Make second expansion optional (partial implementation).

I decided this feature was too impacting to make the permanent default
behavior.  This set of changes makes the default behavior of make the
old behavior (no second expansion).  If you want second expansion, you
must define the .SECONDEXPANSION: special target before the first target
that needs it.

This set of changes ONLY fixes explicit and static pattern rules to work
like this.  Implicit rules still have second expansion enabled all the
time: I'll work on that next.

Note that there is still a backward-incompatibility: now to get the old
SysV behavior using $$@ etc. in the prerequisites list you need to set
.SECONDEXPANSION: as well.

6 files changed, 103 insertions, 126 deletions

diff --git a/tests/scripts/features/order_only b/tests/scripts/features/order_only
index 82a7253..4ebdc2b 100644
--- a/tests/scripts/features/order_only
+++ b/tests/scripts/features/order_only
@@ -5,9 +5,18 @@ $details = "\
 Create makefiles with various combinations of normal and order-only
 prerequisites and ensure they behave properly.  Test the \$| variable.";
 
-open(MAKEFILE,"> $makefile");
+# TEST #0 -- Basics
 
-print MAKEFILE <<'EOF';
+run_make_test('
+%r: | baz ; @echo $< $^ $|
+bar: foo
+foo:;@:
+baz:;@:',
+              '', "foo foo baz\n");
+
+# TEST #1 -- First try: the order-only prereqs need to be built.
+
+run_make_test(q!
 foo: bar | baz
 	@echo '$$^ = $^'
 	@echo '$$| = $|'
@@ -16,34 +25,19 @@ foo: bar | baz
 .PHONY: baz
 
 bar baz:
-	touch $@
-EOF
-
-close(MAKEFILE);
-
-
-# TEST #1 -- just the syntax
-
-&run_make_with_options($makefile, "", &get_logfile);
-$answer = "touch bar\ntouch baz\n\$^ = bar\n\$| = baz\ntouch foo\n";
-&compare_output($answer,&get_logfile(1));
+	touch $@!,
+              '', "touch bar\ntouch baz\n\$^ = bar\n\$| = baz\ntouch foo\n");
 
 
 # TEST #2 -- now we do it again: baz is PHONY but foo should _NOT_ be updated
 
-&run_make_with_options($makefile, "", &get_logfile);
-$answer = "touch baz\n";
-&compare_output($answer,&get_logfile(1));
+run_make_test(undef, '', "touch baz\n");
 
 unlink(qw(foo bar baz));
 
-# Test prereqs that are both order and non-order
-
-$makefile2 = &get_tmpfile;
-
-open(MAKEFILE,"> $makefile2");
+# TEST #3 -- Make sure the order-only prereq was promoted to normal.
 
-print MAKEFILE <<'EOF';
+run_make_test(q!
 foo: bar | baz
 	@echo '$$^ = $^'
 	@echo '$$| = $|'
@@ -54,33 +48,21 @@ foo: baz
 .PHONY: baz
 
 bar baz:
-	touch $@
-EOF
-
-close(MAKEFILE);
-
-# TEST #3 -- Make sure the order-only prereq was promoted to normal.
-
-&run_make_with_options($makefile2, "", &get_logfile);
-$answer = "touch bar\ntouch baz\n\$^ = bar baz\n\$| = \ntouch foo\n";
-&compare_output($answer,&get_logfile(1));
+	touch $@!,
+              '', "touch bar\ntouch baz\n\$^ = bar baz\n\$| = \ntouch foo\n");
 
 
 # TEST #4 -- now we do it again
 
-&run_make_with_options($makefile2, "", &get_logfile);
-$answer = "touch baz\n\$^ = bar baz\n\$| = \ntouch foo\n";
-&compare_output($answer,&get_logfile(1));
+run_make_test(undef, '', "touch baz\n\$^ = bar baz\n\$| = \ntouch foo\n");
 
 unlink(qw(foo bar baz));
 
 # Test empty normal prereqs
 
-$makefile3 = &get_tmpfile;
-
-open(MAKEFILE,"> $makefile3");
+# TEST #5 -- make sure the parser was correct.
 
