Commit 9e0ff6faa2

Josh Wolfe <thejoshwolfe@gmail.com>
2015-11-30 17:14:58
factor analysis code out of codegen
1 parent 020f854
src/analyze.cpp
@@ -0,0 +1,498 @@
+/*
+ * Copyright (c) 2015 Andrew Kelley
+ *
+ * This file is part of zig, which is MIT licensed.
+ * See http://opensource.org/licenses/MIT
+ */
+
+#include "analyze.hpp"
+#include "semantic_info.hpp"
+#include "error.hpp"
+#include "zig_llvm.hpp"
+
+static void add_node_error(CodeGen *g, AstNode *node, Buf *msg) {
+    g->errors.add_one();
+    ErrorMsg *last_msg = &g->errors.last();
+    last_msg->line_start = node->line;
+    last_msg->column_start = node->column;
+    last_msg->line_end = -1;
+    last_msg->column_end = -1;
+    last_msg->msg = msg;
+}
+
+static int parse_version_string(Buf *buf, int *major, int *minor, int *patch) {
+    char *dot1 = strstr(buf_ptr(buf), ".");
+    if (!dot1)
+        return ErrorInvalidFormat;
+    char *dot2 = strstr(dot1 + 1, ".");
+    if (!dot2)
+        return ErrorInvalidFormat;
+
+    *major = (int)strtol(buf_ptr(buf), nullptr, 10);
+    *minor = (int)strtol(dot1 + 1, nullptr, 10);
+    *patch = (int)strtol(dot2 + 1, nullptr, 10);
+
+    return ErrorNone;
+}
+
+static void set_root_export_version(CodeGen *g, Buf *version_buf, AstNode *node) {
+    int err;
+    if ((err = parse_version_string(version_buf, &g->version_major, &g->version_minor, &g->version_patch))) {
+        add_node_error(g, node,
+                buf_sprintf("invalid version string"));
+    }
+}
+
+static void find_declarations(CodeGen *g, AstNode *node);
+
+static void resolve_type_and_recurse(CodeGen *g, AstNode *node) {
+    assert(!node->codegen_node);
+    node->codegen_node = allocate<CodeGenNode>(1);
+    TypeNode *type_node = &node->codegen_node->data.type_node;
+    switch (node->data.type.type) {
+        case AstNodeTypeTypePrimitive:
+            {
+                Buf *name = &node->data.type.primitive_name;
+                auto table_entry = g->type_table.maybe_get(name);
+                if (table_entry) {
+                    type_node->entry = table_entry->value;
+                } else {
+                    add_node_error(g, node,
+                            buf_sprintf("invalid type name: '%s'", buf_ptr(name)));
+                    type_node->entry = g->invalid_type_entry;
+                }
+                break;
+            }
+        case AstNodeTypeTypePointer:
+            {
+                find_declarations(g, node->data.type.child_type);
+                TypeNode *child_type_node = &node->data.type.child_type->codegen_node->data.type_node;
+                if (child_type_node->entry->id == TypeIdUnreachable) {
+                    add_node_error(g, node,
+                            buf_create_from_str("pointer to unreachable not allowed"));
+                }
+                TypeTableEntry **parent_pointer = node->data.type.is_const ?
+                    &child_type_node->entry->pointer_const_parent :
+                    &child_type_node->entry->pointer_mut_parent;
+                const char *const_or_mut_str = node->data.type.is_const ? "const" : "mut";
+                if (*parent_pointer) {
+                    type_node->entry = *parent_pointer;
+                } else {
+                    TypeTableEntry *entry = allocate<TypeTableEntry>(1);
+                    entry->id = TypeIdPointer;
+                    entry->type_ref = LLVMPointerType(child_type_node->entry->type_ref, 0);
+                    buf_resize(&entry->name, 0);
+                    buf_appendf(&entry->name, "*%s %s", const_or_mut_str, buf_ptr(&child_type_node->entry->name));
+                    entry->di_type = g->dbuilder->createPointerType(child_type_node->entry->di_type,
+                            g->pointer_size_bytes * 8, g->pointer_size_bytes * 8, buf_ptr(&entry->name));
+                    g->type_table.put(&entry->name, entry);
+                    type_node->entry = entry;
+                    *parent_pointer = entry;
+                }
+                break;
+            }
+    }
+}
+
+static void find_declarations(CodeGen *g, AstNode *node) {
+    switch (node->type) {
+        case NodeTypeExternBlock:
+            for (int i = 0; i < node->data.extern_block.directives->length; i += 1) {
+                AstNode *directive_node = node->data.extern_block.directives->at(i);
+                Buf *name = &directive_node->data.directive.name;
+                Buf *param = &directive_node->data.directive.param;
+                if (buf_eql_str(name, "link")) {
+                    g->link_table.put(param, true);
+                } else {
+                    add_node_error(g, directive_node,
+                            buf_sprintf("invalid directive: '%s'", buf_ptr(name)));
+                }
+            }
+
+            for (int fn_decl_i = 0; fn_decl_i < node->data.extern_block.fn_decls.length; fn_decl_i += 1) {
+                AstNode *fn_decl = node->data.extern_block.fn_decls.at(fn_decl_i);
+                assert(fn_decl->type == NodeTypeFnDecl);
+                AstNode *fn_proto = fn_decl->data.fn_decl.fn_proto;
+                find_declarations(g, fn_proto);
+                Buf *name = &fn_proto->data.fn_proto.name;
+
+                FnTableEntry *fn_table_entry = allocate<FnTableEntry>(1);
+                fn_table_entry->proto_node = fn_proto;
+                fn_table_entry->is_extern = true;
+                fn_table_entry->calling_convention = LLVMCCallConv;
+                g->fn_table.put(name, fn_table_entry);
+            }
+            break;
+        case NodeTypeFnDef:
+            {
+                AstNode *proto_node = node->data.fn_def.fn_proto;
+                assert(proto_node->type == NodeTypeFnProto);
+                Buf *proto_name = &proto_node->data.fn_proto.name;
+                auto entry = g->fn_table.maybe_get(proto_name);
+                if (entry) {
+                    add_node_error(g, node,
+                            buf_sprintf("redefinition of '%s'", buf_ptr(proto_name)));
+                    assert(!node->codegen_node);
+                    node->codegen_node = allocate<CodeGenNode>(1);
+                    node->codegen_node->data.fn_def_node.skip = true;
+                } else {
+                    FnTableEntry *fn_table_entry = allocate<FnTableEntry>(1);
+                    fn_table_entry->proto_node = proto_node;
+                    fn_table_entry->fn_def_node = node;
+                    fn_table_entry->internal_linkage = proto_node->data.fn_proto.visib_mod != FnProtoVisibModExport;
+                    if (fn_table_entry->internal_linkage) {
+                        fn_table_entry->calling_convention = LLVMFastCallConv;
+                    } else {
+                        fn_table_entry->calling_convention = LLVMCCallConv;
+                    }
+                    g->fn_table.put(proto_name, fn_table_entry);
+                    g->fn_defs.append(fn_table_entry);
+
+                    find_declarations(g, proto_node);
+                }
+                break;
+            }
+        case NodeTypeFnProto:
+            {
+                for (int i = 0; i < node->data.fn_proto.directives->length; i += 1) {
+                    AstNode *directive_node = node->data.fn_proto.directives->at(i);
+                    Buf *name = &directive_node->data.directive.name;
