diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 5a70ba777f97fd91bd078caa58fa6e455a2d0242..8df1641a8b1679f4cef6bf8225279230b38256a6 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,18 @@
+2002-08-20 John David Anglin <dave@hiauly1.hia.nrc.ca>
+
+ * cppinit.c (remove_dup_dir): Add head_ptr argument to handle removal
+ at head.
+ (remove_dup_nonsys_dirs): New function.
+ (remove_dup_dirs): Change argument head to head_ptr. Remove warnings.
+ (merge_include_chains): Remove non-system include directories from
+ quote and bracket include chains when they duplicate equivalent system
+ directories.
+ * doc/cpp.texi (-I): Update.
+ * doc/cppopts.texi (-I): Update.
+ * doc/install.texi (--with-local-prefix): Further document usage of
+ this option.
+ * doc/invoke.texi (-I): Update.
+
2002-08-20 Richard Henderson <rth@redhat.com>
* expr.c (TARGET_MEM_FUNCTIONS): Transform to boolean.
diff --git a/gcc/cppinit.c b/gcc/cppinit.c
index 0c61086a225c2e80129c7fc3a1ed3e83074757f5..bdee5a66b31ec30043c5b82e167a7c49f09657d2 100644
--- a/gcc/cppinit.c
+++ b/gcc/cppinit.c
@@ -94,9 +94,13 @@ static void mark_named_operators PARAMS ((cpp_reader *));
static void append_include_chain PARAMS ((cpp_reader *,
char *, int, int));
static struct search_path * remove_dup_dir PARAMS ((cpp_reader *,
+ struct search_path *,
+ struct search_path **));
+static struct search_path * remove_dup_nonsys_dirs PARAMS ((cpp_reader *,
+ struct search_path **,
struct search_path *));
static struct search_path * remove_dup_dirs PARAMS ((cpp_reader *,
- struct search_path *));
+ struct search_path **));
static void merge_include_chains PARAMS ((cpp_reader *));
static bool push_include PARAMS ((cpp_reader *,
struct pending_option *));
@@ -257,55 +261,92 @@ append_include_chain (pfile, dir, path, cxx_aware)
}
/* Handle a duplicated include path. PREV is the link in the chain
- before the duplicate. The duplicate is removed from the chain and
- freed. Returns PREV. */
+ before the duplicate, or NULL if the duplicate is at the head of
+ the chain. The duplicate is removed from the chain and freed.
+ Returns PREV. */
static struct search_path *
-remove_dup_dir (pfile, prev)
+remove_dup_dir (pfile, prev, head_ptr)
cpp_reader *pfile;
struct search_path *prev;
+ struct search_path **head_ptr;
{
- struct search_path *cur = prev->next;
+ struct search_path *cur;
+
+ if (prev != NULL)
+ {
+ cur = prev->next;
+ prev->next = cur->next;
+ }
+ else
+ {
+ cur = *head_ptr;
+ *head_ptr = cur->next;
+ }
if (CPP_OPTION (pfile, verbose))
fprintf (stderr, _("ignoring duplicate directory \"%s\"\n"), cur->name);
- prev->next = cur->next;
free ((PTR) cur->name);
free (cur);
return prev;
}
+/* Remove duplicate non-system directories for which there is an equivalent
+ system directory latter in the chain. The range for removal is between
+ *HEAD_PTR and END. Returns the directory before END, or NULL if none.
