save progress

devops/docker/repro-builders/debian/scripts/extract-functions.sh

@@ -0,0 +1,67 @@
+#!/bin/bash
+# Extract function fingerprints from ELF binaries
+# Outputs JSON array with function name, offset, size, and hashes
+
+set -euo pipefail
+
+DIR="${1:-.}"
+
+extract_functions_from_binary() {
+    local binary="$1"
+    
+    # Skip non-ELF files
+    file "$binary" 2>/dev/null | grep -q "ELF" || return 0
+    
+    # Get function symbols with objdump
+    objdump -t "$binary" 2>/dev/null | \
+    awk '/\.text.*[0-9a-f]+.*F/ {
+        gsub(/\*.*\*/, "", $1)
+        if ($5 != "" && length($4) > 0) {
+            size = strtonum("0x" $4)
+            if (size >= 16) {
+                print $1, $4, $NF
+            }
+        }
+    }' | while read -r offset size name; do
+        # Skip compiler-generated symbols
+        case "$name" in
+            __*|_GLOBAL_*|.plt*|.text*|frame_dummy|register_tm_clones|deregister_tm_clones|_start|_init|_fini)
+                continue
+                ;;
+        esac
+        
+        # Convert hex size
+        dec_size=$((16#$size))
+        
+        # Compute hash of function bytes
+        local hash=$(objdump -d --start-address="0x$offset" --stop-address="$((16#$offset + dec_size))" "$binary" 2>/dev/null | \
+            grep -E "^[[:space:]]*[0-9a-f]+:" | \
+            awk '{for(i=2;i<=NF;i++){if($i~/^[0-9a-f]{2}$/){printf "%s", $i}}}' | \
+            sha256sum | cut -d' ' -f1)
+        
+        [ -n "$hash" ] || hash="unknown"
+        
+        printf '{"name":"%s","offset":"0x%s","size":%d,"hash":"%s"}\n' \
+            "$name" "$offset" "$dec_size" "$hash"
+    done
+}
+
+# Output JSON array
+echo "["
+first=true
+
+find "$DIR" -type f \( -executable -o -name "*.so" -o -name "*.so.*" \) 2>/dev/null | while read -r binary; do
+    file "$binary" 2>/dev/null | grep -q "ELF" || continue
+    
+    extract_functions_from_binary "$binary" | while read -r json; do
+        [ -z "$json" ] && continue
+        if [ "$first" = "true" ]; then
+            first=false
+            echo "$json"
+        else
+            echo ",$json"
+        fi
+    done
+done
+
+echo "]"