Commit 890714b8ca

Andrew Kelley <superjoe30@gmail.com>
2016-01-19 05:28:54
Revert "delete parseh"
This reverts commit 18374ea8f18b6b48c53e6e7bd23d536ac2e8a807.
1 parent ae2151a
cmake/Findclang.cmake
@@ -0,0 +1,16 @@
+# Copyright (c) 2015 Andrew Kelley
+# This file is MIT licensed.
+# See http://opensource.org/licenses/MIT
+
+# CLANG_FOUND
+# CLANG_INCLUDE_DIR
+# CLANG_LIBRARY
+
+find_path(CLANG_INCLUDE_DIR NAMES clang-c/Index.h PATHS /usr/lib/llvm-3.7/include/)
+
+find_library(CLANG_LIBRARY NAMES clang PATHS /usr/lib/llvm-3.7/lib/)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(CLANG DEFAULT_MSG CLANG_LIBRARY CLANG_INCLUDE_DIR)
+
+mark_as_advanced(CLANG_INCLUDE_DIR CLANG_LIBRARY)
src/main.cpp
@@ -10,6 +10,7 @@
 #include "codegen.hpp"
 #include "os.hpp"
 #include "error.hpp"
+#include "parseh.hpp"
 
 #include <stdio.h>
 
@@ -18,6 +19,7 @@ static int usage(const char *arg0) {
         "Commands:\n"
         "  build                  create executable, object, or library from target\n"
         "  version                print version number and exit\n"
+        "  parseh                 convert a c header file to zig extern declarations\n"
         "Command: build target\n"
         "  --release              build with optimizations on and debug protection off\n"
         "  --static               output will be statically linked\n"
@@ -28,6 +30,10 @@ static int usage(const char *arg0) {
         "  --verbose              turn on compiler debug output\n"
         "  --color [auto|off|on]  enable or disable colored error messages\n"
         "  --libc-path [path]     set the C compiler data path\n"
+        "Command: parseh target\n"
+        "  -isystem [dir]         add additional search path for other .h files\n"
+        "  -dirafter [dir]        same as -isystem but do it last\n"
+        "  -B[prefix]             set the C compiler data path\n"
     , arg0);
     return EXIT_FAILURE;
 }
@@ -150,6 +156,41 @@ static int build(const char *arg0, int argc, char **argv) {
     return 0;
 }
 
+static int parseh(const char *arg0, int argc, char **argv) {
+    char *in_file = nullptr;
+    ZigList<const char *> clang_argv = {0};
+    for (int i = 0; i < argc; i += 1) {
+        char *arg = argv[i];
+        if (arg[0] == '-') {
+            if (arg[1] == 'I') {
+                clang_argv.append(arg);
+            } else if (strcmp(arg, "-isystem") == 0) {
+                if (i + 1 >= argc) {
+                    return usage(arg0);
+                }
+                clang_argv.append("-isystem");
+                clang_argv.append(argv[i + 1]);
+            } else if (arg[1] == 'B') {
+                clang_argv.append(arg);
+            } else {
+                fprintf(stderr, "unrecognized argument: %s", arg);
+                return usage(arg0);
+            }
+        } else if (!in_file) {
+            in_file = arg;
+        } else {
+            return usage(arg0);
+        }
+    }
+    if (!in_file) {
+        fprintf(stderr, "missing target argument");
+        return usage(arg0);
+    }
+
+    parse_h_file(in_file, &clang_argv, stdout);
+    return 0;
+}
+
 int main(int argc, char **argv) {
     char *arg0 = argv[0];
     int (*cmd)(const char *, int, char **) = nullptr;
@@ -162,6 +203,8 @@ int main(int argc, char **argv) {
                 cmd = build;
             } else if (strcmp(arg, "version") == 0) {
                 cmd = version;
+            } else if (strcmp(arg, "parseh") == 0) {
+                cmd = parseh;
             } else {
                 fprintf(stderr, "Unrecognized command: %s\n", arg);
                 return usage(arg0);
src/parseh.cpp
@@ -0,0 +1,662 @@
+/*
+ * Copyright (c) 2015 Andrew Kelley
+ *
+ * This file is part of zig, which is MIT licensed.
