This is a resubmission of a patch originally posted here
http://gcc.gnu.org/ml/gcc-patches/2013-05/msg01488.html
It was only intended as a stop-gap measure to avoid a couple of
libstdc++ testsuite failures on Solaris 9 and 10 where nanosleep only
lives in librt, which is now required since --enable-libstdcxx-time=auto
became the default. On Solaris 11, librt has been folded into libc and
librt only remains as a filter on libc, so linking with unnecessary,
though not really harmful.
As I mentioned in the thread above, I don't really like this solution
for two reasons:
* It splits the knowledge about libstdc++'s need for librt between
libstdc++ and gcc configury.
* It unconditionally links librt into every C++ program instead of doing
this only when necessary.
Therefore I'd suggested an alternative approach, which unfortunately is
far more intrusive:
Follow libgfortran's lead and introduce libstdc++.spec. Here,
target-specific linker switches can be determined by the libstdc++
configury, with configuration well localized, and one can easily handle
stuff like linking -lrt with -z ignore/-z record
resp. --as-needed/--no-as-needed. This provides us with a general
extension mechanism for linking C++ programs, which can be used for
other purposes if the need arises.
The downside of course is that the testsuite needs to be taught about
that file by passing the appropriate -B switches to find it at compile
time.
One way or another, this needs to be adressed to fix the libstdc++
testsuite failures on Solaris.
Thoughts?
Rainer
2013-05-24 Rainer Orth <r...@cebitec.uni-bielefeld.de>
gcc/cp:
* g++spec.c (TIMELIB): Define.
(WITHLIBC, SKIPOPT): Adjust values.
(lang_specific_driver): Add TIME_LIBRARY if not passed explicitly.
gcc:
* config/sol2.h (TIME_LIBRARY): Define.
# HG changeset patch
# Parent d6881ec042d3a6328b763cbf0f38e61bdbb64d79
Add -lrt on Solaris
diff --git a/gcc/config/sol2.h b/gcc/config/sol2.h
--- a/gcc/config/sol2.h
+++ b/gcc/config/sol2.h
@@ -194,6 +194,9 @@ along with GCC; see the file COPYING3.
#endif /* HAVE_LD_EH_FRAME && TARGET_DL_ITERATE_PHDR */
#endif
+/* C++11 programs need -lrt for nanosleep. */
+#define TIME_LIBRARY "rt"
+
#ifndef USE_GLD
/* The default MFLIB_SPEC is GNU ld specific. */
#define MFLIB_SPEC ""
diff --git a/gcc/cp/g++spec.c b/gcc/cp/g++spec.c
--- a/gcc/cp/g++spec.c
+++ b/gcc/cp/g++spec.c
@@ -28,10 +28,12 @@ along with GCC; see the file COPYING3.
#define LANGSPEC (1<<1)
/* This bit is set if they did `-lm' or `-lmath'. */
#define MATHLIB (1<<2)
+/* This bit is set if they did `-lrt' or equivalent. */
+#define TIMELIB (1<<3)
/* This bit is set if they did `-lc'. */
-#define WITHLIBC (1<<3)
+#define WITHLIBC (1<<4)
/* Skip this option. */
-#define SKIPOPT (1<<4)
+#define SKIPOPT (1<<5)
#ifndef MATH_LIBRARY
#define MATH_LIBRARY "m"
@@ -40,6 +42,10 @@ along with GCC; see the file COPYING3.
#define MATH_LIBRARY_PROFILE MATH_LIBRARY
#endif
+#ifndef TIME_LIBRARY
+#define TIME_LIBRARY ""
+#endif
+
#ifndef LIBSTDCXX
#define LIBSTDCXX "stdc++"
#endif
@@ -83,16 +89,22 @@ lang_specific_driver (struct cl_decoded_
/* "-lm" or "-lmath" if it appears on the command line. */
const struct cl_decoded_option *saw_math = NULL;
+ /* "-lrt" or eqivalent if it appears on the command line. */
+ const struct cl_decoded_option *saw_time = NULL;
+
/* "-lc" if it appears on the command line. */
const struct cl_decoded_option *saw_libc = NULL;
/* An array used to flag each argument that needs a bit set for
- LANGSPEC, MATHLIB, or WITHLIBC. */
+ LANGSPEC, MATHLIB, TIMELIB, or WITHLIBC. */
int *args;
/* By default, we throw on the math library if we have one. */
int need_math = (MATH_LIBRARY[0] != '\0');
+ /* By default, we throw on the time library if we have one. */
+ int need_time = (TIME_LIBRARY[0] != '\0');
+
/* True if we saw -static. */
int static_link = 0;
@@ -136,6 +148,11 @@ lang_specific_driver (struct cl_decoded_
args[i] |= MATHLIB;
need_math = 0;
}
+ else if (strcmp (arg, TIME_LIBRARY) == 0)
+ {
+ args[i] |= TIMELIB;
+ need_time = 0;
+ }
else if (strcmp (arg, "c") == 0)
args[i] |= WITHLIBC;
else
@@ -268,6 +285,12 @@ lang_specific_driver (struct cl_decoded_
saw_math = &decoded_options[i];
}
+ if (!saw_time && (args[i] & TIMELIB) && library > 0)
+ {
+ --j;
+ saw_time = &decoded_options[i];
+ }
+
if (!saw_libc && (args[i] & WITHLIBC) && library > 0)
{
--j;
@@ -352,6 +375,15 @@ lang_specific_driver (struct cl_decoded_
added_libraries++;
j++;
}
+ if (saw_time)
+ new_decoded_options[j++] = *saw_time;
+ else if (library > 0 && need_time)
+ {
+ generate_option (OPT_l, TIME_LIBRARY, 1, CL_DRIVER,
+ &new_decoded_options[j]);
+ added_libraries++;
+ j++;
+ }
if (saw_libc)
new_decoded_options[j++] = *saw_libc;
if (shared_libgcc && !static_link)
--
-----------------------------------------------------------------------------
Rainer Orth, Center for Biotechnology, Bielefeld University
