[temp][do not merge] probe: i686-windows-msvc import std under LLVM 23.1.3 (#781 part 3, G1/G2)

.agents/docs/README.md

@@ -18,7 +18,7 @@ superseded_by: 2026-09-07-....md  # when status is superseded
 ---
 ```
 
-327 records.
+330 records.
 
 ## By subject
 
@@ -95,6 +95,12 @@ Records that declare one. Everything else is listed by date below.
 - [SDK toolchains, the payload/engine seam, and openkal across iOS, Android and Web](2026-09-11-sdk-toolchains-and-ios-local-verification.md) — landed
 - [Where a platform's knowledge belongs: iOS, Android and Web across the engine, the index and the plugins](2026-09-11-platform-targets-design-review.md) — active
 
+### toolchain
+
+- [LLVM 23.1.3 Part 2：任务依赖与生态交付记录](2026-10-08-llvm-2313-part2-execution-and-dependencies.md) — active
+- [LLVM 23.1.3 Part 2：Linux aarch64 默认工具链与 glibc 生态闭环](2026-10-08-llvm-2313-linux-aarch64-ecosystem-part2-design.md) — active
+- [LLVM 23.1.3 全平台统一默认:跨仓库联动方案(mcpp × xim-pkgindex)](2026-10-07-llvm-2313-unified-default-cross-repo-design.md) — active
+
 ### triage
 
 - [Eight reports after 2026.9.27.1: what each one is, where it belongs, and one optimisation plan](2026-09-27-eight-reports-by-home-and-one-optimisation-plan.md) — active
@@ -118,6 +124,9 @@ Records that declare one. Everything else is listed by date below.
 
 ### 2026-10
 
+- [LLVM 23.1.3 Part 2：任务依赖与生态交付记录](2026-10-08-llvm-2313-part2-execution-and-dependencies.md) — active
+- [LLVM 23.1.3 Part 2：Linux aarch64 默认工具链与 glibc 生态闭环](2026-10-08-llvm-2313-linux-aarch64-ecosystem-part2-design.md) — active
+- [LLVM 23.1.3 全平台统一默认:跨仓库联动方案(mcpp × xim-pkgindex)](2026-10-07-llvm-2313-unified-default-cross-repo-design.md) — active
 - [2026.10.5.3 发布方案：32 位 x86 的架构词汇、资源编译器的识别与增量（#776 后续）](2026-10-06-windows-x86-arch-vocabulary-and-rc-follow-ups-design.md) — active
 - [下一个版本的发布方案：标准库模块、原生 MSVC LTO 与导出发现、共享库的链接配置、Windows 参数引号（#768 后续、#770、#771）](2026-10-05-std-module-pair-msvc-lto-and-export-discovery-design.md) — active
 - [`mcpp run` hands the terminal to the program, and the follow-ups of #761, #763 and #765 (#766)](2026-10-05-run-terminal-handoff-and-766-follow-ups-design.md) — landed

.gitattributes

@@ -0,0 +1,2 @@
+# The cross-host admission compares the exact source bytes compiled by each host.
+tests/fixtures/openkal-hosted-threads/src/main.cpp.in text eol=lf

.github/actions/bootstrap-mcpp/action.yml

@@ -33,7 +33,7 @@ inputs:
     # `package.name`, so one of the two was simply unreachable — and which one
     # depended on the machine, which is why CI failed on `compat:lua` on
     # Windows and `mcpplibs.capi:lua` on Linux. Never pin below that.
-    default: '2026.9.30.1'
+    default: '2026.10.8.1'
 
 outputs:
   sandbox-key:

.github/actions/setup-macos-llvm/action.yml

@@ -15,7 +15,7 @@ inputs:
     # Floor imposed by the index, not a routine bump — see
     # .github/actions/bootstrap-mcpp/action.yml for why 0.4.69 is required
     # (two packages named `lua` in one repo need openxlings/xlings#381).
-    default: '2026.9.30.1'
+    default: '2026.10.8.1'
   image:
     description: >
       The runner label the job runs on (macos-15, xcode-27). It is part of the
@@ -72,7 +72,7 @@ runs:
