manual: Fix and test @deftypef* function formatting

The manual contained several instances of incorrect formatting
that were correct texinfo but produced incorrectly rendered manuals
or incorrect behaviour from the tooling.

The most important was incorrect quoting of function returns
by failing to use {} to quote the return.  The impact of this
mistake means that 'info libc func' does not jump to the function
in question but instead to the introductory page under the assumption
that func doesn't exist.  The function returns are now correctly
quoted.

The second issue was the use of a category specifier with
@deftypefun which doesn't accept a category specifier.  If a category
specifier is required then @deftypefn needs to be used. This is
corrected by changing the command to @deftypefn for such functions
that used {Deprecated function} as a category.

The last issue is a missing space between the function name and the
arguments which results in odd function names like "epoll_wait(int"
instead of "epoll_wait".  This also impacts the use of 'info libc'
and is corrected.

We additionally remove ';' from the end of function arguments and
add an 'int' return type for dprintf.

Lastly we add a new test check-deftype.sh which verifies the expected
formatting of @deftypefun, @deftypefunx, @deftypefn, and
@deftypefnx.  The new test is also run as the summary file is
generated to ensure we don't generate incorrect results.

The existing check-safety.sh is also run directly as a test to increase
coverage since the existing tests only ran on manual install.

The new tests now run as part of the standard "make check" that
pre-commit CI runs and developers should run.

No regressions on x86_64.

HTML and PDF rendering reviewed and looks correct for all changes.

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>

8 files changed, 104 insertions, 31 deletions

diff --git a/manual/Makefile b/manual/Makefile
index a6c05db540..6a4cfbeb76 100644
--- a/manual/Makefile
+++ b/manual/Makefile
@@ -69,6 +69,11 @@ chapters.% top-menu.%: libc-texinfo.sh $(texis-path) Makefile
 				'$(chapters)' \
 			       '$(appendices) $(licenses)'
 
+# Verify validity of texinfo sources against project rules.
+tests-special += \
+  $(objpfx)check-deftype.out \
+  $(objpfx)check-safety.out \
+  # tests-special
 
 $(objpfx)libc.dvi $(objpfx)libc.pdf $(objpfx)libc.info: \
 	$(addprefix $(objpfx),$(libc-texi-generated))
@@ -83,10 +88,19 @@ $(objpfx)summary.texi: $(objpfx)stamp-summary ;
 $(objpfx)stamp-summary: summary.pl $(filter-out $(objpfx)summary.texi, \
 					$(texis-path))
 	$(SHELL) ./check-safety.sh $(filter-out $(objpfx)%, $(texis-path))
+	$(SHELL) ./check-deftype.sh $(filter-out $(objpfx)%, $(texis-path))
 	LC_ALL=C $(PERL) $^ > $(objpfx)summary-tmp
 	$(move-if-change) $(objpfx)summary-tmp $(objpfx)summary.texi
 	touch $@
 
+$(objpfx)check-safety.out: check-safety.sh
+	$(SHELL) $< > $@ ; \
+	$(evaluate-test)
+
+$(objpfx)check-deftype.out: check-deftype.sh
+	$(SHELL) $< > $@ ; \
+	$(evaluate-test)
+
 # Generate a file which can be added to the `dir' content to provide direct
 # access to the documentation of the function, variables, and other
 # definitions.
@@ -152,10 +166,19 @@ $(objpfx)%.pdf: %.texinfo
 
 
 # Distribution.
-minimal-dist = summary.pl texis.awk tsort.awk libc-texinfo.sh libc.texinfo \
-	       libm-err.texi stamp-libm-err check-safety.sh		    \
-	       $(filter-out summary.texi, $(nonexamples))		    \
-	       $(patsubst %.c.texi,examples/%.c, $(examples))
+minimal-dist = \
+  $(filter-out summary.texi, $(nonexamples)) \
+  $(patsubst %.c.texi,examples/%.c, $(examples)) \
+  check-deftype.sh \
+  check-safety.sh \
+  libc-texinfo.sh \
+  libc.texinfo \
+  libm-err.texi \
+  stamp-libm-err \
+  summary.pl \
+  texis.awk \
+  tsort.awk \
+  # minimal-dist
 
