mamake: tighten the strict mode some more (re: 45feaa5, fbf8f42)

The following changes apply to the strict mode only.

src/cmd/INIT/mamake.c:
- Use a state flag (state.strict) instead of a function for the
  strict mode. Amend the `setv` command to set this flag if the
  varname is `MAMAKE_STRICT`. This is simpler and more elegant.
- Produce a deprecation warning on assigning the 'generated',
  'archive', and 'joint' attributes. Ignore direct assignment of
  'generated' in strict mode. (It is implicitly assigned by 'exec'.
  The other two have always been simply ignored.)
- Make 'info' and 'meta' unknown commands. (These have always
  been ignored and I'd already removed all use of them before
  introducing the strict mode, so no backward compat problem).

src/{cmd/INIT,lib/libast}/Mamfile:
- Do not run mktest to regenerate .tst regression test scripts from
  .rt originals. It is not correct to do this at build time, as the
  originals do not contain the expected output -- it is obtained
  from the programs tested, assumed to be correct, and stored in
  the .tst output. So this must always be done manually and verified
  carefully before committing the changes.

src/Mamfile

@@ -6,7 +6,7 @@ note * Mamfiles are processed by mamake (src/cmd/INIT/mamake.c); we added
 note * indentation to improve readability. The language is documented in
 note * src/cmd/INIT/README-mamake.md.
 note *
-setv MAMAKE_SSTRICT
+setv MAMAKE_STRICT
 make test virtual
 	make test_announce virtual
 		exec - : testing KornShell $KSH_VERSION :

src/cmd/INIT/Mamfile

@@ -388,13 +388,8 @@ make test dontcare virtual
 		exec - regress iffe.tst iffe
 	done
 	make test.mamake virtual
-		make mamake.tst
-			prev mamake.rt
-			exec - if test mamake.rt -nt mamake.tst
-			exec - then "$SHELL" "$INSTALLROOT/bin/mktest" --style=regress mamake.rt > mamake.tst
-			exec - fi
-		done
-		exec - : testing mamake as built by package.sh :
+		prev mamake.tst
+		exec - : testing non-libast mamake at $PWD/mamake :
 		exec - regress mamake.tst mamake
 	done
 done test

src/cmd/INIT/README-mamake.md

@@ -27,18 +27,17 @@ whereas `mamake` is simple and portable, and offers all the same flexibility.
 
 Compared to the 2012-08-01 AT&T distribution,
 ksh 93u+m made a number of changes to `mamake` that make it easier to maintain Mamfiles by hand:
-* If the `MAMAKE_STRICT` variable is set before any other mamake command is executed,
-  some backward incompatible changes are activated to facilitate maintainability.
+* Introduced a strict mode that activates some backward incompatible changes and deprecation warnings.
 * All Mamfiles have been indented for legibility. (See `bin/Mamfile_indent` in the distribution.)
 * Indentation and word separators may use any whitespace (e.g. tabs), not only spaces.
 * Unrecognized commands and rule attributes throw an error instead of being silently ignored.
 * Fixed some crashing bugs and memory leaks.
 * The `silent` and `ignore` command prefixes for shell actions are processed internally
-  for backward compatibility, unless the `MAMAKE_STRICT` variable is set.
+  for backward compatibility, except in the strict mode.
 * The `prev` command may now be used without a prior `make`...`done` to declare a simple
-  prerequisite, provided the `MAMAKE_STRICT` variable is set.
+  prerequisite, provided the strict mode is activated.
 * The `notrace` attribute was added to disable xtrace for a rule's shell action.
-* If `MAMAKE_STRICT` is set, appending attributes to the `done` command
+* In the strict mode, appending attributes to the `done` command
   produces a deprecation warning; please append them to `make` instead.
 * Repeating the rule name in the `done` commnand is now optional so that
   a simple `done` also works to terminate the current rule.
@@ -47,7 +46,7 @@ In addition, the following two simple shell scripts are now provided to aid
 in maintaining and modernising Mamfiles:
 
 * `src/cmd/INIT/utils/Mamfile_indent`: Automatically indent or re-indent a Mamfile.
-* `src/cmd/INIT/utils/Mamfile_rm_unused_vars`: Remove unused `setv` variable
+* `src/cmd/INIT/utils/Mamfile_rm_unused_vars`: Remove unreferenced `setv` variable
   definitions from a Mamfile (except `MAMAKE_STRICT`).
 
 ## Commands ##
@@ -61,10 +60,17 @@ Unrecognized commands or attributes are an error.
 The *argument* is a single word.
 The *operand string* is any arbitrary text until the end of the line.
 