+                    add_node_error(g, directive_node,
+                            buf_sprintf("invalid directive: '%s'", buf_ptr(name)));
+                }
+                for (int i = 0; i < node->data.fn_proto.params.length; i += 1) {
+                    AstNode *child = node->data.fn_proto.params.at(i);
+                    find_declarations(g, child);
+                }
+                find_declarations(g, node->data.fn_proto.return_type);
+                break;
+            }
+            break;
+        case NodeTypeParamDecl:
+            find_declarations(g, node->data.param_decl.type);
+            break;
+        case NodeTypeType:
+            resolve_type_and_recurse(g, node);
+            break;
+        case NodeTypeDirective:
+            // we handled directives in the parent function
+            break;
+        case NodeTypeRootExportDecl:
+            for (int i = 0; i < node->data.root_export_decl.directives->length; i += 1) {
+                AstNode *directive_node = node->data.root_export_decl.directives->at(i);
+                Buf *name = &directive_node->data.directive.name;
+                Buf *param = &directive_node->data.directive.param;
+                if (buf_eql_str(name, "version")) {
+                    set_root_export_version(g, param, directive_node);
+                } else {
+                    add_node_error(g, directive_node,
+                            buf_sprintf("invalid directive: '%s'", buf_ptr(name)));
+                }
+            }
+            break;
+        case NodeTypeFnDecl:
+        case NodeTypeReturnExpr:
+        case NodeTypeRoot:
+        case NodeTypeBlock:
+        case NodeTypeBinOpExpr:
+        case NodeTypeFnCallExpr:
+        case NodeTypeNumberLiteral:
+        case NodeTypeStringLiteral:
+        case NodeTypeUnreachable:
+        case NodeTypeSymbol:
+        case NodeTypeCastExpr:
+        case NodeTypePrefixOpExpr:
+            zig_unreachable();
+    }
+}
+
+static void check_fn_def_control_flow(CodeGen *g, AstNode *node) {
+    // Follow the execution flow and make sure the code returns appropriately.
+    // * A `return` statement in an unreachable type function should be an error.
+    // * Control flow should not be able to reach the end of an unreachable type function.
+    // * Functions that have a type other than void should not return without a value.
+    // * void functions without explicit return statements at the end need the
+    //   add_implicit_return flag set on the codegen node.
+    assert(node->type == NodeTypeFnDef);
+    AstNode *proto_node = node->data.fn_def.fn_proto;
+    assert(proto_node->type == NodeTypeFnProto);
+    AstNode *return_type_node = proto_node->data.fn_proto.return_type;
+    assert(return_type_node->type == NodeTypeType);
+
+    node->codegen_node = allocate<CodeGenNode>(1);
+    FnDefNode *codegen_fn_def = &node->codegen_node->data.fn_def_node;
+
+    assert(return_type_node->codegen_node);
+    TypeTableEntry *type_entry = return_type_node->codegen_node->data.type_node.entry;
+    assert(type_entry);
+    TypeId type_id = type_entry->id;
+
+    AstNode *body_node = node->data.fn_def.body;
+    assert(body_node->type == NodeTypeBlock);
+
+    // TODO once we understand types, do this pass after type checking, and
+    // if an expression has an unreachable value then stop looking at statements after
+    // it. then we can remove the check to `unreachable` in the end of this function.
+    bool prev_statement_return = false;
+    for (int i = 0; i < body_node->data.block.statements.length; i += 1) {
+        AstNode *statement_node = body_node->data.block.statements.at(i);
+        if (statement_node->type == NodeTypeReturnExpr) {
+            if (type_id == TypeIdUnreachable) {
+                add_node_error(g, statement_node,
+                        buf_sprintf("return statement in function with unreachable return type"));
+                return;
+            } else {
+                prev_statement_return = true;
+            }
+        } else if (prev_statement_return) {
+            add_node_error(g, statement_node,
+                    buf_sprintf("unreachable code"));
+        }
+    }
+
+    if (!prev_statement_return) {
+        if (type_id == TypeIdVoid) {
+            codegen_fn_def->add_implicit_return = true;
+        } else if (type_id != TypeIdUnreachable) {
+            add_node_error(g, node,
+                    buf_sprintf("control reaches end of non-void function"));
+        }
+    }
+}
+
+static void analyze_node(CodeGen *g, AstNode *node) {
+    switch (node->type) {
+        case NodeTypeRoot:
+            {
+                // Iterate once over the top level declarations to build the function table
+                for (int i = 0; i < node->data.root.top_level_decls.length; i += 1) {
+                    AstNode *child = node->data.root.top_level_decls.at(i);
+                    find_declarations(g, child);
+                }
+                for (int i = 0; i < node->data.root.top_level_decls.length; i += 1) {
+                    AstNode *child = node->data.root.top_level_decls.at(i);
+                    analyze_node(g, child);
+                }
+                if (!g->out_name) {
+                    add_node_error(g, node,
+                            buf_sprintf("missing export declaration and output name not provided"));
+                } else if (g->out_type == OutTypeUnknown) {
+                    add_node_error(g, node,
+                            buf_sprintf("missing export declaration and export type not provided"));
+                }
+                break;
+            }
+        case NodeTypeRootExportDecl:
+            if (g->root_export_decl) {
+                add_node_error(g, node,
+                        buf_sprintf("only one root export declaration allowed"));
+            } else {
+                g->root_export_decl = node;
+
+                if (!g->out_name)
+                    g->out_name = &node->data.root_export_decl.name;
+
+                Buf *out_type = &node->data.root_export_decl.type;
+                OutType export_out_type;
+                if (buf_eql_str(out_type, "executable")) {
+                    export_out_type = OutTypeExe;
+                } else if (buf_eql_str(out_type, "library")) {
+                    export_out_type = OutTypeLib;
+                } else if (buf_eql_str(out_type, "object")) {
+                    export_out_type = OutTypeObj;
+                } else {
+                    add_node_error(g, node,
+                            buf_sprintf("invalid export type: '%s'", buf_ptr(out_type)));
+                }
+                if (g->out_type == OutTypeUnknown)
+                    g->out_type = export_out_type;
+            }
+            break;
+        case NodeTypeExternBlock:
+            for (int fn_decl_i = 0; fn_decl_i < node->data.extern_block.fn_decls.length; fn_decl_i += 1) {
+                AstNode *fn_decl = node->data.extern_block.fn_decls.at(fn_decl_i);
+                analyze_node(g, fn_decl);
+            }
+            break;
+        case NodeTypeFnDef:
+            {
+                if (node->codegen_node && node->codegen_node->data.fn_def_node.skip) {
+                    // we detected an error with this function definition which prevents us
+                    // from further analyzing it.
+                    break;
+                }
+
+                AstNode *proto_node = node->data.fn_def.fn_proto;
+                assert(proto_node->type == NodeTypeFnProto);
+                analyze_node(g, proto_node);
+
+                check_fn_def_control_flow(g, node);
+                analyze_node(g, node->data.fn_def.body);
+                break;
+            }
+        case NodeTypeFnDecl:
+            {
+                AstNode *proto_node = node->data.fn_decl.fn_proto;
+                assert(proto_node->type == NodeTypeFnProto);
+                analyze_node(g, proto_node);
+                break;
+            }
+        case NodeTypeFnProto:
+            {
+                for (int i = 0; i < node->data.fn_proto.params.length; i += 1) {
+                    AstNode *child = node->data.fn_proto.params.at(i);
+                    analyze_node(g, child);
+                }
+                analyze_node(g, node->data.fn_proto.return_type);
+                break;
+            }
+        case NodeTypeParamDecl:
+            analyze_node(g, node->data.param_decl.type);
+            break;
+
+        case NodeTypeType:
+            // ignore; we handled types with find_declarations
+            break;
+        case NodeTypeBlock:
+            for (int i = 0; i < node->data.block.statements.length; i += 1) {
+                AstNode *child = node->data.block.statements.at(i);
+                analyze_node(g, child);
+            }
+            break;
+        case NodeTypeReturnExpr:
+            if (node->data.return_expr.expr) {
+                analyze_node(g, node->data.return_expr.expr);
+            }
+            break;
+        case NodeTypeBinOpExpr:
+            analyze_node(g, node->data.bin_op_expr.op1);
+            analyze_node(g, node->data.bin_op_expr.op2);
+            break;
+        case NodeTypeFnCallExpr:
+            {
+                Buf *name = hack_get_fn_call_name(g, node->data.fn_call_expr.fn_ref_expr);
+
+                auto entry = g->fn_table.maybe_get(name);
+                if (!entry) {
+                    add_node_error(g, node,
+                            buf_sprintf("undefined function: '%s'", buf_ptr(name)));
+                } else {
+                    FnTableEntry *fn_table_entry = entry->value;
+                    assert(fn_table_entry->proto_node->type == NodeTypeFnProto);
+                    int expected_param_count = fn_table_entry->proto_node->data.fn_proto.params.length;
+                    int actual_param_count = node->data.fn_call_expr.params.length;
+                    if (expected_param_count != actual_param_count) {
+                        add_node_error(g, node,
+                                buf_sprintf("wrong number of arguments. Expected %d, got %d.",
+                                    expected_param_count, actual_param_count));
+                    }
+                }
+
+                for (int i = 0; i < node->data.fn_call_expr.params.length; i += 1) {
+                    AstNode *child = node->data.fn_call_expr.params.at(i);
+                    analyze_node(g, child);
+                }
+                break;
+            }
+        case NodeTypeDirective:
+            // we looked at directives in the parent node
+            break;
+        case NodeTypeCastExpr:
+            zig_panic("TODO");
+            break;
+        case NodeTypePrefixOpExpr:
+            zig_panic("TODO");
+            break;
+        case NodeTypeNumberLiteral:
+        case NodeTypeStringLiteral:
+        case NodeTypeUnreachable:
+        case NodeTypeSymbol:
+            // nothing to do
+            break;
+    }
+}
+
+static void add_types(CodeGen *g) {
+    {
+        TypeTableEntry *entry = allocate<TypeTableEntry>(1);
+        entry->id = TypeIdU8;
+        entry->type_ref = LLVMInt8Type();
+        buf_init_from_str(&entry->name, "u8");
+        entry->di_type = g->dbuilder->createBasicType(buf_ptr(&entry->name), 8, 8, llvm::dwarf::DW_ATE_unsigned);
+        g->type_table.put(&entry->name, entry);
+    }
+    {
+        TypeTableEntry *entry = allocate<TypeTableEntry>(1);
+        entry->id = TypeIdI32;
+        entry->type_ref = LLVMInt32Type();
+        buf_init_from_str(&entry->name, "i32");
+        entry->di_type = g->dbuilder->createBasicType(buf_ptr(&entry->name), 32, 32,
+                llvm::dwarf::DW_ATE_signed);
+        g->type_table.put(&entry->name, entry);
+    }
+    {
+        TypeTableEntry *entry = allocate<TypeTableEntry>(1);
+        entry->id = TypeIdVoid;
+        entry->type_ref = LLVMVoidType();
+        buf_init_from_str(&entry->name, "void");
+        entry->di_type = g->dbuilder->createBasicType(buf_ptr(&entry->name), 0, 0,
+                llvm::dwarf::DW_ATE_unsigned);
+        g->type_table.put(&entry->name, entry);
+
+        // invalid types are void
+        g->invalid_type_entry = entry;
+    }
+    {
+        TypeTableEntry *entry = allocate<TypeTableEntry>(1);
+        entry->id = TypeIdUnreachable;
+        entry->type_ref = LLVMVoidType();
+        buf_init_from_str(&entry->name, "unreachable");
+        entry->di_type = g->invalid_type_entry->di_type;
+        g->type_table.put(&entry->name, entry);
+    }
+}
+
+
+void semantic_analyze(CodeGen *g) {
+    LLVMInitializeAllTargets();
+    LLVMInitializeAllTargetMCs();
+    LLVMInitializeAllAsmPrinters();
+    LLVMInitializeAllAsmParsers();
+    LLVMInitializeNativeTarget();
+
+    g->is_native_target = true;
+    char *native_triple = LLVMGetDefaultTargetTriple();
+
+    LLVMTargetRef target_ref;
+    char *err_msg = nullptr;
+    if (LLVMGetTargetFromTriple(native_triple, &target_ref, &err_msg)) {
+        zig_panic("unable to get target from triple: %s", err_msg);
+    }
+
+    char *native_cpu = LLVMZigGetHostCPUName();
+    char *native_features = LLVMZigGetNativeFeatures();
+
+    LLVMCodeGenOptLevel opt_level = (g->build_type == CodeGenBuildTypeDebug) ?
