Re: [Fwd: Bug#207475: libtool: wrongly hides important compiler output]

[Gary V. Vaughan]

Scott James Remnant wrote:
> Forwarded for discussion purposes ...

Thanks!

> I can see Sam's point, but I can also see the reason for suppressing one
> of two near-identical compilations.

How about a -no-suppress option? (see attachment)

Cheers,
        Gary.

> -----Forwarded Message-----
> From: Sam Hocevar <address@hidden>
> To: Debian Bug Tracking System <address@hidden>
> Subject: Bug#207475: libtool: wrongly hides important compiler output
> Date: Wed, 27 Aug 2003 12:40:32 +0200
>
> Package: libtool
> Version: 1.5-1 (not installed)
> Severity: normal
>
>    My generated libtool scripts contain the following lines (coming from
> /usr/share/libtool/ltmain.sh, line 725):
>
>       # Allow error messages only from the first compilation.
>       suppress_output=' >/dev/null 2>&1'
>
>    Which means that if the -fPIC compilation succeeded, it sends the
> output of the non-PIC compilation to /dev/null, wrongly assuming that
> if a file builds in PIC mode it will build in non-PIC mode (which is
> obviously wrong since one can put broken code between #ifndef PIC). It
> is then highly irritating to get a build error from the buildd that
> simply says "Error 1".
>
>    I suggest that this suppress_output line either be simply removed,
> because it is simply wrong to hide meaningful output from the user, or
> at least be made configurable.
>
> -- System Information:
> Debian Release: testing/unstable
> Architecture: i386
> Kernel: Linux c18 2.4.21-rc5 #2 Wed May 28 22:10:14 CEST 2003 i686
> Locale: LANG=C, LC_CTYPE=fr_FR


--
  ())_.  Gary V. Vaughan    gary@(lilith.warpmail.net|gnu.org)
  ( '/   Research Scientist http://www.oranda.demon.co.uk       ,_())____
  / )=   GNU Hacker         http://www.gnu.org/software/libtool  \'      `&
`(_~)_   Tech' Author       http://sources.redhat.com/autobook   =`---d__/

Index: ChangeLog
from  Gary V. Vaughan  <address@hidden>
        * ltmain.in: Don't suppress output of PIC mode compile if
        -no-suppress option is given.
        * doc/libtool.texi (Invoking libtool): Document it.
        * NEWS: Updated.

Index: NEWS
===================================================================
RCS file: /cvsroot/libtool/libtool/NEWS,v
retrieving revision 1.114
diff -u -p -u -r1.114 NEWS
--- NEWS 7 Oct 2003 11:12:16 -0000 1.114
+++ NEWS 7 Oct 2003 15:07:56 -0000
@@ -4,6 +4,8 @@ New in 1.5b: 2003-??-??; CVS version 1.5
 * libtoolize installs libtool.m4 (and ltdl.m4 if used) to AC_CONFIG_M4_DIR.
 * Mode inferrence removed, shorthand for choosing modes added.
 * Specifying -allow-undefined is now an error.
+* -no-suppress in compile mode shows compiler output for both PIC and non-PIC
+  object compilation.
 * Bug fixes.
 
 New in 1.5.1: 2003-??-??; CVS version 1.5.0a, Libtool team:
Index: ltmain.in
===================================================================
RCS file: /cvsroot/libtool/libtool/ltmain.in,v
retrieving revision 1.347
diff -u -p -u -r1.347 ltmain.in
--- ltmain.in 7 Oct 2003 14:51:05 -0000 1.347
+++ ltmain.in 7 Oct 2003 15:07:57 -0000
@@ -357,6 +357,7 @@ exec_cmd=
     # Get the compilation command and the source file.
     base_compile=
     srcfile="$nonopt"  #  always keep a non-empty value in "srcfile"
+    suppress_opt=yes
     suppress_output=
     arg_mode=normal
     libobj=
@@ -403,6 +404,11 @@ exec_cmd=
          continue
          ;;
 
+       -no-suppress)
+         suppress_opt=no
+         continue
+         ;;
+
        -Xcompiler)
          arg_mode=arg  #  the next one goes into the "base_compile" arg list
          continue      #  The current "srcfile" will either be retained or
@@ -710,7 +716,9 @@ pic_object='$objdir/$objname'
 EOF
 
       # Allow error messages only from the first compilation.
-      suppress_output=' >/dev/null 2>&1'
+      if test "$suppress_opt" = yes; then
+        suppress_output=' >/dev/null 2>&1'
+      fi
     else
       # No PIC object so indicate it doesn't exist in the libtool
       # object file.
Index: doc/libtool.texi
===================================================================
RCS file: /cvsroot/libtool/libtool/doc/libtool.texi,v
retrieving revision 1.137
diff -u -p -u -r1.137 libtool.texi
--- doc/libtool.texi 7 Oct 2003 14:51:06 -0000 1.137
+++ doc/libtool.texi 7 Oct 2003 15:07:59 -0000
@@ -1152,6 +1152,12 @@ linker flags with @samp{-Wl,@var{flag}} 
 You can also pass compile specific flags using @samp{-Wc,@var{flag}}
 and @samp{-Xcompiler @var{flag}}.
 
+If both PIC and non-PIC objects are being built, libtool will normally
+supress the compiler output for the PIC object compilation to save
+showing very similar, if not identical duplicate output for each
+object.  If the @samp{-no-suppress} option is given in compile mode,
+libtool will show the compiler output for both objects.
+
 If the @samp{-static} option is given, then a @samp{.o} file is built,
 even if libtool was configured with @samp{--disable-static}.