Add info about bison, byacc, and yacc.

diff --git a/gdb/doc/snapshots.readme b/gdb/doc/snapshots.readme
index e7ae9a9537622fd612325c249e6a533a95069ce1..3b56fde0ae3432ee1b21f8b323bc38b99387980e 100644 (file)
--- a/gdb/doc/snapshots.readme
+++ b/gdb/doc/snapshots.readme
@@ -150,6 +150,28 @@ Here are some simple guidelines for submitting patches:
        like.  The emacs command ^X4A will create a ChangeLog entry header
        for you.
 
+BISON and BYACC
+
+For various reasons, Cygnus uses byacc rather than bison by default.  When
+a general gdb distribution is made, this default is switched back to bison.
+The snapshots follow the Cygnus default.  Your options, if you do not already
+have byacc installed, include:
+
+    o  Hack the upper level Makefile.in lines that look like:
+
+       BISON = `if [ -f $${rootme}/byacc/byacc ] ; \
+                   then echo $${rootme}/byacc/byacc ; \
+                   else echo byacc ; \                         <== change
+               fi`
+
+       to replace byacc with yacc.
+
+    o  Fetch the byacc snapshot from the same location as the gdb snapshots
+       and install byacc.
+
+    o  Specify BISON=yacc on the make command line to override the default.
+
+
 Thanks for your help and support.
 
 -Fred Fish