 indices = cp fn pg tp vr ky
 generated-dirs += libc
diff --git a/manual/check-deftype.sh b/manual/check-deftype.sh
new file mode 100644
index 0000000000..395c99af6a
--- /dev/null
+++ b/manual/check-deftype.sh
@@ -0,0 +1,50 @@
+#!/bin/sh
+
+# Copyright 2024 Free Software Foundation, Inc.
+# This file is part of the GNU C Library.
+
+# The GNU C Library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+
+# The GNU C Library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+
+# You should have received a copy of the GNU Lesser General Public
+# License along with the GNU C Library; if not, see
+# <https://www.gnu.org/licenses/>.
+
+# Check that the @deftypefun command is called with the expected
+# arguments and includes checking for common mistakes including
+# failure to include a space after the function name, or incorrect
+# quoting.
+
+success=:
+
+# If no arguments are given, take all *.texi files in the current directory.
+test $# != 0 || set *.texi
+
+# We search for all @deftypefun and @deftypefunx command uses.
+# Then we remove all of those that match our expectations.
+# A @deftypefun or @deftypefunx command takes 3 arguments:
+# - return type
+# - name
+# - arguments
+# This is different from @deftypefn which includes an additional
+# category which is implicit here.
+grep -n -r '^@deftypefun' "$@" |
+grep -v '^.*@deftypefunx\?'\
+' \({\?[a-zA-Z0-9_ *]*}\?\) \([a-zA-Z0-9_]*\) (.*)$' &&
+success=false
+
+# We search for all @deftypefn and @deftypefnx command uses.
+# We have 4 arguments in the command including the category.
+grep -n -r '^@deftypefn' "$@" |
+grep -v '^.*@deftypefnx\?'\
+' {\?[a-zA-Z ]*}\? \({\?[a-zA-Z0-9@{}_ *]*}\?\) \([a-zA-Z0-9_]*\) (.*)$' &&
+success=false
+
+$success
diff --git a/manual/ipc.texi b/manual/ipc.texi
index 6a6e5ad410..32c5ac066f 100644
--- a/manual/ipc.texi
+++ b/manual/ipc.texi
@@ -20,7 +20,7 @@ by @theglibc{}.
 @c Need descriptions for all of these functions.
 
 @subsection System V Semaphores
-@deftypefun int semctl (int @var{semid}, int @var{semnum}, int @var{cmd});
+@deftypefun int semctl (int @var{semid}, int @var{semnum}, int @var{cmd})
 @safety{@prelim{}@mtsafe{}@assafe{}@acunsafe{@acucorrupt{/linux}}}
 @c syscall(ipc) ok
 @c
@@ -30,35 +30,35 @@ by @theglibc{}.
 @c semid_ds.
 @end deftypefun
 
-@deftypefun int semget (key_t @var{key}, int @var{nsems}, int @var{semflg});
+@deftypefun int semget (key_t @var{key}, int @var{nsems}, int @var{semflg})
 @safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
 @c syscall(ipc) ok
 @end deftypefun
 
-@deftypefun int semop (int @var{semid}, struct sembuf *@var{sops}, size_t @var{nsops});
+@deftypefun int semop (int @var{semid}, struct sembuf *@var{sops}, size_t @var{nsops})
 @safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
 @c syscall(ipc) ok
 @end deftypefun
 
-@deftypefun int semtimedop (int @var{semid}, struct sembuf *@var{sops}, size_t @var{nsops}, const struct timespec *@var{timeout});
+@deftypefun int semtimedop (int @var{semid}, struct sembuf *@var{sops}, size_t @var{nsops}, const struct timespec *@var{timeout})
 @safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
 @c syscall(ipc) ok
 @end deftypefun
 
 @subsection POSIX Semaphores
 
-@deftypefun int sem_init (sem_t *@var{sem}, int @var{pshared}, unsigned int @var{value});
+@deftypefun int sem_init (sem_t *@var{sem}, int @var{pshared}, unsigned int @var{value})
 @safety{@prelim{}@mtsafe{}@assafe{}@acunsafe{@acucorrupt{}}}
 @c Does not atomically update sem_t therefore AC-unsafe
 @c because it can leave sem_t partially initialized.
 @end deftypefun
 
-@deftypefun int sem_destroy (sem_t *@var{sem});
+@deftypefun int sem_destroy (sem_t *@var{sem})
 @safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
 @c Function does nothing and is therefore always safe.
 @end deftypefun
 
-@deftypefun sem_t *sem_open (const char *@var{name}, int @var{oflag}, ...);
+@deftypefun {sem_t *} sem_open (const char *@var{name}, int @var{oflag}, ...)
 @safety{@prelim{}@mtsafe{}@asunsafe{@asuinit{}}@acunsafe{@acuinit{}}}
 @c pthread_once asuinit
 @c
@@ -67,7 +67,7 @@ by @theglibc{}.
 @c shmfs on Linux.
 @end deftypefun
 
-@deftypefun int sem_close (sem_t *@var{sem});
+@deftypefun int sem_close (sem_t *@var{sem})
 @safety{@prelim{}@mtsafe{}@asunsafe{@asulock{}}@acunsafe{@aculock{}}}
 @c lll_lock asulock aculock
 @c twalk mtsrace{:root}
@@ -77,13 +77,13 @@ by @theglibc{}.
 @c are not updated atomically.
 @end deftypefun
 
-@deftypefun int sem_unlink (const char *@var{name});
+@deftypefun int sem_unlink (const char *@var{name})
 @safety{@prelim{}@mtsafe{}@asunsafe{@asuinit{}}@acunsafe{@acucorrupt{}}}
 @c pthread_once asuinit acucorrupt aculock
 @c mempcpy acucorrupt
 @end deftypefun
 
-@deftypefun int sem_wait (sem_t *@var{sem});
+@deftypefun int sem_wait (sem_t *@var{sem})
 @safety{@prelim{}@mtsafe{}@assafe{}@acunsafe{@acucorrupt{}}}
 @c atomic_fetch_add_relaxed (nwaiters) acucorrupt
 @c
@@ -95,22 +95,22 @@ by @theglibc{}.
 @c waiters count.
 @end deftypefun
 
-@deftypefun int sem_timedwait (sem_t *@var{sem}, const struct timespec *@var{abstime});
+@deftypefun int sem_timedwait (sem_t *@var{sem}, const struct timespec *@var{abstime})
 @safety{@prelim{}@mtsafe{}@assafe{}@acunsafe{@acucorrupt{}}}
 @c Same safety issues as sem_wait.
 @end deftypefun
 
-@deftypefun int sem_trywait (sem_t *@var{sem});
+@deftypefun int sem_trywait (sem_t *@var{sem})
 @safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
 @c All atomic operations are safe in all contexts.
 @end deftypefun
 
-@deftypefun int sem_post (sem_t *@var{sem});
+@deftypefun int sem_post (sem_t *@var{sem})
 @safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
 @c Same safety as sem_trywait.
 @end deftypefun
 
-@deftypefun int sem_getvalue (sem_t *@var{sem}, int *@var{sval});
+@deftypefun int sem_getvalue (sem_t *@var{sem}, int *@var{sval})
 @safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
 @c Atomic write of a value is safe in all contexts.
 @end deftypefun
diff --git a/manual/llio.texi b/manual/llio.texi
index 0eb336f70b..e90fca01d6 100644
--- a/manual/llio.texi
+++ b/manual/llio.texi
@@ -4853,12 +4853,12 @@ of an IOCTL, see @ref{Out-of-Band Data}.
 @manpagefunctionstub{poll,2}
 @end deftypefun
 
-@deftypefun int epoll_create(int @var{size})
+@deftypefun int epoll_create (int @var{size})
 
 @manpagefunctionstub{epoll_create,2}
 @end deftypefun
 
-@deftypefun int epoll_wait(int @var{epfd}, struct epoll_event *@var{events}, int @var{maxevents}, int @var{timeout})
+@deftypefun int epoll_wait (int @var{epfd}, struct epoll_event *@var{events}, int @var{maxevents}, int @var{timeout})
 
 @manpagefunctionstub{epoll_wait,2}
 @end deftypefun
diff --git a/manual/memory.texi b/manual/memory.texi
index 3710d7ec66..58683ee93d 100644
--- a/manual/memory.texi
+++ b/manual/memory.texi
@@ -2935,7 +2935,7 @@ exceed the process' data storage limit.
 @end deftypefun
 
 
-@deftypefun void *sbrk (ptrdiff_t @var{delta})
+@deftypefun {void *} sbrk (ptrdiff_t @var{delta})
 @standards{BSD, unistd.h}
 @safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
 
diff --git a/manual/stdio.texi b/manual/stdio.texi
index c7a2b4a9a1..75aee8ab08 100644
--- a/manual/stdio.texi
+++ b/manual/stdio.texi
@@ -2531,7 +2531,7 @@ store the result in which case @code{-1} is returned.  This was
 changed in order to comply with the @w{ISO C99} standard.
 @end deftypefun
 
