src/backend/blockopt.c

@@ -356,6 +356,9 @@ void block_free(block *b)
             type_free(b->Bcatchtype);
             break;
 #endif
+        case BCjcatch:
+            free(b->BS.BIJCATCH.actionTable);
+            break;
         case BCasm:
             code_free(b->Bcode);
             break;

src/backend/cc.h

@@ -427,6 +427,8 @@ typedef struct block
         struct
         {   Symbol *catchtype;          // one type for each catch block
             #define Bcatchtype BS.BIJCATCH.catchtype
+
+            unsigned *actionTable;      // EH_DWARF: indices into typeTable, first is # of entries
         } BIJCATCH;                     // BCjcatch
 #endif
 #if NTEXCEPTIONS || MARS
@@ -722,6 +724,11 @@ typedef struct FUNC_S
     Funcsym *Fsurrogatesym;     // Fsurrogate: surrogate cast function
 
     char *Fredirect;            // redirect function name to this name in object
+
+    // Array of catch types for EH_DWARF Types Table generation
+    Symbol **typesTable;
+    size_t typesTableDim;       // number used in typesTable[]
+    size_t typesTableCapacity;  // allocated capacity of typesTable[]
 } func_t;
 
 #define func_calloc()   ((func_t *) mem_fcalloc(sizeof(func_t)))

src/backend/symbol.c

@@ -835,6 +835,7 @@ void symbol_free(symbol *s)
                 list_free(&f->Fthunks,(list_free_fp)symbol_free);
               }
                 list_free(&f->Fsymtree,(list_free_fp)symbol_free);
+                free(f->typesTable);
                 func_free(f);
             }
             switch (s->Sclass)

src/s2ir.c

@@ -1077,6 +1077,7 @@ class S2irVisitor : public Visitor
 
             size_t numcases = s->catches->dim;
             bswitch->BS.Bswitch = (targ_llong *) ::malloc(sizeof(targ_llong) * (numcases + 1));
+            assert(bswitch->BS.Bswitch);
             bswitch->BS.Bswitch[0] = numcases;
             bswitch->appendSucc(defaultblock);
             block_next(blx, BCswitch, NULL);
@@ -1089,6 +1090,36 @@ class S2irVisitor : public Visitor
                 if (cs->var)
                     cs->var->csym = tryblock->jcatchvar;
 
+                assert(cs->type);
+
+                Symbol *catchtype = toSymbol(cs->type->toBasetype());
+
+                /* Look for catchtype in typesTable[] using linear search,
+                 * insert if not already there,
+                 * log index in Action Table (i.e. switch case table)
+                 */
+                func_t *f = blx->funcsym->Sfunc;
+                for (size_t j = 0; 1; ++j)
+                {
+                    if (j < f->typesTableDim)
+                    {
+                        if (catchtype != f->typesTable[j])
+                            continue;
+                    }
+                    else
+                    {
+                        if (j == f->typesTableCapacity)
+                        {   // enlarge typesTable[]
+                            f->typesTableCapacity = f->typesTableCapacity * 2 + 4;
+                            f->typesTable = (Symbol **)::realloc(f->typesTable, f->typesTableCapacity * sizeof(Symbol *));
+                            assert(f->typesTable);
+                        }
+                        f->typesTable[j] = catchtype;
+                    }
+                    bswitch->BS.Bswitch[1 + i] = 1 + j;  // index starts at 1
+                    break;
+                }
+
                 block *bcase = blx->curblock;
                 bswitch->appendSucc(bcase);
 
@@ -1123,6 +1154,14 @@ class S2irVisitor : public Visitor
                     block_next(blx, BCgoto, NULL);
             }
 
+            /* Make a copy of the switch case table, which will later become the Action Table.
+             * Need a copy since the bswitch may get rewritten by the optimizer.
+             */
+            bcatch->BS.BIJCATCH.actionTable = (unsigned *)::malloc(sizeof(unsigned) * (numcases + 1));
+            assert(bcatch->BS.BIJCATCH.actionTable);
+            for (size_t i = 0; i < numcases + 1; ++i)
+                bcatch->BS.BIJCATCH.actionTable[i] = (unsigned)bswitch->BS.Bswitch[i];
+
         }
         else
         {