Merge pull request #1077 from YosysHQ/clifford/pr983

elaboration system tasks

frontends/ast/ast.cc

@@ -154,6 +154,7 @@ std::string AST::type2str(AstNodeType type)
 	X(AST_GENIF)
 	X(AST_GENCASE)
 	X(AST_GENBLOCK)
+	X(AST_TECALL)
 	X(AST_POSEDGE)
 	X(AST_NEGEDGE)
 	X(AST_EDGE)

frontends/ast/ast.h

@@ -137,6 +137,7 @@ namespace AST
 		AST_GENIF,
 		AST_GENCASE,
 		AST_GENBLOCK,
+		AST_TECALL,
 		
 		AST_POSEDGE,
 		AST_NEGEDGE,

frontends/ast/genrtlil.cc

@@ -1575,6 +1575,37 @@ RTLIL::SigSpec AstNode::genRTLIL(int width_hint, bool sign_hint)
 			delete always;
 		} break;
 
+	case AST_TECALL: {
+			int sz = children.size();
+			if (str == "$info") {
+				if (sz > 0)
+					log_file_info(filename, linenum, "%s.\n", children[0]->str.c_str());
+				else
+					log_file_info(filename, linenum, "\n");
+			} else if (str == "$warning") {
+				if (sz > 0)
+					log_file_warning(filename, linenum, "%s.\n", children[0]->str.c_str());
+				else
+					log_file_warning(filename, linenum, "\n");
+			} else if (str == "$error") {
+				if (sz > 0)
+					log_file_error(filename, linenum, "%s.\n", children[0]->str.c_str());
+				else
+					log_file_error(filename, linenum, "\n");
+			} else if (str == "$fatal") {
+				// TODO: 1st parameter, if exists, is 0,1 or 2, and passed to $finish()
+				// if no parameter is given, default value is 1
+				// dollar_finish(sz ? children[0] : 1);
+				// perhaps create & use log_file_fatal()
+				if (sz > 0)
+					log_file_error(filename, linenum, "FATAL: %s.\n", children[0]->str.c_str());
+				else
+					log_file_error(filename, linenum, "FATAL.\n");
+			} else {
+				log_file_error(filename, linenum, "Unknown elabortoon system task '%s'.\n", str.c_str());
+			}
+		} break;
+
 	case AST_FCALL: {
 			if (str == "\\$anyconst" || str == "\\$anyseq" || str == "\\$allconst" || str == "\\$allseq")
 			{

frontends/verilog/verilog_lexer.l

@@ -311,6 +311,11 @@ supply1 { return TOK_SUPPLY1; }
 	return TOK_ID;
 }
 
+"$"(info|warning|error|fatal) {
+	frontend_verilog_yylval.string = new std::string(yytext);
+	return TOK_ELAB_TASK;
+}
+
 "$signed"   { return TOK_TO_SIGNED; }
 "$unsigned" { return TOK_TO_UNSIGNED; }
 

frontends/verilog/verilog_parser.y

@@ -133,7 +133,7 @@ struct specify_rise_fall {
 }
 
 %token <string> TOK_STRING TOK_ID TOK_CONSTVAL TOK_REALVAL TOK_PRIMITIVE
-%token <string> TOK_SVA_LABEL TOK_SPECIFY_OPER
+%token <string> TOK_SVA_LABEL TOK_SPECIFY_OPER TOK_ELAB_TASK
 %token TOK_ASSERT TOK_ASSUME TOK_RESTRICT TOK_COVER TOK_FINAL
 %token ATTR_BEGIN ATTR_END DEFATTR_BEGIN DEFATTR_END
 %token TOK_MODULE TOK_ENDMODULE TOK_PARAMETER TOK_LOCALPARAM TOK_DEFPARAM
@@ -2176,6 +2176,15 @@ gen_stmt:
 		if ($6 != NULL)
 			delete $6;
 		ast_stack.pop_back();
+	} |
+	TOK_ELAB_TASK {
+		AstNode *node = new AstNode(AST_TECALL);
+		node->str = *$1;
+		delete $1;
+		ast_stack.back()->children.push_back(node);
+		ast_stack.push_back(node);
+	} opt_arg_list ';'{
+		ast_stack.pop_back();		
 	};
 
 gen_stmt_block:

kernel/log.cc

@@ -282,6 +282,17 @@ void log_file_warning(const std::string &filename, int lineno,
 	va_end(ap);
 }
 
+void log_file_info(const std::string &filename, int lineno,
+                      const char *format, ...)
+{
+	va_list ap;
+	va_start(ap, format);
+	std::string fmt = stringf("%s:%d: Info: %s",
+			filename.c_str(), lineno, format);
+	logv(fmt.c_str(), ap);
+	va_end(ap);
+}
+
 YS_ATTRIBUTE(noreturn)
 static void logv_error_with_prefix(const char *prefix,
                                    const char *format, va_list ap)

kernel/log.h

@@ -80,6 +80,7 @@ void log_warning(const char *format, ...) YS_ATTRIBUTE(format(printf, 1, 2));
 
 // Log with filename to report a problem in a source file.
 void log_file_warning(const std::string &filename, int lineno, const char *format, ...) YS_ATTRIBUTE(format(printf, 3, 4));
+void log_file_info(const std::string &filename, int lineno, const char *format, ...) YS_ATTRIBUTE(format(printf, 3, 4));
 
 void log_warning_noprefix(const char *format, ...) YS_ATTRIBUTE(format(printf, 1, 2));
 YS_NORETURN void log_error(const char *format, ...) YS_ATTRIBUTE(format(printf, 1, 2), noreturn);

tests/various/elab_sys_tasks.sv

@@ -0,0 +1,30 @@
+module test;
+localparam X=1;
+genvar i;
+generate
+if (X == 1)
+  $info("X is 1");
+if (X == 1)
+  $warning("X is 1");
+else
+  $error("X is not 1");
+case (X)
+  1: $info("X is 1 in a case statement");
+endcase
+//case (X-1)
+//  1: $warn("X is 2");
+//  default: $warn("X might be anything in a case statement");
+//endcase
+for (i = 0; i < 3; i = i + 1)
+begin
+  case(i)
+    0: $info;
+    1: $warning;
+    default: $info("default case statemnent");
+  endcase
+end
+
+$info("This is a standalone $info(). Next $info has no parameters");
+$info;
+endgenerate
+endmodule

tests/various/elab_sys_tasks.ys

@@ -0,0 +1 @@
+read_verilog -sv elab_sys_tasks.sv