make: update default rules

The default rules were changed in the 2024 standard:

- Fortran is no longer supported

- The CC macro is set to 'c17' instead of 'c99'

In addition to these changes, CC is set to 'cc' as a non-POSIX
extension:  on my system, at least, there isn't a 'c17' compiler.

Adds 208-224 bytes.

1 files changed, 49 insertions, 14 deletions

diff --git a/miscutils/make.c b/miscutils/make.c
index 02f90f805..07e83166b 100644
--- a/miscutils/make.c
+++ b/miscutils/make.c
@@ -271,6 +271,7 @@ struct globals {
         int lineno;     // Physical line number in file
         int dispno;     // Line number for display purposes
         const char *rulepos;
+        int rule_idx;
 #define IF_MAX 10
         uint8_t clevel;
         uint8_t cstate[IF_MAX + 1];
@@ -301,6 +302,7 @@ struct globals {
 #define lineno          (G.lineno)
 #define dispno          (G.dispno)
 #define rulepos         (G.rulepos)
+#define rule_idx        (G.rule_idx)
 #define clevel          (G.clevel)
 #define cstate          (G.cstate)
 #define numjobs         (G.numjobs)
@@ -1020,11 +1022,8 @@ dyndep(struct name *np, struct rule *imprule)
 }
 
 #define RULES \
-        ".SUFFIXES:.o .c .y .l .a .sh .f\n" \
         ".c.o:\n" \
         "       $(CC) $(CFLAGS) -c $<\n" \
-        ".f.o:\n" \
-        "       $(FC) $(FFLAGS) -c $<\n" \
         ".y.o:\n" \
         "       $(YACC) $(YFLAGS) $<\n" \
         "       $(CC) $(CFLAGS) -c y.tab.c\n" \
@@ -1045,23 +1044,28 @@ dyndep(struct name *np, struct rule *imprule)
         "       $(CC) -c $(CFLAGS) $<\n" \
         "       $(AR) $(ARFLAGS) $@ $*.o\n" \
         "       rm -f $*.o\n" \
-        ".f.a:\n" \
-        "       $(FC) -c $(FFLAGS) $<\n" \
-        "       $(AR) $(ARFLAGS) $@ $*.o\n" \
-        "       rm -f $*.o\n" \
         ".c:\n" \
         "       $(CC) $(CFLAGS) $(LDFLAGS) -o $@ $<\n" \
-        ".f:\n" \
-        "       $(FC) $(FFLAGS) $(LDFLAGS) -o $@ $<\n" \
         ".sh:\n" \
         "       cp $< $@\n" \
         "       chmod a+x $@\n"
 
+#define RULES_2017 \
+        ".SUFFIXES:.o .c .y .l .a .sh .f\n" \
+        ".f.o:\n" \
+        "       $(FC) $(FFLAGS) -c $<\n" \
+        ".f.a:\n" \
+        "       $(FC) -c $(FFLAGS) $<\n" \
+        "       $(AR) $(ARFLAGS) $@ $*.o\n" \
+        "       rm -f $*.o\n" \
+        ".f:\n" \
+        "       $(FC) $(FFLAGS) $(LDFLAGS) -o $@ $<\n"
+
+#define RULES_2024 \
+        ".SUFFIXES:.o .c .y .l .a .sh\n"
+
 #define MACROS \
-        "CC=c99\n" \
         "CFLAGS=-O1\n" \
-        "FC=fort77\n" \
-        "FFLAGS=-O1\n" \
         "YACC=yacc\n" \
         "YFLAGS=\n" \
         "LEX=lex\n" \
@@ -1070,6 +1074,17 @@ dyndep(struct name *np, struct rule *imprule)
         "ARFLAGS=-rv\n" \
         "LDFLAGS=\n"
 
+#define MACROS_2017 \
+        "CC=c99\n" \
+        "FC=fort77\n" \
+        "FFLAGS=-O1\n" \
+
+#define MACROS_2024 \
+        "CC=c17\n"
+
+#define MACROS_EXT \
+        "CC=cc\n"
+
 /*
  * Read the built-in rules using a fake fgets-like interface.
  */
@@ -1078,8 +1093,28 @@ getrules(char *s, int size)
 {
         char *r = s;
 
-        if (rulepos == NULL)
-                rulepos = (RULES MACROS) + (norules ? sizeof(RULES) - 1 : 0);
+        if (rulepos == NULL || *rulepos == '\0') {
+                if (rule_idx == 0) {
+                        rulepos = MACROS;
+                        rule_idx++;
+                } else if (rule_idx == 1) {
+                        if (POSIX_2017)
+                                rulepos = MACROS_2017;
+                        else if (posix)
+                                rulepos = MACROS_2024;
+                        else
+                                rulepos = MACROS_EXT;
+                        rule_idx++;
+                } else if (!norules) {
+                        if (rule_idx == 2) {
+                                rulepos = POSIX_2017 ? RULES_2017 : RULES_2024;
+                                rule_idx++;
+                        } else if (rule_idx == 3) {
+                                rulepos = RULES;
+                                rule_idx++;
+                        }
+                }
+        }
 
         if (*rulepos == '\0')
                 return NULL;