Add command line option to stop the assembler from padding the end of sections to their alignment boundary.

	PR gas/20247
	* as.h (do_not_pad_sections_to_alignment): New global variable.
	* as.c (show_usage): Add --no-pad-sections.
	(parse_args): Likewise.
	* write.c (size_seg): Skip padding the end of the section if
	requested from the command line.
	(SUB_SEGMENT_ALIGN): Likewise.
	* doc/as.texinfo: Document the new option.
	* NEWS: Mention the new feature.
	* testsuite/gas/elf/section11.s: New test.
	* testsuite/gas/elf/section11.d: New test driver.
	* testsuite/gas/elf/elf.exp: Run the new test.

1 files changed, 17 insertions, 1 deletions

diff --git a/gas/doc/as.texinfo b/gas/doc/as.texinfo
index 6d2c325..9ebfda0 100644
--- a/gas/doc/as.texinfo
+++ b/gas/doc/as.texinfo
@@ -235,6 +235,7 @@ gcc(1), ld(1), and the Info entries for @file{binutils} and @file{ld}.
  [@b{-K}] [@b{-L}] [@b{--listing-lhs-width}=@var{NUM}]
  [@b{--listing-lhs-width2}=@var{NUM}] [@b{--listing-rhs-width}=@var{NUM}]
  [@b{--listing-cont-lines}=@var{NUM}] [@b{--keep-locals}]
+ [@b{--no-pad-sections}]
  [@b{-o} @var{objfile}] [@b{-R}]
  [@b{--hash-size}=@var{NUM}] [@b{--reduce-memory-overheads}]
  [@b{--statistics}]
@@ -773,6 +774,11 @@ Set the maximum width of an input source line, as displayed in a listing, to
 Set the maximum number of lines printed in a listing for a single line of input
 to @var{number} + 1.
 
+@item --no-pad-sections
+Stop the assembler for padding the ends of output sections to the alignment
+of that section.  The default is to pad the sections, but this can waste space
+which might be needed on targets which have tight memory constraints.
+
 @item -o @var{objfile}
 Name the object-file output from @command{@value{AS}} @var{objfile}.
 
@@ -2158,6 +2164,7 @@ assembler.)
 * listing::       --listing-XXX to configure listing output
 * M::		  -M or --mri to assemble in MRI compatibility mode
 * MD::            --MD for dependency tracking
+* no-pad-sections:: --no-pad-sections to stop section padding
 * o::             -o to name the object file
 * R::             -R to join data and text sections
 * statistics::    --statistics to see statistics about assembly
@@ -2494,6 +2501,15 @@ The rule is written to the file named in its argument.
 
 This feature is used in the automatic updating of makefiles.
 
+@node no-pad-sections
+@section Output Section Padding
+@kindex --no-pad-sections
+@cindex output section padding
+Normally the assembler will pad the end of each output section up to its
+alignment boundary.  But this can waste space, which can be significant on
+memory constrained targets.  So the @option{--no-pad-sections} option will
+disable this behaviour.
+
 @node o
 @section Name the Object File: @option{-o}
 
@@ -2680,7 +2696,7 @@ do include file processing with the @code{.include} directive
 (@pxref{Include,,@code{.include}}).  You can use the @sc{gnu} C compiler driver
 to get other ``CPP'' style preprocessing by giving the input file a
 @samp{.S} suffix.  @xref{Overall Options, ,Options Controlling the Kind of
-Output, gcc.info, Using GNU CC} .
+Output, gcc info, Using GNU CC}.
 
 Excess whitespace, comments, and character constants
 cannot be used in the portions of the input text that are not