[libc] Move type definitions to their own self contained header files.

[sivachandra]

libc/config/linux/api.td

11

I will do this in a follow up change. I picked 5 of the simple types to switch over to the new way in the change to showcase the new way.

[michaelrj]

libc/include/llvm-libc-types/float_t.h

10

should be __need_float_t

[sivachandra]

Treat the type headers as normal headers without requiring any __need* macros.

[sivachandra]

Remove __need_* macros from api.td.

[michaelrj]

LGTM

libc/config/linux/api.td

 include "config/public_api.td"
 
 include "spec/gnu_ext.td"
 include "spec/linux.td"
 include "spec/llvm_libc_ext.td"
 include "spec/posix.td"
 include "spec/stdc.td"
 
+// TODO: Eliminate all TypeDecl specializations. Since we define all public
+// types in their own self contained header files, the header generator can
+// produce the boiler plate which pulls in the type definitions.
+
 def SizeT : TypeDecl<"size_t"> {
   let Decl = [{
     #define __need_size_t
-    #include <stddef.h>
+    #include <llvm-libc-types/size_t.h>
   }];
 }
 
 def SSizeT : TypeDecl<"ssize_t"> {
   let Decl = [{
     #define __need_ssize_t
-    #include <__posix-types.h>
+    #include <llvm-libc-types/ssize_t.h>
   }];
 }
 
 def StructTm: TypeDecl<"struct tm"> {
   let Decl = [{
     struct tm {
       int tm_sec; // seconds after the minute
       int tm_min; // minutes after the hour
def TimeT: TypeDecl<"time_t"> {
    let Decl = [{
    typedef long time_t;
   }];
 }
 
 def OffT : TypeDecl<"off_t"> {
   let Decl = [{
     #define __need_off_t
-    #include <__posix-types.h>
+    #include <llvm-libc-types/off_t.h>
   }];
 }
 
 def FILE : TypeDecl<"FILE"> {
   let Decl = [{
     typedef struct FILE FILE;
   }];
 }
def IsNanMacro : MacroDef<"isnan"> {
   let Defn = [{
     #define isnan(x) __builtin_isnan(x)
   }];
 }
 
 def FloatT : TypeDecl<"float_t"> {
   let Decl = [{
     #define __need_float_t
-    #include <__llvm-libc-stdc-types.h>
+    #include <llvm-libc-types/float_t.h>
   }];
 }
 
 def DoubleT : TypeDecl<"double_t"> {
   let Decl = [{
     #define __need_double_t
-    #include <__llvm-libc-stdc-types.h>
+    #include <llvm-libc-types/double_t.h>
   }];
 }
 
 def MathAPI : PublicAPI<"math.h"> {
   let Macros = [
     SimpleMacroDef<"MATH_ERRNO", "1">,
     SimpleMacroDef<"MATH_ERREXCEPT", "2">,
     MathErrHandlingMacro,

libc/include/CMakeLists.txt

+add_subdirectory(llvm-libc-types)
 
 add_header(
   llvm_libc_common_h
   HDR
     __llvm-libc-common.h
 )
 
-add_header(
-  libc_posix_types
-  HDR
-    __posix-types.h
-)
-
-add_header(
-  stdc_types
-  HDR
-    __llvm-libc-stdc-types.h
-)
-
 add_gen_header(
   ctype
   DEF_FILE ctype.h.def
   GEN_HDR ctype.h
   DEPENDS
     .llvm_libc_common_h
 )
 

 )
 
 add_gen_header(
   math
   DEF_FILE math.h.def
   GEN_HDR math.h
   DEPENDS
     .llvm_libc_common_h
-    .stdc_types
+    .llvm-libc-types.double_t
+    .llvm-libc-types.float_t
 )
 
 add_gen_header(
   assert_h
   DEF_FILE assert.h.def
   GEN_HDR assert.h
   DEPENDS
     .llvm_libc_common_h
DEPENDS
     .llvm_libc_common_h
 )
 
 add_gen_header(
   unistd
   DEF_FILE unistd.h.def
   GEN_HDR unistd.h
   DEPENDS
-    .libc_posix_types
     .llvm_libc_common_h
+    .llvm-libc-types.size_t
+    .llvm-libc-types.ssize_t
 )
 
 # TODO: Not all platforms will have a include/sys directory. Add the sys
 # directory and the targets for sys/*.h files conditional to the OS requiring
 # them.
 file(MAKE_DIRECTORY "sys")
 
 add_gen_header(
   sys_mman
   DEF_FILE sys/mman.h.def
   GEN_HDR sys/mman.h
   DEPENDS
-    .libc_posix_types
     .llvm_libc_common_h
+    .llvm-libc-types.off_t
+    .llvm-libc-types.ssize_t
 )
 
 add_gen_header(
   sys_syscall
   DEF_FILE sys/syscall.h.def
   GEN_HDR sys/syscall.h
   PARAMS
     syscall_numbers=../config/${LIBC_TARGET_OS}/syscall_numbers.h.inc
   DATA_FILES
     ../config/${LIBC_TARGET_OS}/syscall_numbers.h.inc
 )

libc/include/__posix-types.h

-//===-- Definitions of common POSIX types ---------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-// This header file does not have a header guard. It is internal to LLVM libc
-// and intended to be used to pick specific definitions without polluting the
-// public headers with unnecessary definitions.
-
-#if defined(__need_off_t) && !defined(__llvm_libc_off_t_defined)
-typedef __INT64_TYPE__ off_t;
-#define __llvm_libc_off_t_defined
-#endif // __need_off_t
-
-#if defined(__need_ssize_t) && !defined(__llvm_libc_ssize_t_defined)
-typedef __INT64_TYPE__ ssize_t;
-#define __llvm_libc_ssize_t_defined
-#endif // __need_ssize_t

