-Wstringop-truncation warnings

This patch is aimed at silencing gcc8 -Wstringop-truncation warnings.

Unfortunately adding  __attribute__ ((__nonstring)) doesn't work in a
number of the places patched here, (see
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85643) so if you have
recent glibc headers installed you'll need to configure binutils with
--disable-werror to compile using gcc8 or gcc9.

include/
	* ansidecl.h: Import from gcc.
	* coff/internal.h (struct internal_scnhdr): Add ATTRIBUTE_NONSTRING
	to s_name.
	(struct internal_syment): Add ATTRIBUTE_NONSTRING to _n_name.
bfd/
	* elf-linux-core.h (struct elf_external_linux_prpsinfo32_ugid32),
	(struct elf_external_linux_prpsinfo32_ugid16),
	(struct elf_external_linux_prpsinfo64_ugid32),
	(struct elf_external_linux_prpsinfo64_ugid16): Add ATTRIBUTE_NONSTRING
	to pr_fname and pr_psargs fields.  Remove GCC diagnostic pragmas.
	Move comment to..
	* elf.c (elfcore_write_prpsinfo): ..here.  Indent nested preprocessor
	directives.
	* elf32-arm.c (elf32_arm_nabi_write_core_note): Add ATTRIBUTE_NONSTRING
	to data.
	* elf32-ppc.c (ppc_elf_write_core_note): Likewise.
	* elf32-s390.c (elf_s390_write_core_note): Likewise.
	* elf64-s390.c (elf_s390_write_core_note): Likewise.
	* elfxx-aarch64.c (_bfd_aarch64_elf_write_core_note): Likewise.
	* elf64-x86-64.c (elf_x86_64_write_core_note): Add GCC diagnostic
	pragmas.
	* peXXigen.c (_bfd_XXi_swap_scnhdr_out): Use strnlen to avoid
	false positive gcc-8 warning.
gas/
	* config/obj-evax.c (shorten_identifier): Use memcpy in place
	of strncpy.
	* config/obj-macho.c (obj_mach_o_make_or_get_sect): Ensure
	segname and sectname fields are NUL terminated.

11 files changed, 70 insertions, 51 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 40daa88..0178998 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,24 @@
+2018-05-04  Alan Modra  <amodra@gmail.com>
+
+	* elf-linux-core.h (struct elf_external_linux_prpsinfo32_ugid32),
+	(struct elf_external_linux_prpsinfo32_ugid16),
+	(struct elf_external_linux_prpsinfo64_ugid32),
+	(struct elf_external_linux_prpsinfo64_ugid16): Add ATTRIBUTE_NONSTRING
+	to pr_fname and pr_psargs fields.  Remove GCC diagnostic pragmas.
+	Move comment to..
+	* elf.c (elfcore_write_prpsinfo): ..here.  Indent nested preprocessor
+	directives.
+	* elf32-arm.c (elf32_arm_nabi_write_core_note): Add ATTRIBUTE_NONSTRING
+	to data.
+	* elf32-ppc.c (ppc_elf_write_core_note): Likewise.
+	* elf32-s390.c (elf_s390_write_core_note): Likewise.
+	* elf64-s390.c (elf_s390_write_core_note): Likewise.
+	* elfxx-aarch64.c (_bfd_aarch64_elf_write_core_note): Likewise.
+	* elf64-x86-64.c (elf_x86_64_write_core_note): Add GCC diagnostic
+	pragmas.
+	* peXXigen.c (_bfd_XXi_swap_scnhdr_out): Use strnlen to avoid
+	false positive gcc-8 warning.
+
 2018-05-04  Tulio Magno Quites Machado Filho  <tuliom@linux.ibm.com>
 
 	* elf32-ppc.c (_bfd_elf_ppc_merge_fp_attributes): Fix the order
diff --git a/bfd/cofflink.c b/bfd/cofflink.c
index fb1696a..6ca547c 100644
--- a/bfd/cofflink.c
+++ b/bfd/cofflink.c
@@ -1839,7 +1839,7 @@ _bfd_coff_link_input_bfd (struct coff_final_link_info *flaginfo, bfd *input_bfd)
 
 	    case C_FCN:
 	      if (obj_pe (input_bfd)
-		  && strcmp (isym.n_name, ".bf") != 0
+		  && strncmp (isym.n_name, ".bf", sizeof isym.n_name) != 0
 		  && isym.n_scnum > 0)
 		{
 		  /* For PE, .lf and .ef get their value left alone,
diff --git a/bfd/elf-linux-core.h b/bfd/elf-linux-core.h
index fa06903..f0c4b2f 100644
--- a/bfd/elf-linux-core.h
+++ b/bfd/elf-linux-core.h
@@ -21,25 +21,6 @@
 #ifndef ELF_LINUX_CORE_H
 #define ELF_LINUX_CORE_H
 