+ This algorithm is quadratic in the number system directories, which is
+ acceptable since there aren't usually that many of them. */
+static struct search_path *
+remove_dup_nonsys_dirs (pfile, head_ptr, end)
+ cpp_reader *pfile;
+ struct search_path **head_ptr;
+ struct search_path *end;
+{
+ struct search_path *prev, *cur, *other;
+
+ for (cur = *head_ptr; cur; cur = cur->next)
+ {
+ if (cur->sysp)
+ {
+ for (other = *head_ptr, prev = NULL;
+ other != end;
+ other = other ? other->next : *head_ptr)
+ {
+ if (!other->sysp
+ && INO_T_EQ (cur->ino, other->ino)
+ && cur->dev == other->dev)
+ {
+ other = remove_dup_dir (pfile, prev, head_ptr);
+ if (CPP_OPTION (pfile, verbose))
+ fprintf (stderr,
+ _(" as it is a non-system directory that duplicates a system directory\n"));
+ }
+ prev = other;
+ }
+ }
+ }
+
+ return prev;
+}
+
/* Remove duplicate directories from a chain. Returns the tail of the
chain, or NULL if the chain is empty. This algorithm is quadratic
in the number of -I switches, which is acceptable since there
aren't usually that many of them. */
static struct search_path *
-remove_dup_dirs (pfile, head)
+remove_dup_dirs (pfile, head_ptr)
cpp_reader *pfile;
- struct search_path *head;
+ struct search_path **head_ptr;
{
struct search_path *prev = NULL, *cur, *other;
- for (cur = head; cur; cur = cur->next)
+ for (cur = *head_ptr; cur; cur = cur->next)
{
- for (other = head; other != cur; other = other->next)
+ for (other = *head_ptr; other != cur; other = other->next)
if (INO_T_EQ (cur->ino, other->ino) && cur->dev == other->dev)
{
- if (cur->sysp && !other->sysp)
- {
- cpp_error (pfile, DL_WARNING,
- "changing search order for system directory \"%s\"",
- cur->name);
- if (strcmp (cur->name, other->name))
- cpp_error (pfile, DL_WARNING,
- " as it is the same as non-system directory \"%s\"",
- other->name);
- else
- cpp_error (pfile, DL_WARNING,
- " as it has already been specified as a non-system directory");
- }
- cur = remove_dup_dir (pfile, prev);
+ cur = remove_dup_dir (pfile, prev, head_ptr);
break;
}
prev = cur;
@@ -343,28 +384,33 @@ merge_include_chains (pfile)
else
brack = systm;
- /* This is a bit tricky. First we drop dupes from the quote-include
- list. Then we drop dupes from the bracket-include list.
- Finally, if qtail and brack are the same directory, we cut out
- brack and move brack up to point to qtail.
+ /* This is a bit tricky. First we drop non-system dupes of system
+ directories from the merged bracket-include list. Next we drop
+ dupes from the bracket and quote include lists. Then we drop
+ non-system dupes from the merged quote-include list. Finally,
+ if qtail and brack are the same directory, we cut out brack and
+ move brack up to point to qtail.
We can't just merge the lists and then uniquify them because
then we may lose directories from the <> search path that should
- be there; consider -Ifoo -Ibar -I- -Ifoo -Iquux. It is however
+ be there; consider -Ifoo -Ibar -I- -Ifoo -Iquux. It is however
safe to treat -Ibar -Ifoo -I- -Ifoo -Iquux as if written
-Ibar -I- -Ifoo -Iquux. */
- remove_dup_dirs (pfile, brack);
- qtail = remove_dup_dirs (pfile, quote);
+ remove_dup_nonsys_dirs (pfile, &brack, systm);
+ remove_dup_dirs (pfile, &brack);
if (quote)
{
+ qtail = remove_dup_dirs (pfile, "e);
qtail->next = brack;
+ qtail = remove_dup_nonsys_dirs (pfile, "e, brack);
+
/* If brack == qtail, remove brack as it's simpler. */
- if (brack && INO_T_EQ (qtail->ino, brack->ino)
+ if (qtail && brack && INO_T_EQ (qtail->ino, brack->ino)
&& qtail->dev == brack->dev)
- brack = remove_dup_dir (pfile, qtail);
+ brack = remove_dup_dir (pfile, qtail, "e);
}
else
quote = brack;
diff --git a/gcc/doc/cpp.texi b/gcc/doc/cpp.texi
index 1284a39ad8aafede9fd1ae27c1c59eb83ae2b5c6..71f0d870f4897e67c44efab5c28d20b1345ff652 100644
--- a/gcc/doc/cpp.texi
+++ b/gcc/doc/cpp.texi
@@ -823,11 +823,22 @@ version of GCC in use.
