pgo: replace meson-pgo.sh with several script primitives

All scripts are in the ‘pgo’ directory:

* options: command line options for generate-alt-random-writes.py,
  sourced by other scripts.

* pgo.sh: top-level script, generates a meson build directory, selects
  a PGO method, generates the profiling data, re-configures the meson
  build directory and does the final build.

  This script is intended to be used by end-users, and shows _how_ to
  integrate the script primitives.

  Build servers will most likely *not* want to use this script as-is.

* partial.sh: generates alt-random-write data and runs “foot{,client}
  --version”, and then feeds the alt-random data to the PGO helper
  binary. Does not require a running Wayland session. Touches
  $blddir/pgo-ok on success.

* full-inner.sh: runs “footclient --version”, and then a complex
  “foot” command that first generates alt-random-write data, and then
  “cat’s” it. Requires a running Wayland session, *but*, this script
  is usually not called directly (see below). Touches $blddir/pgo-ok
  onsucces..

* full-current-session.sh: runs full-inner.sh. That is, it runs foot
  in the currently running Wayland session. Note that this will pop up a
  foot window.

* full-headless-sway.sh: generates a custom Sway configuration that
  exec’s foot-headless-sway-inner.sh (see below), and then executes a
  headless Sway. In other words, this script does a *full* PGO build,
  but *without* requiring a running Wayland session. Requires Sway >=
  1.6.2.

* full-headless-sway.sh: runs full-inner.sh + “swaymsg exit”.

To do a custom PGO build, without using pgo.sh, you’d need to:

CFLAGS=”$CFLAGS -O3” meson --buildtype=release -Db_lto=true
meson configure -Db_pgo=generate
ninja
ninja test (only needed if tllist+fcft are built as subprojects)

Run *one* of:
  - partial.sh
  - full-current-session.sh
  - full-headless-sway.sh

meson configure -D b_pgo=use
ninja

meson-pgo.sh

@@ -1,154 +0,0 @@
-#!/bin/sh
-
-# Requirements:
-#
-# * all: build directory must not exist; it is created by the script
-# * all: LC_CTYPE must be set to an UTF-8 locale
-# * full*: must have at least one font installed
-# * full-headless-sway: Sway 1.6.2 must be installed
-
-
-set -e
-
-usage_and_die() {
-    echo "Usage: ${0} none|partial|full|full-headless-sway|[auto] <source-dir> <build-dir>"
-    exit 1
-}
-
-[ ${#} -ge 3 ] || usage_and_die
-
-mode=${1}
-source_dir=$(realpath "${2}")
-build_dir=$(realpath "${3}")
-shift 3
-
-# meson will complain if source dir is invalid
-
-if [ -d "${build_dir}" ]; then
-    echo "${build_dir}: build directory already exists"
-    exit 1
-fi
-
-compiler=other
-do_pgo=no
-
-CFLAGS="${CFLAGS} -O3"
-
-case $(${CC-cc} --version) in
-    *GCC*)
-        compiler=gcc
-        do_pgo=yes
-        ;;
-
-    *clang*)
-        compiler=clang
-
-        if command -v llvm-profdata > /dev/null; then
-            do_pgo=yes
-            CFLAGS="${CFLAGS} -Wno-ignored-optimization-argument"
-        fi
-        ;;
-esac
-
-case ${mode} in
-    partial|full|full-headless-sway)
-    ;;
-
-    none)
-        do_pgo=no
-        ;;
-
-    auto)
-        if command -v sway > /dev/null; then
-            mode=full-headless-sway
-        elif [ -n "${WAYLAND_DISPLAY+x}" ]; then
-            mode=full
-        else
-            mode=partial
-        fi
-        ;;
-
-    *)
-        usage_and_die
-        ;;
-esac
-
-# echo "source: ${source_dir}"
-# echo "build: ${build_dir}"
-# echo "compiler: ${compiler}"
-# echo "mode: ${mode}"
-
-export CFLAGS
-meson "${@}" "${build_dir}"
-
-if [ ${do_pgo} = yes ]; then
-    find . -name "*.gcda" -delete
-    meson configure "${build_dir}" -Db_pgo=generate
-    ninja -C "${build_dir}"
-
-    # If fcft/tllist are subprojects, we need to ensure their tests
-    # have been executed, or we’ll get “profile count data file not
-    # found” errors.
-    ninja -C "${build_dir}" test
-
-    script_options="--scroll --scroll-region --colors-regular --colors-bright --colors-256 --colors-rgb --attr-bold --attr-italic --attr-underline --sixel"
-
-    tmp_file=$(mktemp)
-    pwd=$(pwd)
-
-    cleanup() {
-        rm -f "${tmp_file}"
-        cd "${pwd}"
-    }
-    trap cleanup EXIT INT HUP TERM
-
-    cd "${build_dir}"
-    case ${mode} in
-        full)
-            ./footclient --version
-            ./foot \
-             --config=/dev/null \
-             --term=xterm \
-             sh -c "${source_dir}/scripts/generate-alt-random-writes.py ${script_options} ${tmp_file} && cat ${tmp_file}"
-            ;;
-
-        full-headless-sway)
-            ./footclient --version
-
-            runtime_dir=$(mktemp -d)
-            sway_conf=$(mktemp)
-
-            echo "exec ${build_dir}/foot -o tweak.render-timer=log --config=/dev/null --term=xterm sh -c \"${source_dir}/scripts/generate-alt-random-writes.py ${script_options} ${tmp_file} && cat ${tmp_file}\" && swaymsg exit" > "${sway_conf}"
-            export XDG_RUNTIME_DIR=${runtime_dir}
-            export WLR_BACKENDS=headless
-
-            sway -c "${sway_conf}"
-
-            rm "${sway_conf}"
-            rm -rf "${runtime_dir}"
-            ;;
-
-        partial)
-            ./footclient --version
-            ./foot --version
-            "${source_dir}"/scripts/generate-alt-random-writes.py \
-                --rows=67 \
-                --cols=135 \
-                ${script_options} \
-                "${tmp_file}"
-            ./pgo "${tmp_file}"
-            ;;
-    esac
-
-    cd "${pwd}"
-    rm "${tmp_file}"
-
-    if [ ${compiler} = clang ]; then
-        llvm-profdata \
-            merge \
-            "${build_dir}"/default_*.profraw \
-            --output="${build_dir}"/default.profdata
-    fi
-
-    meson configure "${build_dir}" -Db_pgo=use
-fi

