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authorAlan Modra <amodra@gmail.com>2020-11-17 12:41:36 +1030
committerAlan Modra <amodra@gmail.com>2020-11-18 23:46:39 +1030
commit058430b4a1ed7441dfc2e167bfdb9dc89ea9a209 (patch)
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parent99fabbc9739a87ba3433e66792e93b773896790e (diff)
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Re: Stop Gas from generating line info or address ranges
* doc/as.texi (.nop): Document optional size arg. * dwarf2dbg.c (dwarf2_gen_line_info_1): Only check SEC_ALLOC when ELF. Warn whenever dwarf line number information is ignored. * frags.c (frag_offset_ignore_align_p): New function. * frags.h (frag_offset_ignore_align_p): Declare. * read.c (s_nop): Extend to support optional size arg. * testsuite/gas/elf/dwarf2-20.d: Expect warnings, and exact range. * testsuite/gas/elf/dwarf2-20.s: Emit 16 bytes worth of nops. * testsuite/gas/m68hc11/indexed12.d: Expect warnings.
Diffstat (limited to 'gas/doc')
-rw-r--r--gas/doc/as.texi14
1 files changed, 9 insertions, 5 deletions
diff --git a/gas/doc/as.texi b/gas/doc/as.texi
index 84a7e61..983cec3 100644
--- a/gas/doc/as.texi
+++ b/gas/doc/as.texi
@@ -6169,14 +6169,18 @@ counter, and @code{.nolist} decrements it. Assembly listings are
generated whenever the counter is greater than zero.
@node Nop
-@section @code{.nop}
+@section @code{.nop [@var{size}]}
@cindex @code{nop} directive
@cindex filling memory with no-op instructions
-This directive emits a single no-op instruction. It is provided on all
-architectures, allowing the creation of architecture neutral tests involving
-actual code. The size of the generated instruction is target specific. The
-instruction does affect the generation of DWARF debug line information.
+This directive emits no-op instructions. It is provided on all architectures,
+allowing the creation of architecture neutral tests involving actual code. The
+size of the generated instruction is target specific, but if the optional
+@var{size} argument is given and resolves to an absolute positive value at that
+point in assembly (no forward expressions allowed) then the fewest no-op
+instructions are emitted that equal or exceed a total @var{size} in bytes.
+@code{.nop} does affect the generation of DWARF debug line information.
+Some targets do not support using @code{.nop} with @var{size}.
@node Nops
@section @code{.nops @var{size}[, @var{control}]}