Allow BPF structure passing and returning (#2100)

* Add BPF struct passing and returning tests

programs/bpf/c/src/struct_pass.c

@@ -0,0 +1,17 @@
+#include <solana_sdk.h>
+
+struct foo {const uint8_t *input;};
+void foo(const uint8_t *input, struct foo foo) ;
+
+extern bool entrypoint(const uint8_t *input) {
+  struct foo f;
+  f.input = input;
+  foo(input, f);
+  return true;
+}
+
+void foo(const uint8_t *input, struct foo foo) {
+  sol_log_64(0, 0, 0, (uint64_t)input, (uint64_t)foo.input);
+  sol_assert(input == foo.input);
+}
+

programs/bpf/c/src/struct_ret.c

@@ -0,0 +1,18 @@
+#include <solana_sdk.h>
+
+struct foo {const uint8_t *input;};
+struct foo bar(const uint8_t *input);
+
+extern bool entrypoint(const uint8_t *input) {
+  struct foo foo = bar(input);
+  sol_log_64(0, 0, 0, (uint64_t)input, (uint64_t)foo.input);
+  sol_assert(input == foo.input);
+  return true;
+}
+
+struct foo bar(const uint8_t *input) {
+  struct foo foo;
+  foo.input = input;
+  return foo;
+}
+

programs/native/bpf_loader/build.rs

@@ -18,6 +18,9 @@ fn main() {
         println!("cargo:rerun-if-changed=../../bpf/c/src/bench_alu.c");
         println!("cargo:rerun-if-changed=../../bpf/c/src/move_funds.c");
         println!("cargo:rerun-if-changed=../../bpf/c/src/noop.c");
+        println!("cargo:rerun-if-changed=../../bpf/c/src/noop++.c");
+        println!("cargo:rerun-if-changed=../../bpf/c/src/struct_pass.c");
+        println!("cargo:rerun-if-changed=../../bpf/c/src/struct_ret.c");
         println!("cargo:warning=(not a warning) Compiling C-based BPF programs");
         let status = Command::new("make")
             .current_dir("../../bpf/c")

sdk/bpf/scripts/install.sh

@@ -32,7 +32,7 @@ if [[ ! -r criterion-$machine-$version.md ]]; then
 fi
 
 # Install LLVM
-version=v0.0.5
+version=v0.0.6
 if [[ ! -f llvm-native-$machine-$version.md ]]; then
   (
     filename=solana-llvm-$machine.tar.bz2

tests/programs.rs

@@ -296,10 +296,18 @@ fn test_program_builtin_bpf_noop() {
 
 #[cfg(feature = "bpf_c")]
 #[test]
-fn test_program_bpf_noop_c() {
+fn test_program_bpf_c() {
     logger::setup();
 
-    let mut file = File::open(create_bpf_path("noop")).expect("file open failed");
+    let programs = [
+        "noop",
+        "struct_pass",
+        "struct_ret",
+        //"noop++" // TODO fails with buffer overflow
+    ];
+    for program in programs.iter() {
+        println!("Test program: {:?}", program);
+        let mut file = File::open(create_bpf_path(program)).expect("file open failed");
         let mut elf = Vec::new();
         file.read_to_end(&mut elf).unwrap();
 
@@ -321,3 +329,4 @@ fn test_program_bpf_noop_c() {
             loader.bank.process_transactions(&vec![tx.clone()]),
         );
     }
+}