cex: don't assume the terminal supports "•"

Use of print_unicode_char suggested by Bruno Haible.
https://lists.gnu.org/r/bug-gettext/2020-06/msg00012.html

* src/gram.h (print_dot_fallback, print_dot): New.
* src/gram.c, src/derivation.c: Use it.
* tests/counterexample.at, tests/report.at: Adjust the test suite.
* .travis.yml, README-hacking.md: Adjust.

1 files changed, 108 insertions, 108 deletions

diff --git a/tests/counterexample.at b/tests/counterexample.at
index fa02990d..fd77e96e 100644
--- a/tests/counterexample.at
+++ b/tests/counterexample.at
@@ -46,10 +46,10 @@ y: A | A B;
 AT_BISON_CHECK_CEX([input.y], [], [],
 [[input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
 Shift/reduce conflict on token B:
-  Example              A • B C
-  First derivation     s ::=[ a ::=[ A • ] x ::=[ B C ] ]
-  Example              A • B C
-  Second derivation    s ::=[ y ::=[ A • B ] c ::=[ C ] ]
+  Example              A . B C
+  First derivation     s ::=[ a ::=[ A . ] x ::=[ B C ] ]
+  Example              A . B C
+  Second derivation    s ::=[ y ::=[ A . B ] c ::=[ C ] ]
 
 input.y:4.4: warning: rule useless in parser due to conflicts [-Wother]
 ]])
@@ -76,10 +76,10 @@ bc: B bc C | B C;
 AT_BISON_CHECK_CEX([input.y], [], [],
 [[input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
 Shift/reduce conflict on token B:
-  Example              A • B C
-  First derivation     s ::=[ a ::=[ A • ] bc ::=[ B C ] ]
-  Example              A • B C
-  Second derivation    s ::=[ ac ::=[ A ac ::=[ b ::=[ • B ] ] C ] ]
+  Example              A . B C
+  First derivation     s ::=[ a ::=[ A . ] bc ::=[ B C ] ]
+  Example              A . B C
+  Second derivation    s ::=[ ac ::=[ A ac ::=[ b ::=[ . B ] ] C ] ]
 
 input.y:6.4: warning: rule useless in parser due to conflicts [-Wother]
 ]])
@@ -107,16 +107,16 @@ xby: B | X xby Y;
 AT_BISON_CHECK_CEX([input.y], [], [],
 [[input.y: warning: 2 shift/reduce conflicts [-Wconflicts-sr]
 Shift/reduce conflict on token B:
-  Example              A • B y
-  First derivation     s ::=[ ax ::=[ A x ::=[ • ] ] by ::=[ B y ] ]
-  Example              A • B
-  Second derivation    s ::=[ A xby ::=[ • B ] ]
+  Example              A . B y
+  First derivation     s ::=[ ax ::=[ A x ::=[ . ] ] by ::=[ B y ] ]
+  Example              A . B
+  Second derivation    s ::=[ A xby ::=[ . B ] ]
 
 Shift/reduce conflict on token B:
-  First example        A X • B y $end
-  First derivation     $accept ::=[ s ::=[ ax ::=[ A x ::=[ X x ::=[ • ] ] ] by ::=[ B y ] ] $end ]
-  Second example       A X • B Y $end
-  Second derivation    $accept ::=[ s ::=[ A xby ::=[ X xby ::=[ • B ] Y ] ] $end ]
+  First example        A X . B y $end
+  First derivation     $accept ::=[ s ::=[ ax ::=[ A x ::=[ X x ::=[ . ] ] ] by ::=[ B y ] ] $end ]
+  Second example       A X . B Y $end
+  Second derivation    $accept ::=[ s ::=[ A xby ::=[ X xby ::=[ . B ] Y ] ] $end ]
 