+        LLVMCodeGenLevelNone : LLVMCodeGenLevelAggressive;
+
+    LLVMRelocMode reloc_mode = g->is_static ? LLVMRelocStatic : LLVMRelocPIC;
+
+    g->target_machine = LLVMCreateTargetMachine(target_ref, native_triple,
+            native_cpu, native_features, opt_level, reloc_mode, LLVMCodeModelDefault);
+
+    g->target_data_ref = LLVMGetTargetMachineData(g->target_machine);
+
+
+    g->module = LLVMModuleCreateWithName("ZigModule");
+
+    g->pointer_size_bytes = LLVMPointerSize(g->target_data_ref);
+
+    g->builder = LLVMCreateBuilder();
+    g->dbuilder = new llvm::DIBuilder(*llvm::unwrap(g->module), true);
+
+
+    add_types(g);
+
+    analyze_node(g, g->root);
+}
+
src/analyze.hpp
@@ -0,0 +1,15 @@
+/*
+ * Copyright (c) 2015 Andrew Kelley
+ *
+ * This file is part of zig, which is MIT licensed.
+ * See http://opensource.org/licenses/MIT
+ */
+
+#ifndef ZIG_ANALYZE_HPP
+#define ZIG_ANALYZE_HPP
+
+struct CodeGen;
+
+void semantic_analyze(CodeGen *g);
+
+#endif
src/buffer.cpp
@@ -45,3 +45,20 @@ void buf_appendf(Buf *buf, const char *format, ...) {
     va_end(ap2);
     va_end(ap);
 }
+
+// these functions are not static inline so they can be better used as template parameters
+bool buf_eql_buf(Buf *buf, Buf *other) {
+    assert(buf->list.length);
+    return buf_eql_mem(buf, buf_ptr(other), buf_len(other));
+}
+
+uint32_t buf_hash(Buf *buf) {
+    assert(buf->list.length);
+    // FNV 32-bit hash
+    uint32_t h = 2166136261;
+    for (int i = 0; i < buf_len(buf); i += 1) {
+        h = h ^ ((uint8_t)buf->list.at(i));
+        h = h * 16777619;
+    }
+    return h;
+}
src/buffer.hpp
@@ -132,21 +132,8 @@ static inline bool buf_eql_str(Buf *buf, const char *str) {
     return buf_eql_mem(buf, str, strlen(str));
 }
 
-static inline bool buf_eql_buf(Buf *buf, Buf *other) {
-    assert(buf->list.length);
-    return buf_eql_mem(buf, buf_ptr(other), buf_len(other));
-}
-
-static inline uint32_t buf_hash(Buf *buf) {
-    assert(buf->list.length);
-    // FNV 32-bit hash
-    uint32_t h = 2166136261;
-    for (int i = 0; i < buf_len(buf); i += 1) {
-        h = h ^ ((uint8_t)buf->list.at(i));
-        h = h * 16777619;
-    }
-    return h;
-}
+bool buf_eql_buf(Buf *buf, Buf *other);
+uint32_t buf_hash(Buf *buf);
 
 static inline void buf_upcase(Buf *buf) {
     for (int i = 0; i < buf_len(buf); i += 1) {
src/codegen.cpp
@@ -12,6 +12,8 @@
 #include "config.h"
 #include "error.hpp"
 
+#include "semantic_info.hpp"
+
 #include <stdio.h>
 
 #include <llvm/IR/IRBuilder.h>
@@ -21,88 +23,6 @@
 #include <llvm/Target/TargetMachine.h>
 #include <llvm/Support/TargetParser.h>
 
-struct FnTableEntry {
-    LLVMValueRef fn_value;
-    AstNode *proto_node;
-    AstNode *fn_def_node;
-    bool is_extern;
-    bool internal_linkage;
-    unsigned calling_convention;
-};
-
-enum TypeId {
-    TypeIdUserDefined,
-    TypeIdPointer,
-    TypeIdU8,
-    TypeIdI32,
-    TypeIdVoid,
-    TypeIdUnreachable,
-};
-
-struct TypeTableEntry {
-    TypeId id;
-    LLVMTypeRef type_ref;
-    llvm::DIType *di_type;
-
-    TypeTableEntry *pointer_child;
-    bool pointer_is_const;
-    int user_defined_id;
-    Buf name;
-    TypeTableEntry *pointer_const_parent;
-    TypeTableEntry *pointer_mut_parent;
-};
-
-struct CodeGen {
-    LLVMModuleRef module;
-    AstNode *root;
-    ZigList<ErrorMsg> errors;
-    LLVMBuilderRef builder;
-    llvm::DIBuilder *dbuilder;
-    llvm::DICompileUnit *compile_unit;
-    HashMap<Buf *, FnTableEntry *, buf_hash, buf_eql_buf> fn_table;
-    HashMap<Buf *, LLVMValueRef, buf_hash, buf_eql_buf> str_table;
-    HashMap<Buf *, TypeTableEntry *, buf_hash, buf_eql_buf> type_table;
-    HashMap<Buf *, bool, buf_hash, buf_eql_buf> link_table;
-    TypeTableEntry *invalid_type_entry;
-    LLVMTargetDataRef target_data_ref;
-    unsigned pointer_size_bytes;
-    bool is_static;
-    bool strip_debug_symbols;
-    CodeGenBuildType build_type;
-    LLVMTargetMachineRef target_machine;
-    bool is_native_target;
-    Buf in_file;
-    Buf in_dir;
-    ZigList<llvm::DIScope *> block_scopes;
-    llvm::DIFile *di_file;
-    ZigList<FnTableEntry *> fn_defs;
-    Buf *out_name;
-    OutType out_type;
-    FnTableEntry *cur_fn;
-    bool c_stdint_used;
-    AstNode *root_export_decl;
-    int version_major;
-    int version_minor;
-    int version_patch;
-};
-
-struct TypeNode {
-    TypeTableEntry *entry;
-};
-
-struct FnDefNode {
-    bool add_implicit_return;
-    bool skip;
-    LLVMValueRef *params;
-};
-
-struct CodeGenNode {
-    union {
-        TypeNode type_node; // for NodeTypeType
-        FnDefNode fn_def_node; // for NodeTypeFnDef
-    } data;
-};
-
 CodeGen *create_codegen(AstNode *root, Buf *in_full_path) {
     CodeGen *g = allocate<CodeGen>(1);
     g->root = root;
@@ -140,15 +60,7 @@ void codegen_set_out_name(CodeGen *g, Buf *out_name) {
     g->out_name = out_name;
 }
 
-static void add_node_error(CodeGen *g, AstNode *node, Buf *msg) {
-    g->errors.add_one();
-    ErrorMsg *last_msg = &g->errors.last();
-    last_msg->line_start = node->line;
-    last_msg->column_start = node->column;
-    last_msg->line_end = -1;
-    last_msg->column_end = -1;
-    last_msg->msg = msg;
-}
+static LLVMValueRef gen_expr(CodeGen *g, AstNode *expr_node);
 
 static LLVMTypeRef to_llvm_type(AstNode *type_node) {
     assert(type_node->type == NodeTypeType);
@@ -166,7 +78,6 @@ static llvm::DIType *to_llvm_debug_type(AstNode *type_node) {
     return type_node->codegen_node->data.type_node.entry->di_type;
 }
 
-
 static bool type_is_unreachable(AstNode *type_node) {
     assert(type_node->type == NodeTypeType);
     assert(type_node->codegen_node);
@@ -174,492 +85,6 @@ static bool type_is_unreachable(AstNode *type_node) {
     return type_node->codegen_node->data.type_node.entry->id == TypeIdUnreachable;
 }
 
-
-static int parse_version_string(Buf *buf, int *major, int *minor, int *patch) {
-    char *dot1 = strstr(buf_ptr(buf), ".");
-    if (!dot1)
-        return ErrorInvalidFormat;
-    char *dot2 = strstr(dot1 + 1, ".");
-    if (!dot2)
-        return ErrorInvalidFormat;
-
-    *major = (int)strtol(buf_ptr(buf), nullptr, 10);
-    *minor = (int)strtol(dot1 + 1, nullptr, 10);
-    *patch = (int)strtol(dot2 + 1, nullptr, 10);
-
-    return ErrorNone;
-}
-
-static void set_root_export_version(CodeGen *g, Buf *version_buf, AstNode *node) {
-    int err;
-    if ((err = parse_version_string(version_buf, &g->version_major, &g->version_minor, &g->version_patch))) {
-        add_node_error(g, node,
-                buf_sprintf("invalid version string"));
-    }
-}
-
-static void find_declarations(CodeGen *g, AstNode *node);
-
-static void resolve_type_and_recurse(CodeGen *g, AstNode *node) {
