Create separate error when processes fail

8 files changed, 63 insertions, 29 deletions

diff --git a/src/main/java/org/shedlang/compiler/backends/ProcessRunner.java b/src/main/java/org/shedlang/compiler/backends/ProcessRunner.java
deleted file mode 100644
index d71bd25b..00000000
--- a/src/main/java/org/shedlang/compiler/backends/ProcessRunner.java
+++ /dev/null
@@ -1,26 +0,0 @@
-package org.shedlang.compiler.backends;
-
-import java.io.IOException;
-import java.util.List;
-
-public class ProcessRunner {
-    private ProcessRunner() {
-    }
-
-    /**
-     * Run a process until it exits, inheriting standard IO from its parent
-     * process.
-     */
-    public static void runInheritIo(List<String> args) throws IOException, InterruptedException {
-        var process = new ProcessBuilder(args)
-            .inheritIO()
-            .start();
-
-        var exitCode = process.waitFor();
-        if (exitCode != 0) {
-            // TODO: better error code
-            throw new RuntimeException("exit code: " + exitCode);
-        }
-    }
-
-}
diff --git a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmBackend.java b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmBackend.java
index 69f6a710..a3d2af91 100644
--- a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmBackend.java
+++ b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmBackend.java
@@ -25,7 +25,7 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.Optional;
 
-import static org.shedlang.compiler.backends.ProcessRunner.runInheritIo;
+import static org.shedlang.compiler.util.processes.ProcessRunner.runInheritIo;
 
 public class LlvmBackend implements Backend {
     public static final LlvmBackend DIRECT = new LlvmBackend("llvm", new CodeGen() {
diff --git a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompiler.java b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompiler.java
index 04e13b39..b9d82386 100644
--- a/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompiler.java
+++ b/src/main/java/org/shedlang/compiler/backends/llvm/LlvmCompiler.java
@@ -11,7 +11,7 @@ import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.List;
 
-import static org.shedlang.compiler.backends.ProcessRunner.runInheritIo;
+import static org.shedlang.compiler.util.processes.ProcessRunner.runInheritIo;
 
 public class LlvmCompiler {
     private final Path workingDirectory;
diff --git a/src/main/java/org/shedlang/compiler/backends/wasm/WasmBackend.java b/src/main/java/org/shedlang/compiler/backends/wasm/WasmBackend.java
index 10102a0a..584d8832 100644
--- a/src/main/java/org/shedlang/compiler/backends/wasm/WasmBackend.java
+++ b/src/main/java/org/shedlang/compiler/backends/wasm/WasmBackend.java
@@ -21,7 +21,7 @@ import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.List;
 
-import static org.shedlang.compiler.backends.ProcessRunner.runInheritIo;
+import static org.shedlang.compiler.util.processes.ProcessRunner.runInheritIo;
 
 public class WasmBackend implements Backend {
     public static final WasmBackend DIRECT = new WasmBackend("wasm", new CodeGen() {
diff --git a/src/main/java/org/shedlang/compiler/util/processes/ProcessError.java b/src/main/java/org/shedlang/compiler/util/processes/ProcessError.java
new file mode 100644
index 00000000..04d9bc47
--- /dev/null
+++ b/src/main/java/org/shedlang/compiler/util/processes/ProcessError.java
@@ -0,0 +1,13 @@
+package org.shedlang.compiler.util.processes;
+
+import java.io.IOException;
+
+public class ProcessError extends IOException {
+    public ProcessError(String message) {
+        super(message);
+    }
+
+    public ProcessError(String message, Throwable cause) {
+        super(message, cause);
+    }
+}
diff --git a/src/main/java/org/shedlang/compiler/util/processes/ProcessExitError.java b/src/main/java/org/shedlang/compiler/util/processes/ProcessExitError.java
new file mode 100644
index 00000000..078ed051
--- /dev/null
+++ b/src/main/java/org/shedlang/compiler/util/processes/ProcessExitError.java
@@ -0,0 +1,7 @@
+package org.shedlang.compiler.util.processes;
+
+public class ProcessExitError extends ProcessError {
+    public ProcessExitError(int exitCode) {
+        super("Process exited with exit code: " + exitCode);
+    }
+}
diff --git a/src/main/java/org/shedlang/compiler/util/processes/ProcessRunner.java b/src/main/java/org/shedlang/compiler/util/processes/ProcessRunner.java
new file mode 100644
index 00000000..e7d76715
--- /dev/null
+++ b/src/main/java/org/shedlang/compiler/util/processes/ProcessRunner.java
@@ -0,0 +1,33 @@
+package org.shedlang.compiler.util.processes;
+
+import java.io.IOException;
+import java.util.List;
+
+public class ProcessRunner {
+    private ProcessRunner() {
+    }
+
+    /**
+     * Run a process until it exits, inheriting standard IO from its parent
+     * process.
+     */
+    public static void runInheritIo(List<String> args) throws InterruptedException, ProcessError {
+        var process = startProcessInheritIo(args);
+
+        var exitCode = process.waitFor();
+        if (exitCode != 0) {
+            throw new ProcessExitError(exitCode);
+        }
+    }
+
+    private static Process startProcessInheritIo(List<String> args) throws ProcessError {
+        try {
+            return new ProcessBuilder(args)
+                .inheritIO()
+                .start();
+        } catch (IOException error) {
+            throw new ProcessStartError(error);
+        }
+    }
+
+}
diff --git a/src/main/java/org/shedlang/compiler/util/processes/ProcessStartError.java b/src/main/java/org/shedlang/compiler/util/processes/ProcessStartError.java
new file mode 100644
index 00000000..0222565b
--- /dev/null
+++ b/src/main/java/org/shedlang/compiler/util/processes/ProcessStartError.java
@@ -0,0 +1,7 @@
+package org.shedlang.compiler.util.processes;
+
+public class ProcessStartError extends ProcessError {
+    public ProcessStartError(Throwable cause) {
+        super("Could not start process", cause);
+    }
+}