[PATCH 3/3] try to match the columns in the output of locations

[Akim Demaille]

* src/scan-code.l (indent): New.
(handle_action_dollar, handle_action_at): Use it.
* tests/synclines.at (Output columns): Check it.
---
 src/scan-code.l    | 24 ++++++++++++++++++------
 tests/synclines.at |  9 +++++++++
 2 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/src/scan-code.l b/src/scan-code.l
index 414a28a7..ead6f3b0 100644
--- a/src/scan-code.l
+++ b/src/scan-code.l
@@ -587,6 +587,22 @@ fetch_type_name (char *cp, char const **type_name,
   return cp;
 }
 
+
+/* Compilers such as GCC 9 quote and underline the source code, it is
+   important for the generated code to (try to) be consistent with the
+   columns of the input file. */
+
+static void
+indent (const location *l)
+{
+  if (!no_lines_flag)
+    obstack_printf (&obstack_for_string,
+                    "\n]b4_syncline(%d, %s)dnl\n[%*s",
+                    l->start.line,
+                    quotearg_style (c_quoting_style, l->start.file),
+                    l->end.column - 1, "");
+}
+
 /*------------------------------------------------------------------.
 | TEXT is pointing to a wannabee semantic value (i.e., a '$').      |
 |                                                                   |
@@ -698,12 +714,7 @@ handle_action_dollar (symbol_list *rule, char *text, const 
location *dollar_loc)
       }
       break;
     }
-  if (!no_lines_flag)
-    obstack_printf (&obstack_for_string,
-                    "\n]b4_syncline(%d, %s)dnl\n[%*s",
-                    dollar_loc->start.line,
-                    quotearg_style (c_quoting_style, dollar_loc->start.file),
-                    dollar_loc->end.column - 1, "");
+  indent (dollar_loc);
 }
 
 
@@ -747,6 +758,7 @@ handle_action_at (symbol_list *rule, char *text, const 
location *at_loc)
                       effective_rule_length, n);
       break;
     }
+  indent (at_loc);
 }
 
 
diff --git a/tests/synclines.at b/tests/synclines.at
index f900ba44..a2d24d2a 100644
--- a/tests/synclines.at
+++ b/tests/synclines.at
@@ -532,6 +532,7 @@ AT_DATA([input.y],
 %%
 exp: exp '+' exp {  /* --BEGIN */
                     $$ = $1 + $3;
+                    @$ = @1 + @3;
                     /* --END */ }
    | '0'
 ]])
@@ -561,6 +562,13 @@ AT_CHECK([[sed -ne '/--BEGIN/,/--END/{' \
                             + (yyvsp[0].exp)
 #line 19 "input.y"
                                 ;
+                    (yyloc)
+#line 20 "input.y"
+                       = (yylsp[-2])
+#line 20 "input.y"
+                            + (yylsp[0])
+#line 20 "input.y"
+                                ;
                     /* --END */ }
 ]])
 
@@ -583,6 +591,7 @@ AT_CHECK([[sed -ne '/--BEGIN/,/--END/{' \
               /* --END   */ }
                  {  /* --BEGIN */
                     (yyval.exp) = (yyvsp[-2].exp) + (yyvsp[0].exp);
+                    (yyloc) = (yylsp[-2]) + (yylsp[0]);
                     /* --END */ }
 ]])
 
-- 
2.22.0