[coreboot-gerrit] [S] Change in coreboot[main]: tree: Add kconfig option for testing C2x dialect

[Elyes Haouas (Code Review)]

Elyes Haouas has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/83459?usp=email )

Change subject: tree: Add kconfig option for testing C2x dialect
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tree: Add kconfig option for testing C2x dialect

This adds C2x dialect for testing and prepar for C2x dialect support.

Change-Id: I07db866bebfd25f1a60d18a3228ada2957500234
Signed-off-by: Elyes Haouas 
---
M Makefile.mk
M src/Kconfig
M src/include/stdbool.h
M src/include/stddef.h
4 files changed, 19 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/59/83459/1

diff --git a/Makefile.mk b/Makefile.mk
index bf6363a..1f6415a 100644
--- a/Makefile.mk
+++ b/Makefile.mk
@@ -507,7 +507,11 @@
 # Options controlling the kind of output
 CFLAGS_common += -pipe
 # Options controlling C dialect
+ifeq ($(CONFIG_ALLOW_UNSUPPORTED_C2X),y)
+CFLAGS_common += -std=gnu2x
+else
 CFLAGS_common += -std=gnu11
+endif
 # C language options
 CFLAGS_common += -ffreestanding
 CFLAGS_common += -fno-builtin
diff --git a/src/Kconfig b/src/Kconfig
index ef3c72c..14cea50 100644
--- a/src/Kconfig
+++ b/src/Kconfig
@@ -98,6 +98,13 @@
      On some architectures CLANG does not work that well.
      Use this only to try to get CLANG working.

+config ALLOW_UNSUPPORTED_C2X
+	bool
+	default n
+	help
+	 C2x is not supported. Don't enable this option.
+	 Use only to build test and prepar for C2x dialect.
+
 config ANY_TOOLCHAIN
    bool "Allow building with any toolchain"
    default n
diff --git a/src/include/stdbool.h b/src/include/stdbool.h
index 3733527..a587673 100644
--- a/src/include/stdbool.h
+++ b/src/include/stdbool.h
@@ -3,7 +3,10 @@
 #ifndef __STDBOOL_H__
 #define __STDBOOL_H__

+#if __STDC_VERSION__ < 202300L
 typedef _Bool   bool;
+#endif
+
 #define true    1
 #define false   0

diff --git a/src/include/stddef.h b/src/include/stddef.h
index 82d38c3..6a68152 100644
--- a/src/include/stddef.h
+++ b/src/include/stddef.h
@@ -19,7 +19,12 @@
 typedef __WCHAR_TYPE__ wchar_t;
 typedef __WINT_TYPE__ wint_t;

+#if __STDC_VERSION__ > 202300L
+typedef typeof(nullptr) nullptr_t;
+#define NULL nullptr
+#else
 #define NULL ((void *)0)
+#endif

/* The devicetree data structures are only mutable in ramstage. All other
    stages have a constant devicetree. */