pgo/full-current-session.sh

@@ -0,0 +1,8 @@
+#!/bin/sh
+
+set -eu
+
+srcdir=$(realpath "${1}")
+blddir=$(realpath "${2}")
+
+"${srcdir}"/pgo/full-inner.sh "${srcdir}" "${blddir}"

pgo/full-headless-sway-inner.sh

@@ -0,0 +1,9 @@
+#!/bin/sh
+
+set -u
+
+srcdir=$(realpath "${1}")
+blddir=$(realpath "${2}")
+
+"${srcdir}"/pgo/full-inner.sh "${srcdir}" "${blddir}"
+swaymsg exit

pgo/full-headless-sway.sh

@@ -0,0 +1,24 @@
+#!/bin/sh
+
+set -eu
+
+srcdir=$(realpath "${1}")
+blddir=$(realpath "${2}")
+
+runtime_dir=$(mktemp -d)
+sway_conf=$(mktemp)
+
+cleanup() {
+    rm -f "${sway_conf}"
+    rm -rf "${runtime_dir}"
+}
+trap cleanup EXIT INT HUP TERM
+
+# Generate a custom config that executes our generate-pgo-data script
+> "${sway_conf}" echo "exec '${srcdir}'/pgo/full-headless-sway-inner.sh '${srcdir}' '${blddir}'"
+
+# Run Sway. full-headless-sway-inner.sh ends with a ‘swaymsg exit’
+XDG_RUNTIME_DIR="${runtime_dir}" WLR_BACKENDS=headless sway -c "${sway_conf}"
+
+# Sway’s exit code doesn’t reflect our script’s exit code
+[ -f "${blddir}"/pgo-ok ] || exit 1

pgo/full-inner.sh

@@ -0,0 +1,31 @@
+#!/bin/sh
+
+set -eu
+
+srcdir=$(realpath "${1}")
+blddir=$(realpath "${2}")
+
+. "${srcdir}"/pgo/options
+
+pgo_data=$(mktemp)
+trap "rm -f ${pgo_data}" EXIT INT HUP TERM
+
+rm -f "${blddir}"/pgo-ok
+
+# To ensure profiling data is generated in the build directory
+cd "${blddir}"
+
+LC_CTYPE=en_US.UTF-8 "${blddir}"/footclient --version
+LC_CTYPE=en_US.UTF-8 "${blddir}"/foot \
+        -o tweak.render-timer=log \
+        --config=/dev/null \
+        --term=xterm \
+        sh -c "
+          set -eu
+
+         '${srcdir}/scripts/generate-alt-random-writes.py' \
+            ${script_options} \"${pgo_data}\"
+
+         cat \"${pgo_data}\"
+         "
+touch "${blddir}"/pgo-ok

