pcbjam/scripts/common/inject-dyncall-shims.sh

#!/bin/bash
# Inject dynCall_* shims into Emscripten-generated JS
#
# Emscripten 4.x no longer generates signature-specific dynCall_* functions,
# but the invoke_* wrappers (for C++ exception handling) still call them.
# This script auto-generates shims using getWasmTableEntry() which IS defined.
#
# Usage: inject-dyncall-shims.sh <pcbnew.js>

set -e

JS_FILE="$1"

if [ -z "$JS_FILE" ] || [ ! -f "$JS_FILE" ]; then
    echo "Error: JS file not found: $JS_FILE"
    echo "Usage: $0 <path/to/pcbnew.js>"
    exit 1
fi

echo "Extracting dynCall signatures from $JS_FILE..."

# Extract all unique dynCall_* signatures from the file
# Matches patterns like: dynCall_i, dynCall_ii, dynCall_viijj, etc.
SIGNATURES=$(grep -oE 'dynCall_[a-zA-Z0-9]+' "$JS_FILE" | sort -u | sed 's/dynCall_//')

if [ -z "$SIGNATURES" ]; then
    echo "No dynCall signatures found - nothing to inject"
    exit 0
fi

SIG_COUNT=$(echo "$SIGNATURES" | wc -l | tr -d ' ')
echo "Found $SIG_COUNT unique signatures"

# Generate shim code
SHIM_FILE=$(mktemp)
cat > "$SHIM_FILE" << 'HEADER'

// === dynCall shims for Emscripten exception handling ===
// Auto-generated: maps dynCall_SIG() calls to getWasmTableEntry()
// This fixes "dynCall_* is not defined" errors in Emscripten 4.x
//
// These shims are asyncify-aware: they track Asyncify.exportCallStack so that
// asyncify can rewind through indirect calls (e.g., main loop callbacks,
// timer callbacks, event handlers). Without this tracking, asyncify's doRewind
// fails because it can't find the entry function to re-enter the WASM module.
HEADER

for sig in $SIGNATURES; do
    # Count args: signature length - 1 (first char is return type)
    argcount=$((${#sig} - 1))

    # Generate argument list: index, a0, a1, a2, ...
    args="index"
    call_args=""
    for ((i=0; i<argcount; i++)); do
        args="$args, a$i"
        if [ $i -gt 0 ]; then
            call_args="$call_args, "
        fi
        call_args="${call_args}a$i"
    done

    cat >> "$SHIM_FILE" << SHIMEOF
function dynCall_$sig($args) {
  var tableFunc = getWasmTableEntry(index);
  if (typeof Asyncify !== 'undefined') {
    var rewindKey = '__dyn_${sig}_' + index;
    if (!wasmExports[rewindKey]) wasmExports[rewindKey] = tableFunc;
    Asyncify.exportCallStack.push(rewindKey);
    try {
      return tableFunc($call_args);
    } finally {
      if (!ABORT) {
        Asyncify.exportCallStack.pop();
        Asyncify.maybeStopUnwind();
      }
    }
  }
  return tableFunc($call_args);
}
SHIMEOF
done

echo "" >> "$SHIM_FILE"
echo "// === End dynCall shims ===" >> "$SHIM_FILE"


# Find the insertion point: after getWasmTableEntry definition
# The pattern is:
#   var getWasmTableEntry = funcPtr => {
#     ...
#   };
# We insert after the closing `};`

# Find line number of getWasmTableEntry definition
GWTL_LINE=$(grep -n '^var getWasmTableEntry = funcPtr => {' "$JS_FILE" | head -1 | cut -d: -f1)

if [ -z "$GWTL_LINE" ]; then
    echo "Warning: Could not find getWasmTableEntry definition"
    echo "Trying alternate pattern..."
    GWTL_LINE=$(grep -n 'var getWasmTableEntry' "$JS_FILE" | head -1 | cut -d: -f1)
fi

if [ -z "$GWTL_LINE" ]; then
    echo "Error: Could not find getWasmTableEntry in $JS_FILE"
    echo "The shims need to be inserted after getWasmTableEntry is defined"
    rm "$SHIM_FILE"
    exit 1
fi

# Find the closing `};` after getWasmTableEntry (within next 10 lines)
INSERT_LINE=""
for ((i=GWTL_LINE; i<=GWTL_LINE+10; i++)); do
    LINE_CONTENT=$(sed -n "${i}p" "$JS_FILE")
    if [[ "$LINE_CONTENT" == "};" ]]; then
        INSERT_LINE=$i
        break
    fi
done

if [ -z "$INSERT_LINE" ]; then
    echo "Warning: Could not find closing }; for getWasmTableEntry"
    echo "Inserting after line $GWTL_LINE"
    INSERT_LINE=$GWTL_LINE
fi

echo "Injecting shims after line $INSERT_LINE..."

