make: add posix_2017 pragma

The pragma 'posix_202x' causes the 202X POSIX standard to be
enforced in POSIX mode.  Add an equivalent 'posix_2017' for the
2017 standard.

There's now a DEFAULT_POSIX_LEVEL preprocessor symbol to configure
the default standard.  This is hardcoded to the 2017 standard but
it can also be set to 202X.

Adds 48 bytes.

1 files changed, 40 insertions, 9 deletions

diff --git a/miscutils/make.c b/miscutils/make.c
index 063d0662d..45cdac400 100644
--- a/miscutils/make.c
+++ b/miscutils/make.c
@@ -70,7 +70,15 @@
 #include "common_bufsiz.h"
 #include <glob.h>
 
-#define POSIX_2017 (posix && !(pragma & P_POSIX_202X))
+// Supported POSIX levels
+#define STD_POSIX_2017 0
+#define STD_POSIX_202X 1
+
+#define POSIX_2017 (posix && posix_level == STD_POSIX_2017)
+
+#ifndef DEFAULT_POSIX_LEVEL
+# define DEFAULT_POSIX_LEVEL STD_POSIX_2017
+#endif
 
 #define OPTSTR1 "eij:+knqrsSt"
 #if ENABLE_FEATURE_MAKE_POSIX
@@ -198,14 +206,25 @@ struct macro {
 #define M_VALID     16          // assert macro name is valid
 
 // Constants for PRAGMA.  Order must match strings in set_pragma().
-#define P_MACRO_NAME                    0x01
-#define P_TARGET_NAME                   0x02
-#define P_COMMAND_COMMENT               0x04
-#define P_EMPTY_SUFFIX                  0x08
-#define P_POSIX_202X                    0x10
+enum {
+        BIT_MACRO_NAME = 0,
+        BIT_TARGET_NAME,
+        BIT_COMMAND_COMMENT,
+        BIT_EMPTY_SUFFIX,
+#if ENABLE_PLATFORM_MINGW32
+        BIT_WINDOWS,
+#endif
+        BIT_POSIX_2017,
+        BIT_POSIX_202X,
+
+        P_MACRO_NAME = (1 << BIT_MACRO_NAME),
+        P_TARGET_NAME = (1 << BIT_TARGET_NAME),
+        P_COMMAND_COMMENT = (1 << BIT_COMMAND_COMMENT),
+        P_EMPTY_SUFFIX = (1 << BIT_EMPTY_SUFFIX),
 #if ENABLE_PLATFORM_MINGW32
-# define P_WINDOWS                              0x20
+        P_WINDOWS = (1 << BIT_WINDOWS)
 #endif
+};
 
 // Status of make()
 #define MAKE_FAILURE            0x01
@@ -235,6 +254,7 @@ struct globals {
         bool seen_first;
         llist_t *pragmas;
         unsigned char pragma;
+        unsigned char posix_level;
 #endif
 } FIX_ALIASING;
 
@@ -263,9 +283,11 @@ struct globals {
 #define seen_first      (G.seen_first)
 #define pragmas         (G.pragmas)
 #define pragma          (G.pragma)
+#define posix_level     (G.posix_level)
 #else
 #define posix           0
 #define pragma          0
+#define posix_level     DEFAULT_POSIX_LEVEL
 #endif
 
 static int make(struct name *np, int level);
@@ -591,20 +613,28 @@ static void
 set_pragma(const char *name)
 {
         // Order must match constants above.
+        // POSIX levels must be last and in increasing order
         static const char *p_name =
                 "macro_name\0"
                 "target_name\0"
                 "command_comment\0"
                 "empty_suffix\0"
-                "posix_202x\0"
 #if ENABLE_PLATFORM_MINGW32
                 "windows\0"
 #endif
+                "posix_2017\0"
+                "posix_202x\0"
         ;
         int idx = index_in_strings(p_name, name);
 
         if (idx != -1) {
-                pragma |= 1 << idx;
+                if (idx >= BIT_POSIX_2017) {
+                        // POSIX level is stored in a separate variable.
+                        // No bits in 'pragma' are used.
+                        posix_level = idx - BIT_POSIX_2017;
+                } else {
+                        pragma |= 1 << idx;
+                }
                 return;
         }
         warning("invalid pragma '%s'", name);
@@ -2968,6 +2998,7 @@ int make_main(int argc UNUSED_PARAM, char **argv)
         } else {
                 posix = getenv("PDPMAKE_POSIXLY_CORRECT") != NULL;
         }
+        posix_level = DEFAULT_POSIX_LEVEL;
 #endif
 
         if (!POSIX_2017) {