Add C# IL extractor autobuild and indexing scripts

Introduces autobuild.sh and index-files.sh scripts for the C# IL extractor. These scripts set up environment variables, determine platform-specific extractor paths, and automate extraction of DLL and EXE assemblies for CodeQL analysis.

Author: gfs

binary/extractor/cil/tools/autobuild.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+
+set -eu
+
+if [[ -z "${CODEQL_EXTRACTOR_CIL_ROOT:-}" ]]; then
+  export CODEQL_EXTRACTOR_CIL_ROOT="$(dirname "$(dirname "${BASH_SOURCE[0]}")")"
+fi
+
+# For C# IL, autobuild and buildless extraction are the same - just extract the DLLs
+exec "${CODEQL_EXTRACTOR_CIL_ROOT}/tools/index-files.sh"

binary/extractor/cil/tools/index-files.sh

@@ -0,0 +1,61 @@
+#!/bin/bash
+
+set -eu
+
+# Get the extractor root directory
+if [[ -z "${CODEQL_EXTRACTOR_CIL_ROOT:-}" ]]; then
+  export CODEQL_EXTRACTOR_CIL_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+fi
+
+# Get the trap directory from CodeQL environment
+TRAP_DIR="${CODEQL_EXTRACTOR_CIL_TRAP_DIR}"
+SRC_ARCHIVE="${CODEQL_EXTRACTOR_CIL_SOURCE_ARCHIVE_DIR}"
+
+echo "C# IL Extractor: Starting extraction"
+echo "Source root: $(pwd)"
+echo "TRAP directory: ${TRAP_DIR}"
+echo "Extractor root: ${CODEQL_EXTRACTOR_CIL_ROOT}"
+
+# Ensure TRAP directory exists
+mkdir -p "${TRAP_DIR}"
+mkdir -p "${SRC_ARCHIVE}"
+
+# Determine the platform-specific extractor path
+case "$(uname -s)-$(uname -m)" in
+  Darwin-arm64)
+    PLATFORM_DIR="osx-arm64"
+    ;;
+  Darwin-x86_64)
+    PLATFORM_DIR="osx-x64"
+    ;;
+  Linux-x86_64)
+    PLATFORM_DIR="linux-x64"
+    ;;
+  *)
+    PLATFORM_DIR="win64"
+    ;;
+esac
+
+EXTRACTOR_DLL="${CODEQL_EXTRACTOR_CIL_ROOT}/tools/${PLATFORM_DIR}/Semmle.Extraction.CSharp.IL.dll"
+
+if [[ ! -f "${EXTRACTOR_DLL}" ]]; then
+  echo "ERROR: Extractor not found at ${EXTRACTOR_DLL}"
+  exit 1
+fi
+
+# Create a temporary file list
+FILE_LIST=$(mktemp)
+trap "rm -f ${FILE_LIST}" EXIT
+
+# Find all DLL and EXE files in the source root
+find . -type f \( -name "*.dll" -o -name "*.exe" \) > "${FILE_LIST}"
+
+FILE_COUNT=$(wc -l < "${FILE_LIST}" | tr -d ' ')
+echo "Found ${FILE_COUNT} assemblies to extract"
+
+if [[ "${FILE_COUNT}" -gt 0 ]]; then
+  # Run the extractor with the file list
+  dotnet "${EXTRACTOR_DLL}" "${FILE_LIST}"
+fi
+
+echo "C# IL Extractor: Completed extraction"