         # latest-first: test binaries now link the toolchain's own libc++
         # (A1 root fix in flags.cppm), so new llvm releases are
         # self-consistent — the macOS job is the proof for each new default.
-        xlings install llvm -y || xlings install llvm@20.1.7 -y
+        xlings install llvm@23.1.3 -y || xlings install llvm -y
         LLVM_ROOT=$(find "$HOME/.xlings" -path "*/xpkgs/xim-x-llvm/*/bin/clang++" | head -1 | xargs dirname | xargs dirname)
         ls "$LLVM_ROOT/bin/clang++"
         "$LLVM_ROOT/bin/clang++" --version

.github/actions/use-built-mcpp/use.sh

@@ -29,6 +29,19 @@ fi
 # The toolchain mcpp.toml names for this host is the one the build used, so it
 # is the one whose payloads hold the binary's runtime.
 manifest_toolchain() {
+    # Native ARM64 overrides the platform-wide GCC pin. Consumers must install
+    # the same payload used by build.yml, including the first launch's runtime.
+    if [ "$host" = linux-aarch64 ]; then
+        local native
+        native="$(awk '
+            /^\[/ { in_tc = ($0 == "[target.aarch64-linux-gnu]"); next }
+            in_tc && $1 == "toolchain" { gsub(/"/, "", $3); print $3; exit }
+        ' mcpp.toml)"
+        if [ -n "$native" ]; then
+            printf '%s\n' "$native"
+            return
+        fi
+    fi
     local key
     case "$host" in
         macos-*)   key=macos ;;

.github/probe/stl_coroutine_facts.sh

@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+# TEMPORARY PROBE (do not merge): how the machine's MSVC STL guards its
+# coroutine headers, and which headers of the std module depend on them.
+# Prints; asserts nothing.
+set -u
+vswhere="/c/Program Files (x86)/Microsoft Visual Studio/Installer/vswhere.exe"
+vs=$("$vswhere" -latest -products '*' -property installationPath | tr -d '\r')
+vs=$(cygpath -u "$vs")
+for tools in "$vs"/VC/Tools/MSVC/*; do
+  inc="$tools/include"; mods="$tools/modules"
+  echo "### toolset $(basename "$tools")"
+  echo "--- x86 libraries present:"; ls -d "$tools/lib/x86" 2>&1
+  echo "--- <coroutine> preprocessor lines:"
+  grep -nE '^\s*#\s*(if|ifdef|ifndef|elif|else|endif|error|define _COROUTINE_)|_EMIT_STL|__cpp_impl_coroutine' "$inc/coroutine" | head -40
+  echo "--- <generator> preprocessor lines:"
+  grep -nE '^\s*#\s*(if|ifdef|ifndef|elif|else|endif|error|define _GENERATOR_)|_EMIT_STL|__cpp_impl_coroutine|__cpp_lib_coroutine|include <coroutine>' "$inc/generator" | head -40
+  echo "--- yvals_core.h coroutine feature lines:"
+  grep -nE '__cpp_impl_coroutine|__cpp_lib_coroutine|__cpp_lib_generator' "$inc/yvals_core.h"
+  echo "--- std.ixx lines naming generator/coroutine (with the surrounding conditionals):"
+  grep -nE 'generator|coroutine|^\s*#\s*(if|elif|else|endif)' "$mods/std.ixx" | head -60
+  echo "--- STL headers that use coroutine_handle / suspend_always:"
+  grep -lE 'coroutine_handle|suspend_always' "$inc"/* 2>/dev/null | xargs -n1 basename
+done

.github/probe/x86_msvc_std_cases.sh

@@ -0,0 +1,75 @@
+#!/usr/bin/env bash
+# TEMPORARY PROBE (do not merge): `import std` on i686-windows-msvc with
+# clang 23.1.3 and 22.1.8, mcpp built from the #781 head. Answers G1/G2 of
+# .agents/reviews/2026-10-08-llvm-2313-part3-review-fixes-and-x86-msvc-coroutines-design.md.
+# Prints; asserts nothing.