-    assert(!node->codegen_node);
-    node->codegen_node = allocate<CodeGenNode>(1);
-    TypeNode *type_node = &node->codegen_node->data.type_node;
-    switch (node->data.type.type) {
-        case AstNodeTypeTypePrimitive:
-            {
-                Buf *name = &node->data.type.primitive_name;
-                auto table_entry = g->type_table.maybe_get(name);
-                if (table_entry) {
-                    type_node->entry = table_entry->value;
-                } else {
-                    add_node_error(g, node,
-                            buf_sprintf("invalid type name: '%s'", buf_ptr(name)));
-                    type_node->entry = g->invalid_type_entry;
-                }
-                break;
-            }
-        case AstNodeTypeTypePointer:
-            {
-                find_declarations(g, node->data.type.child_type);
-                TypeNode *child_type_node = &node->data.type.child_type->codegen_node->data.type_node;
-                if (child_type_node->entry->id == TypeIdUnreachable) {
-                    add_node_error(g, node,
-                            buf_create_from_str("pointer to unreachable not allowed"));
-                }
-                TypeTableEntry **parent_pointer = node->data.type.is_const ?
-                    &child_type_node->entry->pointer_const_parent :
-                    &child_type_node->entry->pointer_mut_parent;
-                const char *const_or_mut_str = node->data.type.is_const ? "const" : "mut";
-                if (*parent_pointer) {
-                    type_node->entry = *parent_pointer;
-                } else {
-                    TypeTableEntry *entry = allocate<TypeTableEntry>(1);
-                    entry->id = TypeIdPointer;
-                    entry->type_ref = LLVMPointerType(child_type_node->entry->type_ref, 0);
-                    buf_resize(&entry->name, 0);
-                    buf_appendf(&entry->name, "*%s %s", const_or_mut_str, buf_ptr(&child_type_node->entry->name));
-                    entry->di_type = g->dbuilder->createPointerType(child_type_node->entry->di_type,
-                            g->pointer_size_bytes * 8, g->pointer_size_bytes * 8, buf_ptr(&entry->name));
-                    g->type_table.put(&entry->name, entry);
-                    type_node->entry = entry;
-                    *parent_pointer = entry;
-                }
-                break;
-            }
-    }
-}
-
-static void find_declarations(CodeGen *g, AstNode *node) {
-    switch (node->type) {
-        case NodeTypeExternBlock:
-            for (int i = 0; i < node->data.extern_block.directives->length; i += 1) {
-                AstNode *directive_node = node->data.extern_block.directives->at(i);
-                Buf *name = &directive_node->data.directive.name;
-                Buf *param = &directive_node->data.directive.param;
-                if (buf_eql_str(name, "link")) {
-                    g->link_table.put(param, true);
-                } else {
-                    add_node_error(g, directive_node,
-                            buf_sprintf("invalid directive: '%s'", buf_ptr(name)));
-                }
-            }
-
-            for (int fn_decl_i = 0; fn_decl_i < node->data.extern_block.fn_decls.length; fn_decl_i += 1) {
-                AstNode *fn_decl = node->data.extern_block.fn_decls.at(fn_decl_i);
-                assert(fn_decl->type == NodeTypeFnDecl);
-                AstNode *fn_proto = fn_decl->data.fn_decl.fn_proto;
-                find_declarations(g, fn_proto);
-                Buf *name = &fn_proto->data.fn_proto.name;
-
-                FnTableEntry *fn_table_entry = allocate<FnTableEntry>(1);
-                fn_table_entry->proto_node = fn_proto;
-                fn_table_entry->is_extern = true;
-                fn_table_entry->calling_convention = LLVMCCallConv;
-                g->fn_table.put(name, fn_table_entry);
-            }
-            break;
-        case NodeTypeFnDef:
-            {
-                AstNode *proto_node = node->data.fn_def.fn_proto;
-                assert(proto_node->type == NodeTypeFnProto);
-                Buf *proto_name = &proto_node->data.fn_proto.name;
-                auto entry = g->fn_table.maybe_get(proto_name);
-                if (entry) {
-                    add_node_error(g, node,
-                            buf_sprintf("redefinition of '%s'", buf_ptr(proto_name)));
-                    assert(!node->codegen_node);
-                    node->codegen_node = allocate<CodeGenNode>(1);
-                    node->codegen_node->data.fn_def_node.skip = true;
-                } else {
-                    FnTableEntry *fn_table_entry = allocate<FnTableEntry>(1);
-                    fn_table_entry->proto_node = proto_node;
-                    fn_table_entry->fn_def_node = node;
-                    fn_table_entry->internal_linkage = proto_node->data.fn_proto.visib_mod != FnProtoVisibModExport;
-                    if (fn_table_entry->internal_linkage) {
-                        fn_table_entry->calling_convention = LLVMFastCallConv;
-                    } else {
-                        fn_table_entry->calling_convention = LLVMCCallConv;
-                    }
-                    g->fn_table.put(proto_name, fn_table_entry);
-                    g->fn_defs.append(fn_table_entry);
-
-                    find_declarations(g, proto_node);
-                }
-                break;
-            }
-        case NodeTypeFnProto:
-            {
-                for (int i = 0; i < node->data.fn_proto.directives->length; i += 1) {
-                    AstNode *directive_node = node->data.fn_proto.directives->at(i);
-                    Buf *name = &directive_node->data.directive.name;
-                    add_node_error(g, directive_node,
-                            buf_sprintf("invalid directive: '%s'", buf_ptr(name)));
-                }
-                for (int i = 0; i < node->data.fn_proto.params.length; i += 1) {
-                    AstNode *child = node->data.fn_proto.params.at(i);
-                    find_declarations(g, child);
-                }
-                find_declarations(g, node->data.fn_proto.return_type);
-                break;
-            }
-            break;
-        case NodeTypeParamDecl:
-            find_declarations(g, node->data.param_decl.type);
-            break;
-        case NodeTypeType:
-            resolve_type_and_recurse(g, node);
-            break;
-        case NodeTypeDirective:
-            // we handled directives in the parent function
-            break;
-        case NodeTypeRootExportDecl:
-            for (int i = 0; i < node->data.root_export_decl.directives->length; i += 1) {
