build: do not use $< in plain rules

[Akim Demaille]

With this, I think we can roll our 3.4 release.

commit 3f25104caf222b32557d4a9a4cc532c34d4cbc43
Author: Akim Demaille <address@hidden>
Date:   Mon May 13 18:32:54 2019 +0200

    build: do not use $< in plain rules
    
    It works only in implicit rules (or with GNU Make, but not with
    Solaris Make).
    
    Reported by Bruno Haible.
    http://lists.gnu.org/archive/html/bug-bison/2019-05/msg00009.html
    Diagnosed thanks to Kiyoshi Kanazawa.
    
    * examples/c/reccalc/local.mk, examples/d/local.mk,
    * examples/java/local.mk: Don't use $< in non implicit rules.

diff --git a/examples/c/reccalc/local.mk b/examples/c/reccalc/local.mk
index 85296b83..2fc2bccb 100644
--- a/examples/c/reccalc/local.mk
+++ b/examples/c/reccalc/local.mk
@@ -41,7 +41,7 @@ DASH = -
        $(AM_V_LEX)rm -f $@ address@hidden
        $(AM_V_at)$(MKDIR_P) %D%
        $(AM_V_at)touch address@hidden
-       $(AM_V_at) $(LEX) -o %D%/scan.c --header-file=%D%/scan.h $<
+       $(AM_V_at)$(LEX) -o%D%/scan.c --header-file=%D%/scan.h 
$(srcdir)/%D%/scan.l
        $(AM_V_at)mv address@hidden $@
 
 # Don't use gnulib's system headers.
diff --git a/examples/d/local.mk b/examples/d/local.mk
index 1d8cd51a..8b701efe 100644
--- a/examples/d/local.mk
+++ b/examples/d/local.mk
@@ -27,10 +27,10 @@ EXTRA_DIST += %D%/calc.test
 
 %D%/calc.d: %D%/calc.y $(dependencies)
        $(AM_V_GEN)$(MKDIR_P) %D%
-       $(AM_V_at)$(BISON) $< -o $@
+       $(AM_V_at)$(BISON) $(srcdir)/%D%/calc.y -o $@
 
 %D%/calc: %D%/calc.d
-       $(AM_V_GEN) $(DC) $(DCFLAGS) -of$@ $<
+       $(AM_V_GEN) $(DC) $(DCFLAGS) -of$@ $(srcdir)/%D%/calc.d
 
 dist_d_DATA = %D%/calc.y %D%/Makefile %D%/README.md
 CLEANFILES += %D%/calc %D%/calc.[do]
diff --git a/examples/java/local.mk b/examples/java/local.mk
index b9bcebf5..3ea0cc33 100644
--- a/examples/java/local.mk
+++ b/examples/java/local.mk
@@ -27,10 +27,10 @@ EXTRA_DIST += %D%/Calc.test
 
 %D%/Calc.java: %D%/Calc.y $(dependencies)
        $(AM_V_GEN)$(MKDIR_P) %D%
-       $(AM_V_at)$(BISON) $< -o $@
+       $(AM_V_at)$(BISON) $(srcdir)/%D%/Calc.y -o $@
 
 %D%/Calc.class: %D%/Calc.java
-       $(AM_V_GEN) $(SHELL) $(top_builddir)/javacomp.sh $<
+       $(AM_V_GEN) $(SHELL) $(top_builddir)/javacomp.sh $(srcdir)/%D%/Calc.java
 
 dist_java_DATA = %D%/Calc.y %D%/Makefile %D%/README.md
 CLEANFILES += %D%/*.class %D%/Calc.java