Lookup cmake paths dynamically

Author: ysimonson

Cargo.lock

@@ -32,7 +32,7 @@ sampler = []
 # Only has an impact on Android.
 android-shared-stdcxx = ["llama-cpp-sys-2/shared-stdcxx"]
 mtmd = ["llama-cpp-sys-2/mtmd"]
-shared-ggml = ["llama-cpp-sys-2/shared-ggml"]
+system-ggml = ["llama-cpp-sys-2/system-ggml"]
 
 
 [target.'cfg(all(target_os = "macos", any(target_arch = "aarch64", target_arch = "arm64")))'.dependencies]

llama-cpp-2/Cargo.toml

@@ -68,6 +68,7 @@ cmake = "0.1"
 find_cuda_helper = "0.2.0"
 glob = "0.3.3"
 walkdir = "2"
+pkg-config = "0.3"
 
 [features]
 cuda = []
@@ -80,5 +81,5 @@ native = []
 openmp = []
 # Only has an impact on Android.
 shared-stdcxx = []
-shared-ggml = []
+system-ggml = []
 mtmd = []

llama-cpp-sys-2/Cargo.toml

@@ -686,7 +686,7 @@ fn main() {
         config.define("GGML_OPENMP", "OFF");
     }
 
-    if cfg!(feature = "shared-ggml") {
+    if cfg!(feature = "system-ggml") {
         config.define("LLAMA_USE_SYSTEM_GGML", "ON");
     }
 
@@ -706,6 +706,34 @@ fn main() {
     );
     println!("cargo:rustc-link-search={}", build_dir.display());
 
+    if cfg!(feature = "system-ggml") {
+        // Extract library directory from CMake's found GGML package
+        let cmake_cache = build_dir.join("build").join("CMakeCache.txt");
+        if let Ok(cache_contents) = std::fs::read_to_string(&cmake_cache) {
+            let mut ggml_lib_dirs = std::collections::HashSet::new();
+
+            // Parse CMakeCache.txt to find where GGML libraries were found
+            for line in cache_contents.lines() {
+                if line.starts_with("GGML_LIBRARY:")
+                    || line.starts_with("GGML_BASE_LIBRARY:")
+                    || line.starts_with("GGML_CPU_LIBRARY:")
+                {
+                    if let Some(lib_path) = line.split('=').nth(1) {
+                        if let Some(parent) = Path::new(lib_path).parent() {
+                            ggml_lib_dirs.insert(parent.to_path_buf());
+                        }
+                    }
+                }
+            }
+
+            // Add each unique library directory to the search path
+            for lib_dir in ggml_lib_dirs {
+                println!("cargo:rustc-link-search=native={}", lib_dir.display());
+                debug_log!("Added system GGML library path: {}", lib_dir.display());
+            }
+        }
+    }
+
     if cfg!(feature = "cuda") && !build_shared_libs {
         // Re-run build script if CUDA_PATH environment variable changes
         println!("cargo:rerun-if-env-changed=CUDA_PATH");
@@ -748,10 +776,19 @@ fn main() {
     }
 
     // Link libraries
-    let llama_libs_kind = if build_shared_libs { "dylib" } else { "static" };
+    let llama_libs_kind = if build_shared_libs || cfg!(feature = "system-ggml") {
+        "dylib"
+    } else {
+        "static"
+    };
     let llama_libs = extract_lib_names(&out_dir, build_shared_libs);
     assert_ne!(llama_libs.len(), 0);
 
+    if cfg!(feature = "system-ggml") {
+        println!("cargo:rustc-link-lib={llama_libs_kind}=ggml");
+        println!("cargo:rustc-link-lib={llama_libs_kind}=ggml-base");
+        println!("cargo:rustc-link-lib={llama_libs_kind}=ggml-cpu");
+    }
     for lib in llama_libs {
         let link = format!("cargo:rustc-link-lib={}={}", llama_libs_kind, lib);
         debug_log!("LINK {link}",);