+set -u
+M="${MCPP_BUILT:?}"
+W="$RUNNER_TEMP/x86-msvc-std"; mkdir -p "$W"
+"$M" --version
+
+# case <name> <target> <standard> <toolchain-table> <source-kind>
+case_run() {
+  local name=$1 target=$2 std=$3 tc=$4 src=$5
+  local d="$W/$name"; rm -rf "$d"; mkdir -p "$d/src"; cd "$d"
+  printf '[package]\nname = "p"\nversion = "0.1.0"\nstandard = "%s"\n\n%s\n' "$std" "$tc" > mcpp.toml
+  case "$src" in
+    std)     printf 'import std;\nint main() { std::println("std ok {}", sizeof(void*)); }\n' > src/main.cpp ;;
+    compat)  printf 'import std.compat;\nint main() { std::printf("compat ok %%zu\\n", sizeof(void*)); }\n' > src/main.cpp ;;
+    std20)   printf 'import std;\nint main() { std::cout << "std ok " << sizeof(void*) << "\\n"; }\n' > src/main.cpp ;;
+    coro)    printf '#include <coroutine>\nstruct t { struct promise_type { t get_return_object() { return {}; } std::suspend_never initial_suspend() noexcept { return {}; } std::suspend_never final_suspend() noexcept { return {}; } void return_void() {} void unhandled_exception() {} }; };\nt f() { co_return; }\nint main() { f(); }\n' > src/main.cpp ;;
+  esac
+  echo; echo "################ $name  target=$target standard=$std src=$src"
+  echo "--- mcpp.toml"; cat mcpp.toml
+  echo "--- build"
+  "$M" build --verbose --target "$target" > build.log 2>&1; local rc=$?
+  cat build.log; echo "build rc=$rc"
+  echo "--- lines naming generator / coroutine / __cpp_impl_coroutine:"
+  grep -nE 'generator|coroutine|__cpp_impl_coroutine' build.log | head -30
+  if [ $rc -eq 0 ]; then
+    local exe; exe=$(find target -type f -name 'p.exe' | head -1)
+    echo "--- run $exe"; "$exe"; echo "run rc=$?"
+    command -v file >/dev/null && file "$exe"
+  fi
+}
+
+# A custom triple needs its own section (measured in run 37791590252: without
+# one, `--target i686-windows-msvc` is refused as an unknown target).
+T23='[toolchain]
+windows = "llvm@23.1.3"
+
+[target.i686-windows-msvc]
+toolchain = "llvm@23.1.3"'
+TEMPTY='[toolchain]
+windows = "llvm@23.1.3"
+
+[target.i686-windows-msvc]'
+T22i='[toolchain]
+windows = "llvm@23.1.3"
+
+[target.i686-windows-msvc]
+toolchain = "llvm@22.1.8"'
+T22x='[toolchain]
+windows = "llvm@23.1.3"
+
+[target.x86-windows-msvc]
+toolchain = "llvm@22.1.8"'
+
+# G1: the reported failure, and what the compiler says where.
+case_run g1-23-cxx23-i686        i686-windows-msvc   c++23 "$T23"  std
+# G2: C++20 on the same compiler and target.
+case_run g2-23-cxx20-i686        i686-windows-msvc   c++20 "$T23"  std20
+case_run g2-23-cxx20-i686-compat i686-windows-msvc   c++20 "$T23"  compat
+# Using the coroutine library itself under C++20 (expected to be refused by the
+# STL or the compiler; recorded for the documentation).
+case_run g2-23-cxx20-i686-coro   i686-windows-msvc   c++20 "$T23"  coro
+# The section with nothing in it: what does a user who only names the triple get?
+case_run g1-23-cxx23-i686-empty  i686-windows-msvc   c++23 "$TEMPTY" std
+# Option (b) and G3 were measured in run 37791590252 (both build and run); not repeated.
+exit 0
+# Option (b): llvm 22.1.8 for this target only, in the spelling the note uses
+# and in MSVC's x86 spelling.
+case_run g1b-22-cxx23-i686       i686-windows-msvc   c++23 "$T22i" std
+case_run g1b-22-cxx23-x86        x86-windows-msvc    c++23 "$T22x" std
+# G3: the 64-bit row is unaffected.
+case_run g3-23-cxx23-x64         x86_64-windows-msvc c++23 "$T23"  std

.github/tools/build_examples.sh

@@ -30,7 +30,7 @@ BUILD=(
     # Built here for one reason worth the cost: it is the only example whose
     # CPU-only configuration exercises `cfg(accelerator = "none")` and two rule
     # packages in one build program, and both of those are engine paths that a
-    # description cannot cover. Its `[toolchain] default = "llvm@22.1.8"` means
+    # description cannot cover. Its `[toolchain] default = "llvm@23.1.3"` means
     # this job installs an LLVM payload it otherwise would not -- the CUDA leg
     # takes the clang route, because the nvcc route on the 12.9 line is refused
     # by nvcc's own front end and the 13.x line raises the driver floor to r580.