fix: Remove ALIAS operand parsing limitation (#178)

(fixes #157)

clients/vscode-hlasmplugin/CHANGELOG.md

@@ -19,6 +19,7 @@
 - Files with extension should not be set to hlasm in libs folder
 - Lookahead mode does not work correctly when triggered from AINSERTed code
 - Incorrect relative immediate operand validation
+- Remove ALIAS operand parsing limitation
 
 ## [0.14.0](https://github.com/eclipse/che-che4z-lsp-for-hlasm/compare/0.13.0...0.14.0) (2021-08-18)
 

parser_library/src/checking/asm_instr_check.cpp

@@ -1236,7 +1236,7 @@ bool alias::check(const std::vector<const asm_operand*>& to_check,
         {
             // TO DO - no support for four characters in EBCDIC (¢, ¬, ±, ¦) - we throw an error although it should
             // not be
-            std::regex regex(R"([\.<¢\(\+\|&!\$\*\);¬\-\/¦,%_>\?`,:#@\=\"~±\[\]\{\}\^\\a-zA-Z0-9]*)");
+            static const std::regex regex(R"([\.<¢\(\+\|&!\$\*\);¬\-\/¦,%_>\?`,:#@\=\"~±\[\]\{\}\^\\a-zA-Z0-9]*)");
             std::string substr = first->operand_identifier.substr(2, first->operand_identifier.size() - 3);
             if (!std::regex_match(substr, regex))
             {
@@ -1247,7 +1247,7 @@ bool alias::check(const std::vector<const asm_operand*>& to_check,
         }
         else if (first->operand_identifier[0] == 'X')
         {
-            if (first->operand_identifier.size() % 2 == 1)
+            if ((first->operand_identifier.size() - 3) % 2 == 1)
             {
                 add_diagnostic(diagnostic_op::error_A154_ALIAS_X_format_no_of_chars(first->operand_range));
                 return false;
@@ -1282,10 +1282,6 @@ bool alias::check(const std::vector<const asm_operand*>& to_check,
             }
             return true;
         }
-        else
-        {
-            return false;
-        }
     }
     add_diagnostic(diagnostic_op::error_A151_ALIAS_op_format(first->operand_range));
     return false;

parser_library/src/diagnostic.cpp

@@ -682,6 +682,11 @@ diagnostic_op diagnostic_op::error_A162_PROCESS_uknown_option(const std::string&
         diagnostic_severity::error, "A162", "Error at *PROCESS instruction: unknown assembler option " + option, range);
 }
 
+diagnostic_op diagnostic_op::error_A163_ALIAS_mandatory_label(const range& range)
+{
+    return diagnostic_op(diagnostic_severity::error, "A163", "Label not provided on ALIAS instruction", range);
+}
+
 diagnostic_op diagnostic_op::error_A200_SCOPE_param(const std::string& instr_name, const range& range)
 {
     return diagnostic_op(diagnostic_severity::error,

parser_library/src/diagnostic.h

@@ -279,6 +279,8 @@ struct diagnostic_op
 
     static diagnostic_op error_A162_PROCESS_uknown_option(const std::string& option, const range& range);
 
+    static diagnostic_op error_A163_ALIAS_mandatory_label(const range& range);
+
     // operand parameters
 
     static diagnostic_op error_A200_SCOPE_param(const std::string& instr_name, const range& range);

parser_library/src/parsing/grammar/assembler_operand_rules.g4

@@ -16,7 +16,14 @@
 parser grammar assembler_operand_rules; 
 
 asm_op returns [operand_ptr op]
-	: id lpar asm_op_comma_c rpar
+	:
+	{ ALIAS() }? ORDSYMBOL string
+	{
+		auto range = provider.get_range($ORDSYMBOL,$string.ctx->getStop());
+		collector.add_hl_symbol(token_info(provider.get_range($ORDSYMBOL),hl_scopes::self_def_type));
+		$op = std::make_unique<expr_assembler_operand>(std::make_unique<mach_expr_default>(range),$ctx->getText(),range);
+	}
+	| id lpar asm_op_comma_c rpar
 	{
 		$op = std::make_unique<complex_assembler_operand>(
 			*$id.name,std::move($asm_op_comma_c.asm_ops),
@@ -47,7 +54,7 @@ asm_op returns [operand_ptr op]
 			provider.get_range($lpar.ctx->getStart(),$rpar.ctx->getStop())
 		);
 	}
-	| mach_expr
+	| { !ALIAS() }? mach_expr
 	{
 		std::string upper_case = $mach_expr.ctx->getText();
 		context::to_upper(upper_case);

parser_library/src/parsing/parser_impl.cpp

@@ -235,6 +235,12 @@ bool parser_impl::UNKNOWN()
     return format.form == processing::processing_form::UNKNOWN;
 }
 