 input.y:5.4-9: warning: rule useless in parser due to conflicts [-Wother]
 ]])
@@ -144,10 +144,10 @@ bc: B C;
 AT_BISON_CHECK_CEX([input.y], [], [],
 [[input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
 Shift/reduce conflict on token C:
-  First example        B • C D $end
-  First derivation     $accept ::=[ g ::=[ x ::=[ b ::=[ B • ] cd ::=[ C D ] ] ] $end ]
-  Second example       B • C $end
-  Second derivation    $accept ::=[ g ::=[ x ::=[ bc ::=[ B • C ] ] ] $end ]
+  First example        B . C D $end
+  First derivation     $accept ::=[ g ::=[ x ::=[ b ::=[ B . ] cd ::=[ C D ] ] ] $end ]
+  Second example       B . C $end
+  Second derivation    $accept ::=[ g ::=[ x ::=[ bc ::=[ B . C ] ] ] $end ]
 
 input.y:6.4: warning: rule useless in parser due to conflicts [-Wother]
 ]])
@@ -173,10 +173,10 @@ y: A A B;
 AT_BISON_CHECK_CEX([input.y], [], [],
 [[input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
 Shift/reduce conflict on token A:
-  First example        A • A $end
-  First derivation     $accept ::=[ s ::=[ s ::=[ t ::=[ x ::=[ A • ] ] ] t ::=[ x ::=[ A ] ] ] $end ]
-  Second example       A • A B $end
-  Second derivation    $accept ::=[ s ::=[ t ::=[ y ::=[ A • A B ] ] ] $end ]
+  First example        A . A $end
+  First derivation     $accept ::=[ s ::=[ s ::=[ t ::=[ x ::=[ A . ] ] ] t ::=[ x ::=[ A ] ] ] $end ]
+  Second example       A . A B $end
+  Second derivation    $accept ::=[ s ::=[ t ::=[ y ::=[ A . A B ] ] ] $end ]
 
 ]])
 
@@ -206,16 +206,16 @@ y: Y;
 AT_BISON_CHECK_CEX([input.y], [], [],
 [[input.y: warning: 2 shift/reduce conflicts [-Wconflicts-sr]
 Shift/reduce conflict on token A:
-  Example              b • A X X Y
-  First derivation     a ::=[ r ::=[ b • ] t ::=[ A x ::=[ X ] xy ::=[ X Y ] ] ]
-  Example              b • A X X Y
-  Second derivation    a ::=[ s ::=[ b • xx ::=[ A X X ] y ::=[ Y ] ] ]
+  Example              b . A X X Y
+  First derivation     a ::=[ r ::=[ b . ] t ::=[ A x ::=[ X ] xy ::=[ X Y ] ] ]
+  Example              b . A X X Y
+  Second derivation    a ::=[ s ::=[ b . xx ::=[ A X X ] y ::=[ Y ] ] ]
 
 Shift/reduce conflict on token X:
-  First example        X • X xy
-  First derivation     a ::=[ x ::=[ X • ] t ::=[ X xy ] ]
-  Second example       A X • X
-  Second derivation    a ::=[ t ::=[ A xx ::=[ X • X ] ] ]
+  First example        X . X xy
+  First derivation     a ::=[ x ::=[ X . ] t ::=[ X xy ] ]
+  Second example       A X . X
+  Second derivation    a ::=[ t ::=[ A xx ::=[ X . X ] ] ]
 
 input.y:4.4: warning: rule useless in parser due to conflicts [-Wother]
 input.y:8.4: warning: rule useless in parser due to conflicts [-Wother]
@@ -240,21 +240,21 @@ b : A | b;
 AT_BISON_CHECK_CEX([input.y], [], [],
 [[input.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
 Reduce/reduce conflict on token $end:
-  Example              A b •
-  First derivation     a ::=[ A b • ]
-  Example              A b •
-  Second derivation    a ::=[ A b ::=[ b • ] ]
+  Example              A b .
+  First derivation     a ::=[ A b . ]
+  Example              A b .
+  Second derivation    a ::=[ A b ::=[ b . ] ]
 
 input.y:4.9: warning: rule useless in parser due to conflicts [-Wother]
 ]])
 
 AT_CLEANUP
 
-## ------------------------------- ##
-## Non-unifying R/R lr1 conflict.  ##
-## ------------------------------- ##
+## --------------------------------- ##
+## Non-unifying R/R LR(1) conflict.  ##
+## --------------------------------- ##
 
-AT_SETUP([Non-unifying R/R lr1 conflict])
+AT_SETUP([Non-unifying R/R LR(1) conflict])
 AT_KEYWORDS([cex])
 