-                AstNode *directive_node = node->data.root_export_decl.directives->at(i);
-                Buf *name = &directive_node->data.directive.name;
-                Buf *param = &directive_node->data.directive.param;
-                if (buf_eql_str(name, "version")) {
-                    set_root_export_version(g, param, directive_node);
-                } else {
-                    add_node_error(g, directive_node,
-                            buf_sprintf("invalid directive: '%s'", buf_ptr(name)));
-                }
-            }
-            break;
-        case NodeTypeFnDecl:
-        case NodeTypeReturnExpr:
-        case NodeTypeRoot:
-        case NodeTypeBlock:
-        case NodeTypeBinOpExpr:
-        case NodeTypeFnCallExpr:
-        case NodeTypeNumberLiteral:
-        case NodeTypeStringLiteral:
-        case NodeTypeUnreachable:
-        case NodeTypeSymbol:
-        case NodeTypeCastExpr:
-        case NodeTypePrefixOpExpr:
-            zig_unreachable();
-    }
-}
-
-static void check_fn_def_control_flow(CodeGen *g, AstNode *node) {
-    // Follow the execution flow and make sure the code returns appropriately.
-    // * A `return` statement in an unreachable type function should be an error.
-    // * Control flow should not be able to reach the end of an unreachable type function.
-    // * Functions that have a type other than void should not return without a value.
-    // * void functions without explicit return statements at the end need the
-    //   add_implicit_return flag set on the codegen node.
-    assert(node->type == NodeTypeFnDef);
-    AstNode *proto_node = node->data.fn_def.fn_proto;
-    assert(proto_node->type == NodeTypeFnProto);
-    AstNode *return_type_node = proto_node->data.fn_proto.return_type;
-    assert(return_type_node->type == NodeTypeType);
-
-    node->codegen_node = allocate<CodeGenNode>(1);
-    FnDefNode *codegen_fn_def = &node->codegen_node->data.fn_def_node;
-
-    assert(return_type_node->codegen_node);
-    TypeTableEntry *type_entry = return_type_node->codegen_node->data.type_node.entry;
-    assert(type_entry);
-    TypeId type_id = type_entry->id;
-
-    AstNode *body_node = node->data.fn_def.body;
-    assert(body_node->type == NodeTypeBlock);
-
-    // TODO once we understand types, do this pass after type checking, and
-    // if an expression has an unreachable value then stop looking at statements after
-    // it. then we can remove the check to `unreachable` in the end of this function.
-    bool prev_statement_return = false;
-    for (int i = 0; i < body_node->data.block.statements.length; i += 1) {
-        AstNode *statement_node = body_node->data.block.statements.at(i);
-        if (statement_node->type == NodeTypeReturnExpr) {
-            if (type_id == TypeIdUnreachable) {
-                add_node_error(g, statement_node,
-                        buf_sprintf("return statement in function with unreachable return type"));
-                return;
-            } else {
-                prev_statement_return = true;
-            }
-        } else if (prev_statement_return) {
-            add_node_error(g, statement_node,
-                    buf_sprintf("unreachable code"));
-        }
-    }
-
-    if (!prev_statement_return) {
-        if (type_id == TypeIdVoid) {
-            codegen_fn_def->add_implicit_return = true;
-        } else if (type_id != TypeIdUnreachable) {
-            add_node_error(g, node,
-                    buf_sprintf("control reaches end of non-void function"));
-        }
-    }
-}
-
-static Buf *hack_get_fn_call_name(CodeGen *g, AstNode *node) {
-    // Assume that the expression evaluates to a simple name and return the buf
-    // TODO after type checking works we should be able to remove this hack
-    assert(node->type == NodeTypeSymbol);
-    return &node->data.symbol;
-}
-
-static void analyze_node(CodeGen *g, AstNode *node) {
-    switch (node->type) {
-        case NodeTypeRoot:
-            {
-                // Iterate once over the top level declarations to build the function table
-                for (int i = 0; i < node->data.root.top_level_decls.length; i += 1) {
-                    AstNode *child = node->data.root.top_level_decls.at(i);
-                    find_declarations(g, child);
-                }
-                for (int i = 0; i < node->data.root.top_level_decls.length; i += 1) {
-                    AstNode *child = node->data.root.top_level_decls.at(i);
-                    analyze_node(g, child);
-                }
-                if (!g->out_name) {
-                    add_node_error(g, node,
-                            buf_sprintf("missing export declaration and output name not provided"));
-                } else if (g->out_type == OutTypeUnknown) {
-                    add_node_error(g, node,
-                            buf_sprintf("missing export declaration and export type not provided"));
-                }
-                break;
-            }
-        case NodeTypeRootExportDecl:
-            if (g->root_export_decl) {
-                add_node_error(g, node,
-                        buf_sprintf("only one root export declaration allowed"));
-            } else {
-                g->root_export_decl = node;
-
-                if (!g->out_name)
-                    g->out_name = &node->data.root_export_decl.name;
-
-                Buf *out_type = &node->data.root_export_decl.type;
-                OutType export_out_type;
-                if (buf_eql_str(out_type, "executable")) {
-                    export_out_type = OutTypeExe;
-                } else if (buf_eql_str(out_type, "library")) {
-                    export_out_type = OutTypeLib;
-                } else if (buf_eql_str(out_type, "object")) {
-                    export_out_type = OutTypeObj;
-                } else {
-                    add_node_error(g, node,
-                            buf_sprintf("invalid export type: '%s'", buf_ptr(out_type)));
-                }
-                if (g->out_type == OutTypeUnknown)
-                    g->out_type = export_out_type;
-            }
-            break;
-        case NodeTypeExternBlock:
-            for (int fn_decl_i = 0; fn_decl_i < node->data.extern_block.fn_decls.length; fn_decl_i += 1) {
-                AstNode *fn_decl = node->data.extern_block.fn_decls.at(fn_decl_i);
-                analyze_node(g, fn_decl);
-            }
-            break;
-        case NodeTypeFnDef:
-            {
-                if (node->codegen_node && node->codegen_node->data.fn_def_node.skip) {
-                    // we detected an error with this function definition which prevents us
-                    // from further analyzing it.
