LibRegex: Make get_opcode() return a reference

Previously this would return a pointer which could be null if the
requested opcode was invalid. This should never be the case though
so let's VERIFY() that instead.

4 files changed, 25 insertions, 38 deletions

diff --git a/Userland/Libraries/LibRegex/RegexByteCode.cpp b/Userland/Libraries/LibRegex/RegexByteCode.cpp
index 2f05f61dde..feb20cf743 100644
--- a/Userland/Libraries/LibRegex/RegexByteCode.cpp
+++ b/Userland/Libraries/LibRegex/RegexByteCode.cpp
@@ -90,7 +90,7 @@ static const char* character_class_name(CharClass ch_class)
 OwnPtr<OpCode> ByteCode::s_opcodes[(size_t)OpCodeId::Last + 1];
 bool ByteCode::s_opcodes_initialized { false };
 
-ALWAYS_INLINE OpCode* ByteCode::get_opcode_by_id(OpCodeId id) const
+ALWAYS_INLINE OpCode& ByteCode::get_opcode_by_id(OpCodeId id) const
 {
     if (!s_opcodes_initialized) {
         for (u32 i = (u32)OpCodeId::First; i <= (u32)OpCodeId::Last; ++i) {
@@ -148,27 +148,24 @@ ALWAYS_INLINE OpCode* ByteCode::get_opcode_by_id(OpCodeId id) const
         s_opcodes_initialized = true;
     }
 
-    if (id > OpCodeId::Last)
-        return nullptr;
+    VERIFY(id >= OpCodeId::First && id <= OpCodeId::Last);
 
-    auto* opcode = &*s_opcodes[(u32)id];
+    auto& opcode = s_opcodes[(u32)id];
     opcode->set_bytecode(*const_cast<ByteCode*>(this));
-    return opcode;
+    return *opcode;
 }
 
-OpCode* ByteCode::get_opcode(MatchState& state) const
+OpCode& ByteCode::get_opcode(MatchState& state) const
 {
-    OpCode* op_code;
-
-    if (state.instruction_position >= size()) {
-        op_code = get_opcode_by_id(OpCodeId::Exit);
-    } else
-        op_code = get_opcode_by_id((OpCodeId)at(state.instruction_position));
-
-    if (op_code)
-        op_code->set_state(state);
-
-    return op_code;
+    OpCodeId opcode_id;
+    if (state.instruction_position >= size())
+        opcode_id = OpCodeId::Exit;
+    else
+        opcode_id = (OpCodeId)at(state.instruction_position);
+
+    auto& opcode = get_opcode_by_id(opcode_id);
+    opcode.set_state(state);
+    return opcode;
 }
 
 ALWAYS_INLINE ExecutionResult OpCode_Exit::execute(const MatchInput& input, MatchState& state, MatchOutput&) const
diff --git a/Userland/Libraries/LibRegex/RegexByteCode.h b/Userland/Libraries/LibRegex/RegexByteCode.h
index c7d610b584..7d4cb43007 100644
--- a/Userland/Libraries/LibRegex/RegexByteCode.h
+++ b/Userland/Libraries/LibRegex/RegexByteCode.h
@@ -439,7 +439,7 @@ public:
         bytecode_to_repeat = move(bytecode);
     }
 
-    OpCode* get_opcode(MatchState& state) const;
+    OpCode& get_opcode(MatchState& state) const;
 
 private:
     void insert_string(const StringView& view)
@@ -449,7 +449,7 @@ private:
             empend((ByteCodeValueType)view[i]);
     }
 
-    ALWAYS_INLINE OpCode* get_opcode_by_id(OpCodeId id) const;
+    ALWAYS_INLINE OpCode& get_opcode_by_id(OpCodeId id) const;
     static OwnPtr<OpCode> s_opcodes[(size_t)OpCodeId::Last + 1];
     static bool s_opcodes_initialized;
 };
diff --git a/Userland/Libraries/LibRegex/RegexDebug.h b/Userland/Libraries/LibRegex/RegexDebug.h
index 821870242b..ebe25d8ddb 100644
--- a/Userland/Libraries/LibRegex/RegexDebug.h
+++ b/Userland/Libraries/LibRegex/RegexDebug.h
@@ -39,19 +39,14 @@ public:
         auto& bytecode = regex.parser_result.bytecode;
 
         for (;;) {
-            auto* opcode = bytecode.get_opcode(state);
-            if (!opcode) {
-                dbgln("Wrong opcode... failed!");
-                return;
-            }
-
-            print_opcode("PrintBytecode", *opcode, state);
+            auto& opcode = bytecode.get_opcode(state);
+            print_opcode("PrintBytecode", opcode, state);
             out(m_file, "{}", m_debug_stripline);
 
-            if (is<OpCode_Exit>(*opcode))
+            if (is<OpCode_Exit>(opcode))
                 break;
 
-            state.instruction_position += opcode->size();
+            state.instruction_position += opcode.size();
         }
 
         fflush(m_file);
diff --git a/Userland/Libraries/LibRegex/RegexMatcher.cpp b/Userland/Libraries/LibRegex/RegexMatcher.cpp
index d294a01c83..b402442220 100644
--- a/Userland/Libraries/LibRegex/RegexMatcher.cpp
+++ b/Userland/Libraries/LibRegex/RegexMatcher.cpp
@@ -301,15 +301,10 @@ Optional<bool> Matcher<Parser>::execute(const MatchInput& input, MatchState& sta
 
     for (;;) {
         ++output.operations;
-        auto* opcode = bytecode.get_opcode(state);
-
-        if (!opcode) {
-            dbgln("Wrong opcode... failed!");
-            return {};
-        }
+        auto& opcode = bytecode.get_opcode(state);
 
 #if REGEX_DEBUG
-        s_regex_dbg.print_opcode("VM", *opcode, state, recursion_level, false);
+        s_regex_dbg.print_opcode("VM", opcode, state, recursion_level, false);
 #endif
 
         ExecutionResult result;
@@ -317,14 +312,14 @@ Optional<bool> Matcher<Parser>::execute(const MatchInput& input, MatchState& sta
             --input.fail_counter;
             result = ExecutionResult::Failed_ExecuteLowPrioForks;
         } else {
-            result = opcode->execute(input, state, output);
+            result = opcode.execute(input, state, output);
         }
 
 #if REGEX_DEBUG
-        s_regex_dbg.print_result(*opcode, bytecode, input, state, result);
+        s_regex_dbg.print_result(opcode, bytecode, input, state, result);
 #endif
 
-        state.instruction_position += opcode->size();
+        state.instruction_position += opcode.size();
 
         switch (result) {
         case ExecutionResult::Fork_PrioLow: