Use static picolibc.h file instead of generating it at buildtime

.github/workflows/RustNightly.yml

@@ -80,7 +80,7 @@ jobs:
       - name: Install cargo-hyperlight
         uses: taiki-e/install-action@5939f3337e40968c39aa70f5ecb1417a92fb25a0 # v2.75.15
         with:
-          tool: cargo-hyperlight@0.1.8
+          tool: cargo-hyperlight@0.1.9
 
       - name: Build and move Rust guests
         run: |

.github/workflows/dep_build_guests.yml

@@ -70,7 +70,7 @@ jobs:
       - name: Install cargo-hyperlight
         uses: taiki-e/install-action@5939f3337e40968c39aa70f5ecb1417a92fb25a0 # v2.75.15
         with:
-          tool: cargo-hyperlight@0.1.8
+          tool: cargo-hyperlight@0.1.9
 
       - name: Build Rust guests
         run: |

.github/workflows/dep_code_checks.yml

@@ -76,7 +76,7 @@ jobs:
       - name: Install cargo-hyperlight
         uses: taiki-e/install-action@5939f3337e40968c39aa70f5ecb1417a92fb25a0 # v2.75.15
         with:
-          tool: cargo-hyperlight@0.1.8
+          tool: cargo-hyperlight@0.1.9
 
       - name: clippy exhaustive check (debug)
         run: just clippy-exhaustive debug
@@ -149,7 +149,7 @@ jobs:
       - name: Install cargo-hyperlight
         uses: taiki-e/install-action@5939f3337e40968c39aa70f5ecb1417a92fb25a0 # v2.75.15
         with:
-          tool: cargo-hyperlight@0.1.8
+          tool: cargo-hyperlight@0.1.9
 
       - name: clippy (debug)
         run: |

c.just

@@ -3,7 +3,7 @@ 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 := '-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/libc/include/" + " -I " + root / "src/hyperlight_guest_bin/third_party/picolibc/libc/stdio/"
+c-include-flags-elf := "-I " + root / "src/hyperlight_guest_capi/include/"  + " -I " + root / "src/hyperlight_guest_bin/third_party/picolibc/libc/include/" + " -I " + root / "src/hyperlight_guest_bin/third_party/picolibc/libc/stdio/" + " -I " + root / "src/hyperlight_guest_bin/include/"
 c-linker-options-elf := '--entry "entrypoint" --nostdlib -pie --no-dynamic-linker'
 c-flags-debug-elf := '-O0'
 c-flags-release-elf := '-O3'

src/hyperlight_guest_bin/build.rs

@@ -16,9 +16,8 @@ limitations under the License.
 
 mod build_files;
 
-use std::io::Write;
 use std::path::{Path, PathBuf};
-use std::process::{Command, Stdio};
+use std::process::Command;
 use std::{env, fs};
 
 use anyhow::{Context, Result, bail};
@@ -51,144 +50,6 @@ fn copy_includes<P: AsRef<Path>, Q: AsRef<Path> + std::fmt::Debug>(
     Ok(())
 }
 
-fn detect_cc_feature(test_code: &str) -> Result<bool> {
-    let cc = std::env::var("HYPERLIGHT_GUEST_clang").unwrap_or_else(|_| "clang".into());
-
-    let mut cmd = Command::new(&cc)
-        .arg("-std=c18")
-        .arg("-x")
-        .arg("c")
-        .arg("-")
-        .arg("-fsyntax-only")
-        .stdin(Stdio::piped())
-        .stderr(Stdio::null())
-        .stdout(Stdio::null())
-        .spawn()
-        .with_context(|| "failed to spawn compiler for feature test")?;
-
-    cmd.stdin
-        .as_mut()
-        .unwrap()
-        .write_all(test_code.as_bytes())
-        .with_context(|| "failed to write test code")?;
-
-    Ok(cmd
-        .wait()
-        .with_context(|| "failed to wait on cc command")?
-        .success())
-}
-
-fn gen_config_file(config_dir: &Path) -> Result<()> {
-    let config_h = config_dir.join("picolibc.h");
-
-    let mut file = fs::File::create(&config_h)
-        .with_context(|| format!("Could not create config file {:?}", config_h))?;
-
-    writeln!(file, "/* Generated by hyperlight build script */")?;
-    writeln!(file, "#pragma once")?;
-    writeln!(file)?;
-
-    writeln!(file, "#define _NEWLIB_VERSION \"4.3.0\"")?;
-    writeln!(file, "#define __NEWLIB_VERSION__ \"4.3.0\"")?;
-    writeln!(file, "#define __NEWLIB__ 4")?;
-    writeln!(file, "#define __NEWLIB_MINOR__ 3")?;
-    writeln!(file, "#define __NEWLIB_PATCHLEVEL__ 0")?;
-    writeln!(file, "#define __PICOLIBC_VERSION__ \"1.8.11\"")?;
-    writeln!(file, "#define __PICOLIBC__ 1")?;
-    writeln!(file, "#define __PICOLIBC_MINOR__ 8")?;
-    writeln!(file, "#define __PICOLIBC_PATCHLEVEL__ 11")?;
-    writeln!(file)?;
-
-    // Static configuration
-    writeln!(file, "#define __ASSERT_VERBOSE")?;
-    writeln!(file, "#define __SINGLE_THREAD")?; // -Dsingle-thread=true
-    writeln!(file, "#define __GLOBAL_ERRNO")?; // -Dnewlib-global-errno=true
-    writeln!(file, "#define __INIT_FINI_ARRAY")?; // -Dinitfini-array=true
-    writeln!(file, "#define __TINY_STDIO")?; // tinystdio is now the only stdio
-    writeln!(file, "#define __IO_DEFAULT 'd'")?; // -Dformat-default=double
-    writeln!(file, "#define __IO_FLOAT_EXACT")?; // default
-    writeln!(file, "#define __IO_WCHAR")?; // -Dio-wchar=true
-    writeln!(file, "#define __IEEE_LIBM")?; // math library without errno
-    writeln!(file, "#define __FAST_STRCMP")?; // default optimization
-    writeln!(file, "#define __FAST_BUFIO")?; // -Dfast-bufio=true
-    writeln!(file, "#define __IO_SMALL_ULTOA")?; // avoid division in conversion
-
-    for test in &[
-        "__builtin_alloca",
-        "__builtin_ffs",
-        "__builtin_ffsl",
-        "__builtin_ffsll",
-        "__builtin_ctz",
-        "__builtin_ctzl",
-        "__builtin_ctzll",
-        "__builtin_copysign",
-        "__builtin_copysignl",
-        "__builtin_isinf",
-        "__builtin_isinfl",
-        "__builtin_isnan",
-        "__builtin_isnanl",
-        "__builtin_isfinite",
-        "__builtin_finitel",
-        "__builtin_issignalingl",
-        "__builtin_expect",
-        "__builtin_complex",
-        "__builtin_add_overflow",
-        "__builtin_mul_overflow",
-    ] {
-        let code = format!(
-            r#"
-            #if __has_builtin({test})
-            int main() {{ return 0; }}
-            #else
-            #error "Builtin not supported"
-            #endif
-        "#
-        );
-
-        let has = if detect_cc_feature(&code)? { 1 } else { 0 };
-        writeln!(
-            file,
-            "#define __HAVE_BUILTIN_{} {has}",
-            test.trim_start_matches("__builtin_").to_uppercase()
-        )?;
-    }
-
-    let code = r#"_Complex double x = 1.0 + 2.0*I; int main() { return 0; }"#;
-    let has = if detect_cc_feature(code)? { 1 } else { 0 };
-    writeln!(file, "#define __HAVE_COMPLEX {has}")?;
-
-    // Static undefs
-    writeln!(file, "#undef __ARM_SEMIHOST")?; // -Dsemihost=false
-    writeln!(file, "#undef __SEMIHOST")?; // -Dsemihost=false
-    writeln!(file, "#undef __THREAD_LOCAL_STORAGE")?; // -Dthread-local-storage=false
-    writeln!(file, "#undef __THREAD_LOCAL_STORAGE_API")?;
-    writeln!(file, "#undef __THREAD_LOCAL_STORAGE_RP2040")?;
-    writeln!(file, "#undef __THREAD_LOCAL_STORAGE_STACK_GUARD")?;
-    writeln!(file, "#undef __ENABLE_MALLOC")?; // -Denable-malloc=false
-    writeln!(file, "#undef __MALLOC_CLEAR_FREED")?;
-    writeln!(file, "#undef __MB_CAPABLE")?; // no multibyte support
-    writeln!(file, "#undef __HAVE_FCNTL")?; // freestanding environment
-    writeln!(file, "#undef __STDIO_LOCKING")?; // single-thread
-    writeln!(file, "#undef __IO_C99_FORMATS")?; // -Dio-c99-formats=false
-    writeln!(file, "#undef __IO_LONG_DOUBLE")?; // not enabled
-    writeln!(file, "#undef __IO_LONG_LONG")?; // minimal format
-    writeln!(file, "#undef __IO_MINIMAL_LONG_LONG")?;
-    writeln!(file, "#undef __IO_PERCENT_B")?; // not enabled
-    writeln!(file, "#undef __IO_PERCENT_N")?; // not enabled
-    writeln!(file, "#undef __IO_POS_ARGS")?; // not enabled
-    writeln!(file, "#undef __MATH_ERRNO")?; // IEEE math only
-    writeln!(file, "#undef __OBSOLETE_MATH")?;
-    writeln!(file, "#undef __OBSOLETE_MATH_DOUBLE")?;
-    writeln!(file, "#undef __OBSOLETE_MATH_FLOAT")?;
-    writeln!(file, "#undef __PREFER_SIZE_OVER_SPEED")?; // release build
-    writeln!(file, "#undef __ATOMIC_UNGETC")?; // single-thread
-    writeln!(file, "#undef __IEEEFP_FUNCS")?;
-    writeln!(file, "#undef __INIT_FINI_FUNCS")?; // using INIT_FINI_ARRAY instead
-    writeln!(file, "#undef __HAVE_BITFIELDS_IN_PACKED_STRUCTS")?;
-
-    Ok(())
-}
-
 fn cc_build(picolibc_dir: &PathBuf, target: &str) -> Result<cc::Build> {
     let mut build = cc::Build::new();
     let compiler = env::var("HYPERLIGHT_GUEST_clang").unwrap_or("clang".to_string());
@@ -252,11 +113,6 @@ fn cc_build(picolibc_dir: &PathBuf, target: &str) -> Result<cc::Build> {
         .define("_LIBC", None)
         .define("_FILE_OFFSET_BITS", "64");
 