libc/include/llvm-libc-types/CMakeLists.txt

+add_header(double_t HDR double_t.h)
+add_header(float_t HDR float_t.h)
+add_header(off_t HDR off_t.h)
+add_header(size_t HDR size_t.h)
+add_header(ssize_t HDR ssize_t.h)

libc/include/llvm-libc-types/double_t.h

-//===-- Definitions of common types from the C standard. ------------------===//
+//===-- Definition of double_t type ---------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
-// This header file does not have a header guard. It is internal to LLVM libc
-// and intended to be used to pick specific definitions without polluting the
-// public headers with unnecessary definitions.
+#ifndef __need_double_t
+#error "Cannot include this file without __need_double_t defined."
+#endif
 
-#undef __LLVM_LIBC_FLOAT_T
-#undef __LLVM_LIBC_DOUBLE_T
+#ifndef __llvm_libc_double_t_defined
 
 #if !defined(__FLT_EVAL_METHOD__) || __FLT_EVAL_METHOD__ == 0
-#define __LLVM_LIBC_FLOAT_T float
 #define __LLVM_LIBC_DOUBLE_T double
 #elif __FLT_EVAL_METHOD__ == 1
-#define __LLVM_LIBC_FLOAT_T double
 #define __LLVM_LIBC_DOUBLE_T double
 #elif __FLT_EVAL_METHOD__ == 2
-#define __LLVM_LIBC_FLOAT_T long double
 #define __LLVM_LIBC_DOUBLE_T long double
 #else
 #error "Unsupported __FLT_EVAL_METHOD__ value."
 #endif
 
-#if defined(__need_float_t) && !defined(__llvm_libc_float_t_defined)
-typedef __LLVM_LIBC_FLOAT_T float_t;
-#define __llvm_libc_float_t_defined
-#endif // __need_float_t
-
-#if defined(__need_double_t) && !defined(__llvm_libc_double_t_defined)
 typedef __LLVM_LIBC_DOUBLE_T double_t;
 #define __llvm_libc_double_t_defined
-#endif // __need_double_t
+#undef __LLVM_LIBC_DOUBLE_T
+
+#endif // __llvm_libc_double_t_defined

libc/include/llvm-libc-types/float_t.h

-//===-- Definitions of common types from the C standard. ------------------===//
+//===-- Definition of float_t type ----------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
-// This header file does not have a header guard. It is internal to LLVM libc
-// and intended to be used to pick specific definitions without polluting the
-// public headers with unnecessary definitions.
+#ifndef __need_float_t
+#error "Cannot include this file without __need_off_t defined."
+#endif
 
-#undef __LLVM_LIBC_FLOAT_T
-#undef __LLVM_LIBC_DOUBLE_T
+#ifndef __llvm_libc_float_t_defined
 
 #if !defined(__FLT_EVAL_METHOD__) || __FLT_EVAL_METHOD__ == 0
 #define __LLVM_LIBC_FLOAT_T float
-#define __LLVM_LIBC_DOUBLE_T double
 #elif __FLT_EVAL_METHOD__ == 1
 #define __LLVM_LIBC_FLOAT_T double
-#define __LLVM_LIBC_DOUBLE_T double
 #elif __FLT_EVAL_METHOD__ == 2
 #define __LLVM_LIBC_FLOAT_T long double
-#define __LLVM_LIBC_DOUBLE_T long double
 #else
 #error "Unsupported __FLT_EVAL_METHOD__ value."
 #endif
 
-#if defined(__need_float_t) && !defined(__llvm_libc_float_t_defined)
 typedef __LLVM_LIBC_FLOAT_T float_t;
 #define __llvm_libc_float_t_defined
-#endif // __need_float_t
+#undef __LLVM_LIBC_FLOAT_T
 
-#if defined(__need_double_t) && !defined(__llvm_libc_double_t_defined)
-typedef __LLVM_LIBC_DOUBLE_T double_t;
-#define __llvm_libc_double_t_defined
-#endif // __need_double_t
+#endif // __llvm_libc_float_t_defined

libc/include/llvm-libc-types/off_t.h

+//===-- Definition of off_t type ------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef __need_off_t
+#error "Cannot include this file without __need_off_t defined."
+#endif
+
+#ifndef __llvm_libc_off_t_defined
+typedef __INT64_TYPE__ off_t;
+#define __llvm_libc_off_t_defined
+#endif // __llvm_libc_off_t_defined

libc/include/llvm-libc-types/size_t.h

+//===-- Definition of size_t types ----------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef __need_size_t
+#error "Cannot include this file without __need_size_t defined."
+#endif
+
+#ifndef __llvm_libc_size_t_defined
+// Since __need_size_t is defined, we get the definition of size_t from the
+// standalone C header stddef.h. Also, because __need_size_t is defined,
+// including stddef.h will pull only the type size_t and nothing else.
+#include <stddef.h>
+#define __llvm_libc_size_t_defined
+#endif // __llvm_libc_size_t_defined

libc/include/llvm-libc-types/ssize_t.h

+//===-- Definition of ssize_t type ----------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef __need_ssize_t
+#error "Cannot include this file without __need_ssize_t defined."
+#endif
+
+#ifndef __llvm_libc_ssize_t_defined
+typedef __INT64_TYPE__ ssize_t;
+#define __llvm_libc_ssize_t_defined
+#endif // __llvm_libc_ssize_t_defined