You can add to this list with the @option{-I@var{dir}} command line
option. All the directories named by @option{-I} are searched, in
-left-to-right order, @emph{before} the default directories. You can
-also prevent GCC from searching any of the default directories with the
-@option{-nostdinc} option. This is useful when you are compiling an
+left-to-right order, @emph{before} the default directories. The only
+exception is when @file{dir} is already searched by default. In
+this case, the option is ignored and the search order for system
+directories remains unchanged.
+
+Duplicate directories are removed from the quote and bracket search
+chains before the two chains are merged to make the final search chain.
+Thus, it is possible for a directory to occur twice in the final search
+chain if it was specified in both the quote and bracket chains.
+
+You can prevent GCC from searching any of the default directories with
+the @option{-nostdinc} option. This is useful when you are compiling an
operating system kernel or some other program that does not use the
standard C library facilities, or the standard C library itself.
+@option{-I} options are not ignored as described above when
+@option{-nostdinc} is in effect.
GCC looks for headers requested with @code{@w{#include "@var{file}"}}
first in the directory containing the current file, then in the same
@@ -836,12 +847,6 @@ For example, if @file{/usr/include/sys/stat.h} contains
@code{@w{#include "types.h"}}, GCC looks for @file{types.h} first in
@file{/usr/include/sys}, then in its usual search path.
-If you name a search directory with @option{-I@var{dir}} that is also a
-system include directory, the @option{-I} wins; the directory will be
-searched according to the @option{-I} ordering, and it will not be
-treated as a system include directory. GCC will warn you when a system
-include directory is hidden in this way.
-
@samp{#line} (@pxref{Line Control}) does not change GCC's idea of the
directory containing the current file.
@@ -1074,8 +1079,8 @@ found in that directory will be considered system headers.
All directories named by @option{-isystem} are searched @emph{after} all
directories named by @option{-I}, no matter what their order was on the
command line. If the same directory is named by both @option{-I} and
-@option{-isystem}, @option{-I} wins; it is as if the @option{-isystem} option
-had never been specified at all. GCC warns you when this happens.
+@option{-isystem}, the @option{-I} option is ignored. GCC provides an
+informative message when this occurs if @option{-v} is used.
@findex #pragma GCC system_header
There is also a directive, @code{@w{#pragma GCC system_header}}, which
@@ -1817,9 +1822,7 @@ conformance to the C Standard. CPP follows the host convention when
processing system header files, but when processing user files
@code{__STDC__} is always 1. This has been reported to cause problems;
for instance, some versions of Solaris provide X Windows headers that
-expect @code{__STDC__} to be either undefined or 1. You may be able to
-work around this sort of problem by using an @option{-I} option to
-cancel treatment of those headers as system headers. @xref{Invocation}.
+expect @code{__STDC__} to be either undefined or 1. @xref{Invocation}.
@item __STDC_VERSION__
This macro expands to the C Standard's version number, a long integer
diff --git a/gcc/doc/cppopts.texi b/gcc/doc/cppopts.texi
index b23c9fccdc7d76e08a4cd20e38ad30e7bff65fa7..e2265eb9bd6bd17dc72bd1b9a0d1a8e82b96c456 100644
--- a/gcc/doc/cppopts.texi
+++ b/gcc/doc/cppopts.texi
@@ -51,16 +51,14 @@ for header files.
@xref{Search Path}.
@end ifset
Directories named by @option{-I} are searched before the standard
-system include directories.
-
-It is dangerous to specify a standard system include directory in an
-@option{-I} option. This defeats the special treatment of system
-headers
+system include directories. If the directory @var{dir} is a standard
+system include directory, the option is ignored to ensure that the
+default search order for system directories and the special treatment
+of system headers are not defeated
@ifset cppmanual
(@pxref{System Headers})
@end ifset
-. It can also defeat the repairs to buggy system headers which GCC
-makes when it is installed.