-print MAKEFILE <<'EOF';
+run_make_test(q!
 foo:| baz
 	@echo '$$^ = $^'
 	@echo '$$| = $|'
@@ -89,33 +71,20 @@ foo:| baz
 .PHONY: baz
 
 baz:
-	touch $@
-EOF
-
-close(MAKEFILE);
-
-# TEST #5 -- make sure the parser was correct.
-
-&run_make_with_options($makefile3, "", &get_logfile);
-$answer = "touch baz\n\$^ = \n\$| = baz\ntouch foo\n";
-&compare_output($answer,&get_logfile(1));
-
+	touch $@!,
+              '', "touch baz\n\$^ = \n\$| = baz\ntouch foo\n");
 
 # TEST #6 -- now we do it again: this time foo won't be built
 
-&run_make_with_options($makefile3, "", &get_logfile);
-$answer = "touch baz\n";
-&compare_output($answer,&get_logfile(1));
+run_make_test(undef, '', "touch baz\n");
 
 unlink(qw(foo baz));
 
 # Test order-only in pattern rules
 
-$makefile4 = &get_tmpfile;
-
-open(MAKEFILE,"> $makefile4");
+# TEST #7 -- make sure the parser was correct.
 
-print MAKEFILE <<'EOF';
+run_make_test(q!
 %.w : %.x | baz
 	@echo '$$^ = $^'
 	@echo '$$| = $|'
@@ -125,22 +94,13 @@ all: foo.w
 
 .PHONY: baz
 foo.x baz:
-	touch $@
-EOF
-
-close(MAKEFILE);
-
-# TEST #7 -- make sure the parser was correct.
-
-&run_make_with_options($makefile4, "", &get_logfile);
-$answer = "touch foo.x\ntouch baz\n\$^ = foo.x\n\$| = baz\ntouch foo.w\n";
-&compare_output($answer,&get_logfile(1));
+	touch $@!,
+              '',
+              "touch foo.x\ntouch baz\n\$^ = foo.x\n\$| = baz\ntouch foo.w\n");
 
 # TEST #8 -- now we do it again: this time foo.w won't be built
 
-&run_make_with_options($makefile4, "", &get_logfile);
-$answer = "touch baz\n";
-&compare_output($answer,&get_logfile(1));
+run_make_test(undef, '', "touch baz\n");
 
 unlink(qw(foo.w foo.x baz));
 
@@ -151,8 +111,8 @@ run_make_test('
 %r: | baz ; @echo $< $^ $|
 bar: foo
 foo:;@:
-baz:;@:
-', '', "foo foo baz\n");
+baz:;@:',
+              '', "foo foo baz\n");
 
 
 1;
diff --git a/tests/scripts/features/se_explicit b/tests/scripts/features/se_explicit
index 0e696be..01860a9 100644
--- a/tests/scripts/features/se_explicit
+++ b/tests/scripts/features/se_explicit
@@ -3,9 +3,29 @@ $description = "Test second expansion in ordinary rules.";
 
 $details = "";
 
-# Test #1: automatic variables.
+# TEST #0: Test handing of '$' in prerequisites with and without second
+# expansion.
+
+run_make_test(q!
+ifdef SE
+  .SECONDEXPANSION:
+endif
+foo$$bar: bar$$baz bar$$biz ; @echo '$@ : $^'
+PRE = one two
+bar$$baz: $$(PRE)
+baraz: $$(PRE)
+PRE = three four
+.DEFAULT: ; @echo '$@'
+!,
+              '',
+              "\$\nbar\$biz\nfoo\$bar : bar\$baz bar\$biz");
+
+run_make_test(undef, 'SE=1', "three\nfour\nbariz\nfoo\$bar : baraz bariz");
+
+# TEST #1: automatic variables.
 #
 run_make_test('
+.SECONDEXPANSION:
 .DEFAULT: ; @echo $@
 
 foo: bar baz
@@ -41,6 +61,7 @@ buz.5
 # Test #2: target/pattern -specific variables.
 #
 run_make_test('
+.SECONDEXPANSION:
 .DEFAULT: ; @echo $@
 
 foo.x: $$a $$b
@@ -59,6 +80,7 @@ baz
 # Test #3: order of prerequisites.
 #
 run_make_test('
+.SECONDEXPANSION:
 .DEFAULT: ; @echo $@
 
 all: foo bar baz
diff --git a/tests/scripts/features/se_statpat b/tests/scripts/features/se_statpat
index 3c54622..096b240 100644
--- a/tests/scripts/features/se_statpat
+++ b/tests/scripts/features/se_statpat
@@ -6,6 +6,7 @@ $details = "";
 # Test #1: automatic variables.
 #
 run_make_test('
+.SECONDEXPANSION:
 .DEFAULT: ; @echo $@
 
 foo.a foo.b: foo.%: bar.% baz.%
@@ -41,6 +42,7 @@ a.6
 # Test #2: target/pattern -specific variables.
 #
 run_make_test('
+.SECONDEXPANSION:
 .DEFAULT: ; @echo $@
 
 foo.x foo.y: foo.%: $$(%_a) $$($$*_b)
@@ -60,6 +62,7 @@ baz
 # Test #3: order of prerequisites.
 #
 run_make_test('
+.SECONDEXPANSION:
 .DEFAULT: ; @echo $@
 
 all: foo.a bar.a baz.a
@@ -106,6 +109,7 @@ baz.a.2
 # Test #4: Make sure stem triple-expansion does not happen.
 #
 run_make_test('
+.SECONDEXPANSION:
 foo$$bar: f%r: % $$*.1
 	@echo \'$*\'
 
diff --git a/tests/scripts/features/statipattrules b/tests/scripts/features/statipattrules
index 0ca2bb7..429b56a 100644
--- a/tests/scripts/features/statipattrules
+++ b/tests/scripts/features/statipattrules
@@ -9,79 +9,62 @@ name and the target name with .c.  It also does the same thing
 for another target filtered with .elc and creates a command
 to emacs a .el file";
 
-open(MAKEFILE,"> $makefile");
-print MAKEFILE <<'EOF';
-files = foo.elc bar.o lose.o
-
-$(filter %.o,$(files)): %.o: %.c ; @echo CC -c $(CFLAGS) $< -o $@
-
-$(filter %.elc,$(files)): %.elc: %.el ; @echo emacs $<
-EOF
-close(MAKEFILE);
-
-
 &touch('bar.c', 'lose.c');
 
-#   TEST #1
+#   TEST #0
 #   -------
 
-&run_make_with_options($makefile, '', &get_logfile);
-$answer = "CC -c bar.c -o bar.o\n";
-&compare_output($answer, &get_logfile(1));
+run_make_test('
+files = foo.elc bar.o lose.o
+
+$(filter %.o,$(files)): %.o: %.c ; @echo CC -c $(CFLAGS) $< -o $@
 
+$(filter %.elc,$(files)): %.elc: %.el ; @echo emacs $<
+',
+              '',
+              'CC -c bar.c -o bar.o');
 
-#  TEST #2
+#  TEST #1
 #  -------
 
-&run_make_with_options($makefile, 'lose.o', &get_logfile);
-$answer = "CC -c lose.c -o lose.o\n";
-&compare_output($answer, &get_logfile(1));
+run_make_test(undef, 'lose.o', 'CC -c lose.c -o lose.o');
 
 
-#   TEST #3
+#   TEST #2
 #   -------
 &touch("foo.el");
 
-&run_make_with_options($makefile, 'foo.elc', &get_logfile);
-$answer = "emacs foo.el\n";
-&compare_output($answer, &get_logfile(1));
-
+run_make_test(undef, 'foo.elc', 'emacs foo.el');
 
+# Clean up after the first tests.
 unlink('foo.el', 'bar.c', 'lose.c');
 
 
-# TEST #4 -- PR/1670: don't core dump on invalid static pattern rules
+# TEST #3 -- PR/1670: don't core dump on invalid static pattern rules
 # -------
 
-$makefile2 = &get_tmpfile;
-open(MAKEFILE, "> $makefile2");
-print MAKEFILE "foo: foo%: % ; \@echo \$@\n";
-close(MAKEFILE);
+run_make_test('
+.DEFAULT: ; @echo $@
+foo: foo%: % %.x % % % y.% % ; @echo $@
+',
+              '', ".x\ny.\nfoo");
 
-&run_make_with_options($makefile2, '', &get_logfile);
-$answer = "foo\n";
-&compare_output($answer, &get_logfile(1));
 