-                    break;
-                }
-
-                AstNode *proto_node = node->data.fn_def.fn_proto;
-                assert(proto_node->type == NodeTypeFnProto);
-                analyze_node(g, proto_node);
-
-                check_fn_def_control_flow(g, node);
-                analyze_node(g, node->data.fn_def.body);
-                break;
-            }
-        case NodeTypeFnDecl:
-            {
-                AstNode *proto_node = node->data.fn_decl.fn_proto;
-                assert(proto_node->type == NodeTypeFnProto);
-                analyze_node(g, proto_node);
-                break;
-            }
-        case NodeTypeFnProto:
-            {
-                for (int i = 0; i < node->data.fn_proto.params.length; i += 1) {
-                    AstNode *child = node->data.fn_proto.params.at(i);
-                    analyze_node(g, child);
-                }
-                analyze_node(g, node->data.fn_proto.return_type);
-                break;
-            }
-        case NodeTypeParamDecl:
-            analyze_node(g, node->data.param_decl.type);
-            break;
-
-        case NodeTypeType:
-            // ignore; we handled types with find_declarations
-            break;
-        case NodeTypeBlock:
-            for (int i = 0; i < node->data.block.statements.length; i += 1) {
-                AstNode *child = node->data.block.statements.at(i);
-                analyze_node(g, child);
-            }
-            break;
-        case NodeTypeReturnExpr:
-            if (node->data.return_expr.expr) {
-                analyze_node(g, node->data.return_expr.expr);
-            }
-            break;
-        case NodeTypeBinOpExpr:
-            analyze_node(g, node->data.bin_op_expr.op1);
-            analyze_node(g, node->data.bin_op_expr.op2);
-            break;
-        case NodeTypeFnCallExpr:
-            {
-                Buf *name = hack_get_fn_call_name(g, node->data.fn_call_expr.fn_ref_expr);
-
-                auto entry = g->fn_table.maybe_get(name);
-                if (!entry) {
-                    add_node_error(g, node,
-                            buf_sprintf("undefined function: '%s'", buf_ptr(name)));
-                } else {
-                    FnTableEntry *fn_table_entry = entry->value;
-                    assert(fn_table_entry->proto_node->type == NodeTypeFnProto);
-                    int expected_param_count = fn_table_entry->proto_node->data.fn_proto.params.length;
-                    int actual_param_count = node->data.fn_call_expr.params.length;
-                    if (expected_param_count != actual_param_count) {
-                        add_node_error(g, node,
-                                buf_sprintf("wrong number of arguments. Expected %d, got %d.",
-                                    expected_param_count, actual_param_count));
-                    }
-                }
-
-                for (int i = 0; i < node->data.fn_call_expr.params.length; i += 1) {
-                    AstNode *child = node->data.fn_call_expr.params.at(i);
-                    analyze_node(g, child);
-                }
-                break;
-            }
-        case NodeTypeDirective:
-            // we looked at directives in the parent node
-            break;
-        case NodeTypeCastExpr:
-            zig_panic("TODO");
-            break;
-        case NodeTypePrefixOpExpr:
-            zig_panic("TODO");
-            break;
-        case NodeTypeNumberLiteral:
-        case NodeTypeStringLiteral:
-        case NodeTypeUnreachable:
-        case NodeTypeSymbol:
-            // nothing to do
-            break;
-    }
-}
-
-static void add_types(CodeGen *g) {
-    {
-        TypeTableEntry *entry = allocate<TypeTableEntry>(1);
-        entry->id = TypeIdU8;
-        entry->type_ref = LLVMInt8Type();
-        buf_init_from_str(&entry->name, "u8");
-        entry->di_type = g->dbuilder->createBasicType(buf_ptr(&entry->name), 8, 8, llvm::dwarf::DW_ATE_unsigned);
-        g->type_table.put(&entry->name, entry);
-    }
-    {
-        TypeTableEntry *entry = allocate<TypeTableEntry>(1);
-        entry->id = TypeIdI32;
-        entry->type_ref = LLVMInt32Type();
-        buf_init_from_str(&entry->name, "i32");
-        entry->di_type = g->dbuilder->createBasicType(buf_ptr(&entry->name), 32, 32,
-                llvm::dwarf::DW_ATE_signed);
-        g->type_table.put(&entry->name, entry);
-    }
-    {
-        TypeTableEntry *entry = allocate<TypeTableEntry>(1);
-        entry->id = TypeIdVoid;
-        entry->type_ref = LLVMVoidType();
-        buf_init_from_str(&entry->name, "void");
-        entry->di_type = g->dbuilder->createBasicType(buf_ptr(&entry->name), 0, 0,
-                llvm::dwarf::DW_ATE_unsigned);
-        g->type_table.put(&entry->name, entry);
-
-        // invalid types are void
-        g->invalid_type_entry = entry;
-    }
-    {
-        TypeTableEntry *entry = allocate<TypeTableEntry>(1);
-        entry->id = TypeIdUnreachable;
-        entry->type_ref = LLVMVoidType();
-        buf_init_from_str(&entry->name, "unreachable");
-        entry->di_type = g->invalid_type_entry->di_type;
-        g->type_table.put(&entry->name, entry);
-    }
-}
-
-
-void semantic_analyze(CodeGen *g) {
-    LLVMInitializeAllTargets();
-    LLVMInitializeAllTargetMCs();
-    LLVMInitializeAllAsmPrinters();
-    LLVMInitializeAllAsmParsers();
-    LLVMInitializeNativeTarget();
-
-    g->is_native_target = true;
-    char *native_triple = LLVMGetDefaultTargetTriple();
-
-    LLVMTargetRef target_ref;
-    char *err_msg = nullptr;
-    if (LLVMGetTargetFromTriple(native_triple, &target_ref, &err_msg)) {
-        zig_panic("unable to get target from triple: %s", err_msg);
-    }
-
-    char *native_cpu = LLVMZigGetHostCPUName();
-    char *native_features = LLVMZigGetNativeFeatures();
-
-    LLVMCodeGenOptLevel opt_level = (g->build_type == CodeGenBuildTypeDebug) ?
