add -mllvm support

useful for debugging crashes in llvm optimizer

src/all_types.hpp

@@ -1524,6 +1524,9 @@ struct CodeGen {
     size_t clang_argv_len;
     ZigList<const char *> lib_dirs;
 
+    const char **llvm_argv;
+    size_t llvm_argv_len;
+
     ZigList<FnTableEntry *> test_fns;
     TypeTableEntry *test_fn_type;
 

src/codegen.cpp

@@ -152,6 +152,11 @@ void codegen_set_clang_argv(CodeGen *g, const char **args, size_t len) {
     g->clang_argv_len = len;
 }
 
+void codegen_set_llvm_argv(CodeGen *g, const char **args, size_t len) {
+    g->llvm_argv = args;
+    g->llvm_argv_len = len;
+}
+
 void codegen_set_omit_zigrt(CodeGen *g, bool omit_zigrt) {
     g->omit_zigrt = omit_zigrt;
 }
@@ -4918,6 +4923,17 @@ static void init(CodeGen *g) {
     if (g->module)
         return;
 
+
+    if (g->llvm_argv_len > 0) {
+        const char **args = allocate_nonzero<const char *>(g->llvm_argv_len + 2);
+        args[0] = "zig (LLVM option parsing)";
+        for (size_t i = 0; i < g->llvm_argv_len; i += 1) {
+            args[i + 1] = g->llvm_argv[i];
+        }
+        args[g->llvm_argv_len + 1] = nullptr;
+        ZigLLVMParseCommandLineOptions(g->llvm_argv_len + 1, args);
+    }
+
     if (g->is_test_build) {
         g->windows_subsystem_windows = false;
         g->windows_subsystem_console = true;

src/codegen.hpp

@@ -17,6 +17,7 @@
 CodeGen *codegen_create(Buf *root_src_path, const ZigTarget *target, OutType out_type, BuildMode build_mode);
 
 void codegen_set_clang_argv(CodeGen *codegen, const char **args, size_t len);
+void codegen_set_llvm_argv(CodeGen *codegen, const char **args, size_t len);
 void codegen_set_is_test(CodeGen *codegen, bool is_test);
 void codegen_set_each_lib_rpath(CodeGen *codegen, bool each_lib_rpath);
 

src/main.cpp

@@ -50,6 +50,7 @@ static int usage(const char *arg0) {
         "  --zig-std-dir [path]         directory where zig standard library resides\n"
         "  -dirafter [dir]              same as -isystem but do it last\n"
         "  -isystem [dir]               add additional search path for other .h files\n"
+        "  -mllvm [arg]                 additional arguments to forward to LLVM's option processing\n"
         "Link Options:\n"
         "  --ar-path [path]             set the path to ar\n"
         "  --dynamic-linker [path]      set the path to ld.so\n"
@@ -190,6 +191,7 @@ int main(int argc, char **argv) {
     const char *zig_std_dir = nullptr;
     const char *dynamic_linker = nullptr;
     ZigList<const char *> clang_argv = {0};
+    ZigList<const char *> llvm_argv = {0};
     ZigList<const char *> lib_dirs = {0};
     ZigList<const char *> link_libs = {0};
     ZigList<const char *> frameworks = {0};
@@ -420,6 +422,11 @@ int main(int argc, char **argv) {
                 } else if (strcmp(arg, "-dirafter") == 0) {
                     clang_argv.append("-dirafter");
                     clang_argv.append(argv[i]);
+                } else if (strcmp(arg, "-mllvm") == 0) {
+                    clang_argv.append("-mllvm");
+                    clang_argv.append(argv[i]);
+
+                    llvm_argv.append(argv[i]);
                 } else if (strcmp(arg, "--library-path") == 0 || strcmp(arg, "-L") == 0) {
                     lib_dirs.append(argv[i]);
                 } else if (strcmp(arg, "--library") == 0) {
@@ -604,6 +611,7 @@ int main(int argc, char **argv) {
                 codegen_set_each_lib_rpath(g, each_lib_rpath);
 
             codegen_set_clang_argv(g, clang_argv.items, clang_argv.length);
+            codegen_set_llvm_argv(g, llvm_argv.items, llvm_argv.length);
             codegen_set_strip(g, strip);
             codegen_set_is_static(g, is_static);
             if (libc_lib_dir)

src/zig_llvm.cpp

@@ -602,6 +602,10 @@ void ZigLLVMAddFunctionAttrCold(LLVMValueRef fn_ref) {
     func->setAttributes(new_attr_set);
 }
 
+void ZigLLVMParseCommandLineOptions(int argc, const char *const *argv) {
+    llvm::cl::ParseCommandLineOptions(argc, argv);
+}
+
 
 static_assert((Triple::ArchType)ZigLLVM_LastArchType == Triple::LastArchType, "");
 static_assert((Triple::VendorType)ZigLLVM_LastVendorType == Triple::LastVendorType, "");

src/zig_llvm.hpp

@@ -164,6 +164,8 @@ void ZigLLVMSetFastMath(LLVMBuilderRef builder_wrapped, bool on_state);
 void ZigLLVMAddFunctionAttr(LLVMValueRef fn, const char *attr_name, const char *attr_value);
 void ZigLLVMAddFunctionAttrCold(LLVMValueRef fn);
 
+void ZigLLVMParseCommandLineOptions(int argc, const char *const *argv);
+
 
 // copied from include/llvm/ADT/Triple.h