-# TEST #5 -- bug #12180: core dump on a stat pattern rule with an empty
+# TEST #4 -- bug #12180: core dump on a stat pattern rule with an empty
 #                        prerequisite list.
-#
 run_make_test('
 foo.x bar.x: %.x : ; @echo $@
 
 ',
-'',
-'foo.x
-');
+              '', 'foo.x');
 
 
-# TEST #6 -- bug #13881: double colon static pattern rule does not
+# TEST #5 -- bug #13881: double colon static pattern rule does not
 #                        substitute %.
-#
 run_make_test('
 foo.bar:: %.bar: %.baz
 foo.baz: ;@:
 ',
-'',
-'');
+              '', '');
 
 1;
diff --git a/tests/scripts/misc/general4 b/tests/scripts/misc/general4
index 63320e2..0b5c94a 100644
--- a/tests/scripts/misc/general4
+++ b/tests/scripts/misc/general4
@@ -5,8 +5,7 @@ This tests random features of make's algorithms, often somewhat obscure,
 which have either broken at some point in the past or seem likely to
 break.";
 
-open(MAKEFILE,"> $makefile");
-print MAKEFILE <<'EOF';
+run_make_test('
 # Make sure that subdirectories built as prerequisites are actually handled
 # properly.
 
@@ -16,13 +15,8 @@ dir/subdir: ; @echo mkdir -p dir/subdir
 
 dir/subdir/file.b: dir/subdir ; @echo touch dir/subdir/file.b
 
-dir/subdir/%.a: dir/subdir/%.b ; @echo cp $< $@
-EOF
-close(MAKEFILE);
-
-&run_make_with_options($makefile,"",&get_logfile);
-$answer = "mkdir -p dir/subdir\ntouch dir/subdir/file.b\ncp dir/subdir/file.b dir/subdir/file.a\n";
-&compare_output($answer,&get_logfile(1));
+dir/subdir/%.a: dir/subdir/%.b ; @echo cp $< $@',
+              '', "mkdir -p dir/subdir\ntouch dir/subdir/file.b\ncp dir/subdir/file.b dir/subdir/file.a\n");
 
 # Test implicit rules
 
@@ -47,4 +41,17 @@ fox: baz
               'done bar');
 unlink('bar');
 
+
+# Test implicit rules with '$' in the name (see se_implicit)
+
+run_make_test(q!
+%.foo : baz$$bar ; @echo 'done $<'
+%.foo : bar$$baz ; @echo 'done $<'
+test.foo:
+fox: baz
+.DEFAULT baz$$bar bar$$baz: ; @echo '$@'
+!,
+              '',
+              'done bar');
+
 1;
diff --git a/tests/scripts/variables/automatic b/tests/scripts/variables/automatic
index 484cd16..dc08bd7 100644
--- a/tests/scripts/variables/automatic
+++ b/tests/scripts/variables/automatic
@@ -27,7 +27,7 @@ $(dir)/bar.y baz.z : ; touch $@
 EOF
 close(MAKEFILE);
 
-# TEST #1 -- simple test
+# TEST #0 -- simple test
 # -------
 
 # Touch these into the past
@@ -46,7 +46,7 @@ touch $dir/foo.x\n";
 
 unlink(qw(foo.x bar.y baz.z));
 
-# TEST #2 -- test the SysV emulation of $$@ etc.
+# TEST #1 -- test the SysV emulation of $$@ etc.
 # -------
 
 $makefile2 = &get_tmpfile;
@@ -54,6 +54,7 @@ $makefile2 = &get_tmpfile;
 open(MAKEFILE, "> $makefile2");
 print MAKEFILE "dir = $dir\n";
 print MAKEFILE <<'EOF';
+.SECONDEXPANSION:
 .SUFFIXES:
 .DEFAULT: ; @echo '$@'
 
@@ -78,7 +79,7 @@ $answer = ".x\n$dir/x.z.x\nx\n\$@.x\n$dir.x\nx.z.x\n.y\n$dir/y.z.y\n\y\n\$@.y\n$
 $answer = "$dir/biz.x\n$dir.x\nbiz.x\n";
 &compare_output($answer, &get_logfile(1));
 
-# TEST #3 -- test for Savannah bug #12320.
+# TEST #2 -- test for Savannah bug #12320.
 #
 run_make_test('
 .SUFFIXES: .b .src