# Create output file with shims inserted
head -n "$INSERT_LINE" "$JS_FILE" > "${JS_FILE}.tmp"
cat "$SHIM_FILE" >> "${JS_FILE}.tmp"
tail -n +$((INSERT_LINE + 1)) "$JS_FILE" >> "${JS_FILE}.tmp"

# Replace original file
mv "${JS_FILE}.tmp" "$JS_FILE"
rm "$SHIM_FILE"

echo "Successfully injected $SIG_COUNT dynCall shims into $JS_FILE"

# Fix empty callback arrow functions generated by Emscripten with pthreads
# When pthreads is enabled, Emscripten generates empty {} for some direct-call paths
# because it assumes they won't be used. But they ARE used in certain cases.
# The dynCall_* functions exist (generated above), we just need to call them.
echo "Fixing empty callback arrow functions..."

TOTAL_FIXED=0

# Fix 1: HTML5 event callbacks (3 args) - signature iiii
# Pattern: ((a1, a2, a3) => {})(eventTypeId, ...
# Function pointer is 'callbackfunc' in these contexts
COUNT_BEFORE=$(grep -c '((a1, a2, a3) => {})(eventTypeId,' "$JS_FILE" || true)
if [ "$COUNT_BEFORE" -gt 0 ]; then
    sed -i '' 's/((a1, a2, a3) => {})(eventTypeId,/((a1, a2, a3) => dynCall_iiii(callbackfunc, a1, a2, a3))(eventTypeId,/g' "$JS_FILE"
    COUNT_AFTER=$(grep -c '((a1, a2, a3) => {})(eventTypeId,' "$JS_FILE" || true)
    FIXED=$((COUNT_BEFORE - COUNT_AFTER))
    echo "  Fixed $FIXED HTML5 event callback(s) (dynCall_iiii)"
    TOTAL_FIXED=$((TOTAL_FIXED + FIXED))
fi

# Fix 2: invokeEntryPoint pthread entry (1 arg) - signature ii (returns pointer)
# Pattern in invokeEntryPoint: var result = (a1 => {})(arg);
# Function pointer is 'ptr'
COUNT_BEFORE=$(grep -c 'var result = (a1 => {})(arg);' "$JS_FILE" || true)
if [ "$COUNT_BEFORE" -gt 0 ]; then
    sed -i '' 's/var result = (a1 => {})(arg);/var result = dynCall_ii(ptr, arg);/g' "$JS_FILE"
    COUNT_AFTER=$(grep -c 'var result = (a1 => {})(arg);' "$JS_FILE" || true)
    FIXED=$((COUNT_BEFORE - COUNT_AFTER))
    echo "  Fixed $FIXED pthread entry callback(s) (dynCall_ii)"
    TOTAL_FIXED=$((TOTAL_FIXED + FIXED))
fi

# Fix 3: ___call_sighandler (1 arg) - signature vi (void return)
# Pattern: return (a1 => {})(sig);
# Function pointer is 'fp'
COUNT_BEFORE=$(grep -c 'return (a1 => {})(sig);' "$JS_FILE" || true)
if [ "$COUNT_BEFORE" -gt 0 ]; then
    sed -i '' 's/return (a1 => {})(sig);/return dynCall_vi(fp, sig);/g' "$JS_FILE"
    COUNT_AFTER=$(grep -c 'return (a1 => {})(sig);' "$JS_FILE" || true)
    FIXED=$((COUNT_BEFORE - COUNT_AFTER))
    echo "  Fixed $FIXED signal handler callback(s) (dynCall_vi)"
    TOTAL_FIXED=$((TOTAL_FIXED + FIXED))
fi

# Fix 4: _emscripten_async_call timer (1 arg) - signature vi (void return)
# Pattern: var wrapper = () => (a1 => {})(arg);
# Function pointer is 'func'
COUNT_BEFORE=$(grep -c 'var wrapper = () => (a1 => {})(arg);' "$JS_FILE" || true)
if [ "$COUNT_BEFORE" -gt 0 ]; then
    sed -i '' 's/var wrapper = () => (a1 => {})(arg);/var wrapper = () => dynCall_vi(func, arg);/g' "$JS_FILE"
    COUNT_AFTER=$(grep -c 'var wrapper = () => (a1 => {})(arg);' "$JS_FILE" || true)
    FIXED=$((COUNT_BEFORE - COUNT_AFTER))
    echo "  Fixed $FIXED async timer callback(s) (dynCall_vi)"
    TOTAL_FIXED=$((TOTAL_FIXED + FIXED))
fi

# Fix 5: _emscripten_set_main_loop empty iterFunc callback - signature v (void, no args)
# Pattern: var iterFunc = (() => {});
# The 'func' variable is the function pointer passed to _emscripten_set_main_loop
COUNT_BEFORE=$(grep -c 'var iterFunc = (() => {});' "$JS_FILE" || true)
if [ "$COUNT_BEFORE" -gt 0 ]; then
    sed -i '' 's/var iterFunc = (() => {});/var iterFunc = () => dynCall_v(func);/g' "$JS_FILE"
    COUNT_AFTER=$(grep -c 'var iterFunc = (() => {});' "$JS_FILE" || true)
    FIXED=$((COUNT_BEFORE - COUNT_AFTER))
    echo "  Fixed $FIXED main loop callback(s) (dynCall_v)"
    TOTAL_FIXED=$((TOTAL_FIXED + FIXED))
fi

if [ "$TOTAL_FIXED" -gt 0 ]; then
    echo "Total: Fixed $TOTAL_FIXED empty callback(s)"
else
    echo "No empty callbacks found - nothing to fix"
fi