add initial draft to support of exception handling proposal phase 3 in classic interpreter (bytecodealliance#1884)

Author: ermler

Diff for: build-scripts/config_common.cmake

@@ -312,6 +312,7 @@ else ()
 endif ()
 if (WAMR_BUILD_EXCE_HANDLING EQUAL 1)
   add_definitions (-DWASM_ENABLE_EXCE_HANDLING=1)
+  add_definitions (-DWASM_ENABLE_TAGS=1)
   message ("     Exception Handling enabled")
 endif ()
 if (DEFINED WAMR_BH_VPRINTF)

Diff for: core/iwasm/interpreter/wasm.h

@@ -14,6 +14,13 @@
 extern "C" {
 #endif
 
+
+#if WASM_ENABLE_EXCE_HANDLING != 0
+#define _EXCEWARNING   LOG_WARNING  /* for exception handling misbehavior logging */
+#define _EXCEDEBUG     LOG_VERBOSE  /* for exception handling debugging */
+#define _EXCEVERBOSE   LOG_VERBOSE  /* more excessive tracing of tagbrowsing and stack pointers */
+#endif
+
 /** Value Type */
 #define VALUE_TYPE_I32 0x7F
 #define VALUE_TYPE_I64 0X7E
@@ -65,6 +72,9 @@ extern "C" {
 #if WASM_ENABLE_BULK_MEMORY != 0
 #define SECTION_TYPE_DATACOUNT 12
 #endif
+#if WASM_ENABLE_TAGS != 0
+#define SECTION_TYPE_TAG 13
+#endif
 
 #define SUB_SECTION_TYPE_MODULE 0
 #define SUB_SECTION_TYPE_FUNC 1
@@ -74,20 +84,34 @@ extern "C" {
 #define IMPORT_KIND_TABLE 1
 #define IMPORT_KIND_MEMORY 2
 #define IMPORT_KIND_GLOBAL 3
+#if WASM_ENABLE_TAGS != 0
+#define IMPORT_KIND_TAG 4
+#endif
 
 #define EXPORT_KIND_FUNC 0
 #define EXPORT_KIND_TABLE 1
 #define EXPORT_KIND_MEMORY 2
 #define EXPORT_KIND_GLOBAL 3
+#if WASM_ENABLE_TAGS != 0
+#define EXPORT_KIND_TAG 4
+#endif
 
 #define LABEL_TYPE_BLOCK 0
 #define LABEL_TYPE_LOOP 1
 #define LABEL_TYPE_IF 2
 #define LABEL_TYPE_FUNCTION 3
+#if WASM_ENABLE_EXCE_HANDLING != 0
+#define LABEL_TYPE_TRY 4
+#define LABEL_TYPE_CATCH 5
+#define LABEL_TYPE_CATCH_ALL 6
+#endif
 
 typedef struct WASMModule WASMModule;
 typedef struct WASMFunction WASMFunction;
 typedef struct WASMGlobal WASMGlobal;
+#if WASM_ENABLE_TAGS != 0
+typedef struct WASMTag WASMTag;
+#endif
 
 typedef union V128 {
     int8 i8x16[16];
@@ -197,6 +221,13 @@ typedef struct WASMFunctionImport {
     bool call_conv_wasm_c_api;
 } WASMFunctionImport;
 
+#if WASM_ENABLE_TAGS != 0
+typedef struct WASMTagImport {
+    uint8 attribute; /* the type of the tag (numerical) */
+    uint32 type; /* the type of the catch function (numerical)*/
+} WASMTagImport;
+#endif
+
 typedef struct WASMGlobalImport {
     char *module_name;
     char *field_name;
@@ -223,6 +254,9 @@ typedef struct WASMImport {
         WASMFunctionImport function;
         WASMTableImport table;
         WASMMemoryImport memory;
+#if WASM_ENABLE_TAGS != 0
+        WASMTagImport tag;
+#endif
         WASMGlobalImport global;
         struct {
             char *module_name;
@@ -261,6 +295,10 @@ struct WASMFunction {
     uint32 const_cell_num;
 #endif
 
+#if WASM_ENABLE_EXCE_HANDLING != 0
+    uint32 exception_handler_count;
+#endif
+
 #if WASM_ENABLE_FAST_JIT != 0 || WASM_ENABLE_JIT != 0 \
     || WASM_ENABLE_WAMR_COMPILER != 0
     /* Whether function has opcode memory.grow */
@@ -290,6 +328,13 @@ struct WASMFunction {
 #endif
 };
 
+#if WASM_ENABLE_TAGS != 0
+struct WASMTag {
+    uint8 attribute;    /* the attribute property of the tag (expected to be 0) */
+    uint32 type;         /* the type of the tag (expected valid inden in type table) */
+};
+#endif
+
 struct WASMGlobal {
     uint8 type;
     bool is_mutable;
@@ -417,6 +462,9 @@ struct WASMModule {
     uint32 function_count;
     uint32 table_count;
     uint32 memory_count;
+#if WASM_ENABLE_TAGS != 0
+    uint32 tag_count;
+#endif
     uint32 global_count;
     uint32 export_count;
     uint32 table_seg_count;
@@ -430,18 +478,28 @@ struct WASMModule {
     uint32 import_function_count;
     uint32 import_table_count;
     uint32 import_memory_count;
+#if WASM_ENABLE_TAGS != 0
+    uint32 import_tag_count;
+#endif
     uint32 import_global_count;
 
     WASMImport *import_functions;
     WASMImport *import_tables;
     WASMImport *import_memories;
+#if WASM_ENABLE_TAGS !=  0
+    WASMImport *import_tags;
+#endif
     WASMImport *import_globals;
 
+
     WASMType **types;
     WASMImport *imports;
     WASMFunction **functions;
     WASMTable *tables;
     WASMMemory *memories;
+#if WASM_ENABLE_TAGS != 0
+    WASMTag  *tags;
+#endif
     WASMGlobal *globals;
     WASMExport *exports;
     WASMTableSeg *table_segments;
@@ -625,6 +683,10 @@ typedef struct WASMBranchBlock {
     uint8 *target_addr;
     uint32 *frame_sp;
     uint32 cell_num;
+#if WASM_ENABLE_EXCE_HANDLING != 0
+/* in exception handling, label_type needs to be stored to lookup exception handlers */
+    uint8 label_type;
+#endif
 } WASMBranchBlock;
 
 /* Execution environment, e.g. stack info */

Diff for: core/iwasm/interpreter/wasm_interp.h

@@ -34,6 +34,14 @@ typedef struct WASMInterpFrame {
     uint64 time_started;
 #endif
 
+#if WASM_ENABLE_EXCE_HANDLING != 0
+    /* set to true if the callee returns an exception rather than
+     * result values on the stack
+     */
+    bool exception_raised;
+    uint32_t tag_index;
+#endif
+
 #if WASM_ENABLE_FAST_INTERP != 0
     /* Return offset of the first return value of current frame,
        the callee will put return values here continuously */