Use __glibc_reserved convention in mcontext, sigcontext (bug 21457)

[Joseph Myers <joseph at codesourcery dot com>]

This patch implements the most straightforward part of fixing
namespace issues for sys/ucontext.h and related headers: where fields
in sys/ucontext.h or bits/sigcontext.h are named "reserved", "padding"
or similar, they are renamed to use the __glibc_reserved* naming
convention.  It does not change fields with a leading underscore, or
even those with a prefix such as uc_ or sc_.  It only fixes a small
part of bug 21457, so no XFAILs are removed.

Tested for x86_64 and x86, and with build-many-glibcs.py.

2017-05-03  Joseph Myers  <joseph@codesourcery.com>

	[BZ #21457]
	* sysdeps/unix/sysv/linux/mips/sys/ucontext.h
	[_MIPS_SIM != _ABIO32] (mcontext_t): Rename field reserved to
	__glibc_reserved1.
	* sysdeps/unix/sysv/linux/x86/bits/sigcontext.h
	(struct _fpx_sw_bytes): Rename field padding to __glibc_reserved1.
	(struct _fpxreg): Likewise.
	[!__x86_64__] (struct _fpstate): Rename field reserved to
	__glibc_reserved1.  Rename field padding to __glibc_reserved2.
	[__x86_64__] (struct _fpstate): Rename field padding to
	__glibc_reserved1.
	(struct _xsave_hdr): Rename field reserved1 to __glibc_reserved1.
	Rename field reserved2 to __glibc_reserved2.
	* sysdeps/unix/sysv/linux/x86/sys/ucontext.h
	[__x86_64__] (struct _libc_fpxreg): Rename field padding to
	__glibc_reserved1.
	[__x86_64__] (struct _libc_fpstate): Rename field padding to
	__glibc_reserved1.

diff --git a/sysdeps/unix/sysv/linux/mips/sys/ucontext.h b/sysdeps/unix/sysv/linux/mips/sys/ucontext.h
index c237a51..f766dac 100644
--- a/sysdeps/unix/sysv/linux/mips/sys/ucontext.h
+++ b/sysdeps/unix/sysv/linux/mips/sys/ucontext.h
@@ -98,7 +98,7 @@ typedef struct
     unsigned int fpc_csr;
     unsigned int used_math;
     unsigned int dsp;
-    unsigned int reserved;
+    unsigned int __glibc_reserved1;
   } mcontext_t;
 #endif
 
diff --git a/sysdeps/unix/sysv/linux/x86/bits/sigcontext.h b/sysdeps/unix/sysv/linux/x86/bits/sigcontext.h
index 7d6066c..bc692bc 100644
--- a/sysdeps/unix/sysv/linux/x86/bits/sigcontext.h
+++ b/sysdeps/unix/sysv/linux/x86/bits/sigcontext.h
@@ -32,7 +32,7 @@ struct _fpx_sw_bytes
   __uint32_t extended_size;
   __uint64_t xstate_bv;
   __uint32_t xstate_size;
-  __uint32_t padding[7];
+  __uint32_t __glibc_reserved1[7];
 };
 
 struct _fpreg
@@ -45,7 +45,7 @@ struct _fpxreg
 {
   unsigned short significand[4];
   unsigned short exponent;
-  unsigned short padding[3];
+  unsigned short __glibc_reserved1[3];
 };
 
 struct _xmmreg
@@ -74,10 +74,10 @@ struct _fpstate
   /* FXSR FPU environment.  */
   __uint32_t		_fxsr_env[6];
   __uint32_t		mxcsr;
-  __uint32_t		reserved;
+  __uint32_t		__glibc_reserved1;
   struct _fpxreg	_fxsr_st[8];
   struct _xmmreg	_xmm[8];
-  __uint32_t		padding[56];
+  __uint32_t		__glibc_reserved2[56];
 };
 
 #ifndef sigcontext_struct
@@ -131,7 +131,7 @@ struct _fpstate
   __uint32_t		mxcr_mask;
   struct _fpxreg	_st[8];
   struct _xmmreg	_xmm[16];
-  __uint32_t		padding[24];
+  __uint32_t		__glibc_reserved1[24];
 };
 
 struct sigcontext
@@ -175,8 +175,8 @@ struct sigcontext
 struct _xsave_hdr
 {
   __uint64_t xstate_bv;
-  __uint64_t reserved1[2];
-  __uint64_t reserved2[5];
+  __uint64_t __glibc_reserved1[2];
+  __uint64_t __glibc_reserved2[5];
 };
 
 struct _ymmh_state
diff --git a/sysdeps/unix/sysv/linux/x86/sys/ucontext.h b/sysdeps/unix/sysv/linux/x86/sys/ucontext.h
index 0da12f4..6dad48f 100644
--- a/sysdeps/unix/sysv/linux/x86/sys/ucontext.h
+++ b/sysdeps/unix/sysv/linux/x86/sys/ucontext.h
@@ -95,7 +95,7 @@ struct _libc_fpxreg
 {
   unsigned short int significand[4];
   unsigned short int exponent;
-  unsigned short int padding[3];
+  unsigned short int __glibc_reserved1[3];
 };
 
 struct _libc_xmmreg
@@ -116,7 +116,7 @@ struct _libc_fpstate
   __uint32_t		mxcr_mask;
   struct _libc_fpxreg	_st[8];
   struct _libc_xmmreg	_xmm[16];
-  __uint32_t		padding[24];
+  __uint32_t		__glibc_reserved1[24];
 };
 
 /* Structure to describe FPU registers.  */

-- 
Joseph S. Myers
joseph@codesourcery.com