clangrt-glibc

From 5978020202a4b50eedb64fb9bff1018644ef1a81 Mon Sep 17 00:00:00 2001
From: Taylor Berlioz <nagakamira@gmail.com>
Date: Thu, 30 Jun 2022 12:12:14 -0700
Subject: [PATCH 2/2] do not depend on gcc runtime

Signed-off-by: Taylor Berlioz <nagakamira@gmail.com>
---
 Makeconfig     | 21 +++++++++++++++------
 Makerules      |  2 +-
 config.make.in |  1 +
 configure      | 23 +++++++++++++++++++++++
 configure.ac   |  8 ++++++++
 elf/Makefile   |  4 ++--
 6 files changed, 50 insertions(+), 9 deletions(-)

diff --git a/Makeconfig b/Makeconfig
index c0cf1e28..3d8e9f53 100644
--- a/Makeconfig
+++ b/Makeconfig
@@ -669,22 +669,23 @@ else
 endif
 libgcc_eh := -Wl,--as-needed -lgcc_s $(libunwind) -Wl,--no-as-needed
 gnulib-arch =
-gnulib = -lgcc $(gnulib-arch)
-gnulib-tests := -lgcc $(libgcc_eh)
+gnulib = `$(CC) $(sysdep-LDFLAGS) --print-libgcc-file-name` $(gnulib-arch)
+gnulib-tests := `$(CC) $(sysdep-LDFLAGS) --print-libgcc-file-name` $(libgcc_eh)
 static-gnulib-arch =
 # By default, elf/static-stubs.o, instead of -lgcc_eh, is used to
 # statically link programs.  When --disable-shared is used, we use
 # -lgcc_eh since elf/static-stubs.o isn't sufficient.
 ifeq (yes,$(build-shared))
-static-gnulib = -lgcc $(static-gnulib-arch)
+static-gnulib = `$(CC) $(sysdep-LDFLAGS) --print-libgcc-file-name` $(static-gnulib-arch)
 else
-static-gnulib = -lgcc -lgcc_eh $(static-gnulib-arch)
+static-gnulib = `$(CC) $(sysdep-LDFLAGS) --print-libgcc-file-name` $(static-gnulib-arch)
 endif
-static-gnulib-tests := -lgcc -lgcc_eh $(libunwind)
-libc.so-gnulib := -lgcc
+static-gnulib-tests := `$(CC) $(sysdep-LDFLAGS) --print-libgcc-file-name` $(libunwind)
+libc.so-gnulib := `$(CC) $(sysdep-LDFLAGS) --print-libgcc-file-name`
 endif
 +preinit = $(addprefix $(csu-objpfx),crti.o)
 +postinit = $(addprefix $(csu-objpfx),crtn.o)
+ifeq (no,$(is-clang))
 +prector = `$(CC) $(sysdep-LDFLAGS) --print-file-name=crtbegin.o`
 +postctor = `$(CC) $(sysdep-LDFLAGS) --print-file-name=crtend.o`
 # Variants of the two previous definitions for linking PIE programs.
@@ -699,6 +700,14 @@ else
 +prectorT = `$(CC) $(sysdep-LDFLAGS) --print-file-name=crtbeginT.o`
 +postctorT = `$(CC) $(sysdep-LDFLAGS) --print-file-name=crtend.o`
 endif
+else
++prector = `$(CC) $(sysdep-LDFLAGS) --print-file-name=clang_rt.crtbegin-$(config-machine).o`
++postctor = `$(CC) $(sysdep-LDFLAGS) --print-file-name=clang_rt.crtend-$(config-machine).o`
++prectorS = `$(CC) $(sysdep-LDFLAGS) --print-file-name=clang_rt.crtbegin-$(config-machine).o`
++postctorS = `$(CC) $(sysdep-LDFLAGS) --print-file-name=clang_rt.crtend-$(config-machine).o`
++prectorT = `$(CC) $(sysdep-LDFLAGS) --print-file-name=clang_rt.crtbegin-$(config-machine).o`
++postctorT = `$(CC) $(sysdep-LDFLAGS) --print-file-name=clang_rt.crtend-$(config-machine).o`
+endif
 csu-objpfx = $(common-objpfx)csu/
 elf-objpfx = $(common-objpfx)elf/
 