+### Strict and legacy modes ###
+
+If the `MAMAKE_STRICT` variable is set (`setv MAMAKE_STRICT`),
+some backward incompatible changes and deprecation warnings
+are activated to facilitate human maintenance of the Mamfiles.
+We call this the "strict mode" and its absence the "legacy mode".
+
 ### Comments ###
 
 `note` is the comment command and is ignored.
-For historical reasons, `info` and `meta` are also ignored.
+In the legacy mode, `info` and `meta` are also ignored.
 
 ### Rules ###
 
@@ -97,31 +103,37 @@ comes with the distribution or a file generated by a previously run Mamfile.
 
 One or more *attribute*s may be specified by appending them to the `make` command.
 (They may also be appended to the `done` command; the effect is the same either way.
-This is deprecated and produces a warning if the `MAMAKE_STRICT` variable is defined.)
+This is deprecated and produces a warning in the strict mode.)
 **Attributes apply to the current rule only and do not propagate down to nested rules.**
 The following *attribute*s are available:
-* `archive`: Ignored.
-  Historically used to mark the generation of an `ar`(1) archive.
 * `dontcare`: Marks files that do not need to exist.
   If the file exists then its last-modified timestamp is checked and propagated,
   otherwise it is silently ignored. 
-* `generated`: Marks rules that produce output files generated by a shell action.
-  The `exec` command implicitly assigns this attribute.
 * `ignore`: The timestamp associated with *rule* is ignored in dependency resolution.
 * `implicit`: Marks the current rule as an implicit prerequisite of the enclosing parent rule.
   An implicit prerequisite can make the parent rule out of date without triggering the parent action.
   Implicit prerequisites usually correspond to `#include` prerequisites.
   For example, if `foo.o` is generated from `foo.c` and `foo.c` includes `foo.h`,
   then `foo.h` should be marked as an implicit prerequisite of `foo.c`
   so that touching `foo.h` does not make `foo.c` out of date while making `foo.o` out of date.
-* `joint`: Ignored.
-  Historically used to mark one of a group of rules that are built by a single shell action.
 * `notrace`: Disables echoing (xtrace) of shell action commands.
 * `virtual`: Marks a rule that is not associated with any file.
   The commands within are executed every time the Mamfile is processed.
   By convention, a virtual rule named `all` makes everything,
   and a virtual rule named `install` performs installation.
 
+Specifying the following *attribute*s is deprecated
+and will produce a warning in the strict mode:
+* `archive`: Ignored.
+  Historically used to mark the generation of an `ar`(1) archive.
+* `generated`: Marks rules that produce output files generated by a shell action.
+  The explicit assignment of this attribute is ignored in the strict mode.
+  The `exec` command implicitly assigns this attribute.
+  If a rule has this attribute, other rules dependent on this rule
+  will avoid applying viewpathing based on this rule.
+* `joint`: Ignored.
+  Historically used to mark one of a group of rules that are built by a single shell action.
+
 ### Referencing prerequisites or previously defined rules ###
 
 `prev` *rule* [ *attribute* ... ]
@@ -131,12 +143,12 @@ The `prev` command is used in two ways:
 1. If *rule* is a previously defined rule, `prev` adds a dependency on that rule to the current rule.
    This can be used to make a rule a prerequisite of multiple `make`...`done` blocks without repeating the rule.
    No attributes should be given for this use of `prev`, because the attributes of the referenced rule are used.
-   Superfluous attributes are an error if the `MAMAKE_STRICT` variable has been set, otherwise they are ignored.
+   Superfluous attributes are an error in the strict mode and ignored in the legacy mode.
 
 2. If *rule* is not a previously defined rule, the following applies.
-   If the `MAMAKE_STRICT` variable is not set, `prev` creates an empty dummy
+   In the legacy mode, `prev` creates an empty dummy
    *rule* and ignores the *attribute*s; this is for backward compatibility.
-   If the `MAMAKE_STRICT` variable is set,
+   In the strict mode,
    `prev` creates a rule that declares a dependency on a prerequisite file named by *rule*
    in a manner equivalent to an empty `make`...`done` block,
    with any *attribute*s given applied to the new rule, and

src/cmd/INIT/mamake.c

@@ -27,7 +27,7 @@
  * coded for portability
  */
 
-#define RELEASE_DATE "2024-02-03"
+#define RELEASE_DATE "2024-02-04"
 static char id[] = "\n@(#)$Id: mamake (ksh 93u+m) " RELEASE_DATE " $\0\n";
 
 #if _PACKAGE_ast
@@ -257,6 +257,8 @@ typedef struct View_s			/* viewpath level		*/
 
 static struct				/* program state		*/
 {
+	int		strict;		/* strict mode activated if set */
+
 	Buf_t*		buf;		/* work buffer			*/
 	Buf_t*		old;		/* dropped buffers		*/
 	Buf_t*		opt;		/* option buffer		*/
@@ -610,19 +612,6 @@ search(Dict_t* dict, char* name, void* value)
 	return NULL;
 }
 