 AT_DATA([[input.y]],
@@ -268,21 +268,21 @@ b: D;
 AT_BISON_CHECK_CEX([input.y], [], [],
 [[input.y: warning: 2 reduce/reduce conflicts [-Wconflicts-rr]
 Reduce/reduce conflict on tokens A, C:
-  First example        D • A $end
-  First derivation     $accept ::=[ s ::=[ a ::=[ D • ] A ] $end ]
-  Second example       B D • A $end
-  Second derivation    $accept ::=[ s ::=[ B b ::=[ D • ] A ] $end ]
+  First example        D . A $end
+  First derivation     $accept ::=[ s ::=[ a ::=[ D . ] A ] $end ]
+  Second example       B D . A $end
+  Second derivation    $accept ::=[ s ::=[ B b ::=[ D . ] A ] $end ]
 
 input.y:5.4: warning: rule useless in parser due to conflicts [-Wother]
 ]])
 
 AT_CLEANUP
 
-## ------------------------------- ##
-## Non-unifying R/R lr2 conflict.  ##
-## ------------------------------- ##
+## --------------------------------- ##
+## Non-unifying R/R LR(2) conflict.  ##
+## --------------------------------- ##
 
-AT_SETUP([Non-unifying R/R lr2 conflict])
+AT_SETUP([Non-unifying R/R LR(2) conflict])
 AT_KEYWORDS([cex])
 
 AT_DATA([[input.y]],
@@ -297,10 +297,10 @@ AT_BISON_CHECK_CEX([input.y], [], [],
 [[input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
 Shift/reduce conflict on token J:
 time limit exceeded: XXX
-  First example        H i • J $end
-  First derivation     $accept ::=[ s ::=[ a ::=[ H i • ] J ] $end ]
-  Second example       H i • J K $end
-  Second derivation    $accept ::=[ a ::=[ H i ::=[ i • J K ] ] $end ]
+  First example        H i . J $end
+  First derivation     $accept ::=[ s ::=[ a ::=[ H i . ] J ] $end ]
+  Second example       H i . J K $end
+  Second derivation    $accept ::=[ a ::=[ H i ::=[ i . J K ] ] $end ]
 
 input.y:4.4-6: warning: rule useless in parser due to conflicts [-Wother]
 ]])
@@ -329,10 +329,10 @@ b: A B C | A B D;
 AT_BISON_CHECK_CEX([input.y], [], [],
 [[input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
 Shift/reduce conflict on token B:
-  Example              N A • B C
-  First derivation     s ::=[ n ::=[ N a ::=[ A • ] B ] C ]
-  Example              N A • B C
-  Second derivation    s ::=[ n ::=[ N b ::=[ A • B C ] ] ]
+  Example              N A . B C
+  First derivation     s ::=[ n ::=[ N a ::=[ A . ] B ] C ]
+  Example              N A . B C
+  Second derivation    s ::=[ n ::=[ N b ::=[ A . B C ] ] ]
 
 input.y:5.4: warning: rule useless in parser due to conflicts [-Wother]
 ]])
@@ -362,16 +362,16 @@ C : A c A;
 AT_BISON_CHECK_CEX([input.y], [], [],
 [[input.y: warning: 4 reduce/reduce conflicts [-Wconflicts-rr]
 Reduce/reduce conflict on tokens b, c:
-  Example              B • b A A c A
-  First derivation     S ::=[ B ::=[ A ::=[ B • ] b A ] C ::=[ A c A ] ]
-  Example              B • b A c A
-  Second derivation    S ::=[ B C ::=[ A ::=[ B ::=[ A ::=[ • ] b A ] ] c A ] ]
+  Example              B . b A A c A
+  First derivation     S ::=[ B ::=[ A ::=[ B . ] b A ] C ::=[ A c A ] ]
+  Example              B . b A c A
+  Second derivation    S ::=[ B C ::=[ A ::=[ B ::=[ A ::=[ . ] b A ] ] c A ] ]
 