-    // TODO: this is wrong, it should generate config file to out_dir/include
-    // but how downstream crates get at it then? And TBH I think having piclibc
-    // headers (features.h) depend on a build time header is odd
-    gen_config_file(&picolibc_dir.join("libc/include"))?;
-
     match target {
         "x86" | "x86_64" => {
             build.include(picolibc_dir.join("libm/machine/x86"));
@@ -323,6 +179,7 @@ fn init_submodule() -> Result<()> {
 fn cargo_main() -> Result<()> {
     println!("cargo:rerun-if-changed=build.rs");
     println!("cargo:rerun-if-changed=third_party/picolibc");
+    println!("cargo:rerun-if-changed=include/picolibc.h");
     println!("cargo:rerun-if-env-changed=HYPERLIGHT_GUEST_TOOLCHAIN_ROOT");
 
     let out_dir = env::var("OUT_DIR").expect("cargo OUT_DIR not set");
@@ -332,15 +189,21 @@ fn cargo_main() -> Result<()> {
     fs::create_dir_all(&include_dir)
         .with_context(|| format!("Could not create include dir {include_dir:?}"))?;
 
+    let manifest_dir = env::var("CARGO_MANIFEST_DIR").expect("cargo MANIFEST_DIR not set");
+    let manifest_dir = PathBuf::from(manifest_dir);
+    let picolibc_dir = manifest_dir.join("third_party/picolibc");
+
     if cfg!(feature = "libc") {
-        if !Path::new("third_party/picolibc/COPYING.picolibc").exists() {
+        if !picolibc_dir.join("COPYING.picolibc").exists() {
             eprintln!("Setting up submodules");
             init_submodule().with_context(|| "failed to init picolibc submodule")?;
         }
 
-        let picolibc_dir = PathBuf::from("third_party/picolibc");
         let mut build = cc_build(&picolibc_dir, &target)?;
 
+        // include for picolibc configuration: picolibc.h
+        build.include(manifest_dir.join("include"));
+
         add_libc(&mut build, &picolibc_dir, &target)?;
         add_libm(&mut build, &picolibc_dir, &target)?;
 
@@ -349,7 +212,8 @@ fn cargo_main() -> Result<()> {
         }
 
         build.compile("hyperlight_guest_bin");
-        copy_includes(&include_dir, "third_party/picolibc/libc/include")?;
+        copy_includes(&include_dir, picolibc_dir.join("libc/include"))?;
+        copy_includes(&include_dir, manifest_dir.join("include"))?;
     }
 
     let include_str = include_dir