From 8d34ee63f69e61c352acfbc94fbc451621645053 Mon Sep 17 00:00:00 2001
From: Roger Ferrer Ibanez <rofirrim@gmail.com>
Date: Fri, 22 Dec 2017 11:57:41 +0000
Subject: [PATCH] Changes for graph-glr

You will need a bison with graph glr to test this.
---
 Makefile.am             | 19 +++++++++++++++++++
 configure.ac            | 39 +++++++++++++++++++++++++++++++++++++++
 src/frontend/cxx03.y.in | 11 ++++++++---
 3 files changed, 66 insertions(+), 3 deletions(-)

diff --git a/Makefile.am b/Makefile.am
index 51933c3ea5..ab71c14680 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -423,6 +423,9 @@ EXTRA_DIST += src/frontend/c99-scanner.c
 
 EXTRA_DIST += src/frontend/cxx03.l
 EXTRA_DIST += src/frontend/cxx03.y
+if ENABLE_GRAPH_GLR
+EXTRA_DIST += src/frontend/cxx03-glr.y
+endif
 EXTRA_DIST += src/frontend/cxx03.y.in
 EXTRA_DIST += src/frontend/cxx-scanner.c
 
@@ -461,6 +464,9 @@ BUILT_SOURCES += src/frontend/cxx03.l
 
 BUILT_SOURCES += src/frontend/c99.y
 BUILT_SOURCES += src/frontend/cxx03.y
+if ENABLE_GRAPH_GLR
+BUILT_SOURCES += src/frontend/cxx03-glr.y
+endif
 
 BUILT_SOURCES += src/frontend/cxx-parser.h
 BUILT_SOURCES += src/frontend/c99-parser.h
@@ -593,16 +599,29 @@ CLEANFILES += src/frontend/cxx-parser.c
 CLEANFILES += src/frontend/cxx-parser-internal.h
 CLEANFILES += src/frontend/cxx-parser.output
 CLEANFILES += src/frontend/cxx03.y
+if ENABLE_GRAPH_GLR
+CLEANFILES += src/frontend/cxx03-glr.y
+endif
 endif
 
 src/frontend/cxx03.y : $(TPP) $(top_srcdir)/src/frontend/cxx03.y.in $(addprefix $(top_srcdir)/, $(ADDITIONAL_GRAMMARS))
 	$(TPP_verbose)(rm -f src/frontend/cxx03.y && $(TPP) -o src/frontend/cxx03.y -D CPLUSPLUS -I$(top_srcdir)/src/frontend $(top_srcdir)/src/frontend/cxx03.y.in && chmod -w src/frontend/cxx03.y)
 
+src/frontend/cxx03-glr.y : $(TPP) $(top_srcdir)/src/frontend/cxx03.y.in $(addprefix $(top_srcdir)/, $(ADDITIONAL_GRAMMARS))
+	$(TPP_verbose)(rm -f src/frontend/cxx03-glr.y && $(TPP) -o src/frontend/cxx03-glr.y -D CPLUSPLUS -D GRAPH_GLR -I$(top_srcdir)/src/frontend $(top_srcdir)/src/frontend/cxx03.y.in && chmod -w src/frontend/cxx03-glr.y)
+
 src/frontend/cxx-parser-internal.h : src/frontend/cxx-parser.c
 if BISON_BUILDING
+if ENABLE_GRAPH_GLR
+src/frontend/cxx-parser.c : src/frontend/cxx03-glr.y
+	rm -f src/frontend/cxx-parser.c
+	$(BISON_verbose)$(BISON) -pmcxx --debug --defines=src/frontend/cxx-parser-internal.h --report=all --output=src/frontend/cxx-parser.c src/frontend/cxx03-glr.y
+	chmod -w src/frontend/cxx-parser.c
+else
 src/frontend/cxx-parser.c : src/frontend/cxx03.y
 	$(BISON_verbose)$(BISON) -pmcxx --debug --defines=src/frontend/cxx-parser-internal.h --report=all --output=src/frontend/cxx-parser.c src/frontend/cxx03.y
 endif
+endif
 
