[src/trunk]: src/usr.bin/make make(1): split main into manageable pieces

[rillig <rillig%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/f843ac248719
branches:  trunk
changeset: 956842:f843ac248719
user:      rillig <rillig%NetBSD.org@localhost>
date:      Sun Nov 08 12:40:04 2020 +0000

description:
make(1): split main into manageable pieces

The purpose of a main function is to give a high-level overview about the
whole program.  270 lines of code with lots of tricky details did not serve this
purpose.  Split the code into functions corresponding to the phases.

diffstat:

 usr.bin/make/main.c |  140 ++++++++++++++++++++++++++++++---------------------
 1 files changed, 83 insertions(+), 57 deletions(-)

diffs (198 lines):

diff -r d1c5e51c7335 -r f843ac248719 usr.bin/make/main.c
--- a/usr.bin/make/main.c       Sun Nov 08 12:21:27 2020 +0000
+++ b/usr.bin/make/main.c       Sun Nov 08 12:40:04 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: main.c,v 1.447 2020/11/08 12:21:27 rillig Exp $        */
+/*     $NetBSD: main.c,v 1.448 2020/11/08 12:40:04 rillig Exp $        */
 
 /*
  * Copyright (c) 1988, 1989, 1990, 1993
@@ -109,7 +109,7 @@
 #include "trace.h"
 
 /*     "@(#)main.c     8.3 (Berkeley) 3/19/94" */
-MAKE_RCSID("$NetBSD: main.c,v 1.447 2020/11/08 12:21:27 rillig Exp $");
+MAKE_RCSID("$NetBSD: main.c,v 1.448 2020/11/08 12:40:04 rillig Exp $");
 #if defined(MAKE_NATIVE) && !defined(lint)
 __COPYRIGHT("@(#) Copyright (c) 1988, 1989, 1990, 1993 "
            "The Regents of the University of California.  "
@@ -1310,59 +1310,8 @@
 }
 
 static void
-CleanUp(void)
+main_Init(int argc, char **argv)
 {
-#ifdef CLEANUP
-       Lst_Destroy(opts.variables, free);
-       Lst_Free(opts.makefiles);       /* don't free, may be used in GNodes */
-       Lst_Destroy(opts.create, free);
-#endif
-
-       /* print the graph now it's been processed if the user requested it */
-       if (DEBUG(GRAPH2))
-               Targ_PrintGraph(2);
-
-       Trace_Log(MAKEEND, NULL);
-
-       if (enterFlagObj)
-               printf("%s: Leaving directory `%s'\n", progname, objdir);
-       if (opts.enterFlag)
-               printf("%s: Leaving directory `%s'\n", progname, curdir);
-
-#ifdef USE_META
-       meta_finish();
-#endif
-       Suff_End();
-       Targ_End();
-       Arch_End();
-       Var_End();
-       Parse_End();
-       Dir_End();
-       Job_End();
-       Trace_End();
-}
-
-/*-
- * main --
- *     The main function, for obvious reasons. Initializes variables
- *     and a few modules, then parses the arguments give it in the
- *     environment and on the command line. Reads the system makefile
- *     followed by either Makefile, makefile or the file given by the
- *     -f argument. Sets the .MAKEFLAGS PMake variable based on all the
- *     flags it has received by then uses either the Make or the Compat
- *     module to create the initial list of targets.
- *
- * Results:
- *     If -q was given, exits -1 if anything was out-of-date. Else it exits
- *     0.
- *
- * Side Effects:
- *     The program exits when done. Targets are created. etc. etc. etc.
- */
-int
-main(int argc, char **argv)
-{
-       Boolean outOfDate;      /* FALSE if all targets up to date */
        struct stat sa;
        const char *machine;
        const char *machine_arch;
@@ -1543,7 +1492,11 @@
        InitVarTargets();
 
        InitDefSysIncPath(syspath);
+}
 
+static void
+main_ReadFiles(void)
+{
        /*
         * Read in the built-in rules first, followed by the specified
         * makefiles, or the default makefile and Makefile, in that order,
@@ -1555,7 +1508,11 @@
                ReadAllMakefiles(opts.makefiles);
        else
                ReadFirstDefaultMakefile();
+}
 
+static void
+main_PrepareMaking(void)
+{
        /* In particular suppress .depend for '-r -V .OBJDIR -f /dev/null' */
        if (!opts.noBuiltins || opts.printVars == PVM_NONE) {
                /* ignore /dev/null and anything starting with "no" */
@@ -1615,22 +1572,91 @@
        /* print the initial graph, if the user requested it */
        if (DEBUG(GRAPH1))
                Targ_PrintGraph(1);
+}
 
+static Boolean
+main_Run(void)
+{
        /* print the values of any variables requested by the user */
        if (opts.printVars != PVM_NONE) {
                doPrintVars();
-               outOfDate = FALSE;
+               return FALSE;
        } else {
-               outOfDate = runTargets();
+               return runTargets();
        }
+}
 
-       CleanUp();
+static void
+main_CleanUp(void)
+{
+#ifdef CLEANUP
+       Lst_Destroy(opts.variables, free);
+       Lst_Free(opts.makefiles);       /* don't free, may be used in GNodes */
+       Lst_Destroy(opts.create, free);
+#endif
+
+       /* print the graph now it's been processed if the user requested it */
+       if (DEBUG(GRAPH2))
+               Targ_PrintGraph(2);
+
+       Trace_Log(MAKEEND, NULL);
 
+       if (enterFlagObj)
+               printf("%s: Leaving directory `%s'\n", progname, objdir);
+       if (opts.enterFlag)
+               printf("%s: Leaving directory `%s'\n", progname, curdir);
+
+#ifdef USE_META
+       meta_finish();
+#endif
+       Suff_End();
+       Targ_End();
+       Arch_End();
+       Var_End();
+       Parse_End();
+       Dir_End();
+       Job_End();
+       Trace_End();
+}
+
+static int
+main_Exit(Boolean outOfDate)
+{
        if (DEBUG(LINT) && (errors > 0 || Parse_GetFatals() > 0))
                return 2;       /* Not 1 so -q can distinguish error */
        return outOfDate ? 1 : 0;
 }
 
+/*-
+ * main --
+ *     The main function, for obvious reasons. Initializes variables
+ *     and a few modules, then parses the arguments give it in the
+ *     environment and on the command line. Reads the system makefile
+ *     followed by either Makefile, makefile or the file given by the
+ *     -f argument. Sets the .MAKEFLAGS PMake variable based on all the
+ *     flags it has received by then uses either the Make or the Compat
+ *     module to create the initial list of targets.
+ *
+ * Results:
+ *     If -q was given, exits -1 if anything was out-of-date. Else it exits
+ *     0.
+ *
+ * Side Effects:
+ *     The program exits when done. Targets are created. etc. etc. etc.
+ */
+int
+main(int argc, char **argv)
+{
+       Boolean outOfDate;
+
+       main_Init(argc, argv);
+       main_ReadFiles();
+       main_PrepareMaking();
+       outOfDate = main_Run();
+       main_CleanUp();
+       return main_Exit(outOfDate);
+}
+
 /* Open and parse the given makefile, with all its side effects.
  *
  * Results: