add comment documenting hard-coded opcode for reading mips thread pointer

[musl] / configure

diff --git a/configure b/configure
index 99cb04d..d944a47 100755 (executable)
--- a/configure
+++ b/configure
@@ -134,6 +134,7 @@ shared=auto
 static=yes
 wrapper=auto
 gcc_wrapper=no
+clang_wrapper=no
 
 for arg ; do
 case "$arg" in
@@ -158,8 +159,9 @@ case "$arg" in
 --enable-visibility|--enable-visibility=yes) visibility=yes ;;
 --disable-visibility|--enable-visibility=no) visibility=no ;;
 --enable-wrapper|--enable-wrapper=yes) wrapper=detect ;;
---enable-wrapper=all) wrapper=yes ; gcc_wrapper=yes ;;
+--enable-wrapper=all) wrapper=yes ; gcc_wrapper=yes ; clang_wrapper=yes ;;
 --enable-wrapper=gcc) wrapper=yes ; gcc_wrapper=yes ;;
+--enable-wrapper=clang) wrapper=yes ; clang_wrapper=yes ;;
 --disable-wrapper|--enable-wrapper=no) wrapper=no ;;
 --enable-gcc-wrapper|--enable-gcc-wrapper=yes) wrapper=yes ; gcc_wrapper=yes ;;
 --disable-gcc-wrapper|--enable-gcc-wrapper=no) wrapper=no ;;
@@ -230,6 +232,8 @@ cc_ver="$(LC_ALL=C $CC -v 2>&1)"
 cc_family=unknown
 if fnmatch '*gcc\ version*' "$cc_ver" ; then
 cc_family=gcc
+elif fnmatch '*clang\ version*' "$cc_ver" ; then
+cc_family=clang
 fi
 echo "$cc_family"
 
@@ -247,6 +251,9 @@ echo "none"
 elif test "$cc_family" = gcc ; then
 gcc_wrapper=yes
 echo "gcc"
+elif test "$cc_family" = clang ; then
+clang_wrapper=yes
+echo "clang"
 else
 echo "none"
 if test "$wrapper" = detect ; then
@@ -259,6 +266,9 @@ if test "$gcc_wrapper" = yes ; then
 tools="$tools tools/musl-gcc"
 tool_libs="$tool_libs lib/musl-gcc.specs"
 fi
+if test "$clang_wrapper" = yes ; then
+tools="$tools tools/musl-clang tools/ld.musl-clang"
+fi
 
 #
 # Find the target architecture
@@ -340,6 +350,22 @@ tryflag CFLAGS_MEMOPS -fno-tree-loop-distribute-patterns
 #
 test "$debug" = yes && CFLAGS_AUTO=-g
 
+#
+# Preprocess asm files to add extra debugging information if debug is
+# enabled, our assembler supports the needed directives, and the
+# preprocessing script has been written for our architecture.
+#
+printf "checking whether we should preprocess assembly to add debugging information... "
+if fnmatch '-g*|*\ -g*' "$CFLAGS_AUTO $CFLAGS" &&
+   test -f "tools/add-cfi.$ARCH.awk" &&
+   printf ".file 1 \"srcfile.s\"\n.line 1\n.cfi_startproc\n.cfi_endproc" | $CC -g -x assembler -c -o /dev/null 2>/dev/null -
+then
+  ADD_CFI=yes
+else
+  ADD_CFI=no
+fi
+printf "%s\n" "$ADD_CFI"
+
 #
 # Possibly add a -O option to CFLAGS and select modules to optimize with
 # -O3 based on the status of --enable-optimize and provided CFLAGS.
@@ -450,10 +476,18 @@ if test "x$visibility" = xauto ; then
 # - the -include option
 # - the attributes/pragmas used in vis.h
 # - linking code that takes the address of protected symbols
+# - gcc 3.x bug that wrongly claims declarations mismatch
 printf "checking whether global visibility preinclude works... "
-echo 'int (*fp)(void);' > "$tmpc"
-echo 'int foo(void) { }' >> "$tmpc"
-echo 'int bar(void) { fp = foo; return foo(); }' >> "$tmpc"
+cat > "$tmpc" <<EOF
+__attribute__((__visibility__("default")))
+extern struct a *const x;
+typedef struct a b;
+extern b *const x;
+b *const x;
+int (*fp)(void);
+int foo(void) { }
+int bar(void) { fp = foo; return foo(); }
+EOF
 if $CC $CFLAGS_C99FSE $CPPFLAGS $CFLAGS \
   -DSHARED -fPIC -I./src/internal -include vis.h \
   -nostdlib -shared -Wl,-Bsymbolic-functions \
@@ -473,6 +507,12 @@ fi
 # Some patched GCC builds have these defaults messed up...
 tryldflag LDFLAGS_AUTO -Wl,--hash-style=both
 
+# Prevent linking if there are undefined symbols; if any exist,
+# libc.so will crash at runtime during relocation processing.
+# The common way this can happen is failure to link the compiler
+# runtime library; implementation error is also a possibility.
+tryldflag LDFLAGS_AUTO -Wl,--no-undefined
+
 test "$shared" = "no" || {
 # Disable dynamic linking if ld is broken and can't do -Bsymbolic-functions
 LDFLAGS_DUMMY=
@@ -532,6 +572,9 @@ fi
 else
 SUBARCH=${SUBARCH}-nofpu
 fi
+if trycppif __SH_FDPIC__ "$t" ; then
+SUBARCH=${SUBARCH}-fdpic
+fi
 fi
 
 test "$SUBARCH" \
@@ -596,10 +639,12 @@ LIBCC = $LIBCC
 OPTIMIZE_GLOBS = $OPTIMIZE_GLOBS
 ALL_TOOLS = $tools
 TOOL_LIBS = $tool_libs
+ADD_CFI = $ADD_CFI
 EOF
 test "x$static" = xno && echo "STATIC_LIBS ="
 test "x$shared" = xno && echo "SHARED_LIBS ="
 test "x$cc_family" = xgcc && echo 'WRAPCC_GCC = $(CC)'
+test "x$cc_family" = xclang && echo 'WRAPCC_CLANG = $(CC)'
 exec 1>&3 3>&-
 
 printf "done\n"