+ * See http://opensource.org/licenses/MIT
+ */
+
+#include "parseh.hpp"
+#include "config.h"
+
+#include <clang-c/Index.h>
+
+#include <string.h>
+
+struct TypeDef {
+    Buf alias;
+    Buf target;
+};
+
+struct Arg {
+    Buf name;
+    Buf *type;
+};
+
+struct Fn {
+    Buf name;
+    Buf *return_type;
+    Arg *args;
+    int arg_count;
+    bool is_variadic;
+};
+
+struct Field {
+    Buf name;
+    Buf *type;
+};
+
+struct Struct {
+    Buf name;
+    ZigList<Field*> fields;
+    bool have_def;
+};
+
+struct ParseH {
+    CXTranslationUnit tu;
+    FILE *f;
+    ZigList<Fn *> fn_list;
+    ZigList<Struct *> struct_list;
+    ZigList<TypeDef *> type_def_list;
+    ZigList<Struct *> incomplete_struct_list;
+    Fn *cur_fn;
+    Struct *cur_struct;
+    int arg_index;
+    int cur_indent;
+    CXSourceRange range;
+    CXSourceLocation location;
+};
+
+static const int indent_size = 4;
+
+struct TypeMapping {
+    const char *c_name;
+    const char *zig_name;
+};
+
+static const TypeMapping type_mappings[] = {
+    {
+        "int8_t",
+        "i8",
+    },
+    {
+        "uint8_t",
+        "u8",
+    },
+    {
+        "uint16_t",
+        "u16",
+    },
+    {
+        "uint32_t",
+        "u32",
+    },
+    {
+        "uint64_t",
+        "u64",
+    },
+    {
+        "int16_t",
+        "i16",
+    },
+    {
+        "int32_t",
+        "i32",
+    },
+    {
+        "int64_t",
+        "i64",
+    },
+    {
+        "intptr_t",
+        "isize",
+    },
+    {
+        "uintptr_t",
+        "usize",
+    },
+};
+
+static bool have_struct_def(ParseH *p, Buf *name) {
+    for (int i = 0; i < p->struct_list.length; i += 1) {
+        Struct *struc = p->struct_list.at(i);
+        if (struc->fields.length > 0 && buf_eql_buf(&struc->name, name)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+static const char *c_to_zig_name(const char *name) {
+    for (int i = 0; i < array_length(type_mappings); i += 1) {
+        const TypeMapping *mapping = &type_mappings[i];
+        if (strcmp(mapping->c_name, name) == 0)
+            return mapping->zig_name;
+    }
+    return nullptr;
+}
+
+static bool str_has_prefix(const char *str, const char *prefix) {
+    while (*prefix) {
+        if (*str && *str == *prefix) {
+            str += 1;
+            prefix += 1;
+        } else {
+            return false;
+        }
+    }
+    return true;
+}
+
+static const char *prefixes_stripped(CXType type) {
+    CXString name = clang_getTypeSpelling(type);
+    const char *c_name = clang_getCString(name);
+
+    static const char *prefixes[] = {
+        "struct ",
+        "enum ",
+        "const ",
+    };
+
+start_over:
+
+    for (int i = 0; i < array_length(prefixes); i += 1) {
+        const char *prefix = prefixes[i];
+        if (str_has_prefix(c_name, prefix)) {
+            c_name += strlen(prefix);
+            goto start_over;
+        }
+    }
+    return c_name;
+}
+
+static void print_location(ParseH *p) {
+    CXFile file;
+    unsigned line, column, offset;
+    clang_getFileLocation(p->location, &file, &line, &column, &offset);
+    CXString file_name = clang_getFileName(file);
+
+    fprintf(stderr, "%s line %u, column %u\n", clang_getCString(file_name), line, column);
+}
+
+static bool resolves_to_void(ParseH *p, CXType raw_type) {
+    if (raw_type.kind == CXType_Unexposed) {
+        CXType canonical = clang_getCanonicalType(raw_type);
+        if (canonical.kind == CXType_Unexposed)
+            zig_panic("clang C api insufficient");
+        else
+            return resolves_to_void(p, canonical);
+    }
+    if (raw_type.kind == CXType_Void) {
+        return true;
+    } else if (raw_type.kind == CXType_Typedef) {