-/*
- * return true if in strict mode
- */
-
-static int
-strict(void)
-{
-	static int found = -1;
-	if (found < 0)
-		found = search(state.vars, "MAMAKE_STRICT", NULL) != NULL;
-	return found;
-}
-
 /*
  * low level for walk()
  */
@@ -1277,7 +1266,7 @@ run(Rule_t* r, char* s)
 	if (x)
 	{
 		/* stubs for backward compat */
-		if (!strict())
+		if (!state.strict)
 			append(buf,
 				"alias silent=\n"
 				"ignore() { env \"$@\" || :; }\n"
@@ -1504,8 +1493,9 @@ attributes(Rule_t* r, char* s)
 				flag = RULE_dontcare;
 			break;
 		case 'g':
+			/* 'exec' assigns this attribute; ignore explicit assignment in strict mode */
 			if (n == 9 && !strncmp(t, "generated", n))
-				flag = RULE_generated;
+				flag = state.strict ? -1 : RULE_generated;
 			break;
 		case 'i':
 			if (n == 6 && !strncmp(t, "ignore", n))
@@ -1537,6 +1527,9 @@ attributes(Rule_t* r, char* s)
 			t[n] = '\0';
 			report(3, "unknown attribute", t, 0);
 		}
+		/* deprecate ignored attributes */
+		else if (state.strict)
+			report(1, "deprecated", t, 0);
 	}
 }
 
@@ -1751,12 +1744,12 @@ make(Rule_t* r)
 			if (*t)
 			{	/* target is optional; use it for sanity check if present */
 				q = rule(expand(buf, t));
-				if (q != r && (t[0] != '$' || strict()))
+				if (q != r && (t[0] != '$' || state.strict))
 					report(3, "mismatched done statement", t, 0);
 				if (*v)
 				{
-					if (strict())
-						report(1, v, "done: attributes are deprecated here, please move them to 'make'", 0);
+					if (state.strict)
+						report(1, v, "done: attributes deprecated; move to 'make'", 0);
 					attributes(r, v);
 				}
 			}
@@ -1810,7 +1803,7 @@ make(Rule_t* r)
 		case KEY('p','r','e','v'):
 		{
 			char *name = expand(buf, t);
-			if (!strict())
+			if (!state.strict)
 				q = rule(name); /* for backward compat */
 			else if (!(q = (Rule_t*)search(state.rules, name, NULL)))
 			{	/*
@@ -1840,6 +1833,8 @@ make(Rule_t* r)
 			continue;
 		}
 		case KEY('s','e','t','v'):
+			if (strcmp(t, "MAMAKE_STRICT") == 0)
+				state.strict = 1;
 			if (!search(state.vars, t, NULL))
 			{
 				if (*v == '"')
@@ -1859,11 +1854,14 @@ make(Rule_t* r)
 				probe();
 			}
 			continue;
-		case KEY('i','n','f','o'):
 		case KEY('n','o','t','e'):
-		case KEY('m','e','t','a'):
 			/* comment command */
 			continue;
+		case KEY('i','n','f','o'):
+		case KEY('m','e','t','a'):
+			if (!state.strict)
+				continue;
+			/* FALLTHROUGH */
 		default:
 			report(3, "unknown command", u, 0);
 		}

src/cmd/INIT/mamake.rt

@@ -1,5 +1,17 @@
 NOTE regression tests for the mamake command
 
+# To regenerate mamake.tst from this file:
+#
+#	bin/package use
+#	cd $INSTALLROOT   # needed to stop mamake complaining about not being under VPATH
+#	mktest $PACKAGEROOT/src/cmd/INIT/mamake.rt > $PACKAGEROOT/src/cmd/INIT/mamake.tst
+#
+# WARNING: the regeneration assumes mamake's output is correct, so VERIFY THE RESULTS!
+# Always do 'git diff mamake.tst' to check that no unexpected changes have been made.
+
+# ======
+# the one original AT&T test -- uses legacy mode
+
 UNIT mamake
 
 TEST macros

src/lib/libast/Mamfile

@@ -4999,11 +4999,8 @@ make install virtual
 done install
 make test dontcare virtual
 	make test.mamake virtual
-		make mamake.tst
-			prev ${PACKAGEROOT}/src/cmd/INIT/mamake.rt
-			exec - mktest --style=regress ${PACKAGEROOT}/src/cmd/INIT/mamake.rt > mamake.tst
-		done
-		exec - : testing the libast rebuild of mamake :
-		exec - regress mamake.tst mamake
+		prev ${PACKAGEROOT}/src/cmd/INIT/mamake.tst
+		exec - : testing the libast rebuild of mamake at $PWD/mamake :
+		exec - regress ${PACKAGEROOT}/src/cmd/INIT/mamake.tst mamake
 	done
 done test