+.
@item -o @var{file}
@opindex o
diff --git a/gcc/doc/install.texi b/gcc/doc/install.texi
index d8c92a4611b6761065ebd0ad12e4e762390ed2fb..9e2d6296f428a2a31557b83b57c2c6d2828b4007 100644
--- a/gcc/doc/install.texi
+++ b/gcc/doc/install.texi
@@ -467,6 +467,43 @@ any in that directory---are not part of GCC@. They are part of other
programs---perhaps many others. (GCC installs its own header files in
another directory which is based on the @option{--prefix} value.)
+Both the local-prefix include directory and the GCC-prefix include
+directory are part of GCC's "system include" directories. Although these
+two directories are not fixed, they need to be searched in the proper
+order for the correct processing of the include_next directive. The
+local-prefix include directory is searched before the GCC-prefix
+include directory. Another characteristic of system include directories
+is that pedantic warnings are turned off for headers in these directories.
+
+Some autoconf macros add @option{-I @var{directory}} options to the
+compiler command line, to ensure that directories containing installed
+packages' headers are searched. When @var{directory} is one of GCC's
+system include directories, GCC will ignore the option so that system
+directories continue to be processed in the correct order. This
+may result in a search order different from what was specified but the
+directory will still be searched.
+
+GCC automatically searches for ordinary libraries using
+@env{GCC_EXEC_PREFIX}. Thus, when the same installation prefix is
+used for both GCC and packages, GCC will automatically search for
+both headers and libraries. This provides a configuration that is
+easy to use. GCC behaves in a manner similar to that when it is
+installed as a system compiler in @file{/usr}.
+
+Sites that need to install multiple versions of GCC may not want to
+use the above simple configuration. It is possible to use the
+@option{--program-prefix}, @option{--program-suffix} and
+@option{--program-transform-name} options to install multiple versions
+into a single directory, but it may be simpler to use different prefixes
+and the @option{--with-local-prefix} option to specify the location of the
+site-specific files for each version. It will then be necessary for
+users to specify explicitly the location of local site libraries
+(e.g., with @env{LIBRARY_PATH}).
+
+The same value can be used for both @option{--with-local-prefix} and
+@option{--prefix} provided it is not @file{/usr}. This can be used
+to avoid the default search of @file{/usr/local/include}.
+
@strong{Do not} specify @file{/usr} as the @option{--with-local-prefix}!
The directory you use for @option{--with-local-prefix} @strong{must not}
contain any of the system's standard header files. If it did contain
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 3119c454e644d55812d138fe477d0ca596edbc44..d2fc0f74d0e7095ff7c2bdb7b3b84e12155397ea 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -4281,15 +4281,13 @@ one @option{-I} option, the directories are scanned in left-to-right
order; the standard system directories come after.
If a standard system include directory, or a directory specified with
-@option{-isystem}, is also specified with @option{-I}, it will be
-searched only in the position requested by @option{-I}. Also, it will
-not be considered a system include directory. If that directory really
-does contain system headers, there is a good chance that they will
-break. For instance, if GCC's installation procedure edited the headers
-in @file{/usr/include} to fix bugs, @samp{-I/usr/include} will cause the
-original, buggy headers to be found instead of the corrected ones. GCC
-will issue a warning when a system include directory is hidden in this
-way.
+@option{-isystem}, is also specified with @option{-I}, the @option{-I}
+option will be ignored. The directory will still be searched but as a
+system directory at its normal position in the system include chain.
+This is to ensure that GCC's procedure to fix buggy system headers and
+the ordering for the include_next directive are not inadvertantly changed.
+If you really need to change the search order for system directories,
+use the @option{-nostdinc} and/or @option{-isystem} options.
@item -I-
@opindex I-