir_mod.types.infos.items.len);
var field_vals = std.ArrayList(c.LLVMValueRef).empty;
defer field_vals.deinit(self.e.alloc);
var i: u32 = 0;
while (i < n) : (i += 1) {
const tid = TypeId.fromIndex(i);
const bit: u64 = if (self.e.ir_mod.types.isUnsignedInt(tid)) 1 else 0;
field_vals.append(self.e.alloc, c.LLVMConstInt(self.e.cached_i1, bit, 0)) catch unreachable;
}
const arr_ty = c.LLVMArrayType(self.e.cached_i1, n);
const arr_init = c.LLVMConstArray(self.e.cached_i1, field_vals.items.ptr, n);
const global = c.LLVMAddGlobal(self.e.llvm_module, arr_ty, "__sx_type_is_unsigned");
c.LLVMSetInitializer(global, arr_init);
c.LLVMSetGlobalConstant(global, 1);
c.LLVMSetLinkage(global, c.LLVMPrivateLinkage);
self.e.type_is_unsigned_array = global;
self.e.type_is_unsigned_array_len = n;
return global;
}
/// Build (or return cached) a global constant array of {ptr, i64} string values
/// for the field names of a struct type.
pub fn getOrBuildFieldNameArray(self: Reflection, struct_type: TypeId) c.LLVMValueRef {
if (self.e.field_name_arrays.get(struct_type.index())) |g| return g;
const info = self.e.ir_mod.types.get(struct_type);
// Collect name StringIds from struct fields, union fields, or enum variants
var name_ids = std.ArrayList(StringId).empty;
defer name_ids.deinit(self.e.alloc);
switch (info) {
.@"struct" => |s| {
for (s.fields) |f| name_ids.append(self.e.alloc, f.name) catch unreachable;
},
.@"union" => |u| {
for (u.fields) |f| name_ids.append(self.e.alloc, f.name) catch unreachable;
},
.tagged_union => |u| {
for (u.fields) |f| name_ids.append(self.e.alloc, f.name) catch unreachable;
},
.@"enum" => |e| {
for (e.variants) |v| name_ids.append(self.e.alloc, v) catch unreachable;
},
else => {},
}
const string_ty = self.e.getStringStructType();
const n: u32 = @intCast(name_ids.items.len);
// Build constant initializer: [N x {ptr, i64}]
var field_vals = std.ArrayList(c.LLVMValueRef).empty;
defer field_vals.deinit(self.e.alloc);
for (name_ids.items) |name_id| {
const name_str = self.e.ir_mod.types.getString(name_id);
const str_z = self.e.alloc.dupeZ(u8, name_str) catch unreachable;
defer self.e.alloc.free(str_z);
const global_str = c.LLVMAddGlobal(self.e.llvm_module, c.LLVMArrayType(self.e.cached_i8, @intCast(name_str.len + 1)), "fld.str");
c.LLVMSetInitializer(global_str, c.LLVMConstStringInContext(self.e.context, str_z.ptr, @intCast(name_str.len + 1), 1));
c.LLVMSetGlobalConstant(global_str, 1);
c.LLVMSetLinkage(global_str, c.LLVMPrivateLinkage);
// Build fat pointer {ptr, len} as constant struct
const len_val = c.LLVMConstInt(self.e.cached_i64, name_str.len, 0);
var struct_fields = [2]c.LLVMValueRef{ global_str, len_val };
const const_struct = c.LLVMConstStructInContext(self.e.context, &struct_fields, 2, 0);
field_vals.append(self.e.alloc, const_struct) catch unreachable;
}
// Create global array [N x {ptr, i64}]
const array_ty = c.LLVMArrayType(string_ty, n);
const array_init = c.LLVMConstArray(string_ty, field_vals.items.ptr, n);
const global = c.LLVMAddGlobal(self.e.llvm_module, array_ty, "field_names");
c.LLVMSetInitializer(global, array_init);
c.LLVMSetGlobalConstant(global, 1);
c.LLVMSetLinkage(global, c.LLVMPrivateLinkage);
self.e.field_name_arrays.put(struct_type.index(), global) catch unreachable;
return global;
}
/// The always-linked tag-name table: a `[N x {ptr, i64}]` global of tag
/// names indexed by global tag id (the `TagRegistry` namespace; slot 0 is
/// the reserved "" no-error name). `error_tag_name_get` GEPs into it at the
/// runtime tag id. Built once per module. Always emitted (not trace-gated)
/// so `{}` interpolation of an error tag works even in release builds.