+        CXCursor typedef_cursor = clang_getTypeDeclaration(raw_type);
+        CXType underlying_type = clang_getTypedefDeclUnderlyingType(typedef_cursor);
+        return resolves_to_void(p, underlying_type);
+    }
+    return false;
+}
+
+static Buf *to_zig_type(ParseH *p, CXType raw_type) {
+    if (raw_type.kind == CXType_Unexposed) {
+        CXType canonical = clang_getCanonicalType(raw_type);
+        if (canonical.kind == CXType_Unexposed)
+            zig_panic("clang C api insufficient");
+        else
+            return to_zig_type(p, canonical);
+    }
+    switch (raw_type.kind) {
+        case CXType_Invalid:
+        case CXType_Unexposed:
+            zig_unreachable();
+        case CXType_Void:
+            zig_panic("void type encountered");
+        case CXType_Bool:
+            return buf_create_from_str("bool");
+        case CXType_SChar:
+            return buf_create_from_str("i8");
+        case CXType_UChar:
+        case CXType_Char_U:
+        case CXType_Char_S:
+            return buf_create_from_str("u8");
+        case CXType_WChar:
+            print_location(p);
+            zig_panic("TODO wchar");
+        case CXType_Char16:
+            print_location(p);
+            zig_panic("TODO char16");
+        case CXType_Char32:
+            print_location(p);
+            zig_panic("TODO char32");
+        case CXType_UShort:
+            return buf_create_from_str("c_ushort");
+        case CXType_UInt:
+            return buf_create_from_str("c_uint");
+        case CXType_ULong:
+            return buf_create_from_str("c_ulong");
+        case CXType_ULongLong:
+            return buf_create_from_str("c_ulonglong");
+        case CXType_UInt128:
+            print_location(p);
+            zig_panic("TODO uint128");
+        case CXType_Short:
+            return buf_create_from_str("c_short");
+        case CXType_Int:
+            return buf_create_from_str("c_int");
+        case CXType_Long:
+            return buf_create_from_str("c_long");
+        case CXType_LongLong:
+            return buf_create_from_str("c_longlong");
+        case CXType_Int128:
+            print_location(p);
+            zig_panic("TODO int128");
+        case CXType_Float:
+            return buf_create_from_str("f32");
+        case CXType_Double:
+            return buf_create_from_str("f64");
+        case CXType_LongDouble:
+            return buf_create_from_str("f128");
+        case CXType_IncompleteArray:
+            {
+                CXType pointee_type = clang_getArrayElementType(raw_type);
+                Buf *pointee_buf = to_zig_type(p, pointee_type);
+                if (clang_isConstQualifiedType(pointee_type)) {
+                    return buf_sprintf("&const %s", buf_ptr(pointee_buf));
+                } else {
+                    return buf_sprintf("&%s", buf_ptr(pointee_buf));
+                }
+            }
+        case CXType_Pointer:
+            {
+                CXType pointee_type = clang_getPointeeType(raw_type);
+                Buf *pointee_buf;
+                if (resolves_to_void(p, pointee_type)) {
+                    pointee_buf = buf_create_from_str("u8");
+                } else {
+                    pointee_buf = to_zig_type(p, pointee_type);
+                }
+                if (clang_isConstQualifiedType(pointee_type)) {
+                    return buf_sprintf("&const %s", buf_ptr(pointee_buf));
+                } else {
+                    return buf_sprintf("&%s", buf_ptr(pointee_buf));
+                }
+            }
+        case CXType_Record:
+            {
+                const char *name = prefixes_stripped(raw_type);
+                return buf_sprintf("%s", name);
+            }
+        case CXType_Enum:
+            {
+                const char *name = prefixes_stripped(raw_type);
+                return buf_sprintf("%s", name);
+            }
+        case CXType_Typedef:
+            {
+                const char *name = prefixes_stripped(raw_type);
+                const char *zig_name = c_to_zig_name(name);
+                if (zig_name) {
+                    return buf_create_from_str(zig_name);
+                } else {
+                    CXCursor typedef_cursor = clang_getTypeDeclaration(raw_type);
+                    CXType underlying_type = clang_getTypedefDeclUnderlyingType(typedef_cursor);
+                    if (resolves_to_void(p, underlying_type)) {
+                        return buf_create_from_str("u8");
+                    } else {
+                        return buf_create_from_str(name);
+                    }
+                }
+            }
+        case CXType_ConstantArray:
+            {
+                CXType child_type = clang_getArrayElementType(raw_type);
+                Buf *zig_child_type = to_zig_type(p, child_type);
+                long size = (long)clang_getArraySize(raw_type);
+                return buf_sprintf("[%s; %ld]", buf_ptr(zig_child_type), size);
+            }
+        case CXType_FunctionProto:
+            fprintf(stderr, "warning: TODO function proto\n");
+            print_location(p);
+            return buf_create_from_str("u8");
+        case CXType_FunctionNoProto:
+            print_location(p);
+            zig_panic("TODO function no proto");
+        case CXType_BlockPointer:
+            print_location(p);
+            zig_panic("TODO block pointer");
+        case CXType_Vector:
+            print_location(p);
+            zig_panic("TODO vector");
+        case CXType_LValueReference:
+        case CXType_RValueReference:
+        case CXType_VariableArray:
+        case CXType_DependentSizedArray:
+        case CXType_MemberPointer:
+        case CXType_ObjCInterface:
+        case CXType_ObjCObjectPointer:
+        case CXType_NullPtr:
+        case CXType_Overload:
+        case CXType_Dependent:
+        case CXType_ObjCId:
+        case CXType_ObjCClass:
+        case CXType_ObjCSel:
+        case CXType_Complex:
+            print_location(p);
+            zig_panic("TODO");
+    }
+
+    zig_unreachable();
+}
+
+static bool is_storage_class_export(CX_StorageClass storage_class) {
+    switch (storage_class) {
+        case CX_SC_Invalid:
+            zig_unreachable();
+        case CX_SC_None:
+        case CX_SC_Extern:
+        case CX_SC_Auto:
+            return true;
+        case CX_SC_Static:
+        case CX_SC_PrivateExtern:
+        case CX_SC_OpenCLWorkGroupLocal:
+        case CX_SC_Register:
+            return false;
+    }
+    zig_unreachable();
+}
+
+static enum CXChildVisitResult visit_fn_children(CXCursor cursor, CXCursor parent, CXClientData client_data) {
+    ParseH *p = (ParseH*)client_data;
+    enum CXCursorKind kind = clang_getCursorKind(cursor);
+
+    switch (kind) {
+    case CXCursor_ParmDecl:
+        {
+            assert(p->cur_fn);
+            assert(p->arg_index < p->cur_fn->arg_count);
+            CXString name = clang_getCursorSpelling(cursor);
+            Buf *arg_name = &p->cur_fn->args[p->arg_index].name;
+            buf_init_from_str(arg_name, clang_getCString(name));
+            if (buf_len(arg_name) == 0) {
+                buf_appendf(arg_name, "arg%d", p->arg_index);
+            }
+
+            p->arg_index += 1;
+            return CXChildVisit_Continue;
+        }
+    default:
+        return CXChildVisit_Recurse;
+    }
+}
+
+static enum CXChildVisitResult visit_struct_children(CXCursor cursor, CXCursor parent, CXClientData client_data) {