-/* gcc-8 warns (*) on all the strncpy calls in this file about
-   possible string truncation.  The "truncation" is not a bug.  We
-   have an external representation of structs with fields that are not
-   necessarily NULL terminated and corresponding internal
-   representation fields that are one larger so that they can always
-   be NULL terminated.
-   gcc versions between 4.2 and 4.6 do not allow pragma control of
-   diagnostics inside functions, giving a hard error if you try to use
-   the finer control available with later versions.
-   gcc prior to 4.2 warns about diagnostic push and pop.
-   gcc-5, gcc-6 and gcc-7 warn that -Wstringop-truncation is unknown,
-   unless you also add #pragma GCC diagnostic ignored "-Wpragma".
-   (*) Depending on your system header files!  */
-
-#if GCC_VERSION >= 8000
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wstringop-truncation"
-#endif
-
 /* External 32-bit structure for PRPSINFO.  This structure is
    ABI-defined, thus we choose to use char arrays here in order to
    avoid dealing with different types in different architectures.
@@ -64,8 +45,8 @@ struct elf_external_linux_prpsinfo32_ugid32
     char pr_ppid[4];
     char pr_pgrp[4];
     char pr_sid[4];
-    char pr_fname[16];			/* Filename of executable.  */
-    char pr_psargs[80];			/* Initial part of arg list.  */
+    char pr_fname[16] ATTRIBUTE_NONSTRING;  /* Filename of executable.  */
+    char pr_psargs[80] ATTRIBUTE_NONSTRING; /* Initial part of arg list.  */
   };
 
 /* Helper function to copy an elf_internal_linux_prpsinfo in host
@@ -116,8 +97,8 @@ struct elf_external_linux_prpsinfo32_ugid16
     char pr_ppid[4];
     char pr_pgrp[4];
     char pr_sid[4];
-    char pr_fname[16];			/* Filename of executable.  */
-    char pr_psargs[80];			/* Initial part of arg list.  */
+    char pr_fname[16] ATTRIBUTE_NONSTRING;  /* Filename of executable.  */
+    char pr_psargs[80] ATTRIBUTE_NONSTRING; /* Initial part of arg list.  */
   };
 
 /* Helper function to copy an elf_internal_linux_prpsinfo in host
@@ -169,8 +150,8 @@ struct elf_external_linux_prpsinfo64_ugid32
     char pr_ppid[4];
     char pr_pgrp[4];
     char pr_sid[4];
-    char pr_fname[16];			/* Filename of executable.  */
-    char pr_psargs[80];			/* Initial part of arg list.  */
+    char pr_fname[16] ATTRIBUTE_NONSTRING;  /* Filename of executable.  */
+    char pr_psargs[80] ATTRIBUTE_NONSTRING; /* Initial part of arg list.  */
   };
 
 /* Helper function to copy an elf_internal_linux_prpsinfo in host
@@ -222,8 +203,8 @@ struct elf_external_linux_prpsinfo64_ugid16
     char pr_ppid[4];
     char pr_pgrp[4];
     char pr_sid[4];
-    char pr_fname[16];			/* Filename of executable.  */
-    char pr_psargs[80];			/* Initial part of arg list.  */
+    char pr_fname[16] ATTRIBUTE_NONSTRING;  /* Filename of executable.  */
+    char pr_psargs[80] ATTRIBUTE_NONSTRING; /* Initial part of arg list.  */
   };
 
 /* Helper function to copy an elf_internal_linux_prpsinfo in host
@@ -250,8 +231,4 @@ swap_linux_prpsinfo64_ugid16_out
   strncpy (to->pr_psargs, from->pr_psargs, sizeof (to->pr_psargs));
 }
 