pub fn getOrBuildTagNameArray(self: Reflection) c.LLVMValueRef {
if (self.e.tag_name_array) |g| return g;
const string_ty = self.e.getStringStructType();
const names = self.e.ir_mod.types.tags.names.items;
var field_vals = std.ArrayList(c.LLVMValueRef).empty;
defer field_vals.deinit(self.e.alloc);
for (names) |name_str| {
const str_z = self.e.alloc.dupeZ(u8, name_str) catch unreachable;
defer self.e.alloc.free(str_z);
const global_str = c.LLVMAddGlobal(self.e.llvm_module, c.LLVMArrayType(self.e.cached_i8, @intCast(name_str.len + 1)), "tag.str");
c.LLVMSetInitializer(global_str, c.LLVMConstStringInContext(self.e.context, str_z.ptr, @intCast(name_str.len + 1), 1));
c.LLVMSetGlobalConstant(global_str, 1);
c.LLVMSetLinkage(global_str, c.LLVMPrivateLinkage);
const len_val = c.LLVMConstInt(self.e.cached_i64, name_str.len, 0);
var struct_fields = [2]c.LLVMValueRef{ global_str, len_val };
const const_struct = c.LLVMConstStructInContext(self.e.context, &struct_fields, 2, 0);
field_vals.append(self.e.alloc, const_struct) catch unreachable;
}
const n: u32 = @intCast(names.len);
const array_ty = c.LLVMArrayType(string_ty, n);
const array_init = c.LLVMConstArray(string_ty, field_vals.items.ptr, n);
const global = c.LLVMAddGlobal(self.e.llvm_module, array_ty, "tag_names");
c.LLVMSetInitializer(global, array_init);
c.LLVMSetGlobalConstant(global, 1);
c.LLVMSetLinkage(global, c.LLVMPrivateLinkage);
self.e.tag_name_array = global;
return global;
}
/// An interned constant sx `string` (`{ ptr, i64 }`) of the cached string
/// struct type, backed by a private NUL-terminated data global. Cached by
/// content so a path/name shared by many push sites is emitted once.
fn buildStringConst(self: Reflection, s: []const u8) c.LLVMValueRef {
if (self.e.frame_str_cache.get(s)) |v| return v;
const str_z = self.e.alloc.dupeZ(u8, s) catch unreachable;
defer self.e.alloc.free(str_z);
const data = c.LLVMAddGlobal(self.e.llvm_module, c.LLVMArrayType(self.e.cached_i8, @intCast(s.len + 1)), "frame.str");
c.LLVMSetInitializer(data, c.LLVMConstStringInContext(self.e.context, str_z.ptr, @intCast(s.len + 1), 1));
c.LLVMSetGlobalConstant(data, 1);
c.LLVMSetLinkage(data, c.LLVMPrivateLinkage);
c.LLVMSetUnnamedAddress(data, c.LLVMGlobalUnnamedAddr);
var fields = [_]c.LLVMValueRef{ data, c.LLVMConstInt(self.e.cached_i64, s.len, 0) };
const str_const = c.LLVMConstNamedStruct(self.e.getStringStructType(), &fields, 2);
const key = self.e.alloc.dupe(u8, s) catch return str_const;
self.e.frame_str_cache.put(key, str_const) catch self.e.alloc.free(key);
return str_const;
}
/// Build the interned `Frame` global for a `.trace_frame` push site and
/// return its address as `i64` (the value `sx_trace_push` stores). Resolves
/// the instruction's span + current function to `{file,line,col,func}`. The
/// file is shown as its basename so trace output is machine-independent
/// (the harness passes absolute paths); full paths live in DWARF.
pub fn emitTraceFrame(self: Reflection, instruction: *const Inst) c.LLVMValueRef {
const file = std.fs.path.basename(self.e.current_func_file);
const src = self.e.sourceForFile(self.e.current_func_file);
const loc = errors.SourceLoc.compute(src, instruction.span.start);
const func_name = self.e.ir_mod.types.getString(self.e.ir_mod.functions.items[self.e.current_func_idx].name);
var fields = [_]c.LLVMValueRef{
self.buildStringConst(file),
c.LLVMConstInt(self.e.cached_i32, loc.line, 0),
c.LLVMConstInt(self.e.cached_i32, loc.col, 0),
self.buildStringConst(func_name),
self.buildStringConst(errors.lineAt(src, instruction.span.start)),
};
const frame_ty = self.e.getFrameStructType();
const frame_const = c.LLVMConstNamedStruct(frame_ty, &fields, 5);
const g = c.LLVMAddGlobal(self.e.llvm_module, frame_ty, "trace.frame");
c.LLVMSetInitializer(g, frame_const);
c.LLVMSetGlobalConstant(g, 1);
c.LLVMSetLinkage(g, c.LLVMPrivateLinkage);
return c.LLVMConstPtrToInt(g, self.e.cached_i64);
}
};