[committed] libstdc++: Build libstdc++_libbacktrace.a as PIC [PR111936]

[committed] libstdc++: Build libstdc++_libbacktrace.a as PIC [PR111936]

[Jonathan Wakely]

Tested x86_64-linux. Pushed to trunk, will backport to 12 and 13.

-- >8 --

In order for std::stacktrace to be used in a shared library, the
libbacktrace symbols need to be built with -fPIC. Add the libtool
-prefer-pic flag to the commands in src/libbacktrace/Makefile so that
the archive contains PIC objects.

libstdc++-v3/ChangeLog:

	PR libstdc++/111936
	* src/libbacktrace/Makefile.am: Add -prefer-pic to libtool
	compile commands.
	* src/libbacktrace/Makefile.in: Regenerate.
---
 libstdc++-v3/src/libbacktrace/Makefile.am | 8 ++++++--
 libstdc++-v3/src/libbacktrace/Makefile.in | 7 ++++---
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/libstdc++-v3/src/libbacktrace/Makefile.am b/libstdc++-v3/src/libbacktrace/Makefile.am
index 492d3b6e952..e3cede97463 100644
--- a/libstdc++-v3/src/libbacktrace/Makefile.am
+++ b/libstdc++-v3/src/libbacktrace/Makefile.am
@@ -49,9 +49,13 @@ WARN_FLAGS = -W -Wall -Wwrite-strings -Wmissing-format-attribute \
 	     -Wcast-qual
 C_WARN_FLAGS = $(WARN_FLAGS) -Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition -Wno-unused-but-set-variable
 CXX_WARN_FLAGS = $(WARN_FLAGS) -Wno-unused-parameter
-AM_CFLAGS = $(C_WARN_FLAGS)
+AM_CFLAGS = \
+	$(glibcxx_lt_pic_flag) $(glibcxx_compiler_shared_flag) \
+	$(C_WARN_FLAGS)
 AM_CFLAGS += $(EXTRA_CFLAGS)
-AM_CXXFLAGS = $(CXX_WARN_FLAGS) -fno-rtti -fno-exceptions
+AM_CXXFLAGS = \
+	$(glibcxx_lt_pic_flag) $(glibcxx_compiler_shared_flag) \
+	$(CXX_WARN_FLAGS) -fno-rtti -fno-exceptions
 AM_CXXFLAGS += $(EXTRA_CXXFLAGS)
 
 obj_prefix = std_stacktrace
diff --git a/libstdc++-v3/src/libbacktrace/Makefile.in b/libstdc++-v3/src/libbacktrace/Makefile.in
index a85c6d118ea..ce80d246766 100644
--- a/libstdc++-v3/src/libbacktrace/Makefile.in
+++ b/libstdc++-v3/src/libbacktrace/Makefile.in
@@ -472,9 +472,10 @@ libstdc___libbacktrace_la_CPPFLAGS = \
 
 C_WARN_FLAGS = $(WARN_FLAGS) -Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition -Wno-unused-but-set-variable
 CXX_WARN_FLAGS = $(WARN_FLAGS) -Wno-unused-parameter
-AM_CFLAGS = $(C_WARN_FLAGS) $(EXTRA_CFLAGS)
-AM_CXXFLAGS = $(CXX_WARN_FLAGS) -fno-rtti -fno-exceptions \
-	$(EXTRA_CXXFLAGS)
+AM_CFLAGS = $(glibcxx_lt_pic_flag) $(glibcxx_compiler_shared_flag) \
+	$(C_WARN_FLAGS) $(EXTRA_CFLAGS)
+AM_CXXFLAGS = $(glibcxx_lt_pic_flag) $(glibcxx_compiler_shared_flag) \
+	$(CXX_WARN_FLAGS) -fno-rtti -fno-exceptions $(EXTRA_CXXFLAGS)
 obj_prefix = std_stacktrace
 
 # Each FILE.c in SOURCES will be compiled to SHORTNAME-FILE.o
-- 
2.41.0