-#if GCC_VERSION >= 8000
-#pragma GCC diagnostic pop
-#endif
-
 #endif
diff --git a/bfd/elf.c b/bfd/elf.c
index bd9ffcc..21bc4e7 100644
--- a/bfd/elf.c
+++ b/bfd/elf.c
@@ -10508,9 +10508,22 @@ elfcore_write_note (bfd *abfd,
   return buf;
 }
 
+/* gcc-8 warns (*) on all the strncpy calls in this function about
+   possible string truncation.  The "truncation" is not a bug.  We
+   have an external representation of structs with fields that are not
+   necessarily NULL terminated and corresponding internal
+   representation fields that are one larger so that they can always
+   be NULL terminated.
+   gcc versions between 4.2 and 4.6 do not allow pragma control of
+   diagnostics inside functions, giving a hard error if you try to use
+   the finer control available with later versions.
+   gcc prior to 4.2 warns about diagnostic push and pop.
+   gcc-5, gcc-6 and gcc-7 warn that -Wstringop-truncation is unknown,
+   unless you also add #pragma GCC diagnostic ignored "-Wpragma".
+   (*) Depending on your system header files!  */
 #if GCC_VERSION >= 8000
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wstringop-truncation"
+# pragma GCC diagnostic push
+# pragma GCC diagnostic ignored "-Wstringop-truncation"
 #endif
 char *
 elfcore_write_prpsinfo (bfd  *abfd,
@@ -10531,16 +10544,16 @@ elfcore_write_prpsinfo (bfd  *abfd,
     }
 
 #if defined (HAVE_PRPSINFO_T) || defined (HAVE_PSINFO_T)
-#if defined (HAVE_PRPSINFO32_T) || defined (HAVE_PSINFO32_T)
+# if defined (HAVE_PRPSINFO32_T) || defined (HAVE_PSINFO32_T)
   if (bed->s->elfclass == ELFCLASS32)
     {
-#if defined (HAVE_PSINFO32_T)
+#  if defined (HAVE_PSINFO32_T)
       psinfo32_t data;
       int note_type = NT_PSINFO;
-#else
+#  else
       prpsinfo32_t data;
       int note_type = NT_PRPSINFO;
-#endif
+#  endif
 
       memset (&data, 0, sizeof (data));
       strncpy (data.pr_fname, fname, sizeof (data.pr_fname));
@@ -10549,15 +10562,15 @@ elfcore_write_prpsinfo (bfd  *abfd,
 				 "CORE", note_type, &data, sizeof (data));
     }
   else
-#endif
+# endif
     {
-#if defined (HAVE_PSINFO_T)
+# if defined (HAVE_PSINFO_T)
       psinfo_t data;
       int note_type = NT_PSINFO;
-#else
+# else
       prpsinfo_t data;
       int note_type = NT_PRPSINFO;
-#endif
+# endif
 
       memset (&data, 0, sizeof (data));
       strncpy (data.pr_fname, fname, sizeof (data.pr_fname));
@@ -10571,7 +10584,7 @@ elfcore_write_prpsinfo (bfd  *abfd,
   return NULL;
 }
 #if GCC_VERSION >= 8000
-#pragma GCC diagnostic pop
+# pragma GCC diagnostic pop
 #endif
 
 char *
diff --git a/bfd/elf32-arm.c b/bfd/elf32-arm.c
index a42db44..5a3b58f 100644
--- a/bfd/elf32-arm.c
+++ b/bfd/elf32-arm.c
@@ -2168,7 +2168,7 @@ elf32_arm_nabi_write_core_note (bfd *abfd, char *buf, int *bufsiz,
 
     case NT_PRPSINFO:
       {
-	char data[124];
+	char data[124] ATTRIBUTE_NONSTRING;
 	va_list ap;
 
 	va_start (ap, note_type);
diff --git a/bfd/elf32-ppc.c b/bfd/elf32-ppc.c
index 7f4ed01..462c8af 100644
--- a/bfd/elf32-ppc.c
+++ b/bfd/elf32-ppc.c
@@ -2405,7 +2405,7 @@ ppc_elf_write_core_note (bfd *abfd, char *buf, int *bufsiz, int note_type, ...)
 
