gas alpha-linux segfault with .prologue outside .ent

[Luke Deller]

Hi,

The GNU assembler (from binutils-2.13.1) for an alpha-linux target produces
a segmentation fault for the following input:

    # begin gasbug.s
    foo:
            .prologue 0
            nop
    # end gasbug.s

The segmentation fault can be avoided by placing the above function inside
a .ent/.end pair, ie:

    # begin gasworks.s
    .ent foo
    foo:
            .prologue 0
            nop
    .end foo
    # end gasworks.s

The problem appears to be a missing error check in the function
s_alpha_prologue in gas/config/tc-alpha.c ... here is the full back trace
from gdb:

$ gdb alpha-linux-as
GNU gdb 5.2.1
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Type "show copying" to see the conditions.
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This GDB was configured as "i686-pc-linux-gnu"...
(gdb) set args -o /dev/null gasbug.s
(gdb) run
Starting program: /usr/local/crossdev/bin/alpha-linux-as -o /dev/null gasbug.s

Program received signal SIGSEGV, Segmentation fault.
0x0806a0d9 in symbol_get_bfdsym (s=0x0) at symbols.c:2242
2242      if (LOCAL_SYMBOL_CHECK (s))
(gdb) bt
#0  0x0806a0d9 in symbol_get_bfdsym (s=0x0) at symbols.c:2242
#1  0x08074582 in s_alpha_prologue (ignore=0) at config/tc-alpha.c:4535
#2  0x0805fa33 in read_a_source_file (name=0xbffff83c "gasbug.s") at
read.c:818
#3  0x0804c1f4 in perform_an_assembly_pass (argc=0, argv=0x8125204)
    at as.c:1074
#4  0x0804be7c in main (argc=2, argv=0x8125200) at as.c:885
#5  0x4003d106 in __libc_start_main () from /lib/libc.so.6
(gdb)


PS: I built binutils on Gentoo linux(x86) with gcc-3.2, configured with:
    ./configure --enable-64-bit-bfd --target=alpha-linux \
    --prefix=/usr/local/crossdev