+    ParseH *p = (ParseH*)client_data;
+    enum CXCursorKind kind = clang_getCursorKind(cursor);
+
+    switch (kind) {
+    case CXCursor_FieldDecl:
+        {
+            assert(p->cur_struct);
+            CXString name = clang_getCursorSpelling(cursor);
+            Field *field = allocate<Field>(1);
+            buf_init_from_str(&field->name, clang_getCString(name));
+            CXType cursor_type = clang_getCursorType(cursor);
+            field->type = to_zig_type(p, cursor_type);
+
+            p->cur_struct->fields.append(field);
+
+            return CXChildVisit_Continue;
+        }
+    default:
+        return CXChildVisit_Recurse;
+    }
+}
+
+static bool handle_struct_cursor(ParseH *p, CXCursor cursor, const char *name, bool expect_name) {
+    p->cur_struct = allocate<Struct>(1);
+
+    buf_init_from_str(&p->cur_struct->name, name);
+
+    bool got_name = (buf_len(&p->cur_struct->name) != 0);
+    if (expect_name != got_name)
+        return false;
+
+    clang_visitChildren(cursor, visit_struct_children, p);
+
+    if (p->cur_struct->fields.length > 0) {
+        p->struct_list.append(p->cur_struct);
+    } else {
+        p->incomplete_struct_list.append(p->cur_struct);
+    }
+
+    p->cur_struct = nullptr;
+
+    return true;
+}
+
+
+static enum CXChildVisitResult fn_visitor(CXCursor cursor, CXCursor parent, CXClientData client_data) {
+    ParseH *p = (ParseH*)client_data;
+    enum CXCursorKind kind = clang_getCursorKind(cursor);
+    CXString name = clang_getCursorSpelling(cursor);
+
+    p->range = clang_getCursorExtent(cursor);
+    p->location = clang_getRangeStart(p->range);
+
+    switch (kind) {
+    case CXCursor_FunctionDecl:
+        {
+            CX_StorageClass storage_class = clang_Cursor_getStorageClass(cursor);
+            if (!is_storage_class_export(storage_class))
+                return CXChildVisit_Continue;
+
+            CXType fn_type = clang_getCursorType(cursor);
+            if (clang_getFunctionTypeCallingConv(fn_type) != CXCallingConv_C) {
+                print_location(p);
+                fprintf(stderr, "warning: skipping non c calling convention function, not yet supported\n");
+                return CXChildVisit_Continue;
+            }
+
+            assert(!p->cur_fn);
+            p->cur_fn = allocate<Fn>(1);
+
+            p->cur_fn->is_variadic = clang_isFunctionTypeVariadic(fn_type);
+
+            CXType return_type = clang_getResultType(fn_type);
+            if (!resolves_to_void(p, return_type)) {
+                p->cur_fn->return_type = to_zig_type(p, return_type);
+            }
+
+            buf_init_from_str(&p->cur_fn->name, clang_getCString(name));
+
+            p->cur_fn->arg_count = clang_getNumArgTypes(fn_type);
+            p->cur_fn->args = allocate<Arg>(p->cur_fn->arg_count);
+
+            for (int i = 0; i < p->cur_fn->arg_count; i += 1) {
+                CXType param_type = clang_getArgType(fn_type, i);
+                p->cur_fn->args[i].type = to_zig_type(p, param_type);
+            }
+
+            p->arg_index = 0;
+
+            clang_visitChildren(cursor, visit_fn_children, p);
+
+            p->fn_list.append(p->cur_fn);
+            p->cur_fn = nullptr;
+
+            return CXChildVisit_Recurse;
+        }
+    case CXCursor_CompoundStmt:
+    case CXCursor_FieldDecl:
+    case CXCursor_TypedefDecl:
+        {
+            CXType underlying_type = clang_getTypedefDeclUnderlyingType(cursor);
+
+            if (resolves_to_void(p, underlying_type)) {
+                return CXChildVisit_Continue;
+            }
+
+            if (underlying_type.kind == CXType_Unexposed) {
+                underlying_type = clang_getCanonicalType(underlying_type);
+            }
