support module level assembly

closes #256

3 files changed, 27 insertions, 2 deletions

diff --git a/src/all_types.hpp b/src/all_types.hpp
index c92ab364c5..d3d1a907d1 100644
--- a/src/all_types.hpp
+++ b/src/all_types.hpp
@@ -1460,6 +1460,8 @@ struct CodeGen {
     ConstExprValue const_void_val;
 
     ConstExprValue panic_msg_vals[PanicMsgIdCount];
+
+    Buf global_asm;
 };
 
 enum VarLinkage {
diff --git a/src/codegen.cpp b/src/codegen.cpp
index 5e803795f1..83b7e01614 100644
--- a/src/codegen.cpp
+++ b/src/codegen.cpp
@@ -73,6 +73,8 @@ CodeGen *codegen_create(Buf *root_source_dir, const ZigTarget *target) {
     g->is_test_build = false;
     g->want_h_file = true;
 
+    buf_resize(&g->global_asm, 0);
+
     // reserve index 0 to indicate no error
     g->error_decls.append(nullptr);
 
@@ -3725,6 +3727,10 @@ static void do_code_gen(CodeGen *g) {
     }
     assert(!g->errors.length);
 
+    if (buf_len(&g->global_asm) != 0) {
+        LLVMSetModuleInlineAsm(g->module, buf_ptr(&g->global_asm));
+    }
+
     ZigLLVMDIBuilderFinalize(g->dbuilder);
 
     if (g->verbose) {
diff --git a/src/ir.cpp b/src/ir.cpp
index 4f3f756d49..6f5f5fbbd2 100644
--- a/src/ir.cpp
+++ b/src/ir.cpp
@@ -9896,13 +9896,30 @@ static TypeTableEntry *ir_analyze_instruction_slice_type(IrAnalyze *ira,
 static TypeTableEntry *ir_analyze_instruction_asm(IrAnalyze *ira, IrInstructionAsm *asm_instruction) {
     assert(asm_instruction->base.source_node->type == NodeTypeAsmExpr);
 
+    AstNodeAsmExpr *asm_expr = &asm_instruction->base.source_node->data.asm_expr;
+
+    bool global_scope = (scope_fn_entry(asm_instruction->base.scope) == nullptr);
+    if (global_scope) {
+        if (asm_expr->output_list.length != 0 || asm_expr->input_list.length != 0 ||
+            asm_expr->clobber_list.length != 0)
+        {
+            ir_add_error(ira, &asm_instruction->base,
+                buf_sprintf("global assembly cannot have inputs, outputs, or clobbers"));
+            return ira->codegen->builtin_types.entry_invalid;
+        }
+
+        buf_append_char(&ira->codegen->global_asm, '\n');
+        buf_append_buf(&ira->codegen->global_asm, asm_expr->asm_template);
+
+        ir_build_const_from(ira, &asm_instruction->base);
+        return ira->codegen->builtin_types.entry_void;
+    }
+
     if (!ir_emit_global_runtime_side_effect(ira, &asm_instruction->base))
         return ira->codegen->builtin_types.entry_invalid;
 
     // TODO validate the output types and variable types
 
-    AstNodeAsmExpr *asm_expr = &asm_instruction->base.source_node->data.asm_expr;
-
     IrInstruction **input_list = allocate<IrInstruction *>(asm_expr->input_list.length);
     IrInstruction **output_types = allocate<IrInstruction *>(asm_expr->output_list.length);