-        LLVMCodeGenLevelNone : LLVMCodeGenLevelAggressive;
-
-    LLVMRelocMode reloc_mode = g->is_static ? LLVMRelocStatic : LLVMRelocPIC;
-
-    g->target_machine = LLVMCreateTargetMachine(target_ref, native_triple,
-            native_cpu, native_features, opt_level, reloc_mode, LLVMCodeModelDefault);
-
-    g->target_data_ref = LLVMGetTargetMachineData(g->target_machine);
-
-
-    g->module = LLVMModuleCreateWithName("ZigModule");
-
-    g->pointer_size_bytes = LLVMPointerSize(g->target_data_ref);
-
-    g->builder = LLVMCreateBuilder();
-    g->dbuilder = new llvm::DIBuilder(*llvm::unwrap(g->module), true);
-
-
-    add_types(g);
-
-    analyze_node(g, g->root);
-}
-
-static LLVMValueRef gen_expr(CodeGen *g, AstNode *expr_node);
-
 static void add_debug_source_node(CodeGen *g, AstNode *node) {
     llvm::unwrap(g->builder)->SetCurrentDebugLocation(llvm::DebugLoc::get(
                 node->line + 1, node->column + 1,
src/codegen.hpp
@@ -41,8 +41,6 @@ void codegen_set_strip(CodeGen *codegen, bool strip);
 void codegen_set_out_type(CodeGen *codegen, OutType out_type);
 void codegen_set_out_name(CodeGen *codegen, Buf *out_name);
 
-void semantic_analyze(CodeGen *g);
-
 void code_gen_optimize(CodeGen *g);
 
 void code_gen(CodeGen *g);
src/main.cpp
@@ -13,6 +13,7 @@
 #include "tokenizer.hpp"
 #include "error.hpp"
 #include "codegen.hpp"
+#include "analyze.hpp"
 
 #include <stdio.h>
 #include <string.h>
src/semantic_info.hpp
@@ -0,0 +1,106 @@
+/*
+ * Copyright (c) 2015 Andrew Kelley
+ *
+ * This file is part of zig, which is MIT licensed.
+ * See http://opensource.org/licenses/MIT
+ */
+
+#ifndef ZIG_SEMANTIC_INFO_HPP
+#define ZIG_SEMANTIC_INFO_HPP
+
+#include "codegen.hpp"
+#include "hash_map.hpp"
+
+#include <llvm/IR/DIBuilder.h>
+#include <llvm/IR/DiagnosticInfo.h>
+
+struct FnTableEntry {
+    LLVMValueRef fn_value;
+    AstNode *proto_node;
+    AstNode *fn_def_node;
+    bool is_extern;
+    bool internal_linkage;
+    unsigned calling_convention;
+};
+
+enum TypeId {
+    TypeIdUserDefined,
+    TypeIdPointer,
+    TypeIdU8,
+    TypeIdI32,
+    TypeIdVoid,
+    TypeIdUnreachable,
+};
+
+struct TypeTableEntry {
+    TypeId id;
+    LLVMTypeRef type_ref;
+    llvm::DIType *di_type;
+
+    TypeTableEntry *pointer_child;
+    bool pointer_is_const;
+    int user_defined_id;
+    Buf name;
+    TypeTableEntry *pointer_const_parent;
+    TypeTableEntry *pointer_mut_parent;
+};
+
+struct CodeGen {
+    LLVMModuleRef module;
+    AstNode *root;
+    ZigList<ErrorMsg> errors;
+    LLVMBuilderRef builder;
+    llvm::DIBuilder *dbuilder;
+    llvm::DICompileUnit *compile_unit;
+    HashMap<Buf *, FnTableEntry *, buf_hash, buf_eql_buf> fn_table;
+    HashMap<Buf *, LLVMValueRef, buf_hash, buf_eql_buf> str_table;
+    HashMap<Buf *, TypeTableEntry *, buf_hash, buf_eql_buf> type_table;
+    HashMap<Buf *, bool, buf_hash, buf_eql_buf> link_table;
+    TypeTableEntry *invalid_type_entry;
+    LLVMTargetDataRef target_data_ref;
+    unsigned pointer_size_bytes;
+    bool is_static;
+    bool strip_debug_symbols;
+    CodeGenBuildType build_type;
+    LLVMTargetMachineRef target_machine;
+    bool is_native_target;
+    Buf in_file;
+    Buf in_dir;
+    ZigList<llvm::DIScope *> block_scopes;
+    llvm::DIFile *di_file;
+    ZigList<FnTableEntry *> fn_defs;
+    Buf *out_name;
+    OutType out_type;
+    FnTableEntry *cur_fn;
+    bool c_stdint_used;
+    AstNode *root_export_decl;
+    int version_major;
+    int version_minor;
+    int version_patch;
+};
+
+struct TypeNode {
+    TypeTableEntry *entry;
+};
+
+struct FnDefNode {
+    bool add_implicit_return;
+    bool skip;
+    LLVMValueRef *params;
+};
+
+struct CodeGenNode {
+    union {
+        TypeNode type_node; // for NodeTypeType
+        FnDefNode fn_def_node; // for NodeTypeFnDef
+    } data;
+};
+
+static inline Buf *hack_get_fn_call_name(CodeGen *g, AstNode *node) {
+    // Assume that the expression evaluates to a simple name and return the buf
+    // TODO after type checking works we should be able to remove this hack
+    assert(node->type == NodeTypeSymbol);
+    return &node->data.symbol;
+}
+
+#endif
CMakeLists.txt
@@ -22,6 +22,7 @@ include_directories(
 )
 
 set(ZIG_SOURCES
+    "${CMAKE_SOURCE_DIR}/src/analyze.cpp"
     "${CMAKE_SOURCE_DIR}/src/buffer.cpp"
     "${CMAKE_SOURCE_DIR}/src/error.cpp"
     "${CMAKE_SOURCE_DIR}/src/main.cpp"