From 417f33ee539708096f5d43444351a5ec66377cbe Mon Sep 17 00:00:00 2001
From: mmelnich <m.y.melnich@gmail.com>
Date: Wed, 12 Aug 2026 18:09:36 -0700
Subject: [PATCH] install.sh: draw a real progress bar during the build steps

Three rendering tiers, chosen by probing the terminal:

  2  a terminal with colour and UTF-8: a bar redrawn in place, block glyphs
  1  a terminal without one of those: the same bar in ASCII
  0  not a terminal: one line per step, no escapes, no carriage returns

Tier 0 is a requirement rather than a fallback. Redirected output becomes
install.log, CI transcripts and bug reports, and control characters make all
three unreadable, so run_build_step falls straight through to run_step there
and the bytes are identical to before this change. CI already asserts that
redirected output contains no escape sequence and no carriage return.

The bar is determinate. Both build tools already report progress on the
stream being captured anyway -- Ninja writes "[12/34]" and Make writes
"[ 42%]" -- so it tracks real work rather than elapsed time. A spinner would
have conveyed nothing. Steps with no parseable progress keep their existing
one-line form rather than growing a fake bar.

Implementation note: the parsing loop necessarily runs in a subshell, so the
build command's exit status is passed back through a file rather than a
variable, and checked explicitly.

Verified: redirected output byte-identical and escape-free; under a pty the
bar advances through 5%, 20%, 49% during the RandBLAS build and each step
resolves to a "done" line.
---
 install/install.sh | 106 +++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 103 insertions(+), 3 deletions(-)

diff --git a/install/install.sh b/install/install.sh
index d6030c3a..4cf4c869 100755
--- a/install/install.sh
+++ b/install/install.sh
@@ -170,6 +170,44 @@ else
     C_OK=""; C_ERR=""; C_WARN=""; C_BOLD=""; C_OFF=""
 fi
 
+# Progress rendering tier.
+#   2  a terminal that can draw: redraw a bar in place, with block characters
+#   1  a terminal without colour or UTF-8: same bar, ASCII, still redrawn
+#   0  not a terminal: one line per step, no escapes, no carriage returns
+#
+# Tier 0 is not a fallback, it is a requirement. Redirected output ends up in
+# install.log, in CI transcripts and in bug reports, and control characters
+# make all three unreadable. CI asserts that redirected output contains no
+# escape sequence and no carriage return.
+PROGRESS_TIER=0
+if [[ -t 1 && "$WANT_PROGRESS" == "1" && "${TERM:-}" != "dumb" ]]; then
+    if [[ -z "${NO_COLOR:-}" && "${LC_ALL:-${LC_CTYPE:-${LANG:-}}}" == *[Uu][Tt][Ff]* ]]; then
+        PROGRESS_TIER=2
+    else
+        PROGRESS_TIER=1
+    fi
+fi
+
+if (( PROGRESS_TIER >= 2 )); then
+    BAR_FULL="━"; BAR_EMPTY="─"
+else
+    BAR_FULL="#"; BAR_EMPTY="-"
+fi
+
+# draw_bar <percent> <label>: redraw the current step's bar in place.
+draw_bar() {
+    local pct="$1" label="$2" width=28 filled i bar=""
+    (( pct > 100 )) && pct=100
+    filled=$(( pct * width / 100 ))
+    for ((i = 0; i < width; i++)); do
+        if (( i < filled )); then bar+="$BAR_FULL"; else bar+="$BAR_EMPTY"; fi
+    done
+    # \r and a trailing clear-to-end, so a shorter line never leaves debris
+    # from a longer one behind it.
+    printf '\r%s[%d/%d]%s %s %s %3d%%\033[K' \
+        "$C_BOLD" "$STEP" "$TOTAL_STEPS" "$C_OFF" "$label" "$bar" "$pct"
+}
+
 note() { printf '%s\n' "$*"; }
 warn() { printf '%swarning:%s %s\n' "$C_WARN" "$C_OFF" "$*" >&2; }
 
