feat(guest): replace musl with picolibc

Signed-off-by: Tomasz Andrzejak <andreiltd@gmail.com>

Author: andreiltd

.gitmodules

@@ -0,0 +1,4 @@
+[submodule "src/hyperlight_guest_bin/third_party/picolibc"]
+	path = src/hyperlight_guest_bin/third_party/picolibc
+	url = https://github.com/picolibc/picolibc.git
+	shallow = true

Cargo.lock

@@ -2,8 +2,8 @@ mkdir := if os() == "windows" { "mkdir -f -p" } else { "mkdir -p"}
 
 # Elf options
 # We don't support stack protectors at the moment, but Arch Linux clang auto-enables them for -linux platforms, so explicitly disable them.
-c-compile-options-elf := '-nobuiltininc -H --target=x86_64-unknown-linux-none -fno-stack-protector -fstack-clash-protection -mstack-probe-size=4096 -fPIC'
-c-include-flags-elf := "-I " + root / "src/hyperlight_guest_capi/include/"  + " -I " + root / "src/hyperlight_guest_bin/third_party/musl/include/" + " -I " + root / "src/hyperlight_guest_bin/third_party/musl/arch/x86_64" + " -I " + root / "src/hyperlight_guest_bin/third_party/printf"
+c-compile-options-elf := '-nostdlibinc -H --target=x86_64-unknown-linux-none -fno-stack-protector -fstack-clash-protection -mstack-probe-size=4096 -fPIC'
+c-include-flags-elf := "-I " + root / "src/hyperlight_guest_capi/include/"  + " -I " + root / "src/hyperlight_guest_bin/third_party/picolibc/newlib/libc/include/" + " -I " + root / "src/hyperlight_guest_bin/third_party/picolibc/newlib/libc/tinystdio/"
 c-linker-options-elf := '--entry "entrypoint" --nostdlib -pie'
 c-flags-debug-elf := '-O0'
 c-flags-release-elf := '-O3'

c.just

@@ -19,7 +19,7 @@ PROFILE=$([ "$TARGET" = "debug" ] && echo "dev" || echo "$TARGET")
 if [[ "$PACKAGE" == "hyperlight-host" ]]; then
     REQUIRED_FEATURES=("kvm" "mshv3")
 elif [[ "$PACKAGE" == "hyperlight-guest-bin" ]]; then
-    REQUIRED_FEATURES=("printf")
+    REQUIRED_FEATURES=("libc")
 else 
     REQUIRED_FEATURES=()
 fi
@@ -68,4 +68,4 @@ if [[ -n "$features" ]]; then
         echo "Testing $PACKAGE with all features: $all_features"
         (set -x; cargo clippy -p "$PACKAGE" --all-targets --no-default-features --features "$all_features" --profile="$PROFILE" -- -D warnings)
     fi
-fi
+fi

hack/clippy-package-features.sh

@@ -14,9 +14,9 @@ and third-party code used by our C-API needed to build a native hyperlight-guest
 """
 
 [features]
-default = ["libc", "printf"]
-libc = [] # compile musl libc
-printf = [ "libc" ] # compile printf
+default = ["libc"]
+libc = [] # compile libc from picolibc
+libm = ["libc"] # compile libm from picolibc
 trace_guest = ["hyperlight-common/trace_guest", "hyperlight-guest/trace_guest", "hyperlight-guest-tracing/trace"]
 mem_profile = ["hyperlight-common/unwind_guest","hyperlight-common/mem_profile"]
 
@@ -32,6 +32,7 @@ spin = "0.10.0"
 workspace = true
 
 [build-dependencies]
+anyhow = "1"
 cc = "1.2"
 cfg-if = "1.0"
 glob = "0.3.3"