Implement exception raising.

lit-test/libartiq_personality/Makefile

@@ -1,4 +1,4 @@
 CC ?= clang
 
-libartiq_personality.so: ../../soc/runtime/artiq_personality.c
-	$(CC) -Wall -Werror -I. -fPIC -shared -o $@ $<
+libartiq_personality.so: ../../soc/runtime/artiq_personality.c artiq_terminate.c
+	$(CC) -Wall -Werror -I. -I../../soc/runtime -fPIC -shared -o $@ $^

lit-test/libartiq_personality/artiq_terminate.c

@@ -0,0 +1,14 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <inttypes.h>
+#include <unwind.h>
+#include <artiq_personality.h>
+
+void __artiq_terminate(struct artiq_exception *exn) {
+  printf("Uncaught %s: %s (%"PRIi64", %"PRIi64", %"PRIi64")\n"
+         "at %s:%"PRIi32":%"PRIi32"",
+         exn->name, exn->message,
+         exn->param[0], exn->param[1], exn->param[1],
+         exn->file, exn->line, exn->column + 1);
+  exit(1);
+}

lit-test/not.py

@@ -0,0 +1,2 @@
+import sys, subprocess
+exit(not subprocess.call(sys.argv[1:]))

lit-test/test/exceptions/raise.py

@@ -1,4 +1,6 @@
-# RUN: %python -m artiq.compiler.testbench.jit %s
+# RUN: %not %python -m artiq.compiler.testbench.jit %s
 # REQUIRES: exceptions
 
+# CHECK-L: Uncaught ZeroDivisionError: cannot divide by zero (0, 0, 0)
+# CHECK-L: at input.py:${LINE:+1}:0
 1/0

lit-test/test/lit.cfg

@@ -9,9 +9,13 @@ config.test_format = lit.formats.ShTest()
 config.suffixes = ['.py']
 
 python_executable = 'python3'
+
 harness = '{} {}'.format(python_executable, os.path.join(root, 'harness.py'))
 config.substitutions.append( ('%python', harness) )
 
+not_ = '{} {}'.format(python_executable, os.path.join(root, 'not.py'))
+config.substitutions.append( ('%not', not_) )
+
 if os.name == 'posix':
     personality_build = os.path.join(root, 'libartiq_personality')
     if subprocess.call(['make', '-sC', personality_build]) != 0:

soc/runtime/artiq_personality.c

@@ -1,25 +1,41 @@
 #include <stdint.h>
 #include <stdlib.h>
+#include <string.h>
 #include <stdio.h>
 #include <unwind.h>
+#include "artiq_personality.h"
 
-struct artiq_exception {
-  const char *name;
-  const char *file;
-  int32_t line;
-  int32_t column;
-  const char *message;
-  int64_t param[3];
+#define ARTIQ_EXCEPTION_CLASS 0x4152545141525451LL // 'ARTQARTQ'
+
+struct artiq_raised_exception {
+  struct _Unwind_Exception unwind;
+  struct artiq_exception artiq;
 };
 
-void __artiq_raise(struct artiq_exception *artiq_exn) {
-  printf("raised %s\n", artiq_exn->name);
-  abort();
+static void __artiq_cleanup(_Unwind_Reason_Code reason, struct _Unwind_Exception *exc) {
+  struct artiq_raised_exception *inflight = (struct artiq_raised_exception*) exc;
+  // The in-flight exception is statically allocated, so we don't need to free it.
+  // But, we clear it to mark it as processed.
+  memset(&inflight->artiq, 0, sizeof(struct artiq_exception));
 }
 
-_Unwind_Reason_Code __artiq_personality(int version,
-    _Unwind_Action actions, uint64_t exceptionClass,
-    struct _Unwind_Exception *exceptionObject,
-    struct _Unwind_Context *context) {
+void __artiq_raise(struct artiq_exception *artiq_exn) {
+  static struct artiq_raised_exception inflight;
+  memcpy(&inflight.artiq, artiq_exn, sizeof(struct artiq_exception));
+  inflight.unwind.exception_class = ARTIQ_EXCEPTION_CLASS;
+  inflight.unwind.exception_cleanup = &__artiq_cleanup;
+
+  _Unwind_Reason_Code result = _Unwind_RaiseException(&inflight.unwind);
+  if(result == _URC_END_OF_STACK) {
+    __artiq_terminate(&inflight.artiq);
+  } else {
+    fprintf(stderr, "__artiq_raise: unexpected error (%d)\n", result);
+    abort();
+  }
+}
+
+_Unwind_Reason_Code __artiq_personality(
+        int version, _Unwind_Action actions, uint64_t exceptionClass,
+        struct _Unwind_Exception *exceptionObject, struct _Unwind_Context *context) {
   abort();
 }

soc/runtime/artiq_personality.h

@@ -0,0 +1,31 @@
+#ifndef __ARTIQ_PERSONALITY_H
+#define __ARTIQ_PERSONALITY_H
+
+#include <stdint.h>
+
+struct artiq_exception {
+  union {
+    void *typeinfo;
+    const char *name;
+  };
+  const char *file;
+  int32_t line;
+  int32_t column;
+  const char *message;
+  int64_t param[3];
+};
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void __artiq_terminate(struct artiq_exception *artiq_exn)
+        __attribute__((noreturn));
+
+void __artiq_raise(struct artiq_exception *artiq_exn);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __ARTIQ_PERSONALITY_H */