From bf2255c90b8284b9b3d9a8fc229cb4229aa4c319 Mon Sep 17 00:00:00 2001
From: 2over12 <ian.smith@trailofbits.com>
Date: Thu, 30 Nov 2023 17:05:37 -0500
Subject: [PATCH] Custom llvm for lifting bits (#1038)

---
 .github/workflows/vcpkg_ci_amd64.yml |  3 +-
 .github/workflows/vcpkg_ci_mac.yml   |  3 +-
 ports/llvm-17/portfile.cmake         | 46 +++++++++++++++++++---------
 ports/llvm-17/vcpkg.json             | 15 ++++++++-
 4 files changed, 50 insertions(+), 17 deletions(-)

diff --git a/.github/workflows/vcpkg_ci_amd64.yml b/.github/workflows/vcpkg_ci_amd64.yml
index dd681580..187c578a 100644
--- a/.github/workflows/vcpkg_ci_amd64.yml
+++ b/.github/workflows/vcpkg_ci_amd64.yml
@@ -42,7 +42,8 @@ jobs:
           - { os: 'ubuntu', name: 'ubuntu-v2', tag: '22.04' }
         llvm: [
           'llvm-16',
-          'llvm-17'
+          'llvm-17',
+          'llvm-17[liftingbits-llvm]'
         ]
         target_arch: [ 'x64', 'arm64' ]
 
diff --git a/.github/workflows/vcpkg_ci_mac.yml b/.github/workflows/vcpkg_ci_mac.yml
index 6c70ce9f..a510c43a 100644
--- a/.github/workflows/vcpkg_ci_mac.yml
+++ b/.github/workflows/vcpkg_ci_mac.yml
@@ -39,7 +39,8 @@ jobs:
           - { runner: 'macos-13', xcode: '15.0' }
         llvm: [
           'llvm-16',
-          'llvm-17'
+          'llvm-17',
+          'llvm-17[liftingbits-llvm]'
         ]
         target_arch: [ 'x64', 'arm64' ]
 
diff --git a/ports/llvm-17/portfile.cmake b/ports/llvm-17/portfile.cmake
index d227413d..61bb22af 100644
--- a/ports/llvm-17/portfile.cmake
+++ b/ports/llvm-17/portfile.cmake
@@ -1,19 +1,37 @@
 vcpkg_check_linkage(ONLY_STATIC_LIBRARY)
 
-vcpkg_from_github(
-    OUT_SOURCE_PATH SOURCE_PATH
-    REPO llvm/llvm-project
-    REF llvmorg-${VERSION}
-    SHA512 df68879cb3f23489e19bbec4aac1898d213e837132072f8bbc1a49eb561c8cc7ccdb6ae9202b68b0915c84c8f2b41e536ab690697eb8ab8c9f44d5ae600b575b
-    HEAD_REF release/17.x
-    PATCHES
-        0001-Fix-install-paths.patch
-        0006-Fix-libffi.patch
-        0020-fix-FindZ3.cmake.patch
-        0021-fix-find_dependency.patch
-        0026-fix-prefix-path-calc.patch
-        0029-Do-not-attempt-macro-expansion-on-invalid-sourceloc.patch
-)
+
+if("liftingbits-llvm" IN_LIST FEATURES)
+    vcpkg_from_github(
+        OUT_SOURCE_PATH SOURCE_PATH
+        REPO trail-of-forks/llvm-project
+        REF b779442fffcf46f2dfc104217e1413d7d5b538d6
+        SHA512 700ddc8c4b39b260a2041385128ef2bbe3bf6c0ff45d933d3d50d15f737892e2c7e817a4a11cda606b91364b99b10c884b76e040b321696effac7ce172720552
+        HEAD_REF main
+        PATCHES
+            0001-Fix-install-paths.patch
+            0006-Fix-libffi.patch
+            0020-fix-FindZ3.cmake.patch
+            0021-fix-find_dependency.patch
+            0026-fix-prefix-path-calc.patch
+            0029-Do-not-attempt-macro-expansion-on-invalid-sourceloc.patch
+    )
+else()
+      vcpkg_from_github(
+        OUT_SOURCE_PATH SOURCE_PATH
+        REPO llvm/llvm-project
+        REF llvmorg-${VERSION}
+        SHA512 df68879cb3f23489e19bbec4aac1898d213e837132072f8bbc1a49eb561c8cc7ccdb6ae9202b68b0915c84c8f2b41e536ab690697eb8ab8c9f44d5ae600b575b
+        HEAD_REF release/17.x
+        PATCHES
+            0001-Fix-install-paths.patch
+            0006-Fix-libffi.patch
+            0020-fix-FindZ3.cmake.patch
+            0021-fix-find_dependency.patch
+            0026-fix-prefix-path-calc.patch
+            0029-Do-not-attempt-macro-expansion-on-invalid-sourceloc.patch
+    )  
+endif()
 
 string(REPLACE "." ";" VERSION_LIST ${VERSION})
 list(GET VERSION_LIST 0 LLVM_VERSION_MAJOR)
diff --git a/ports/llvm-17/vcpkg.json b/ports/llvm-17/vcpkg.json
index 2d6628ac..85e33487 100644
--- a/ports/llvm-17/vcpkg.json
+++ b/ports/llvm-17/vcpkg.json
@@ -30,6 +30,19 @@
     "utils"
   ],
   "features": {
+    "liftingbits-llvm": {
+      "description": "Custom llvm source tree that allows for custom calling convention registration. These custom calling conventions allow for specifying binary level compatibility.",
+      "dependencies": [
+        {
+          "name": "llvm-17",
+          "default-features": false,
+          "features": [
+            "libunwind",
+            "enable-rtti"
+          ]
+        }
+      ]
+    },
     "bolt": {
       "description": "BOLT is a post-link optimizer developed to speed up large applications.",
       "dependencies": [
@@ -439,4 +452,4 @@
       "description": "Build LLVM utils."
     }
   }
-}
+}
\ No newline at end of file