Solved an output issue on AIX due to the use of setbuf() after output

in tversion. Indeed, this is disallowed by ISO C.
  * doc/README.dev: added a note about tests_start_mpfr and this issue.
  * tests/tests.c: moved test_version() after setbuf().
  * tests/tversion.c: moved tests_start_mpfr() earlier, before any
    printf().

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@11877 280ebfd0-de03-0410-8827-d642c229c3f4

3 files changed, 15 insertions, 6 deletions

diff --git a/doc/README.dev b/doc/README.dev
index 33d1e193e..82d2478e2 100644
--- a/doc/README.dev
+++ b/doc/README.dev
@@ -1279,6 +1279,10 @@ of mismatch between a header and a library, an error message is output
 
 3. Otherwise test_version() returns with value 0 (everything is fine).
 
+Note: The tests_start_mpfr function does a setbuf on stdout to disable
+buffering. As a consequence, no operations on stdout (such as printf)
+must be done before this function is called.
+
 With Automake 1.13+, the tests are run in parallel if a -j make option
 is used. In case of failure, information can be found in the log file
 of each failed test program and in the global tests/test-suite.log file
diff --git a/tests/tests.c b/tests/tests.c
index 766e576b1..3b9d32922 100644
--- a/tests/tests.c
+++ b/tests/tests.c
@@ -137,7 +137,8 @@ void (*dummy_func)(mpfr_srcptr) = mpfr_dump;
    of "make check") but a different library that is already installed,
    i.e. any test result would be meaningless; in such a case, we exit
    immediately with an error (exit status = 1).
-   Return value: 0 for no errors, 1 in case of any non-fatal error. */
+   Return value: 0 for no errors, 1 in case of any non-fatal error.
+   Note: If the return value is 0, no data must be sent to stdout. */
 int
 test_version (void)
 {
@@ -248,11 +249,13 @@ test_version (void)
 void
 tests_start_mpfr (void)
 {
-  test_version ();
-
-  /* don't buffer, so output is not lost if a test causes a segv etc */
+  /* Don't buffer, so output is not lost if a test causes a segv, etc.
+     Warning! No operations must have already been done on stdout
+     (this is a requirement of ISO C, and this is important on AIX). */
   setbuf (stdout, NULL);
 
+  test_version ();
+
 #if defined HAVE_LOCALE_H && defined HAVE_SETLOCALE
   /* Added on 2005-07-09. This allows to test MPFR under various
      locales. New bugs will probably be found, in particular with
diff --git a/tests/tversion.c b/tests/tversion.c
index 817ffe5eb..6384cfa95 100644
--- a/tests/tversion.c
+++ b/tests/tversion.c
@@ -37,6 +37,8 @@ main (void)
   if (test_version ())
     exit (1);
 
+  tests_start_mpfr ();
+
   /*********************** MPFR version and patches ************************/
 
   printf ("[tversion] MPFR %s\n", MPFR_VERSION_STRING);
@@ -368,7 +370,6 @@ main (void)
 
   /************************** Runtime information **************************/
 
-  tests_start_mpfr ();
   if (locale != NULL)
     printf ("[tversion] Locale: %s\n", locale);
   /* The memory limit should not be changed for "make check".
@@ -378,9 +379,10 @@ main (void)
   if (tests_memory_limit != DEFAULT_MEMORY_LIMIT)
     printf ("[tversion] Warning! Memory limit changed to %" MPFR_EXP_FSPEC
             "u\n", (mpfr_ueexp_t) tests_memory_limit);
-  tests_end_mpfr ();
 
   /*************************************************************************/
 
+  tests_end_mpfr ();
+
   return err;
 }