+bool parser_impl::ALIAS()
+{
+    auto& [format, opcode] = *proc_status;
+    return opcode.type == instruction_type::ASM && *opcode.value == "ALIAS";
+}
+
 antlr4::misc::IntervalSet parser_impl::getExpectedTokens()
 {
     if (proc_status->first.kind == processing::processing_kind::LOOKAHEAD)

parser_library/src/parsing/parser_impl.h

@@ -93,6 +93,7 @@ class parser_impl : public antlr4::Parser
     bool CA();
     bool MAC();
     bool UNKNOWN();
+    bool ALIAS();
 
 private:
     antlr4::misc::IntervalSet getExpectedTokens() override;

parser_library/src/processing/instruction_sets/asm_processor.cpp

@@ -642,6 +642,7 @@ asm_processor::process_table_t asm_processor::create_table(context::hlasm_contex
     table.emplace(h_ctx.ids().add("CCW1"), [this](rebuilt_statement stmt) { process_CCW(std::move(stmt)); });
     table.emplace(h_ctx.ids().add("CNOP"), [this](rebuilt_statement stmt) { process_CNOP(std::move(stmt)); });
     table.emplace(h_ctx.ids().add("START"), [this](rebuilt_statement stmt) { process_START(std::move(stmt)); });
+    table.emplace(h_ctx.ids().add("ALIAS"), [this](rebuilt_statement stmt) { process_ALIAS(std::move(stmt)); });
 
     return table;
 }
@@ -817,4 +818,18 @@ void asm_processor::process_START(rebuilt_statement stmt)
     hlasm_ctx.ord_ctx.set_available_location_counter_value(start_section_alignment, offset);
 }
 
+void asm_processor::process_ALIAS(rebuilt_statement stmt)
+{
+    if (!check(stmt, hlasm_ctx, checker_, *this))
+        return;
+    auto symbol_name = find_label_symbol(stmt);
+    if (symbol_name->empty())
+    {
+        add_diagnostic(diagnostic_op::error_A163_ALIAS_mandatory_label(stmt.stmt_range_ref()));
+        return;
+    }
+
+    // TODO: check that the symbol_name is an external symbol
+}
+
 } // namespace hlasm_plugin::parser_library::processing

parser_library/src/processing/instruction_sets/asm_processor.h

@@ -64,6 +64,7 @@ class asm_processor : public low_language_processor
     void process_CCW(rebuilt_statement stmt);
     void process_CNOP(rebuilt_statement stmt);
     void process_START(rebuilt_statement stmt);
+    void process_ALIAS(rebuilt_statement stmt);
 
     template<checking::data_instr_type instr_type>
     void process_data_instruction(rebuilt_statement stmt);

parser_library/test/checking/asm_instr_check_test.cpp

@@ -876,14 +876,10 @@ TEST_F(instruction_test, ainsert)
 
 TEST_F(instruction_test, alias)
 {
-    // TO DO - not working due to self-defining terms issues
-
-    /*
     EXPECT_FALSE(checker.check("ALIAS", test_alias_false, range(), collector));
     EXPECT_TRUE(checker.check("ALIAS", test_alias_true_one, range(), collector));
     EXPECT_TRUE(checker.check("ALIAS", test_alias_true_two, range(), collector));
     EXPECT_FALSE(checker.check("ALIAS", test_acontrol_true, range(), collector));
-    */
 }
 
 TEST_F(instruction_test, amode)

parser_library/test/processing/asm_instr_test.cpp

@@ -14,6 +14,7 @@
 
 #include "gtest/gtest.h"
 
+#include "../common_testing.h"
 #include "analyzer.h"
 #include "ebcdic_encoding.h"
 
@@ -132,4 +133,82 @@ CNOPSYM CNOP ADDR,16
     auto symbol = ctx.ord_ctx.get_symbol(ctx.ids().add("CNOPSYM"));
     ASSERT_NE(symbol, nullptr);
     EXPECT_EQ(symbol->value().get_reloc().offset(), 4);
-}
+}
+
+TEST(asm_instr_processing, ALIAS_mandatory_label)
+{
+    std::string input = R"(
+  ALIAS C'SOMESTRING'
+  ALIAS X'434343434343'
+)";
+
+    analyzer a(input);
+    a.analyze();
+    a.collect_diags();
+
+    EXPECT_TRUE(matches_message_codes(a.diags(), { "A163", "A163" }));
+}
+
+TEST(asm_instr_processing, ALIAS_external_missing)
+{
+    /* TODO: label must be an external symbol
+    std::string input = R"(
+A ALIAS C'SOMESTRING'
+)";
+
+    analyzer a(input);
+    a.analyze();
+    a.collect_diags();
+
+    EXPECT_TRUE(matches_message_codes(a.diags(), { "????" }));
+    */
+}
+
+TEST(asm_instr_processing, ALIAS_external_present)
+{
+    std::string input = R"(
+A DSECT
+B START
+C CSECT
+D DXD F
+  DC Q(A)
+  ENTRY E
+E DS 0H
+  DC V(F)
+G RSECT
+H COM
+  EXTRN I
+  WXTRN J
+A ALIAS C'STRING'
+B ALIAS C'STRING'
+C ALIAS C'STRING'
+D ALIAS C'STRING'
+E ALIAS C'STRING'
+F ALIAS C'STRING'
+G ALIAS C'STRING'
+H ALIAS C'STRING'
+I ALIAS C'STRING'
+J ALIAS C'STRING'
+)";
+
+    analyzer a(input);
+    a.analyze();
+    a.collect_diags();
+
+    EXPECT_TRUE(a.diags().empty());
+}
+
+TEST(asm_instr_processing, ALIAS_with_opsyn)
+{
+    std::string input = R"(
+X OPSYN ALIAS
+L X     C'SOMESTRING'
+  EXTRN L
+)";
+
+    analyzer a(input);
+    a.analyze();
+    a.collect_diags();
+
+    EXPECT_TRUE(a.diags().empty());
+}