Merge branch 'fix-libm' into 'master'

Strip conflicting symbols from compiler builtins

See merge request redox-os/relibc!734

Makefile

@@ -201,6 +201,7 @@ $(BUILD)/debug/libc.a: $(BUILD)/debug/librelibc.a $(BUILD)/openlibm/libopenlibm.
 $(BUILD)/debug/librelibc.a: $(SRC)
 	$(CARGO) rustc $(CARGOFLAGS) -- --emit link=$@ -g -C debug-assertions=no $(RUSTCFLAGS)
 	./renamesyms.sh "$@" "$(BUILD)/debug/deps/"
+	./stripcore.sh "$@"
 	touch $@
 
 $(BUILD)/debug/crt0.o: $(SRC)
@@ -238,6 +239,7 @@ $(BUILD)/release/librelibc.a: $(SRC)
 	# TODO: Better to only allow a certain whitelisted set of symbols? Perhaps
 	# use some cbindgen hook, specify them manually, or grep for #[unsafe(no_mangle)].
 	./renamesyms.sh "$@" "$(BUILD)/release/deps/"
+	./stripcore.sh "$@"
 	touch $@
 
 $(BUILD)/release/crt0.o: $(SRC)

stripcore.sh

@@ -0,0 +1,17 @@
+#!/usr/bin/env bash
+
+# This script exists as a workaround for https://github.com/rust-lang/rust/issues/142119
+
+set -e
+
+target=$1
+
+if [ -z "$target" ]; then
+    echo "Usage:\n\t./stripcore.sh TARGET"
+    exit 1
+fi
+
+for sym in cbrtf ceilf copysignf fabsf fdimf floorf fmaxf fminf fmofd rintf roundf sqrtf truncf \
+            cbrt ceil copysign fabs fdim floor fmax fmin fmod rint round sqrt trunc; do \
+    objcopy --globalize-symbol=$sym --strip-symbol=$sym "$target"; \
+done