re PR c/69502 (attribute aligned reduces alignment contrary to documentation)

2018-11-11  Sandra Loosemore  <sandra@codesourcery.com>

	PR c/69502

	gcc/
	* doc/extend.texi (Common Type Attributes): For the align type
	attribute, copy language about decreasing alignment from the
	corresponding variable attribute.

From-SVN: r266025

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 066ef79f51d3a6d9c057c8bc31be8f90356869b1..07661bbe7c591fd453b639fe28e9cb142e564d11 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2018-11-11  Sandra Loosemore  <sandra@codesourcery.com>
+
+       PR c/69502
+       * doc/extend.texi (Common Type Attributes): For the align type
+       attribute, copy language about decreasing alignment from the
+       corresponding variable attribute.
+
 2018-11-11  Xianmiao Qu  <xianmiao_qu@c-sky.com>
 
        * config/csky/csky.md (*fpuv2_nmulsf3_1, *fpuv2_nmuldf3_1): Handle

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 022d0e0c121e3bb732a63fce5c8f886c9e84ecab..ebdc0cec789eb54021c8b2acbb6aac7dc9fa02ea 100644 (file)
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -7101,8 +7101,11 @@ up to a maximum of 8-byte alignment, then specifying @code{aligned(16)}
 in an @code{__attribute__} still only provides you with 8-byte
 alignment.  See your linker documentation for further information.
 
-The @code{aligned} attribute can only increase alignment.  Alignment
-can be decreased by specifying the @code{packed} attribute.  See below.
+When used on a struct, or struct member, the @code{aligned} attribute can
+only increase the alignment; in order to decrease it, the @code{packed}
+attribute must be specified as well.  When used as part of a typedef, the
+@code{aligned} attribute can both increase and decrease alignment, and
+specifying the @code{packed} attribute generates a warning.
 
 @cindex @code{warn_if_not_aligned} type attribute
 @item warn_if_not_aligned (@var{alignment})