On 15/08/2024 21:27, Nick Bowler wrote:
On 2024-08-15 14:13, Ileana Dumitrescu wrote:Printing the differences on the second run seems like a better default, while keeping the option for -no-suppress for the complete log. Maybe adding an informational message about -no-suppress with the diff would help resolve some confusion?However, I also wonder if the suppression should be decided by a verbosity option/variable rather than a compile mode option.Yes, I was a bit surprised to discover that the existing --verbose flag which is documented in the manual to "Print out ... additional messages not ordinary seen by default" does not disable this suppression. If it did, then presumably automated build robots (at least when it comes to Automake-generated packages) could just build with make LIBTOOLFLAGS=--verbose and be done.
I have generated a patch to update the default suppression for PIC compilations from the second compilation being discarded to outputting a diff of the first and second compilations. If verbosity has been set, there should be output from both compilations. The -no-suppress option has also been removed, and the documentation updated. Does anyone have any issues or updates for this? -- Ileana Dumitrescu GPG Public Key: FA26 CA78 4BE1 8892 7F22 B99F 6570 EA01 146F 7354
From 4801e3ac05f46b6caa6258aa03c1aecb34437040 Mon Sep 17 00:00:00 2001
From: Ileana Dumitrescu <ileanadumitresc...@gmail.com>
Date: Mon, 19 Aug 2024 17:58:35 +0300
Subject: [PATCH] ltmain.in: Update suppression output for PIC compilations
libtool is assuming that the second PIC compilation will be identical to
the first, but this is not always true. Instead of discarding the output
of the second compilation, a diff of the first and second compilation
will be output by default. To see the output of both compilations, just
add '--verbose' to LIBTOOLFLAGS instead.
* build-aux/ltmain.in: Remove '-no-suppress' option from libtool's
compile mode options and rely on verbose libtool builds for removing
output suppression.
* doc/libtool.texi: Update documentation for option removal.
---
build-aux/ltmain.in | 23 ++++++++++++-----------
doc/libtool.texi | 29 +++++++++--------------------
2 files changed, 21 insertions(+), 31 deletions(-)
diff --git a/build-aux/ltmain.in b/build-aux/ltmain.in
index b69bf91f..6d741555 100644
--- a/build-aux/ltmain.in
+++ b/build-aux/ltmain.in
@@ -1373,8 +1373,8 @@ func_mode_compile ()
# 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=
+ save_compile_output=
arg_mode=normal
libobj=
later=
@@ -1415,11 +1415,6 @@ func_mode_compile ()
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
@@ -1618,6 +1613,12 @@ compiler."
func_append command " -o $lobj"
fi
+ # Save and print output from the first compilation, if not verbose.
+ if $opt_quiet; then
+ save_compile_output=' >first_compile.log 2>&1; cat first_compile.log'
+ fi
+
+ func_append command "$save_compile_output"
func_show_eval_locale "$command" \
'test -n "$output_obj" && $RM $removelist; exit $EXIT_FAILURE'
@@ -1647,9 +1648,10 @@ compiler."
'error=$?; $opt_dry_run || $RM $removelist; exit $error'
fi
- # Allow error messages only from the first compilation.
- if test yes = "$suppress_opt"; then
- suppress_output=' >/dev/null 2>&1'
+ # Show output diff for first and second compilations, if not verbose.
+ if $opt_quiet; then
+ suppress_output=' >second_compile.log 2>&1; diff first_compile.log second_compile.log;
+ $RM first_compile.log second_compile.log'
fi
fi
@@ -1665,7 +1667,7 @@ compiler."
func_append command " -o $obj"
fi
- # Suppress compiler output if we already did a PIC compilation.
+ # Suppress output from second compilation, if not verbose.
func_append command "$suppress_output"
func_show_eval_locale "$command" \
'$opt_dry_run || $RM $removelist; exit $EXIT_FAILURE'
@@ -1747,7 +1749,6 @@ Compile a source file into a libtool library object.
This mode accepts the following additional options:
-o OUTPUT-FILE set the output file name to OUTPUT-FILE
- -no-suppress do not suppress compiler output for multiple passes
-prefer-pic try to build PIC objects only
-prefer-non-pic try to build non-PIC objects only
-shared do not build a '.o' file suitable for static linking
diff --git a/doc/libtool.texi b/doc/libtool.texi
index 04ab34f1..a51a02ea 100644
--- a/doc/libtool.texi
+++ b/doc/libtool.texi
@@ -581,19 +581,15 @@ pic_object='@value{objdir}/foo.o'
non_pic_object='foo.o'
@end example
-@cindex @option{-no-suppress}, libtool compile mode option
-Notice the second run of GCC has its output discarded. This is
-done so the compiler warnings aren't annoyingly duplicated. If you
-need to see both sets of warnings (you might have conditional code
-inside @samp{#ifdef PIC} for example), you can turn off suppression by
-passing the @option{-no-suppress} option to libtool's compile mode:
-
-@example
-burger$ @kbd{libtool --mode=compile gcc -no-suppress -I. -g -O -c hello.c}
-gcc -I. -g -O -c hello.c -fPIC -DPIC -o @value{objdir}/hello.o
-gcc -I. -g -O -c hello.c -o hello.o
-burger$
-@end example
+Notice the second run of GCC has previously been discarded. The code
+has been revised to diff the output of the first and second compilation.
+This is done so the compiler warnings aren't annoyingly duplicated, while
+allowing for easier debugging. If you need to see both sets of warnings
+(you might have conditional code inside @samp{#ifdef PIC} for example),
+you can turn off suppression by using libtool's @option{--verbose} option
+like so: @samp{make LIBTOOLFLAGS=--verbose} (@pxref{Libtool Flags, ,
+@code{_LIBADD}@comma{} @code{_LDFLAGS}@comma{} and @code{_LIBTOOLFLAGS},
+automake, The Automake Manual}).
@node Linking libraries
@@ -1397,13 +1393,6 @@ This will also ensure that make won't try to use a temporarily corrupted
recompilation on platforms that support @option{-c} and @option{-o}
together, but it's the only way to make it safe for those that don't.
-@item -no-suppress
-If both PIC and non-PIC objects are being built, libtool will normally
-suppress the compiler output for the PIC object compilation to save
-showing very similar, if not identical duplicate output for each
-object. If the @option{-no-suppress} option is given in compile mode,
-libtool will show the compiler output for both objects.
-
@item -prefer-pic
Libtool will try to build only PIC objects.
--
2.45.2
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