Initial FlexOS release.

Signed-off-by: Hugo Lefeuvre <[email protected]>
Signed-off-by: Sebastian Rauch <[email protected]>
Signed-off-by: Stefan Teodorescu <[email protected]>
Signed-off-by: Vlad-Andrei Badoiu <[email protected]>

Config.uk

@@ -168,6 +168,15 @@ config CROSS_COMPILE
 		need to set this unless you want the configured build
 		directory to select the cross-compiler automatically.
 
+
+config LLVM_TARGET_ARCH
+	string "Custom cross-compiler LLVM target (optional)"
+	help
+		Same as running 'make LLVM_TARGET_ARCH=target' but stored for
+		default make runs in this build directory.  You don't
+		need to set this unless you want the configured build
+		directory to select the cross-compiler automatically.
+		This is used for LLVM based compilers such as clang or rustc.
 #config PARALLEL_JOBS
 #	int "Number of jobs to run simultaneously (0 for auto)"
 #	default "0"

Makefile

@@ -317,6 +317,8 @@ CXXINCLUDES :=
 CXXINCLUDES-y :=
 GOCFLAGS :=
 GOCFLAGS-y :=
+RUSTCFLAGS :=
+RUSTCFLAGS-y :=
 GOCINCLUDES :=
 GOCINCLUDES-y :=
 DBGFLAGS :=
@@ -513,6 +515,7 @@ ifeq ($(sub_make_exec), 1)
 ifeq ($(UK_HAVE_DOT_CONFIG),y)
 # Hide troublesome environment variables from sub processes
 unexport CONFIG_CROSS_COMPILE
+unexport CONFIG_LLVM_TARGET_ARCH
 unexport CONFIG_COMPILER
 #unexport CC
 #unexport LD
@@ -546,6 +549,10 @@ ifneq ("$(origin CROSS_COMPILE)","undefined")
 CONFIG_CROSS_COMPILE := $(CROSS_COMPILE:"%"=%)
 endif
 
+ifneq ("$(origin LLVM_TARGET_ARCH)","undefined")
+CONFIG_LLVM_TARGET_ARCH := $(LLVM_TARGET_ARCH:"%"=%)
+endif
+
 ifneq ("$(origin COMPILER)","undefined")
 	CONFIG_COMPILER := $(COMPILER:"%"=%)
 else
@@ -561,6 +568,13 @@ CC		:= $(CONFIG_CROSS_COMPILE)$(CONFIG_COMPILER)
 CPP		:= $(CC)
 CXX		:= $(CPP)
 GOC		:= $(CONFIG_CROSS_COMPILE)gccgo-7
+# We use rustc because the gcc frontend is experimental and missing features such
+# as borrowing checking
+ifneq ("$(origin LLVM_TARGET_ARCH)","undefined")
+RUSTC		:= rustc --target=$(CONFIG_LLVM_TARGET_ARCH)
+else
+RUSTC		:= rustc
+endif
 AS		:= $(CC)
 AR		:= $(CONFIG_CROSS_COMPILE)gcc-ar
 NM		:= $(CONFIG_CROSS_COMPILE)gcc-nm

Makefile.uk

@@ -7,6 +7,12 @@
 COMPFLAGS    += -nostdlib
 COMPFLAGS    += -U __linux__ -U __FreeBSD__ -U __sun__
 COMPFLAGS    += -fno-omit-frame-pointer
+# treat "attribute directive ignored" as error for FlexOS, this is indicative
+# that a rewriting pass failed
+COMPFLAGS    += -Werror=attributes
+# because of Coccinelle, a good number of __unused attributes have to be removed
+# as a consequence we experience many spurious warnings. Disable them for now
+COMPFLAGS    += -Wno-unused-variable
 COMPFLAGS-$(call have_gcc)	+= -fno-tree-sra -fno-split-stack -nostdinc
 
 ifneq ($(HAVE_STACKPROTECTOR),y)
@@ -21,6 +27,30 @@ CINCLUDES    += -I$(CONFIG_UK_BASE)/include
 CXXINCLUDES  += -I$(CONFIG_UK_BASE)/include
 GOCINCLUDES  += -I$(CONFIG_UK_BASE)/include
 
+RUSTCFLAGS-y	+= --emit=obj --crate-type=rlib --edition=2018 \
+		-Cpanic=abort -Cembed-bitcode=n \
+		-Zbinary_dep_depinfo=y -Zsymbol-mangling-version=v0 \
+		-Cforce-unwind-tables=n -Ccodegen-units=1 \
+		-Dunsafe_op_in_unsafe_fn -Drust_2018_idioms
+
+
+RUSTCFLAGS-$(CONFIG_OPTIMIZE_NONE)         += -Copt-level="0"
+RUSTCFLAGS-$(CONFIG_OPTIMIZE_SIZE)         += -Copt-level="s"
+RUSTCFLAGS-$(CONFIG_OPTIMIZE_PERF)         += -Copt-level="2"
+
+RUSTCFLAGS-$(CONFIG_DEBUG_SYMBOLS_LVL0)     += -Cdebuginfo=0
+RUSTCFLAGS-$(CONFIG_DEBUG_SYMBOLS_LVL1)     += -Cdebuginfo=1
+RUSTCFLAGS-$(CONFIG_DEBUG_SYMBOLS_LVL2)     += -Cdebuginfo=2
+# NOTE: There is not level 3 in rustc
+RUSTCFLAGS-$(CONFIG_DEBUG_SYMBOLS_LVL3)     += -Cdebuginfo=2
+
+# NOTE: rustc supports LTO only with clang
+ifeq ($(call have_clang),y)
+RUSTCFLAGS-$(CONFIG_OPTIMIZE_LTO)	+= -Clinker-plugin-lto
+else
+RUSTCFLAGS-y	+= -Cembed-bitcode=n -Clto=n
+endif
+
 LIBLDFLAGS  += -nostdlib -Wl,-r -Wl,-d -Wl,--build-id=none -no-pie
 LIBLDFLAGS-$(call have_gcc)	+= -nostdinc