+            bool skip_typedef;
+            if (underlying_type.kind == CXType_Unexposed) {
+                fprintf(stderr, "warning: unexposed type\n");
+                print_location(p);
+                skip_typedef = true;
+            } else if (underlying_type.kind == CXType_Record) {
+                CXCursor decl_cursor = clang_getTypeDeclaration(underlying_type);
+                skip_typedef = handle_struct_cursor(p, decl_cursor, clang_getCString(name), false);
+            } else if (underlying_type.kind == CXType_Invalid) {
+                fprintf(stderr, "warning: invalid type\n");
+                print_location(p);
+                skip_typedef = true;
+            } else {
+                skip_typedef = false;
+            }
+
+            CXType typedef_type = clang_getCursorType(cursor);
+            const char *name_str = prefixes_stripped(typedef_type);
+            if (!skip_typedef && c_to_zig_name(name_str)) {
+                skip_typedef = true;
+            }
+
+            if (!skip_typedef) {
+                TypeDef *type_def = allocate<TypeDef>(1);
+                buf_init_from_str(&type_def->alias, name_str);
+                buf_init_from_buf(&type_def->target, to_zig_type(p, underlying_type));
+                p->type_def_list.append(type_def);
+            }
+
+            return CXChildVisit_Continue;
+        }
+    case CXCursor_StructDecl:
+        {
+            handle_struct_cursor(p, cursor, clang_getCString(name), true);
+
+            return CXChildVisit_Continue;
+        }
+    default:
+        return CXChildVisit_Recurse;
+    }
+}
+
+static void print_indent(ParseH *p) {
+    for (int i = 0; i < p->cur_indent; i += 1) {
+        fprintf(p->f, " ");
+    }
+}
+
+void parse_h_file(const char *target_path, ZigList<const char *> *clang_argv, FILE *f) {
+    ParseH parse_h = {0};
+    ParseH *p = &parse_h;
+    p->f = f;
+    CXIndex index = clang_createIndex(1, 0);
+
+    char *ZIG_PARSEH_CFLAGS = getenv("ZIG_PARSEH_CFLAGS");
+    if (ZIG_PARSEH_CFLAGS) {
+        Buf tmp_buf = BUF_INIT;
+        char *start = ZIG_PARSEH_CFLAGS;
+        char *space = strstr(start, " ");
+        while (space) {
+            if (space - start > 0) {
+                buf_init_from_mem(&tmp_buf, start, space - start);
+                clang_argv->append(buf_ptr(buf_create_from_buf(&tmp_buf)));
+            }
+            start = space + 1;
+            space = strstr(start, " ");
+        }
+        buf_init_from_str(&tmp_buf, start);
+        clang_argv->append(buf_ptr(buf_create_from_buf(&tmp_buf)));
+    }
+    clang_argv->append("-isystem");
+    clang_argv->append(ZIG_HEADERS_DIR);
+
+    clang_argv->append(nullptr);
+
+    enum CXErrorCode err_code;
+    if ((err_code = clang_parseTranslationUnit2(index, target_path,
+            clang_argv->items, clang_argv->length - 1,
+            NULL, 0, CXTranslationUnit_None, &p->tu)))
+    {
+        zig_panic("parse translation unit failure");
+    }
+
+
+    unsigned diag_count = clang_getNumDiagnostics(p->tu);
+
+    if (diag_count > 0) {
+        for (unsigned i = 0; i < diag_count; i += 1) {
+            CXDiagnostic diagnostic = clang_getDiagnostic(p->tu, i);
+            CXSourceLocation location = clang_getDiagnosticLocation(diagnostic);
+
+            CXFile file;
+            unsigned line, column, offset;
+            clang_getSpellingLocation(location, &file, &line, &column, &offset);
+            CXString text = clang_getDiagnosticSpelling(diagnostic);
+            CXString file_name = clang_getFileName(file);
+            fprintf(stderr, "%s line %u, column %u: %s\n", clang_getCString(file_name),
+                    line, column, clang_getCString(text));
+        }
+
+        exit(1);
