From aaacde11f2e814814fdd19dfb683e76f1dede4d5 Mon Sep 17 00:00:00 2001
From: Florian Weimer <fweimer@redhat.com>
Date: Mon, 12 Jul 2021 18:43:32 +0200
Subject: Reduce <limits.h> pollution due to dynamic PTHREAD_STACK_MIN

<limits.h> used to be a header file with no declarations.
GCC's libgomp includes it in a #pragma GCC visibility hidden block.
Including <unistd.h> from <limits.h> (indirectly) declares everything
in <unistd.h> with hidden visibility, resulting in linker failures.

This commit avoids C declarations in assembler mode and only declares
__sysconf in <limits.h> (and not the entire contents of <unistd.h>).
The __sysconf symbol is already part of the ABI.  PTHREAD_STACK_MIN
is no longer defined for __USE_DYNAMIC_STACK_SIZE && __ASSEMBLER__
because there is no possible definition.

Additionally, PTHREAD_STACK_MIN is now defined by <pthread.h> for
__USE_MISC because this is what developers expect based on the macro
name.  It also helps to avoid libgomp linker failures in GCC because
libgomp includes <pthread.h> before its visibility hacks.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
---
 sysdeps/unix/sysv/linux/include/bits/pthread_stack_min-dynamic.h | 7 +++++++
 1 file changed, 7 insertions(+)
 create mode 100644 sysdeps/unix/sysv/linux/include/bits/pthread_stack_min-dynamic.h

(limited to 'sysdeps/unix/sysv/linux/include/bits/pthread_stack_min-dynamic.h')

diff --git a/sysdeps/unix/sysv/linux/include/bits/pthread_stack_min-dynamic.h b/sysdeps/unix/sysv/linux/include/bits/pthread_stack_min-dynamic.h
new file mode 100644
index 0000000000..d66f584b21
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/include/bits/pthread_stack_min-dynamic.h
@@ -0,0 +1,7 @@
+/* Don't define PTHREAD_STACK_MIN to __sysconf (_SC_THREAD_STACK_MIN)
+   for glibc build.  */
+#ifdef _ISOMAC
+# include <sysdeps/unix/sysv/linux/bits/pthread_stack_min-dynamic.h>
+#else
+# include <bits/pthread_stack_min.h>
+#endif
-- 
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