Syslinux - Apr 2021 - [PATCH wip.makefixes 0/3] Build fixes for current syslinux

I was attempting to build the latest version of syslinux from git. The
version at HEAD didn't build, so I tried the version on the
wip.makefixes branch. In the course of trying to build that version, I
ran into a few issues; these patches address some of those.

With these patches, the build gets further, though it still fails with
undefined references to `opendir`, `readdir`, and `closedir`, referenced
from `com32/modules/dir.c`.

/home/josh/src/syslinux/com32/modules/dir.c:80: undefined reference to
`opendir'
ld: /home/josh/src/syslinux/com32/modules/dir.c:86: undefined reference to
`readdir'
ld: /home/josh/src/syslinux/com32/modules/dir.c:110: undefined reference to
`closedir'
ld: /home/josh/src/syslinux/com32/modules/dir.c:148: undefined reference to
`closedir'

Josh Triplett (3):
  Mark e820_types as extern in header to avoid duplicate symbol
  Mark tcp_conn_ops as extern in header to avoid duplicate symbol
  Pass --wide to readelf to avoid truncating symbol names

 com32/gplinclude/memory.h | 2 +-
 core/export.pl            | 2 +-
 core/include/core_pxe.h   | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

-- 
2.31.0

Signed-off-by: Josh Triplett <josh at joshtriplett.org>
---
 com32/gplinclude/memory.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/com32/gplinclude/memory.h b/com32/gplinclude/memory.h
index fe33c18d..1128d539 100644
--- a/com32/gplinclude/memory.h
+++ b/com32/gplinclude/memory.h
@@ -37,7 +37,7 @@ struct e820entry {
     uint64_t type;		/* type of memory segment */
 } __attribute__ ((packed));
 
-const char *const e820_types[5];
+extern const char *const e820_types[5];
 
 void get_type(int, char *, int);
 void detect_memory_e820(struct e820entry *desc, int size_map, int *size_found);
-- 
2.31.0

Signed-off-by: Josh Triplett <josh at joshtriplett.org>
---
 core/include/core_pxe.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/core/include/core_pxe.h b/core/include/core_pxe.h
index 19664f9b..54185e09 100644
--- a/core/include/core_pxe.h
+++ b/core/include/core_pxe.h
@@ -265,7 +265,7 @@ void ftp_open(struct url_info *url, int flags, struct inode
*inode,
 int ftp_readdir(struct inode *inode, struct dirent *dirent);
 
 /* tcp.c */
-const struct pxe_conn_ops tcp_conn_ops;
+extern const struct pxe_conn_ops tcp_conn_ops;
 
 extern void gpxe_init(void);
 extern int pxe_init(bool quiet);
-- 
2.31.0

Current versions of readelf truncate symbol names to fit in 80
characters, even when not sending output to a terminal. Pass the --wide
option to prevent this.

Without this, the truncation marker would end up in the generated
libcore.S assembly file, resulting in lines like this:

	.globl	__syslinux_core_[...]
__syslinux_core_[...]	= 0x00008862
	.type	__syslinux_core_[...], STT_OBJECT
	.size	__syslinux_core_[...], 2

And errors like this:

libcore.S: Assembler messages:
libcore.S:203: Error: junk at end of line, first unrecognized character is
`['
libcore.S:204: Error: invalid character '[' in mnemonic
libcore.S:205: Error: unrecognized symbol type ""
libcore.S:205: Error: junk at end of line, first unrecognized character is
`['
libcore.S:206: Error: expected comma after name `__syslinux_core_' in .size
directive

Signed-off-by: Josh Triplett <josh at joshtriplett.org>
---
 core/export.pl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/core/export.pl b/core/export.pl
index 16c63dbf..ad7d1528 100755
--- a/core/export.pl
+++ b/core/export.pl
@@ -22,7 +22,7 @@ my %fsyms;			# Files in which this symbol occurs
 my $readelf = $ENV{'READELF'} || 'readelf';
 
 foreach my $infile (@infiles) {
-    open(my $in, '-|', $readelf, '--dyn-syms', $infile)
+    open(my $in, '-|', $readelf, '--wide',
'--dyn-syms', $infile)
 	or die "$0: $infile: $!\n";
 
     while (my $line = <$in>) {
-- 
2.31.0