 Reduce/reduce conflict on tokens b, c:
-  Example              C • c A A b A
-  First derivation     S ::=[ C ::=[ A ::=[ C • ] c A ] B ::=[ A b A ] ]
-  Example              C • c A b A
-  Second derivation    S ::=[ C B ::=[ A ::=[ C ::=[ A ::=[ • ] c A ] ] b A ] ]
+  Example              C . c A A b A
+  First derivation     S ::=[ C ::=[ A ::=[ C . ] c A ] B ::=[ A b A ] ]
+  Example              C . c A b A
+  Second derivation    S ::=[ C B ::=[ A ::=[ C ::=[ A ::=[ . ] c A ] ] b A ] ]
 
 ]])
 
@@ -397,55 +397,55 @@ AT_BISON_CHECK_CEX([input.y], [], [],
 [[input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
 input.y: warning: 6 reduce/reduce conflicts [-Wconflicts-rr]
 Reduce/reduce conflict on token A:
-  First example        • c A A $end
-  First derivation     $accept ::=[ a ::=[ b ::=[ • ] d ::=[ c A A ] ] $end ]
-  Second example       • c A A $end
-  Second derivation    $accept ::=[ a ::=[ c ::=[ • ] d ::=[ c A A ] ] $end ]
+  First example        . c A A $end
+  First derivation     $accept ::=[ a ::=[ b ::=[ . ] d ::=[ c A A ] ] $end ]
+  Second example       . c A A $end
+  Second derivation    $accept ::=[ a ::=[ c ::=[ . ] d ::=[ c A A ] ] $end ]
 
 Reduce/reduce conflict on token A:
 time limit exceeded: XXX
-  First example        b • c A A $end
-  First derivation     $accept ::=[ a ::=[ b d ::=[ a ::=[ b ::=[ • ] d ::=[ c A A ] ] ] ] $end ]
-  Second example       b • A $end
-  Second derivation    $accept ::=[ a ::=[ b d ::=[ c ::=[ • ] A ] ] $end ]
+  First example        b . c A A $end
+  First derivation     $accept ::=[ a ::=[ b d ::=[ a ::=[ b ::=[ . ] d ::=[ c A A ] ] ] ] $end ]
+  Second example       b . A $end
+  Second derivation    $accept ::=[ a ::=[ b d ::=[ c ::=[ . ] A ] ] $end ]
 
 Reduce/reduce conflict on token A:
 time limit exceeded: XXX
-  First example        c • c A A $end
-  First derivation     $accept ::=[ a ::=[ c d ::=[ a ::=[ b ::=[ • ] d ::=[ c A A ] ] ] ] $end ]
-  Second example       c • A $end
-  Second derivation    $accept ::=[ a ::=[ c d ::=[ c ::=[ • ] A ] ] $end ]
+  First example        c . c A A $end
+  First derivation     $accept ::=[ a ::=[ c d ::=[ a ::=[ b ::=[ . ] d ::=[ c A A ] ] ] ] $end ]
+  Second example       c . A $end
+  Second derivation    $accept ::=[ a ::=[ c d ::=[ c ::=[ . ] A ] ] $end ]
 
 Shift/reduce conflict on token A:
 time limit exceeded: XXX
-  First example        b c • c A A $end
-  First derivation     $accept ::=[ a ::=[ b d ::=[ a ::=[ c d ::=[ a ::=[ b ::=[ • ] d ::=[ c A A ] ] ] ] ] ] $end ]
-  Second example       b c • A
-  Second derivation    a ::=[ b d ::=[ c • A ] ]
+  First example        b c . c A A $end
+  First derivation     $accept ::=[ a ::=[ b d ::=[ a ::=[ c d ::=[ a ::=[ b ::=[ . ] d ::=[ c A A ] ] ] ] ] ] $end ]
+  Second example       b c . A
+  Second derivation    a ::=[ b d ::=[ c . A ] ]
 
 Reduce/reduce conflict on token A:
-  First example        b c • c A A $end
-  First derivation     $accept ::=[ a ::=[ b d ::=[ a ::=[ c d ::=[ a ::=[ b ::=[ • ] d ::=[ c A A ] ] ] ] ] ] $end ]
-  Second example       b c • A $end
-  Second derivation    $accept ::=[ a ::=[ b d ::=[ a ::=[ c d ::=[ c ::=[ • ] A ] ] ] ] $end ]
+  First example        b c . c A A $end
+  First derivation     $accept ::=[ a ::=[ b d ::=[ a ::=[ c d ::=[ a ::=[ b ::=[ . ] d ::=[ c A A ] ] ] ] ] ] $end ]
+  Second example       b c . A $end
+  Second derivation    $accept ::=[ a ::=[ b d ::=[ a ::=[ c d ::=[ c ::=[ . ] A ] ] ] ] $end ]
 
