[newlib-cygwin] Cygwin: Make gmondump conform to its doc + adjust doc

[newlib-cygwin] Cygwin: Make gmondump conform to its doc + adjust doc

[Corinna Vinschen]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=99a4b087d41b71ccb2d39900c74ef4b8cf0320fc

commit 99a4b087d41b71ccb2d39900c74ef4b8cf0320fc
Author: Mark Geisert <mark@maxrnd.com>
Date:   Mon Aug 2 02:25:53 2021 -0700

    Cygwin: Make gmondump conform to its doc + adjust doc
    
    The doc for gmondump says 1 or more FILENAME are expected, but 0 is
    handled. That's an oversight. Make invocation with 0 FILENAMEs print a
    one-line help message.
    
    Reword the beginning of profiler's description doc to clarify target's
    child processes are run but only optionally profiled.

Diff:
---
 winsup/doc/utils.xml    |  7 ++++---
 winsup/utils/gmondump.c | 12 ++++++++++++
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/winsup/doc/utils.xml b/winsup/doc/utils.xml
index 659541f00..0b9e38549 100644
--- a/winsup/doc/utils.xml
+++ b/winsup/doc/utils.xml
@@ -2240,9 +2240,10 @@ specifying an empty password.
 
     <refsect1 id="profiler-desc">
       <title>Description</title>
-    <para>The <command>profiler</command> utility executes a given program, and
-      optionally the children of that program, collecting the location of the
-      CPU instruction pointer (IP) many times per second. This gives a profile
+    <para>The <command>profiler</command> utility executes a given program and
+      any children of that program, collecting the location of the CPU
+      instruction pointer (IP) many times per second. (It is optional to
+      collect this info from child processes.) This info gives a profile
       of the program's execution, showing where the most time is being spent.
       This profiling technique is called "IP sampling".</para>
 
diff --git a/winsup/utils/gmondump.c b/winsup/utils/gmondump.c
index e469f01f1..ec9db0598 100644
--- a/winsup/utils/gmondump.c
+++ b/winsup/utils/gmondump.c
@@ -46,6 +46,14 @@ OPTIONS are:\n\
   exit (where == stderr ? 1 : 0 );
 }
 
+void __attribute__ ((__noreturn__))
+usage1 (FILE *where)
+{
+  fprintf (where, "Usage: %s [OPTIONS] FILENAME...\n", pgm);
+
+  exit (where == stderr ? 1 : 0 );
+}
+
 void
 note (const char *fmt, ...)
 {
@@ -248,6 +256,10 @@ main(int argc, char **argv)
         ;
       }
 
+  if (optind >= argc)
+    /* Print one-line help and exit. */
+    usage1 (ofile);
+
   for (int i = optind; i < argc; i++)
     gmondump1 (argv[i]);