Make improvements

- You can now run `make -j8 toolchain` on Windows
- You can now run `make -j` on MacOS ARM64 and BSD OSes
- You can now use our Emacs dev environment on MacOS/Windows
- Fix bug where the x16 register was being corrupted by --ftrace
- The programs under build/bootstrap/ are updated as fat binaries
- The Makefile now explains how to download cosmocc-0.0.12 toolchain
- The build scripts under bin/ now support "cosmo" branded toolchains
- stat() now goes faster on Windows (shaves 100ms off `make` latency)
- Code cleanup and added review on the Windows signal checking code
- posix_spawnattr_setrlimit() now works around MacOS ARM64 bugs
- Landlock Make now favors posix_spawn() on non-Linux/OpenBSD
- posix_spawn() now has better --strace logging on Windows
- fstatat() can now avoid EACCES in more cases on Windows
- fchmod() can now change the readonly bit on Windows

build/config.mk

@@ -16,6 +16,12 @@ CONFIG_CCFLAGS += -O2 $(BACKTRACES)
 CONFIG_CPPFLAGS += -DSYSDEBUG
 TARGET_ARCH ?= -msse3
 endif
+ifeq ($(MODE), x86_64)
+ENABLE_FTRACE = 1
+CONFIG_OFLAGS ?= -g
+CONFIG_CCFLAGS += -O2 $(BACKTRACES)
+CONFIG_CPPFLAGS += -DSYSDEBUG
+endif
 ifeq ($(MODE), aarch64)
 ENABLE_FTRACE = 1
 CONFIG_OFLAGS ?= -g
@@ -39,8 +45,8 @@ CONFIG_CPPFLAGS += -DSYSDEBUG
 endif
 ifeq ($(MODE), aarch64-zero)
 CONFIG_OFLAGS ?= -g
-OVERRIDE_CFLAGS += -O0
-OVERRIDE_CXXFLAGS += -O0
+OVERRIDE_CFLAGS += -O0 -fdce
+OVERRIDE_CXXFLAGS += -O0 -fdce
 CONFIG_CPPFLAGS += -DSYSDEBUG
 endif
 
@@ -166,7 +172,7 @@ ifeq ($(MODE), aarch64-dbg)
 ENABLE_FTRACE = 1
 CONFIG_OFLAGS ?= -g
 CONFIG_CPPFLAGS += -DMODE_DBG -D__SANITIZE_UNDEFINED__
-CONFIG_CCFLAGS += $(BACKTRACES) -DSYSDEBUG -O0 -fno-inline
+CONFIG_CCFLAGS += $(BACKTRACES) -DSYSDEBUG -O0 -fno-inline -fdce
 CONFIG_COPTS += -fsanitize=undefined
 QUOTA ?= -C64 -L300
 endif

build/definitions.mk

@@ -94,17 +94,24 @@ endif
 
 ifeq ($(PREFIX),)
 ifeq ($(USE_SYSTEM_TOOLCHAIN),)
-ifneq ("$(wildcard o/third_party/gcc/bin/x86_64-pc-linux-gnu-*)","")
-PREFIX = o/third_party/gcc/bin/x86_64-pc-linux-gnu-
+ifeq ($(ARCH),x86_64)
+ifneq ("$(wildcard o/third_party/gcc/bin/x86_64-linux-cosmo-*)","")
+PREFIX = o/third_party/gcc/bin/x86_64-linux-cosmo-
 else
 IGNORE := $(shell build/bootstrap/unbundle.com)
 PREFIX = o/third_party/gcc/bin/x86_64-linux-musl-
 endif
-ifeq ($(ARCH), aarch64)
+endif # ($(ARCH),x86_64))
+ifeq ($(ARCH),aarch64)
+ifneq ("$(wildcard o/third_party/gcc/bin/aarch64-linux-cosmo-*)","")
+PREFIX = o/third_party/gcc/bin/aarch64-linux-cosmo-
+else
+IGNORE := $(shell build/bootstrap/unbundle.com)
 PREFIX = o/third_party/gcc/bin/aarch64-linux-musl-
 endif
-endif
-endif
+endif # ($(ARCH),aarch64)
+endif # ($(USE_SYSTEM_TOOLCHAIN),)
+endif # ($(PREFIX),)
 
 AS = $(PREFIX)as
 CC = $(PREFIX)gcc
@@ -116,7 +123,7 @@ GCC = $(PREFIX)gcc
 STRIP = $(PREFIX)strip
 OBJCOPY = $(PREFIX)objcopy
 OBJDUMP = $(PREFIX)objdump
-ifneq ($(wildcard $(PWD)/$(PREFIX)addr2line), )
+ifneq ($(wildcard $(PWD)/$(PREFIX)addr2line),)
 ADDR2LINE = $(PWD)/$(PREFIX)addr2line
 else
 ADDR2LINE = $(PREFIX)addr2line

build/objdump

@@ -1,6 +1,29 @@
 #!/bin/sh
-if printf '%s\n' "$*" | grep aarch64 >/dev/null 2>&1; then
-  exec o/third_party/gcc/bin/aarch64-linux-musl-objdump "$@"
-else
-  exec o/third_party/gcc/bin/x86_64-linux-musl-objdump "$@"
+COSMO=${COSMO:-/opt/cosmo}
+
+if [ -n "$OBJDUMP" ]; then
+  exec "$OBJDUMP" "$@"
+fi
+
+find_objdump() {
+  if [ -x o/third_party/gcc/bin/$1-linux-cosmo-objdump ]; then
+    OBJDUMP=o/third_party/gcc/bin/$1-linux-cosmo-objdump
+  elif [ -x o/third_party/gcc/bin/$1-linux-musl-objdump ]; then
+    OBJDUMP=o/third_party/gcc/bin/$1-linux-musl-objdump
+  elif [ -x "$COSMO/o/third_party/gcc/bin/$1-linux-cosmo-objdump" ]; then
+    OBJDUMP="$COSMO/o/third_party/gcc/bin/$1-linux-cosmo-objdump"
+  elif [ -x "$COSMO/o/third_party/gcc/bin/$1-linux-musl-objdump" ]; then
+    OBJDUMP="$COSMO/o/third_party/gcc/bin/$1-linux-musl-objdump"
+  else
+    echo "error: toolchain not found (try running 'cosmocc --update' or 'make' in the cosmo monorepo)" >&2
+    exit 1
+  fi
+}
+
+if printf '%s\n' "$*" | grep aarch64 >/dev/null 2>&1; then
+  find_objdump aarch64
+  exec "$OBJDUMP" "$@"
+else
+  find_objdump x86_64
+  exec "$OBJDUMP" "$@"
 fi