parse_aut: add support for #line

Fixes issue #232.

* spot/parseaut/parseaut.yy, spot/parseaut/public.hh,
spot/parseaut/scanaut.ll: Add support for #line.
* tests/core/parseaut.test: Test it.
* NEWS: Mention it.

NEWS

@@ -191,6 +191,12 @@ New in spot 2.9.6.dev (not yet released)
     setting SPOT_SIMULATION_REDUCTION environment variable or using the
     "-x simul-method=..." option (see spot-x(7)).
 
+  - The automaton parser will now recognize lines of the form
+      #line 10 "filename"
+    that may occur *between* the automata of an input stream to specify
+    that error messages should be emitted as if the next automaton
+    was read from "filename" starting on line 10.  (Issue #232)
+
   Python:
 
   - Bindings for functions related to games.

spot/parseaut/parseaut.yy

@@ -255,6 +255,7 @@ extern "C" int strverscmp(const char *s1, const char *s2);
 %token ACCPAIRS "Acceptance-Pairs:"
 %token ACCSIG "Acc-Sig:";
 %token ENDOFHEADER "---";
+%token <str> LINEDIRECTIVE "#line"
 
 
 %left '|'
@@ -338,6 +339,10 @@ extern "C" int strverscmp(const char *s1, const char *s2);
 
 %%
 aut: aut-1     { res.h->loc = @$; YYACCEPT; }
+/* Not how we do not accept garbage before LINEDIRECTIVE. This is because
+   all error will be relative to the specified filename, so that filename
+   must not be changed after any error was reported. */
+   | LINEDIRECTIVE { res.h->filename = *$1; } aut
    | ENDOFFILE { YYABORT; }
    | error ENDOFFILE { YYABORT; }
    | error aut-1
@@ -2635,6 +2640,7 @@ namespace spot
     check_version(r);
     last_loc = r.h->loc;
     last_loc.step();
+    filename_ = r.h->filename; // in case it was changed
     if (r.h->aborted)
       {
 	if (opts_.ignore_abort)

spot/parseaut/public.hh

@@ -69,7 +69,7 @@ namespace spot
     /// Format of the automaton.
     parsed_aut_type type = parsed_aut_type::Unknown;
     /// Name of the stream (used for displaying syntax errors)
-    const std::string filename;
+    std::string filename;
     /// \brief Syntax errors that occurred during parsing.
     ///
     /// Note that the parser does not print any diagnostic.

spot/parseaut/scanaut.ll

@@ -1,5 +1,5 @@
 /* -*- coding: utf-8 -*-
-** Copyright (C) 2014-2018, 2020 Laboratoire de Recherche et Développement
+** Copyright (C) 2014-2018, 2020, 2021 Laboratoire de Recherche et Développement
 ** de l'Epita (LRDE).
 **
 ** This file is part of Spot, a model checking library.
@@ -90,6 +90,27 @@ identifier  [[:alpha:]_][[:alnum:]_.-]*
 			  BEGIN(in_COMMENT);
 			  yyextra->comment_level = 1;
 			}
+<INITIAL>"#line"[ \t]+[0-9]+[ \t]+\"[^\"\n]*\" {
+			    errno = 0;
+			    char* end;
+			    unsigned long n = strtoul(yytext + 5, &end, 10);
+			    yylval->num = n;
+			    if (errno || yylval->num != n)
+                              {
+			         error_list.push_back(spot::parse_aut_error(*yylloc, "value too large"));                             }
+                            else if (error_list.empty())
+                              {
+			         char* beg = strchr(end, '"');
+                                 end = strrchr(beg + 1, '"');
+			         yylval->str = new std::string(beg + 1, end);
+                                 yylloc->initialize(nullptr, n - 1, yylloc->begin.column);
+                                 return token::LINEDIRECTIVE;
+                              }
+                            else
+                              {
+			         error_list.push_back(spot::parse_aut_error(*yylloc, "#line may not occur after any error"));
+                              }
+                          }
 <INITIAL>"HOA:"           BEGIN(in_HOA); return token::HOA;
 <INITIAL,in_HOA>"--ABORT--" BEGIN(INITIAL); throw spot::hoa_abort{*yylloc};
 <INITIAL>"never"	  BEGIN(in_NEVER); return token::NEVER;

tests/core/parseaut.test

@@ -1,7 +1,7 @@
 #!/bin/sh
 # -*- coding: utf-8 -*-
-# Copyright (C) 2014-2018, 2020 Laboratoire de Recherche et Développement de
+# Copyright (C) 2014-2018, 2020-2021 Laboratoire de Recherche et
-# l'Epita (LRDE).
+# Développement de l'Epita (LRDE).
 #
 # This file is part of Spot, a model checking library.
 #
@@ -69,6 +69,7 @@ input:2.1-9: ... previously defined here.
 EOF
 
 cat >input <<EOF
+#line 1 "hoa"
 HOA: v1
 States: 1
 Start: 0
@@ -80,6 +81,7 @@ State: 0 {0}
 State: 1 {0}
 [t] 1
 --END--
+#line 1 "lbtt"
 2 1t
 2 1
 1 -1 "b"
@@ -103,17 +105,18 @@ EOF
 
 diff='different state numbers have been used'
 expecterr input <<EOF
-input:8.5: state number is larger than state count...
+hoa:8.5: state number is larger than state count...
-input:2.1-9: ... declared here.
+hoa:2.1-9: ... declared here.
-input:9.8: state number is larger than state count...
+hoa:9.8: state number is larger than state count...
-input:2.1-9: ... declared here.
+hoa:2.1-9: ... declared here.
-input:10.5: state number is larger than state count...
+hoa:10.5: state number is larger than state count...
-input:2.1-9: ... declared here.
+hoa:2.1-9: ... declared here.
-input:12.1-19.2: 2 states have been declared, but 3 $diff
+lbtt:1.1-8.2: 2 states have been declared, but 3 $diff
-input:25.5-10: non-Boolean transition label (replaced by true)
+lbtt:14.5-10: non-Boolean transition label (replaced by true)
 EOF
 
 cat >input <<EOF
+#line 1 /* incomplete line directive */
 HOA: v1
 States: 1
 Start: 0
@@ -125,15 +128,22 @@ State: 0 {0}
 State: 0 {0}
 [t] 0
 --END--
+#line 1 "foo" /* line directive at the end is ignored */
 EOF
 
 expecterr input <<EOF
-input:8.2: AP number is larger than the number of APs...
+input:1.1: syntax error, unexpected invalid token
-input:4.1-5: ... declared here
+input:9.2: AP number is larger than the number of APs...
-input:9.1-8: redeclaration of state 0
+input:5.1-5: ... declared here
+input:10.1-8: redeclaration of state 0
+input:1.1-7: leading garbage was ignored
 EOF
 
 cat >input <<EOF
+#line 0 invalid
+#line -0 "invalid"
+#line 99999999999999 "too large"
+#line 1 "real"
 HOA: v1
 States: 0
 AP: 1 "a" "b"
@@ -143,7 +153,11 @@ Acceptance: 0 t
 EOF
 
 expecterr input <<EOF
-input:3.1-13: found 2 atomic propositions instead of the 1 announced
+input:1.1: syntax error, unexpected invalid token
+input:3.1-32: value too large
+input:4.1-14: #line may not occur after any error
+input:7.1-13: found 2 atomic propositions instead of the 1 announced
+input:1.1-2.18: leading garbage was ignored
 EOF
 
 cat >input <<EOF