Lua Metaprogram: Scan codepaths collapse + more reviews.

This commit is contained in:
2026-07-11 13:45:22 -04:00
parent 2b00956862
commit 072231c46b
9 changed files with 870 additions and 1457 deletions
+41 -185
View File
@@ -1,8 +1,9 @@
--- passes/offsets.lua — Branch-offset generator.
---
--- Scans every source for `MipsAtom_(name) { ... }` (and the raw `MipsCode code_<name> { ... }` form) declarations,
--- computes the word offset from each `atom_offset(F, T)` marker to its target `atom_label(T)` declaration,
--- and emits `<dir_basename>.offsets.h` with one `#define _atom_offset_F_T = N` per branch.
--- Reads the pre-scanned SourceScan payload (produced once upstream by `duffle.scan_source`)
--- for `MipsAtom_(name)` and `MipsCode code_<name>` declarations, computes the word offset
--- from each `atom_offset(F, T)` marker to its target `atom_label(T)` declaration, and emits
--- `<dir_basename>.offsets.h` with one `#define _atom_offset_F_T = N` per branch.
---
--- The offset is `target_word - branch_word - 1` (the standard MIPS branch-immediate encoding: branch_offset = relative_pc_in_words - 1).
---
@@ -13,8 +14,7 @@
-- Module-scope requires + package.path setup
-- ════════════════════════════════════════════════════════════════════════════
-- Resolve `arg[0]` to an absolute-ish script directory so that `require("duffle")` resolves against `scripts/` regardless of CWD.
-- Bootstrap: see `ps1_meta.lua` for the rationale.
-- Bootstrap: same as entry scripts. See `ps1_meta.lua` for the rationale.
-- Bootstrap: load `scripts/duffle_paths.lua` (sets package.path + package.cpath).
-- Uses `debug.getinfo` to find this file's own directory, so it works
-- both standalone and when require'd from the orchestrator.
@@ -29,21 +29,6 @@ local count_token_words = word_count_eval.count_token_words
-- Constants
-- ════════════════════════════════════════════════════════════════════════════
-- C qualifier keywords that may precede a `MipsAtom_` declaration
-- (and should be skipped by `skip_qualifiers`).
local QUALIFIER_KEYWORDS = {
["static"] = true, ["const"] = true, ["volatile"] = true,
["extern"] = true, ["register"] = true, ["auto"] = true,
["inline"] = true, ["typedef"] = true,
["internal"] = true, ["LP_"] = true, ["global"] = true, ["gkknown"] = true,
}
-- Atom declaration identifiers.
local ATOM_PREFIX = "MipsAtom_"
local CODE_DECL = "MipsCode"
local CODE_RAW_PREFIX = "code_" -- raw atom form: `MipsCode code_<name> { ... }`
local CODE_RAW_PREFIX_LEN = 5 -- = #CODE_RAW_PREFIX
-- Marker-call identifiers inside atom bodies.
local LABEL_MARKER = "atom_label"
local OFFSET_MARKER = "atom_offset"
@@ -64,6 +49,7 @@ local OFFSET_MACRO_COL = 44
--- @field text string -- the full source text
--- @field dir string -- the directory containing the source
--- @field basename string -- filename without extension
--- @field scan table -- pre-scanned SourceScan payload (from duffle.scan_source)
--- @class PassCtx
--- @field sources SourceFile[] -- all source files in the build
@@ -75,17 +61,13 @@ local OFFSET_MACRO_COL = 44
--- @field upstream table<string, table> -- per-pass upstream outputs
--- @field flags table -- CLI flags
--- @field dry_run boolean -- if true, compute but don't write
--- @field verbose boolean -- if true, log diagnostic info
--- @field verbose boolean -- log diagnostic info
--- @class PassResult
--- @field outputs table[] -- {kind=, path=} entries describing emit files
--- @field errors table[] -- {line=, msg=} entries; build-stops
--- @field warnings table[] -- {line=, msg=} entries; build-succeeds
--- @class Atom
--- @field name string -- atom name (e.g. "cube_g4_face")
--- @field body string -- the brace-delimited body (without the braces)
--- @class BranchOffset
--- @field tag string -- the marker tag (e.g. "F" in `atom_offset(F, T)`)
--- @field target string -- the target label name (e.g. "T" in `atom_offset(F, T)`)
@@ -98,44 +80,7 @@ local OFFSET_MACRO_COL = 44
--- @field offsets BranchOffset[] -- per-branch offset list
-- ════════════════════════════════════════════════════════════════════════════
-- Local helpers
-- ════════════════════════════════════════════════════════════════════════════
-- Returns true if `s` starts with `prefix`.
-- @param s string
-- @param prefix string
-- @return boolean
local function starts_with(s, prefix)
if #s < #prefix then return false end
for pos = 1, #prefix do
if s:sub(pos, pos) ~= prefix:sub(pos, pos) then return false end
end
return true
end
-- Replace every non-alphanumeric char in `s` with underscore.
-- @param s string
-- @return string
local function to_alnum_underscore(s)
local out = ""
for pos = 1, #s do
local ch = s:sub(pos, pos)
if duffle.is_alnum(ch) then out = out .. ch else out = out .. "_" end
end
return out
end
-- Right-pad `s` with spaces to width `w`. If `s` is already `w` or
-- wider, no padding is added.
-- @param s string
-- @param w integer
-- @return string
local function pad_right(s, w)
return s .. string.rep(" ", math.max(0, w - #s))
end
-- ════════════════════════════════════════════════════════════════════════════
-- Marker-call helpers
-- Per-token marker-call helpers (atom_label / atom_offset inside bodies)
-- ════════════════════════════════════════════════════════════════════════════
-- Extract comma-separated identifier args from a parenthesized group after a function-like macro call.
@@ -254,123 +199,12 @@ local function find_marker_call_end(tok)
end
-- ════════════════════════════════════════════════════════════════════════════
-- Atom scanner
-- Per-atom body scan (for atom_label / atom_offset markers)
-- ════════════════════════════════════════════════════════════════════════════
--- Skip C qualifier keywords (`static`, `const`, etc.) and return the position past the last qualifier.
--- @param source string
--- @param pos integer
--- @return integer
local function skip_qualifiers(source, pos)
while true do
pos = duffle.skip_ws_and_cmt(source, pos)
local ident, after = duffle.read_ident(source, pos)
if not ident then return pos end
if QUALIFIER_KEYWORDS[ident] then pos = after else return pos end
end
end
-- (internal) Try to parse the wrapped atom form: `MipsAtom_(<name>) { ... }`.
-- Returns the parsed Atom (name + body + position past body), or nil if the form didn't match.
-- @param source_text string
-- @param after_pos integer -- position just past `MipsAtom_`
-- @return Atom|nil
local function try_wrapped_atom(source_text, after_pos)
local paren_pos = duffle.skip_ws_and_cmt(source_text, after_pos)
if source_text:sub(paren_pos, paren_pos) ~= "(" then return nil end
local inner, after_paren = duffle.read_parens(source_text, paren_pos)
-- scan: MipsAtom_(<name>)
local name_start = 1
while name_start <= #inner and duffle.is_space(inner:sub(name_start, name_start)) do
name_start = name_start + 1
end
local name_end = name_start
while name_end <= #inner and duffle.is_alnum(inner:sub(name_end, name_end)) do
name_end = name_end + 1
end
local name = inner:sub(name_start, name_end - 1)
if name == "" then return nil end
local brace_pos = duffle.scan_to_char(source_text, "{", after_paren)
-- scan: MipsAtom_(<name>) {
if not brace_pos then return nil end
local body, after_brace = duffle.read_braces(source_text, brace_pos)
-- scan: MipsAtom_(<name>) { <body> }
return { name = name, body = body, after_brace = after_brace }
end
-- (internal) Try to parse the raw atom form: `MipsCode code_<name> { ... }`.
-- @param source_text string
-- @param after_pos integer -- position just past `MipsCode`
-- @return Atom|nil
local function try_raw_atom(source_text, after_pos)
local next_pos = duffle.skip_ws_and_cmt(source_text, after_pos)
local next_ident, next_after = duffle.read_ident(source_text, next_pos)
-- scan: MipsCode <next_ident>
if not next_ident then return nil end
if not starts_with(next_ident, CODE_RAW_PREFIX) then return nil end
if #next_ident <= CODE_RAW_PREFIX_LEN then return nil end
local atom_name = next_ident:sub(CODE_RAW_PREFIX_LEN + 1)
-- scan: MipsCode code_<name>
local brace_pos = duffle.scan_to_char(source_text, "{", next_after)
-- scan: MipsCode code_<name> {
if not brace_pos then return nil end
local body, after_brace = duffle.read_braces(source_text, brace_pos)
-- scan: MipsCode code_<name> { <body> }
return { name = atom_name, body = body, after_brace = after_brace }
end
--- Find every `MipsAtom_(name) { ... }` (or raw `MipsCode code_<name> { ... }`) declaration in a source.
