Enable emjs error handling (pyodide#1080)

jmsmdy · Jan 12, 2021 · f6a67d9 · f6a67d9
1 parent 96fcf0e
commit f6a67d9
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Showing 5 changed files with 30 additions and 12 deletions.
diff --git a/Makefile b/Makefile
@@ -15,7 +15,8 @@ PYODIDE_CXX=$(PYODIDE_ROOT)/ccache/em++
 CC=emcc
 CXX=em++
 OPTFLAGS=-O2
-CFLAGS=$(OPTFLAGS) -g -I$(PYTHONINCLUDE) -Wno-warn-absolute-paths -Werror=int-conversion -Werror=incompatible-pointer-types -fPIC
+CFLAGS=$(OPTFLAGS) -g -I$(PYTHONINCLUDE) -fPIC \
+	-Wno-warn-absolute-paths -Werror=int-conversion -Werror=incompatible-pointer-types
 
 LDFLAGS=\
 	-O2 \

diff --git a/src/core/error_handling.c b/src/core/error_handling.c
@@ -25,7 +25,7 @@ error_handling_init()
     Module.handle_js_error = function(e)
     {
       let err = Module.hiwire.new_value(e);
-      PyodideErr_SetJsError(err);
+      _PyodideErr_SetJsError(err);
       Module.hiwire.decref(err);
     };
   });

diff --git a/src/core/error_handling.h b/src/core/error_handling.h
@@ -36,28 +36,45 @@ log_error(char* msg);
  */
 
 // clang-format off
+#ifdef DEBUG_F
+// Yes, the "do {} while(0)" trick solves the same problem in the same way in
+// javascript!
+#define LOG_EM_JS_ERROR(__funcname__, err)                                     \
+  do {                                                                         \
+    console.error(                                                             \
+      `EM_JS raised exception on line __LINE__ in func __funcname__`);         \
+    console.error("Error was:", err);                                          \
+  } while (0)
+#else
+#define LOG_EM_JS_ERROR(__funcname__, err)
+#endif
+
+// Need an extra layer to expand LOG_EM_JS_ERROR.
+#define EM_JS_DEFER(ret, func_name, args, body...)                             \
+  EM_JS(ret, func_name, args, body)
+
 #define EM_JS_REF(ret, func_name, args, body...)                               \
-  EM_JS(ret, func_name, args, {                                                \
+  EM_JS_DEFER(ret, func_name, args, {                                          \
     "use strict";                                                              \
     try    /* intentionally no braces, body already has them */                \
       body /* <== body of func */                                              \
     catch (e) {                                                                \
-        /* Dummied out until calling code is ready to catch these errors */    \
-        throw e;                                                               \
+        LOG_EM_JS_ERROR(func_name, err);                                       \
         Module.handle_js_error(e);                                             \
         return 0;                                                              \
     }                                                                          \
-    throw new Error("Assertion error: control reached end of function without return");\
+    throw new Error(                                                           \
+      "Assertion error: control reached end of function without return"        \
+    );                                                                         \
   })
 
 #define EM_JS_NUM(ret, func_name, args, body...)                               \
-  EM_JS(ret, func_name, args, {                                                \
+  EM_JS_DEFER(ret, func_name, args, {                                          \
     "use strict";                                                              \
     try    /* intentionally no braces, body already has them */                \
       body /* <== body of func */                                              \
     catch (e) {                                                                \
-        /* Dummied out until calling code is ready to catch these errors */    \
-        throw e;                                                               \
+        LOG_EM_JS_ERROR(func_name, err);                                       \
         Module.handle_js_error(e);                                             \
         return -1;                                                             \
     }                                                                          \
@@ -98,7 +115,7 @@ log_error(char* msg);
              __FILE__);                                                        \
     log_error(msg);                                                            \
     free(msg);                                                                 \
-    goto finally                                                               \
+    goto finally;                                                              \
   } while (0)
 
 #else

diff --git a/src/core/hiwire.c b/src/core/hiwire.c
@@ -222,7 +222,7 @@ EM_JS_REF(JsRef, hiwire_float64array, (f64 * ptr, int len), {
   return Module.hiwire.new_value(array);
 })
 
-EM_JS_NUM(errcode, hiwire_throw_error, (JsRef idmsg), {
+EM_JS(void, hiwire_throw_error, (JsRef idmsg), {
   let jsmsg = Module.hiwire.get_value(idmsg);
   Module.hiwire.decref(idmsg);
   throw new Error(jsmsg);

diff --git a/src/core/hiwire.h b/src/core/hiwire.h
@@ -312,7 +312,7 @@ hiwire_push_object_pair(JsRef idobj, JsRef idkey, JsRef idval);
  * The message is conventionally a Javascript string, but that is not required.
  * TODO: should be hiwire_set_error.
  */
-errcode
+void
 hiwire_throw_error(JsRef idmsg);
 
 /**
-Original file line number
+Diff line change
@@ Expand Up @@
      * The message is conventionally a Javascript string, but that is not required.
      * TODO: should be hiwire_set_error.
      */
-    errcode
+    void
     hiwire_throw_error(JsRef idmsg);
     /**
@@ Expand Down @@