From: Sandra Loosemore Date: Mon, 5 Mar 2018 06:31:24 +0000 (-0500) Subject: configfiles.texi (Configuration Files): Move info about conditionalizing $target... X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=e095eec19a54ef1639a5954534ccbbc3acd2fd83;p=gcc.git configfiles.texi (Configuration Files): Move info about conditionalizing $target-protos.h to... 2018-03-05 Sandra Loosemore gcc/ * doc/configfiles.texi (Configuration Files): Move info about conditionalizing $target-protos.h to... * doc/sourcebuild.texi (Back End): Here. Explain how $target.h differs from $target-protos.h. From-SVN: r258240 --- diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 4daf25f2a62..bd2c768820f 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2018-03-05 Sandra Loosemore + + * doc/configfiles.texi (Configuration Files): Move info about + conditionalizing $target-protos.h to... + * doc/sourcebuild.texi (Back End): Here. Explain how $target.h + differs from $target-protos.h. + 2018-03-05 Kito Cheng Chung-Ju Wu diff --git a/gcc/doc/configfiles.texi b/gcc/doc/configfiles.texi index 91045bd2aaf..fcd1d99dbd7 100644 --- a/gcc/doc/configfiles.texi +++ b/gcc/doc/configfiles.texi @@ -59,12 +59,10 @@ machine. @item @file{tm_p.h}, which includes the header @file{@var{machine}-protos.h} that contains prototypes for functions in the target -@file{@var{machine}.c} file. The header @file{@var{machine}-protos.h} -can include prototypes of functions that use rtl and tree data -structures inside appropriate @code{#ifdef RTX_CODE} and @code{#ifdef -TREE_CODE} conditional code segements. The -@file{@var{machine}-protos.h} is included after the @file{rtl.h} -and/or @file{tree.h} would have been included. The @file{tm_p.h} also +@file{@var{machine}.c} file. The +@file{@var{machine}-protos.h} header is included after the @file{rtl.h} +and/or @file{tree.h} would have been included. +The @file{tm_p.h} also includes the header @file{tm-preds.h} which is generated by @file{genpreds} program during the build to define the declarations and inline functions for the predicate functions. diff --git a/gcc/doc/sourcebuild.texi b/gcc/doc/sourcebuild.texi index bf44d158683..b9672ca8b8e 100644 --- a/gcc/doc/sourcebuild.texi +++ b/gcc/doc/sourcebuild.texi @@ -822,6 +822,23 @@ manual needs to be installed as info for this to work, or to be a chapter of this manual. @end itemize +The @file{@var{machine}.h} header is included very early in GCC's +standard sequence of header files, while @file{@var{machine}-protos.h} +is included late in the sequence. Thus @file{@var{machine}-protos.h} +can include declarations referencing types that are not defined when +@file{@var{machine}.h} is included, specifically including those from +@file{rtl.h} and @file{tree.h}. Since both RTL and tree types may not +be available in every context where @file{@var{machine}-protos.h} is +included, in this file you should guard declarations using these types +inside appropriate @code{#ifdef RTX_CODE} or @code{#ifdef TREE_CODE} +conditional code segments. + +If the backend uses shared data structures that require @code{GTY} markers +for garbage collection (@pxref{Type Information}), you must declare those +in @file{@var{machine}.h} rather than @file{@var{machine}-protos.h}. +Any definitions required for building libgcc must also go in +@file{@var{machine}.h}. + GCC uses the macro @code{IN_TARGET_CODE} to distinguish between machine-specific @file{.c} and @file{.cc} files and machine-independent @file{.c} and @file{.cc} files. Machine-specific