--- @param source_text string
--- @return Atom[]
local function find_atoms(source_text)
local atoms = {}
local pos = 1
local src_len = #source_text
while pos <= src_len do
pos = duffle.skip_ws_and_cmt(source_text, pos); if pos > src_len then break end
pos = skip_qualifiers(source_text, pos); if pos > src_len then break end
local ident, after = duffle.read_ident(source_text, pos)
-- scan: <ident>
if not ident then pos = pos + 1; goto continue end
if ident == ATOM_PREFIX then
-- scan: MipsAtom_(<name>) { <body> }
local atom = try_wrapped_atom(source_text, after)
if atom then
atoms[#atoms + 1] = { name = atom.name, body = atom.body }
pos = atom.after_brace
else
pos = pos + 1
end
elseif ident == CODE_DECL then
-- scan: MipsCode code_<name> { <body> }
local atom = try_raw_atom(source_text, after)
if atom then
atoms[#atoms + 1] = { name = atom.name, body = atom.body }
pos = atom.after_brace
else
pos = after
end
else
pos = after
end
::continue::
end
return atoms
end
-- ════════════════════════════════════════════════════════════════════════════
-- Per-atom body scan
-- ════════════════════════════════════════════════════════════════════════════
-- (internal) Count words emitted by the rest of `tok` after a marker call
-- (the marker call itself emits 0 words, but the source pattern may bundle the marker with the next instruction on the same line,
-- separated by no top-level comma).
-- (internal) Count words emitted by the rest of `tok` after a marker call
-- (the marker call itself emits 0 words, but the source pattern may bundle the marker with the next instruction on the same line,
-- separated by no top-level comma).
-- Returns the word count contributed by that rest.
-- @param tok string
-- @param word_counts table
@@ -435,8 +269,15 @@ local function compute_offsets(labels, branches)
return results
end
-- (internal) Build a constant-table entry `{macro_name, enum_name, value}`
-- from a BranchOffset.
-- Right-pad `s` with spaces to width `w`. If `s` is already `w` or wider, no padding is added.
-- @param s string
-- @param w integer
-- @return string
local function pad_right(s, w)
return s .. string.rep(" ", math.max(0, w - #s))
end
-- (internal) Build a constant-table entry `{macro_name, enum_name, value}` from a BranchOffset.
-- @param r BranchOffset
-- @return table
local function make_offset_const(r)
@@ -501,13 +342,28 @@ end
local M = {}
-- (internal) Process one source: find atoms, scan bodies, write header.
-- Project the pre-scanned SourceScan entries into the {name, body} shape this pass needs.
-- MipsAtom_ entries have kind="atom"; MipsCode code_<name> entries have kind="raw_atom".
-- @param scan table -- SourceScan from duffle.scan_source
-- @return table[] -- list of {name=, body=}
local function project_atoms(scan)
local out = {}
for _, a in ipairs(scan.atoms) do
out[#out + 1] = { name = a.raw_name, body = a.body }
end
for _, a in ipairs(scan.raw_atoms) do
out[#out + 1] = { name = a.name, body = a.body }
end
return out
end
-- (internal) Process one source: project atoms from scan, scan bodies, write header.
-- Returns the offsets_h path if a header was written, or nil.
-- @param ctx PassCtx
-- @param src SourceFile
-- @return string|nil -- the offsets_h path
local function process_source(ctx, src)
local atoms = find_atoms(src.text)
local atoms = project_atoms(src.scan)
if #atoms == 0 then return nil end
local atoms_data = {}
@@ -528,9 +384,9 @@ local function process_source(ctx, src)
return out_path
end
--- Run the offsets pass.
--- For each source, emits a per-module `<dir_basename>.offsets.h` containing `#define _atom_offset_F_T = N` constants for every `atom_offset(F, T)` reference
--- in the source's atoms.
--- Run the offsets pass.
--- For each source, emits a per-module `<dir_basename>.offsets.h` containing `#define _atom_offset_F_T = N` constants
--- for every `atom_offset(F, T)` reference in the source's atoms.
--- @param ctx PassCtx
--- @return PassResult
function M.run(ctx)