     case NT_PRPSINFO:
       {
-	char data[128];
+	char data[128] ATTRIBUTE_NONSTRING;
 	va_list ap;
 
 	va_start (ap, note_type);
diff --git a/bfd/elf32-s390.c b/bfd/elf32-s390.c
index 18010c0..b3603bd 100644
--- a/bfd/elf32-s390.c
+++ b/bfd/elf32-s390.c
@@ -3942,7 +3942,7 @@ elf_s390_write_core_note (bfd *abfd, char *buf, int *bufsiz,
 
     case NT_PRPSINFO:
       {
-	char data[124] = { 0 };
+	char data[124] ATTRIBUTE_NONSTRING = { 0 };
 	const char *fname, *psargs;
 
 	va_start (ap, note_type);
diff --git a/bfd/elf64-s390.c b/bfd/elf64-s390.c
index 2d02e82..bfa0234 100644
--- a/bfd/elf64-s390.c
+++ b/bfd/elf64-s390.c
@@ -3751,7 +3751,7 @@ elf_s390_write_core_note (bfd *abfd, char *buf, int *bufsiz,
 
     case NT_PRPSINFO:
       {
-	char data[136] = { 0 };
+	char data[136] ATTRIBUTE_NONSTRING = { 0 };
 	const char *fname, *psargs;
 
 	va_start (ap, note_type);
diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
index c1237bb..a0ebd2c 100644
--- a/bfd/elf64-x86-64.c
+++ b/bfd/elf64-x86-64.c
@@ -439,6 +439,10 @@ elf_x86_64_grok_psinfo (bfd *abfd, Elf_Internal_Note *note)
 }
 
 #ifdef CORE_HEADER
+# if GCC_VERSION >= 8000
+#  pragma GCC diagnostic push
+#  pragma GCC diagnostic ignored "-Wstringop-truncation"
+# endif
 static char *
 elf_x86_64_write_core_note (bfd *abfd, char *buf, int *bufsiz,
 			    int note_type, ...)
@@ -524,6 +528,9 @@ elf_x86_64_write_core_note (bfd *abfd, char *buf, int *bufsiz,
     }
   /* NOTREACHED */
 }
+# if GCC_VERSION >= 8000
+#  pragma GCC diagnostic pop
+# endif
 #endif
 
 /* Functions for the x86-64 ELF linker.	 */
diff --git a/bfd/elfxx-aarch64.c b/bfd/elfxx-aarch64.c
index 08e7cd9..45a732d 100644
--- a/bfd/elfxx-aarch64.c
+++ b/bfd/elfxx-aarch64.c
@@ -653,7 +653,7 @@ _bfd_aarch64_elf_write_core_note (bfd *abfd, char *buf, int *bufsiz, int note_ty
 
     case NT_PRPSINFO:
       {
-	char data[136];
+	char data[136] ATTRIBUTE_NONSTRING;
 	va_list ap;
 
 	va_start (ap, note_type);
diff --git a/bfd/peXXigen.c b/bfd/peXXigen.c
index 32ce195..a62d126 100644
--- a/bfd/peXXigen.c
+++ b/bfd/peXXigen.c
@@ -1051,9 +1051,10 @@ _bfd_XXi_swap_scnhdr_out (bfd * abfd, void * in, void * out)
        by ld --omagic, or by obcopy --writable-text.  */
 
     for (p = known_sections; p->section_name; p++)
-      if (strcmp (scnhdr_int->s_name, p->section_name) == 0)
+      if (strncmp (scnhdr_int->s_name, p->section_name,
+		   sizeof scnhdr_int->s_name) == 0)
 	{
-	  if (strcmp (scnhdr_int->s_name, ".text")
+	  if (strncmp (scnhdr_int->s_name, ".text", sizeof scnhdr_int->s_name)
 	      || (bfd_get_file_flags (abfd) & WP_TEXT))
 	    scnhdr_int->s_flags &= ~IMAGE_SCN_MEM_WRITE;
 	  scnhdr_int->s_flags |= p->must_have;
@@ -1066,7 +1067,7 @@ _bfd_XXi_swap_scnhdr_out (bfd * abfd, void * in, void * out)
   if (coff_data (abfd)->link_info
       && ! bfd_link_relocatable (coff_data (abfd)->link_info)
       && ! bfd_link_pic (coff_data (abfd)->link_info)
-      && strcmp (scnhdr_int->s_name, ".text") == 0)
+      && strncmp (scnhdr_int->s_name, ".text", sizeof scnhdr_int->s_name) == 0)
     {
       /* By inference from looking at MS output, the 32 bit field
 	 which is the combination of the number_of_relocs and