Generate a script to rerun the failed sub-command in cargo-test-bpf (#18582)

* Generate a script to rerun the failed sub-command in cargo-test-bpf

* Generate a script to rerun the failed sub-command in cargo-build-bpf

* Add cargo-build-bpf test for generate-child-script-on-failure option

sdk/cargo-test-bpf/src/main.rs

@@ -4,6 +4,8 @@ use clap::{
 use std::{
     env,
     ffi::OsStr,
+    fs::File,
+    io::{prelude::*, BufWriter},
     path::{Path, PathBuf},
     process::exit,
     process::Command,
@@ -16,6 +18,7 @@ struct Config {
     cargo_build_bpf: PathBuf,
     extra_cargo_test_args: Vec<String>,
     features: Vec<String>,
+    generate_child_script_on_failure: bool,
     test_name: Option<String>,
     no_default_features: bool,
     no_run: bool,
@@ -33,6 +36,7 @@ impl Default for Config {
             cargo_build_bpf: PathBuf::from("cargo-build-bpf"),
             extra_cargo_test_args: vec![],
             features: vec![],
+            generate_child_script_on_failure: false,
             test_name: None,
             no_default_features: false,
             no_run: false,
@@ -43,13 +47,13 @@ impl Default for Config {
     }
 }
 
-fn spawn<I, S>(program: &Path, args: I)
+fn spawn<I, S>(program: &Path, args: I, generate_child_script_on_failure: bool)
 where
     I: IntoIterator<Item = S>,
     S: AsRef<OsStr>,
 {
     let args = args.into_iter().collect::<Vec<_>>();
-    print!("Running: {}", program.display());
+    print!("cargo-test-bpf child: {}", program.display());
     for arg in args.iter() {
         print!(" {}", arg.as_ref().to_str().unwrap_or("?"));
     }
@@ -65,6 +69,29 @@ where
 
     let exit_status = child.wait().expect("failed to wait on child");
     if !exit_status.success() {
+        if !generate_child_script_on_failure {
+            exit(1);
+        }
+        eprintln!("cargo-test-bpf exited on command execution failure");
+        let script_name = format!(
+            "cargo-test-bpf-child-script-{}.sh",
+            program.file_name().unwrap().to_str().unwrap(),
+        );
+        let file = File::create(&script_name).unwrap();
+        let mut out = BufWriter::new(file);
+        for (key, value) in env::vars() {
+            writeln!(out, "{}=\"{}\" \\", key, value).unwrap();
+        }
+        write!(out, "{}", program.display()).unwrap();
+        for arg in args.iter() {
+            write!(out, " {}", arg.as_ref().to_str().unwrap_or("?")).unwrap();
+        }
+        writeln!(out).unwrap();
+        out.flush().unwrap();
+        eprintln!(
+            "To rerun the failed command for debugging use {}",
+            script_name,
+        );
         exit(1);
     }
 }
@@ -99,7 +126,11 @@ fn test_bpf_package(config: &Config, target_directory: &Path, package: &cargo_me
     build_bpf_args.push("--bpf-out-dir");
     build_bpf_args.push(&bpf_out_dir);
 
-    spawn(&config.cargo_build_bpf, &build_bpf_args);
+    spawn(
+        &config.cargo_build_bpf,
+        &build_bpf_args,
+        config.generate_child_script_on_failure,
+    );
 
     // Pass --bpf-out-dir along to the solana-program-test crate
     env::set_var("BPF_OUT_DIR", bpf_out_dir);
@@ -124,7 +155,11 @@ fn test_bpf_package(config: &Config, target_directory: &Path, package: &cargo_me
     for extra_cargo_test_arg in &config.extra_cargo_test_args {
         cargo_args.push(extra_cargo_test_arg);
     }
-    spawn(&config.cargo, &cargo_args);
+    spawn(
+        &config.cargo,
+        &cargo_args,
+        config.generate_child_script_on_failure,
+    );
 }
 
 fn test_bpf(config: Config, manifest_path: Option<PathBuf>) {
@@ -239,6 +274,12 @@ fn main() {
                 .takes_value(false)
                 .help("Run without accessing the network"),
         )
+        .arg(
+            Arg::with_name("generate_child_script_on_failure")
+                .long("generate-child-script-on-failure")
+                .takes_value(false)
+                .help("Generate rerun-script.sh to rerun test command on failure"),
+        )
         .arg(
             Arg::with_name("verbose")
                 .short("v")
@@ -271,6 +312,7 @@ fn main() {
         features: values_t!(matches, "features", String)
             .ok()
             .unwrap_or_else(Vec::new),
+        generate_child_script_on_failure: matches.is_present("generate_child_script_on_failure"),
         test_name: value_t!(matches, "test", String).ok(),
         no_default_features: matches.is_present("no_default_features"),
         no_run: matches.is_present("no_run"),