feat: add clang support to llvm-core Conan recipe

.github/actions/bolt-build-base/action.yml

@@ -24,3 +24,8 @@ runs:
       shell: bash
       run: |
         ./scripts/install-bolt-deps.sh
+
+    - name: Override PR-modified Conan recipes
+      shell: bash
+      run: |
+        ./.github/actions/bolt-build-base/override-changed-recipes.sh "${GITHUB_BASE_REF:-main}"

.github/actions/bolt-build-base/override-changed-recipes.sh

           conan upload -r ci --confirm "*" 
       - name: Upload packages to conan remote 
         env: 
           CONAN_LOGIN_USERNAME: ${{ secrets.CONAN_ADMIN_USERNAME }} 
           CONAN_PASSWORD: ${{ secrets.CONAN_ADMIN_PASSWORD }} 
         run: | 
           conan remote auth ci 
           conan upload -r ci --confirm "*" 
@@ -0,0 +1,71 @@
+#!/usr/bin/env bash
+# Copyright (c) ByteDance Ltd. and/or its affiliates.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# Detect Conan recipes modified compared to a base branch and add them
+# to an override remote at index 0. This ensures modified recipes
+# rebuild from source while everything else reuses cached binaries
+# from the CI remote.
+#
+# Two sources of recipe changes:
+#   1. scripts/conan/patches/*.patch — CCI recipe patches
+#   2. scripts/conan/recipes/<name>/  — bolt-local recipes
+#
+# Usage: ./scripts/override-changed-recipes.sh [base_ref]
+#   base_ref: git ref to diff against (default: main)
+set -euo pipefail
+
+BASE_REF="${1:-main}"
+CCI_HOME="${CONAN_HOME:-$HOME/.conan2}/conan-center-index"
+OVERRIDE_DIR="${CONAN_HOME:-$HOME/.conan2}/patched-recipes"
+
+changed_files=$(git diff --name-only "origin/${BASE_REF}" -- scripts/conan/ 2> /dev/null || true)
+if [ -z "$changed_files" ]; then
+  echo "ℹ️  No Conan recipe changes detected."
+  exit 0
+fi
+
+rm -rf "${OVERRIDE_DIR}"
+mkdir -p "${OVERRIDE_DIR}/recipes"
+
+override_recipes=""
+
+# 1. CCI patches: extract recipe names from patch diff content
+for patch_file in $(echo "$changed_files" | grep '^scripts/conan/patches/.*\.patch$' || true); do
+  if [ ! -f "$patch_file" ]; then
+    continue
+  fi
+  for recipe in $(sed -n 's|.*recipes/\([^/]*\)/.*|\1|p' "$patch_file" | sort -u); do
+    if [ -d "${CCI_HOME}/recipes/${recipe}" ] && [ ! -d "${OVERRIDE_DIR}/recipes/${recipe}" ]; then
+      cp -r "${CCI_HOME}/recipes/${recipe}" "${OVERRIDE_DIR}/recipes/${recipe}"
+      override_recipes="${override_recipes} ${recipe}"
+    fi
+  done
+done
+
+# 2. bolt-local recipes: extract recipe name from path
+for recipe in $(echo "$changed_files" | sed -n 's|^scripts/conan/recipes/\([^/]*\)/.*|\1|p' | sort -u); do
+  if [ -d "scripts/conan/recipes/${recipe}" ] && [ ! -d "${OVERRIDE_DIR}/recipes/${recipe}" ]; then
+    cp -r "scripts/conan/recipes/${recipe}" "${OVERRIDE_DIR}/recipes/${recipe}"
+    override_recipes="${override_recipes} ${recipe}"
+  fi
+done
+
+if [ -z "$override_recipes" ]; then
+  echo "ℹ️  No recipe overrides needed."
+  exit 0
+fi
+
+conan remote add --index=0 -t "local-recipes-index" "bolt-patched" "${OVERRIDE_DIR}"
+echo "✅ Override recipes:${override_recipes}"

conanfile.py

@@ -352,6 +352,7 @@ def configure(self):
             self.options[llvm_core].with_z3 = False
             self.options[llvm_core].with_zstd = False
             self.options[llvm_core].with_ffi = False
+            self.options[llvm_core].with_clang = True
 
         if self.options.get_safe("enable_hdfs") and self.options.get_safe(
             "use_arrow_hdfs"
@@ -451,6 +452,15 @@ def generate(self):
             tc.cache_variables["ENABLE_BOLT_JIT"] = "ON"
             tc.preprocessor_definitions["ENABLE_BOLT_JIT"] = 1
 