-@deftypefun dprintf (int @var{fd}, @var{template}, ...)
+@deftypefun int dprintf (int @var{fd}, @var{template}, ...)
 @standards{POSIX, stdio.h}
 @safety{@mtsafe{@mtslocale{}}@asunsafe{@ascuheap{}}@acunsafe{@acsmem{}}}
 This function formats its arguments according to @var{template} and
diff --git a/manual/threads.texi b/manual/threads.texi
index 25e99c9606..9ea137cb96 100644
--- a/manual/threads.texi
+++ b/manual/threads.texi
@@ -592,7 +592,7 @@ destructor for the thread-specific data is not called during destruction, nor
 is it called during thread exit.
 @end deftypefun
 
-@deftypefun void *pthread_getspecific (pthread_key_t @var{key})
+@deftypefun {void *} pthread_getspecific (pthread_key_t @var{key})
 @standards{POSIX, pthread.h}
 @safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
 @c pthread_getspecific ok
diff --git a/manual/time.texi b/manual/time.texi
index 64aad8fdc5..90bc9a2566 100644
--- a/manual/time.texi
+++ b/manual/time.texi
@@ -1829,7 +1829,7 @@ can be placed in the buffer @var{s} the return value is zero, with the
 same problems indicated in the @code{strftime} documentation.
 @end deftypefun
 
-@deftypefun {Deprecated function} {char *} asctime (const struct tm *@var{brokentime})
+@deftypefn {Deprecated function} {char *} asctime (const struct tm *@var{brokentime})
 @standards{ISO, time.h}
 @safety{@prelim{}@mtunsafe{@mtasurace{:asctime} @mtslocale{}}@asunsafe{}@acsafe{}}
 @c asctime @mtasurace:asctime @mtslocale
@@ -1863,9 +1863,9 @@ string.)
 @strong{Portability note:}
 This obsolescent function is deprecated in C23.
 Programs should instead use @code{strftime} or even @code{sprintf}.
-@end deftypefun
+@end deftypefn
 
-@deftypefun {Deprecated function} {char *} asctime_r (const struct tm *@var{brokentime}, char *@var{buffer})
+@deftypefn {Deprecated function} {char *} asctime_r (const struct tm *@var{brokentime}, char *@var{buffer})
 @standards{???, time.h}
 @safety{@prelim{}@mtsafe{@mtslocale{}}@assafe{}@acsafe{}}
 @c asctime_r @mtslocale
@@ -1884,9 +1884,9 @@ it returns @code{NULL}.
 @strong{Portability Note:}
 POSIX.1-2024 removed this obsolescent function.
 Programs should instead use @code{strftime} or even @code{sprintf}.
-@end deftypefun
+@end deftypefn
 
-@deftypefun {Deprecated function} {char *} ctime (const time_t *@var{time})
+@deftypefn {Deprecated function} {char *} ctime (const time_t *@var{time})
 @standards{ISO, time.h}
 @safety{@prelim{}@mtunsafe{@mtasurace{:tmbuf} @mtasurace{:asctime} @mtsenv{} @mtslocale{}}@asunsafe{@ascuheap{} @asulock{}}@acunsafe{@aculock{} @acsmem{} @acsfd{}}}
 @c ctime @mtasurace:tmbuf @mtasurace:asctime @mtsenv @mtslocale @ascuheap @asulock @aculock @acsmem @acsfd
@@ -1909,9 +1909,9 @@ Calling @code{ctime} also sets the time zone state as if
 @strong{Portability note:}
 This obsolescent function is deprecated in C23.
 Programs should instead use @code{strftime} or even @code{sprintf}.
-@end deftypefun
+@end deftypefn
 
-@deftypefun {Deprecated function} {char *} ctime_r (const time_t *@var{time}, char *@var{buffer})
+@deftypefn {Deprecated function} {char *} ctime_r (const time_t *@var{time}, char *@var{buffer})
 @standards{???, time.h}
 @safety{@prelim{}@mtsafe{@mtsenv{} @mtslocale{}}@asunsafe{@ascuheap{} @asulock{}}@acunsafe{@aculock{} @acsmem{} @acsfd{}}}
 @c ctime_r @mtsenv @mtslocale @ascuheap @asulock @aculock @acsmem @acsfd
@@ -1935,7 +1935,7 @@ it returns @code{NULL}.
 @strong{Portability Note:}
 POSIX.1-2024 removed this obsolescent function.
 Programs should instead use @code{strftime} or even @code{sprintf}.
-@end deftypefun
+@end deftypefn
 
 @node Parsing Date and Time
 @subsection Convert textual time and date information back