+    }
+
+
+    CXCursor cursor = clang_getTranslationUnitCursor(p->tu);
+    clang_visitChildren(cursor, fn_visitor, p);
+
+    for (int struct_i = 0; struct_i < p->struct_list.length; struct_i += 1) {
+        Struct *struc = p->struct_list.at(struct_i);
+        fprintf(f, "struct %s {\n", buf_ptr(&struc->name));
+        p->cur_indent += indent_size;
+        for (int field_i = 0; field_i < struc->fields.length; field_i += 1) {
+            Field *field = struc->fields.at(field_i);
+            print_indent(p);
+            fprintf(f, "%s: %s,\n", buf_ptr(&field->name), buf_ptr(field->type));
+        }
+
+        p->cur_indent -= indent_size;
+        fprintf(f, "}\n\n");
+    }
+
+    int total_typedef_count = p->type_def_list.length;
+    for (int i = 0; i < p->incomplete_struct_list.length; i += 1) {
+        Struct *struc = p->incomplete_struct_list.at(i);
+        struc->have_def = have_struct_def(p, &struc->name);
+        total_typedef_count += (int)!struc->have_def;
+    }
+
+    if (total_typedef_count) {
+        for (int i = 0; i < p->incomplete_struct_list.length; i += 1) {
+            Struct *struc = p->incomplete_struct_list.at(i);
+            if (struc->have_def)
+                continue;
+
+            fprintf(f, "struct %s;\n", buf_ptr(&struc->name));
+        }
+
+        for (int type_def_i = 0; type_def_i < p->type_def_list.length; type_def_i += 1) {
+            TypeDef *type_def = p->type_def_list.at(type_def_i);
+            fprintf(f, "type %s = %s;\n", buf_ptr(&type_def->alias), buf_ptr(&type_def->target));
+        }
+
+        fprintf(f, "\n");
+    }
+
+    if (p->fn_list.length) {
+        fprintf(f, "extern {\n");
+        p->cur_indent += indent_size;
+        for (int fn_i = 0; fn_i < p->fn_list.length; fn_i += 1) {
+            Fn *fn = p->fn_list.at(fn_i);
+            print_indent(p);
+            fprintf(p->f, "fn %s(", buf_ptr(&fn->name));
+            for (int arg_i = 0; arg_i < fn->arg_count; arg_i += 1) {
+                Arg *arg = &fn->args[arg_i];
+                fprintf(p->f, "%s: %s", buf_ptr(&arg->name), buf_ptr(arg->type));
+                if (arg_i + 1 < fn->arg_count || fn->is_variadic) {
+                    fprintf(p->f, ", ");
+                }
+            }
+            if (fn->is_variadic) {
+                fprintf(p->f, "...");
+            }
+            fprintf(p->f, ")");
+            if (fn->return_type) {
+                fprintf(p->f, " -> %s", buf_ptr(fn->return_type));
+            }
+            fprintf(p->f, ";\n");
+        }
+        p->cur_indent -= indent_size;
+        fprintf(f, "}\n");
+    }
+}
src/parseh.hpp
@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2015 Andrew Kelley
+ *
+ * This file is part of zig, which is MIT licensed.
+ * See http://opensource.org/licenses/MIT
+ */
+
+
+#ifndef ZIG_PARSEH_HPP
+#define ZIG_PARSEH_HPP
+
+#include "buffer.hpp"
+
+#include <stdio.h>
+
+void parse_h_file(const char *target_path, ZigList<const char *> *clang_argv, FILE *f);
+
+#endif
CMakeLists.txt
@@ -16,6 +16,9 @@ find_package(llvm)
 include_directories(${LLVM_INCLUDE_DIRS})
 link_directories(${LLVM_LIBDIRS})
 
+find_package(clang)
+include_directories(${CLANG_INCLUDE_DIR})
+
 include_directories(
     ${CMAKE_SOURCE_DIR}
     ${CMAKE_BINARY_DIR}
@@ -33,6 +36,7 @@ set(ZIG_SOURCES
     "${CMAKE_SOURCE_DIR}/src/util.cpp"
     "${CMAKE_SOURCE_DIR}/src/errmsg.cpp"
     "${CMAKE_SOURCE_DIR}/src/zig_llvm.cpp"
+    "${CMAKE_SOURCE_DIR}/src/parseh.cpp"
 )
 
 set(TEST_SOURCES
@@ -143,6 +147,7 @@ set_target_properties(zig PROPERTIES
     COMPILE_FLAGS ${EXE_CFLAGS})
 target_link_libraries(zig LINK_PUBLIC
     ${LLVM_LIBRARIES}
+    ${CLANG_LIBRARY}
 )
 install(TARGETS zig DESTINATION bin)