@@ -286,6 +324,68 @@ run_step() {
     fi
 }
 
+# run_build_step <label> <command...>: like run_step, but drives a real
+# progress bar from the build tool's own output.
+#
+# Both build tools already report progress on the stream we are capturing
+# anyway -- Ninja writes "[12/34]" and Make writes "[ 42%]" -- so the bar
+# tracks actual work rather than elapsed time. A spinner would convey nothing;
+# this says how much is left.
+#
+# Falls straight through to run_step at tier 0, so redirected output is
+# byte-identical to what it was before any of this existed.
+run_build_step() {
+    local label="$1"; shift
+    if (( PROGRESS_TIER == 0 )); then
+        run_step "$label" "$@"
+        return
+    fi
+
+    STEP=$((STEP + 1))
+    local t0 t1 status statusfile
+    t0=$(date +%s)
+    {
+        printf '\n===== [%d/%d] %s =====\n' "$STEP" "$TOTAL_STEPS" "$label"
+        printf '$ %s\n' "$*"
+    } >> "$LOG"
+
+    draw_bar 0 "$label"
+
+    # The while loop runs in a subshell, so the command's exit status cannot
+    # come back through a variable; pass it through a file instead.
+    statusfile="$(mktemp)"
+    {
+        "$@" 2>&1
+        printf '%d\n' "$?" > "$statusfile"
+    } | while IFS= read -r line; do
+        printf '%s\n' "$line" >> "$LOG"
+        if [[ "$line" =~ ^\[([0-9]+)/([0-9]+)\] ]]; then
+            # Ninja: [12/34]
+            draw_bar $(( 100 * ${BASH_REMATCH[1]} / ${BASH_REMATCH[2]} )) "$label"
+        elif [[ "$line" =~ ^\[[[:space:]]*([0-9]+)%\] ]]; then
+            # Make: [ 42%]
+            draw_bar "${BASH_REMATCH[1]}" "$label"
+        fi
+    done
+    status="$(cat "$statusfile" 2>/dev/null || echo 1)"
+    rm -f "$statusfile"
+
+    if [[ "$status" == "0" ]]; then
+        t1=$(date +%s)
+        printf '\r%s[%d/%d]%s %s ... %sdone%s (%ds)\033[K\n' \
+            "$C_BOLD" "$STEP" "$TOTAL_STEPS" "$C_OFF" "$label" \
+            "$C_OK" "$C_OFF" "$((t1 - t0))"
+    else
+        printf '\r%s[%d/%d]%s %s ... %sFAILED%s\033[K\n' \
+            "$C_BOLD" "$STEP" "$TOTAL_STEPS" "$C_OFF" "$label" \
+            "$C_ERR" "$C_OFF" >&2
+        printf '\nStep "%s" failed. Full output: %s\n' "$label" "$LOG" >&2
+        printf 'The last 20 log lines:\n' >&2
+        tail -20 "$LOG" >&2
+        exit 1
+    fi
+}
+
 skip_step() {
     STEP=$((STEP + 1))
     printf '%s[%d/%d]%s %s\n' "$C_BOLD" "$STEP" "$TOTAL_STEPS" "$C_OFF" "$1"
@@ -630,7 +730,7 @@ if (( BUILD_BLASPP )); then
         fi
         printf '%sdone%s (requested %s)\n' "$C_OK" "$C_OFF" "$BLAS_INT_RESOLVED"
 
-        run_step "Building and installing BLAS++" \
+        run_build_step "Building and installing BLAS++" \
             cmake --build "$PROJECT_DIR/build/blaspp-build-$BLAS_INT_RESOLVED" \
                 -j "$JOBS" --target install
 
@@ -739,7 +839,7 @@ fi
 RB_ARGS+=("${OPENMP_FLAGS[@]}")
 
 run_step "Configuring RandBLAS" cmake "${RB_ARGS[@]}"
-run_step "Building and installing RandBLAS" \
+run_build_step "Building and installing RandBLAS" \
     cmake --build "$RANDBLAS_BUILD" -j "$JOBS" --target install
 
 #==============================================================================
@@ -884,7 +984,7 @@ build_examples() {
             -DRandom123_DIR="$RANDOM123_DIR" \
             -DFETCHCONTENT_BASE_DIR="$PROJECT_DIR/build/fetchcontent-cache" \
             "${OPENMP_FLAGS[@]}"
-    run_step "Building examples" \
+    run_build_step "Building examples" \
         cmake --build "$PROJECT_DIR/build/examples-build" -j "$JOBS"
 }