+            # Verify clang exists in llvm-core package.
+            llvm_dep = self.dependencies["llvm-core"]
+            clang_path = os.path.join(str(llvm_dep.package_folder), "bin", "clang")
+            if not os.path.exists(clang_path):
+                raise Exception(
+                    f"clang not found at {clang_path}. "
+                    "Ensure llvm-core is built with -o llvm-core/*:with_clang=True"
+                )
+
             # TODO: Refactor the IR codegen of expression evaluation
             # Disable it right now
             tc.cache_variables["ENABLE_BOLT_EXPR_JIT"] = "OFF"

scripts/conan/patches/llvm-core-add-clang-support.patch

@@ -0,0 +1,64 @@
+diff --git a/recipes/llvm-core/all/conandata.yml b/recipes/llvm-core/all/conandata.yml
+index dd26cdba..bc4c16a9 100644
+--- a/recipes/llvm-core/all/conandata.yml
++++ b/recipes/llvm-core/all/conandata.yml
+@@ -6,6 +6,9 @@ sources:
+     "cmake":
+       url: https://github.com/llvm/llvm-project/releases/download/llvmorg-19.1.7/cmake-19.1.7.src.tar.xz
+       sha256: 11c5a28f90053b0c43d0dec3d0ad579347fc277199c005206b963c19aae514e3
++    "clang":
++      url: https://github.com/llvm/llvm-project/releases/download/llvmorg-19.1.7/clang-19.1.7.src.tar.xz
++      sha256: 11e5e4ecab5338b9914de3b83a4622cb200de466b7c56ba675afb72fa7d64675
+   "13.0.0":
+     url: https://github.com/llvm/llvm-project/releases/download/llvmorg-13.0.0/llvm-13.0.0.src.tar.xz
+     sha256: 408d11708643ea826f519ff79761fcdfc12d641a2510229eec459e72f8163020
+diff --git a/recipes/llvm-core/all/conanfile.py b/recipes/llvm-core/all/conanfile.py
+index e8290099..fb18c9dd 100644
+--- a/recipes/llvm-core/all/conanfile.py
++++ b/recipes/llvm-core/all/conanfile.py
+@@ -171,6 +171,7 @@ class LLVMCoreConan(ConanFile):
+         "with_xml2": [True, False],
+         "with_z3": [True, False],
+         "with_zstd": [True, False],
++        "with_clang": [True, False],
+     }
+     default_options = {
+         "shared": False,
+@@ -193,6 +194,7 @@ class LLVMCoreConan(ConanFile):
+         "with_z3": True,
+         "with_zlib": True,
+         "with_zstd": True,
++        "with_clang": False,
+     }
+
+     @property
+@@ -301,6 +303,8 @@ class LLVMCoreConan(ConanFile):
+             # LLVM >=15 split up several components in its release, including cmake
+             get(self, **sources["llvm"], destination='llvm-main', strip_root=True)
+             get(self, **sources["cmake"], destination='cmake', strip_root=True)
++            if "clang" in sources:
++                get(self, **sources["clang"], destination='clang', strip_root=True)
+
+     def _apply_resource_limits(self, cmake_definitions):
+         if os.getenv("CONAN_CENTER_BUILD_SERVICE"):
+@@ -373,6 +377,9 @@ class LLVMCoreConan(ConanFile):
+         if self.options.targets != "all":
+             cmake_variables["LLVM_TARGETS_TO_BUILD"] = self.options.targets
+
++        if self.options.with_clang:
++            cmake_variables["LLVM_ENABLE_PROJECTS"] = "clang"
++
+         self._apply_resource_limits(cmake_variables)
+
+         if is_msvc(self):
+@@ -415,7 +422,9 @@ class LLVMCoreConan(ConanFile):
+             "LLVMTableGenGlobalISel.*",
+             "CONAN_LIB.*",
+             "LLVMExegesis.*",
+-            "LLVMCFIVerify.*"
++            "LLVMCFIVerify.*",
++            "clang.*",
++            "libclang.*",
+         ]
+         graphviz_options = textwrap.dedent(f"""
+             set(GRAPHVIZ_EXECUTABLES OFF)

scripts/install-bolt-deps.sh

@@ -19,7 +19,7 @@ CUR_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" > /dev/null && pwd)"
 cd "${CUR_DIR}"
 
 CONAN_CENTER_COMMIT_ID="bad5c95b810e859c1c31553b92584246fe436d69"
-CCI_HOME="${CONAN_HOME:-~/.conan2}/conan-center-index"
+CCI_HOME="${CONAN_HOME:-$HOME/.conan2}/conan-center-index"
 
 if ! command -v conan &> /dev/null; then
   echo "❌ Error: 'conan' command not found."