Enforce compilation without system headers

This patch introduces HOST_CPPFLAGS to be used for all
objects being compiled with HOSTCC rather then the target
compiler.

Since glibc is not linked into the EC, no glibc include files
should be included in the EC code base. Hence, create local
definitions for clock_t and wchar_t that match what the glibc
include would have done, and remove some unneeded includes.

Due to very eager optimization, we have to give gcc a little
notch to not kick out memset.

Signed-off-by: Stefan Reinauer <reinauer@chromium.org>
BUG=chrome-os-partner:43025
BUG=chrome-os-partner:49517
BRANCH=none
TEST=compile tested

Change-Id: Idf3a2881fa8352756b0927b09c6a97473358f239
Reviewed-on: https://chromium-review.googlesource.com/322435
Commit-Ready: Patrick Georgi <pgeorgi@chromium.org>
Tested-by: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-by: Patrick Georgi <pgeorgi@chromium.org>

6 files changed, 133 insertions, 0 deletions

diff --git a/builtin/assert.h b/builtin/assert.h
new file mode 100644
index 0000000000..7e5f04b375
--- /dev/null
+++ b/builtin/assert.h
@@ -0,0 +1,12 @@
+/* Copyright 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef __CROS_EC_ASSERT_H__
+#define __CROS_EC_ASSERT_H__
+
+#include "util.h"
+#define assert(x...) ASSERT(x)
+
+#endif /* __CROS_EC_ASSERT_H__ */
diff --git a/builtin/stdarg.h b/builtin/stdarg.h
new file mode 100644
index 0000000000..66ab940b16
--- /dev/null
+++ b/builtin/stdarg.h
@@ -0,0 +1,24 @@
+/* Copyright 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef __CROS_EC_STDARG_H__
+#define __CROS_EC_STDARG_H__
+
+/* We use -nostdinc -ffreestanding to keep host system include files
+ * from contaminating our build.
+ * Unfortunately this also gets us rid of the _compiler_ includes, like
+ * stdarg.h. To work around the issue, we define varargs directly here.
+ */
+
+#ifdef __GNUC__
+#define va_start(v, l)		__builtin_va_start(v, l)
+#define va_end(v)		__builtin_va_end(v)
+#define va_arg(v, l)		__builtin_va_arg(v, l)
+typedef __builtin_va_list	va_list;
+#else
+#include_next <stdarg.h>
+#endif
+
+#endif /* __CROS_EC_STDARG_H__ */
diff --git a/builtin/stddef.h b/builtin/stddef.h
new file mode 100644
index 0000000000..505dd9f515
--- /dev/null
+++ b/builtin/stddef.h
@@ -0,0 +1,30 @@
+/* Copyright 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef __CROS_EC_STDDEF_H__
+#define __CROS_EC_STDDEF_H__
+
+#ifndef __SIZE_TYPE__
+#define __SIZE_TYPE__ unsigned long
+#endif
+
+typedef __SIZE_TYPE__ size_t;
+/* There is a GCC macro for a size_t type, but not for a ssize_t type.
+ * The following construct convinces GCC to make __SIZE_TYPE__ signed.
+ */
+#define unsigned signed
+typedef __SIZE_TYPE__ ssize_t;
+#undef unsigned
+
+#ifndef NULL
+#define NULL ((void *)0)
+#endif
+
+#ifndef __WCHAR_TYPE__
+#define __WCHAR_TYPE__ int
+#endif
+typedef __WCHAR_TYPE__ wchar_t;
+
+#endif /* __CROS_EC_STDDEF_H__ */
diff --git a/builtin/stdint.h b/builtin/stdint.h
new file mode 100644
index 0000000000..75cf8d8ebf
--- /dev/null
+++ b/builtin/stdint.h
@@ -0,0 +1,38 @@
+/* Copyright 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef __CROS_EC_STDINT_H__
+#define __CROS_EC_STDINT_H__
+
+typedef unsigned char      uint8_t;
+typedef signed char        int8_t;
+
+typedef unsigned short     uint16_t;
+typedef signed short       int16_t;
+
+typedef unsigned int       uint32_t;
+typedef signed int         int32_t;
+
+typedef unsigned long long uint64_t;
+typedef signed long long   int64_t;
+
+typedef int                intptr_t;
+typedef unsigned int       uintptr_t;
+
+#ifndef UINT16_MAX
+#define UINT16_MAX (65535U)
+#endif
+#ifndef INT16_MAX
+#define INT16_MAX (32767U)
+#endif
+
+#ifndef UINT32_MAX
+#define UINT32_MAX (4294967295U)
+#endif
+#ifndef INT32_MAX
+#define INT32_MAX (2147483647U)
+#endif
+
+#endif /* __CROS_EC_STDINT_H__ */
diff --git a/builtin/string.h b/builtin/string.h
new file mode 100644
index 0000000000..d30dda8324
--- /dev/null
+++ b/builtin/string.h
@@ -0,0 +1,16 @@
+/* Copyright 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/* This header is only needed for CR50 compatibility */
+
+#ifndef __CROS_EC_STRINGS_H__
+#define __CROS_EC_STRINGS_H__
+
+#include <stddef.h>
+
+void *memcpy(void *dest, const void *src, size_t len);
+void *memset(void *dest, int c, size_t len);
+
+#endif /* __CROS_EC_STRINGS_H__ */
diff --git a/builtin/time.h b/builtin/time.h
new file mode 100644
index 0000000000..a069ae18c9
--- /dev/null
+++ b/builtin/time.h
@@ -0,0 +1,13 @@
+/* Copyright 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/* This header is only needed for CR50 compatibility */
+
+#ifndef __CROS_EC_TIME_H__
+#define __CROS_EC_TIME_H__
+
+#include <timer.h>
+
+#endif /* __CROS_EC_TIME_H__ */