diff --git a/Makerules b/Makerules
index 8c5588bb..e3260bc4 100644
--- a/Makerules
+++ b/Makerules
@@ -647,7 +647,7 @@ LDFLAGS-c.so += -e __libc_main
 # between libc.so and ld.so, which can make it impossible to upgrade.
 $(common-objpfx)libc_pic.os: $(common-objpfx)libc_pic.a
 	$(LINK.o) -nostdlib -nostartfiles -r -o $@ \
-	$(LDFLAGS-c_pic.os) -Wl,-d $(whole-archive) $^ -o $@
+	$(LDFLAGS-c_pic.os) $(whole-archive) $^ -o $@
 
 ifeq (,$(strip $(shlib-lds-flags)))
 # Generate a list of -R options to excise .gnu.glibc-stub.* sections.
diff --git a/config.make.in b/config.make.in
index ecde84a7..576cdea8 100644
--- a/config.make.in
+++ b/config.make.in
@@ -72,6 +72,7 @@ have-cc-with-libunwind = @libc_cv_cc_with_libunwind@
 bind-now = @bindnow@
 have-hash-style = @libc_cv_hashstyle@
 use-default-link = @use_default_link@
+is-clang = @libc_cv_compiler_is_clang@
 have-cxx-thread_local = @libc_cv_cxx_thread_local@
 have-loop-to-function = @libc_cv_cc_loop_to_function@
 have-textrel_ifunc = @libc_cv_textrel_ifunc@
diff --git a/configure b/configure
index 31c37700..00dbeb9c 100755
--- a/configure
+++ b/configure
@@ -641,6 +641,7 @@ PYTHON
 PYTHON_PROG
 AUTOCONF
 NM
+libc_cv_compiler_is_clang
 BISON
 AWK
 SED
@@ -5226,6 +5227,28 @@ if test $libc_cv_compiler_ok != yes; then :
   critic_missing="$critic_missing compiler"
 fi
 
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+#ifndef __clang__
+# error not clang
+#endif
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_cpp "$LINENO"; then :
+  libc_cv_compiler_is_clang=yes
+else
+  libc_cv_compiler_is_clang=no
+fi
+rm -f conftest.err conftest.i conftest.$ac_ext
+
+
 if test -n "$ac_tool_prefix"; then
   # Extract the first word of "${ac_tool_prefix}nm", so it can be a program name with args.
 set dummy ${ac_tool_prefix}nm; ac_word=$2
diff --git a/configure.ac b/configure.ac
index 33e98a4f..a5835162 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1063,6 +1063,14 @@ AC_PREPROC_IFELSE([AC_LANG_PROGRAM([[]], [[
 AS_IF([test $libc_cv_compiler_ok != yes],
       [critic_missing="$critic_missing compiler"])
 
+AC_PREPROC_IFELSE([AC_LANG_PROGRAM([[]], [[
+#ifndef __clang__
+# error not clang
+#endif]])],
+	       [libc_cv_compiler_is_clang=yes],
+	       [libc_cv_compiler_is_clang=no])
+AC_SUBST(libc_cv_compiler_is_clang)
+
 AC_CHECK_TOOL(NM, nm, false)
 
 if test "x$maintainer" = "xyes"; then
diff --git a/elf/Makefile b/elf/Makefile
index 0e240811..f2bb03f0 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -1207,7 +1207,7 @@ $(objpfx)librtld.map: $(objpfx)dl-allobjs.os $(common-objpfx)libc_pic.a
 		echo ".globl $$symbol"; \
 		echo "$$symbol:"; \
 	done | $(CC) -o $@T.o $(ASFLAGS) -c -x assembler -
-	$(reloc-link) -o $@.o $@T.o '-Wl,-(' $^ -lgcc '-Wl,-)' -Wl,-Map,$@T
+	$(reloc-link) -o $@.o $@T.o "-Wl,-(" $^ `$(reloc-link) --print-libgcc-file-name` "-Wl,-)" -Wl,-Map,$@T
 	rm -f %@T.o $@.o
 	mv -f $@T $@
 
@@ -1237,7 +1237,7 @@ $(objpfx)rtld-libc.a: $(objpfx)librtld.mk FORCE
 	$(MAKE) -f $< -f rtld-Rules
 
 $(objpfx)librtld.os: $(objpfx)dl-allobjs.os $(objpfx)rtld-libc.a
-	$(LINK.o) -nostdlib -nostartfiles -r -o $@ '-Wl,-(' $^ -lgcc '-Wl,-)' \
+	$(LINK.o) -nostdlib -nostartfiles -r -o $@ "-Wl,-(" $^ `$(reloc-link) --print-libgcc-file-name` "-Wl,-)" \
 		  -Wl,-Map,$@.map
 
 generated += librtld.map librtld.mk rtld-libc.a librtld.os.map
-- 
2.34.1