 # These are obtained when invoking bison, if we write a rule like 'a b : d' it
 # breaks parallel compilations since bison gets invoked twice.
diff --git a/configure.ac b/configure.ac
index d37ca60b34..574ef78947 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1904,6 +1904,7 @@ flex_good=no
 
 force_bison=no
 bison_good=no
+enable_graph_glr=no
 
 force_gperf=no
 gperf_good=no
@@ -2020,6 +2021,35 @@ then
     esac
   fi
 
+  if test x$bison_good = xyes;
+  then
+     dnl Check if the current bison supports %graph-glr-parser
+     AC_MSG_CHECKING([bison supports %graph-glr-parser])
+
+     # Mini grammar file using %graph-glr
+     cat <<EOF > tmp.y
+%graph-glr-parser
+%token A
+%start test
+
+%%
+test : A
+;
+EOF
+
+     AS_IF([$BISON -o /dev/null tmp.y &> /dev/null],
+        [
+            enable_graph_glr=yes
+            AC_MSG_RESULT([yes])
+        ],
+        [
+            AC_MSG_RESULT([no])
+        ]
+      )
+
+     rm -f tmp.y
+  fi
+
   dnl Check gperf
   AC_ARG_ENABLE([gperf-regeneration],
           AS_HELP_STRING([--enable-gperf-regeneration], [Forces gperf regeneration, even if the version is not recommended or properly detected.]),
@@ -2074,6 +2104,14 @@ AM_CONDITIONAL([BISON_BUILDING], test x$bison_good = xyes)
 AM_CONDITIONAL([FLEX_BUILDING], test x$flex_good = xyes)
 AM_CONDITIONAL([GPERF_BUILDING], test x$gperf_good = xyes)
 
+ENABLE_GRAPH_GLR=$enable_graph_glr
+AC_SUBST([ENABLE_GRAPH_GLR])
+AM_CONDITIONAL([ENABLE_GRAPH_GLR], test x$enable_graph_glr = xyes)
+if test x$enable_graph_glr = xyes;
+then
+    AC_DEFINE([ENABLE_GRAPH_GLR], 1, [Define to 1 if the Graph GLR algorithm is used])
+fi
+
 dnl --------------------- End of Regeneration files ---------------------
 
 dnl --------------------- Type environments -----------------------------
@@ -2520,6 +2558,7 @@ print_tool()
 
 print_tool "Flex " "$FLEX"
 print_tool "GNU bison " "$BISON"
+echo "    - Graph GLR is enabled:" $enable_graph_glr
 print_tool "GNU gperf " "$GPERF"
 
 print_tool "git content tracker" "$GIT"
diff --git a/src/frontend/cxx03.y.in b/src/frontend/cxx03.y.in
index fb18984f51..41dc014b42 100644
--- a/src/frontend/cxx03.y.in
+++ b/src/frontend/cxx03.y.in
@@ -51,7 +51,12 @@
 
 %}
 
+/*!ifnot GRAPH_GLR*/
 %glr-parser
+/*!endif*/
+/*!if GRAPH_GLR*/
+%graph-glr-parser
+/*!endif*/
 
 %union {
 	token_atrib_t token_atrib;
@@ -64,9 +69,6 @@
 };
 
 
-// This is a specific feature of rofi-bison 2.3
-// %default-merge <ambiguityHandler>
-
 %parse-param {AST* parsed_tree}
 
 %locations
@@ -4891,6 +4893,9 @@ nested_name_specifier_0 : class_or_namespace_name
     $$ = $1;
 }
 | decltype_specifier
+{
+	$$ = $1;
+}
 ;
 
 nested_name_specifier_1 : nested_name_specifier_0