pgo/options

@@ -0,0 +1 @@
+script_options="--scroll --scroll-region --colors-regular --colors-bright --colors-256 --colors-rgb --attr-bold --attr-italic --attr-underline --sixel"

pgo/partial.sh

@@ -0,0 +1,28 @@
+#!/bin/sh
+
+set -eu
+
+srcdir=$(realpath "${1}")
+blddir=$(realpath "${2}")
+
+. "${srcdir}"/pgo/options
+
+pgo_data=$(mktemp)
+trap "rm -f ${pgo_data}" EXIT INT HUP TERM
+
+rm -f "${blddir}"/pgo-ok
+
+"${srcdir}"/scripts/generate-alt-random-writes.py \
+           --rows=67 \
+           --cols=135 \
+           ${script_options} \
+           "${pgo_data}"
+
+# To ensure profiling data is generated in the build directory
+cd "${blddir}"
+
+"${blddir}"/footclient --version
+"${blddir}"/foot --version
+"${blddir}"/pgo "${pgo_data}"
+
+touch "${blddir}"/pgo-ok

pgo/pgo.sh

@@ -0,0 +1,101 @@
+#!/bin/sh
+
+set -eu
+
+usage_and_die() {
+    echo "Usage: ${0} none|partial|full-current-session|full-headless-sway|[auto] <source-dir> <build-dir> [meson options]"
+    exit 1
+}
+
+[ ${#} -ge 3 ] || usage_and_die
+
+mode=${1}
+srcdir=$(realpath "${2}")
+blddir=$(realpath "${3}")
+shift 3
+
+if [ -e "${blddir}" ]; then
+    echo "error: ${blddir}: build directory already exists"
+    exit 1
+fi
+
+compiler=other
+do_pgo=no
+
+CFLAGS="${CFLAGS-} -O3"
+
+case $(${CC-cc} --version) in
+    *GCC*)
+        compiler=gcc
+        do_pgo=yes
+        ;;
+
+    *clang*)
+        compiler=clang
+
+        if command -v llvm-profdata > /dev/null; then
+            do_pgo=yes
+            CFLAGS="${CFLAGS} -Wno-ignored-optimization-argument"
+        fi
+        ;;
+esac
+
+case ${mode} in
+    partial|full-current-session|full-headless-sway)
+    ;;
+
+    none)
+        do_pgo=no
+        ;;
+
+    auto)
+        # TODO: once Sway 1.6.2 has been released, prefer
+        # full-headless-sway
+
+        if [ -n "${WAYLAND_DISPLAY+x}" ]; then
+            mode=full-current-session
+        elif command -v sway > /dev/null; then
+            mode=full-headless-sway
+        else
+            mode=partial
+        fi
+        ;;
+
+    *)
+        usage_and_die
+        ;;
+esac
+
+# echo "source: ${srcdir}"
+# echo "build: ${blddir}"
+# echo "compiler: ${compiler}"
+# echo "mode: ${mode}"
+# echo "CFLAGS: ${CFLAGS}"
+
+export CFLAGS
+meson "${@}" "${blddir}" "${srcdir}" --buildtype=release -Db_lto=true
+
+if [ ${do_pgo} = yes ]; then
+    find . -name "*.gcda" -delete
+    meson configure "${blddir}" -Db_pgo=generate
+    ninja -C "${blddir}"
+
+    # If fcft/tllist are subprojects, we need to ensure their tests
+    # have been executed, or we’ll get “profile count data file not
+    # found” errors.
+    ninja -C "${blddir}" test
+
+    # Run mode-dependent script to generate profiling data
+    "${srcdir}"/pgo/${mode}.sh "${srcdir}" "${blddir}"
+
+    if [ ${compiler} = clang ]; then
+        llvm-profdata \
+            merge \
+            "${blddir}"/default_*.profraw \
+            --output="${blddir}"/default.profdata
+    fi
+
+    meson configure "${blddir}" -Db_pgo=use
+fi
+
+ninja -C "${blddir}"