 Shift/reduce conflict on token A:
-  First example        b c • A $end
-  First derivation     $accept ::=[ a ::=[ b d ::=[ a ::=[ c d ::=[ c ::=[ • ] A ] ] ] ] $end ]
-  Second example       b c • A
-  Second derivation    a ::=[ b d ::=[ c • A ] ]
+  First example        b c . A $end
+  First derivation     $accept ::=[ a ::=[ b d ::=[ a ::=[ c d ::=[ c ::=[ . ] A ] ] ] ] $end ]
+  Second example       b c . A
+  Second derivation    a ::=[ b d ::=[ c . A ] ]
 
 Reduce/reduce conflict on token $end:
-  Example              b d •
-  First derivation     a ::=[ b d • ]
-  Example              b d •
-  Second derivation    a ::=[ b d ::=[ d • ] ]
+  Example              b d .
+  First derivation     a ::=[ b d . ]
+  Example              b d .
+  Second derivation    a ::=[ b d ::=[ d . ] ]
 
 Reduce/reduce conflict on token $end:
-  Example              c d •
-  First derivation     a ::=[ c d • ]
-  Example              c d •
-  Second derivation    a ::=[ c d ::=[ d • ] ]
+  Example              c d .
+  First derivation     a ::=[ c d . ]
+  Example              c d .
+  Second derivation    a ::=[ c d ::=[ d . ] ]
 
 input.y:5.4: warning: rule useless in parser due to conflicts [-Wother]
 input.y:6.15: warning: rule useless in parser due to conflicts [-Wother]
@@ -474,10 +474,10 @@ i: %empty | i J;
 AT_BISON_CHECK_CEX([input.y], [], [],
 [[input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
 Shift/reduce conflict on token J:
-  Example              H i J • J J
-  First derivation     s ::=[ a ::=[ H i ::=[ i J • ] J J ] ]
-  Example              H i J • J J
-  Second derivation    s ::=[ a ::=[ H i J • J ] J ]
+  Example              H i J . J J
+  First derivation     s ::=[ a ::=[ H i ::=[ i J . ] J J ] ]
+  Example              H i J . J J
+  Second derivation    s ::=[ a ::=[ H i J . J ] J ]
 
 input.y:5.13-15: warning: rule useless in parser due to conflicts [-Wother]
 ]])
@@ -507,10 +507,10 @@ d: D;
 AT_BISON_CHECK_CEX([input.y], [], [],
 [[input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
 Shift/reduce conflict on token D:
-  Example              A a • D
-  First derivation     s ::=[ A a a ::=[ b ::=[ c ::=[ • ] ] ] d ::=[ D ] ]
-  Example              A a • D
-  Second derivation    s ::=[ A a d ::=[ • D ] ]
+  Example              A a . D
+  First derivation     s ::=[ A a a ::=[ b ::=[ c ::=[ . ] ] ] d ::=[ D ] ]
+  Example              A a . D
+  Second derivation    s ::=[ A a d ::=[ . D ] ]
 
 ]])
 
@@ -538,10 +538,10 @@ d: D;
 AT_BISON_CHECK_CEX([input.y], [], [],
 [[input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
 Shift/reduce conflict on token D:
-  First example        A a • D E $end
-  First derivation     $accept ::=[ s ::=[ A a a ::=[ b ::=[ c ::=[ • ] ] ] d ::=[ D ] E ] $end ]
-  Second example       A a • D $end
-  Second derivation    $accept ::=[ s ::=[ A a d ::=[ • D ] ] $end ]
+  First example        A a . D E $end
+  First derivation     $accept ::=[ s ::=[ A a a ::=[ b ::=[ c ::=[ . ] ] ] d ::=[ D ] E ] $end ]
+  Second example       A a . D $end
+  Second derivation    $accept ::=[ s ::=[ A a d ::=[ . D ] ] $end ]
 
 ]])