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[libc] limits.h: include compiler limits if not already included
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Authored by alfredfo on Aug 15 2023, 4:46 PM.

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michaelrj
thesamesam

Commits

rG002cba03298a: [libc] limits.h: include compiler limits if not already included

Summary

The LLVM-libc build itself will override include paths and prefer it's
own limits.h over the compiler's limits.h. Because we rely on the
compiler limits.h for numerical limits in LLVM-libc it needs to be
include_next:ed if not already included. The other method to work
around this is to define all numeric macros in place.

Signed-off-by: Alfred Persson Forsberg <cat@catcream.org>

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Repository: rG LLVM Github Monorepo

Event Timeline

alfredfo created this revision.Aug 15 2023, 4:46 PM

Herald added projects: Restricted Project, Restricted Project. · View Herald TranscriptAug 15 2023, 4:46 PM

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alfredfo requested review of this revision.Aug 15 2023, 4:46 PM

s/fi/endif

move out of linux check

Harbormaster completed remote builds in B252805: Diff 550550.Aug 15 2023, 6:25 PM

This seems right. I'd normally prefer for Michael to take a look but I'll merge it to unbreak the build. We can revert it later if needed.

This revision is now accepted and ready to land.Aug 15 2023, 6:58 PM

Closed by commit rG002cba03298a: [libc] limits.h: include compiler limits if not already included (authored by alfredfo, committed by thesamesam). · Explain WhyAug 15 2023, 6:59 PM

This revision was automatically updated to reflect the committed changes.

thesamesam added a commit: rG002cba03298a: [libc] limits.h: include compiler limits if not already included.

Lgtm, it would be nice to add a comment explaining why we're checking gcc and clang limits

alfredfo added a reverting change: rGd3e045934a3d: Revert "[libc] Add limits.h".Aug 16 2023, 9:24 PM

Revision Contents

Path

Size

libc/

include/

llvm-libc-macros/

limits-macros.h

5 lines

Diff 550550

libc/include/llvm-libc-macros/limits-macros.h

	#ifndef __LLVM_LIBC_MACROS_LIMITS_MACROS_H			#ifndef __LLVM_LIBC_MACROS_LIMITS_MACROS_H
	#define __LLVM_LIBC_MACROS_LIMITS_MACROS_H			#define __LLVM_LIBC_MACROS_LIMITS_MACROS_H

				#if !defined _GCC_LIMITS_H_ && !defined __CLANG_LIMITS_H && \
				__has_include_next(<limits.h>)
				#include_next <limits.h>
				#endif

	#ifdef __linux__			#ifdef __linux__
	#include <linux/limits.h>			#include <linux/limits.h>
	#endif			#endif

	#ifndef SSIZE_MAX			#ifndef SSIZE_MAX
	#define SSIZE_MAX __LONG_MAX__			#define SSIZE_MAX __LONG_MAX__
	#endif			#endif

	#endif // __LLVM_LIBC_MACROS_LIMITS_MACROS_H			#endif // __LLVM_LIBC_MACROS_LIMITS_MACROS_H