make: restore warning about invalid macro name

Commit 90c5352a9 (make: change how macros are read from the
environment) was intended to ignore environment variables with
invalid names.  It had the unintended consequence of also ignoring
macros with invalid names defined in makefiles.  This was because
such macros can have the same level (3) as those imported from the
environment.

Rather than use the level to detect importing from the environment
add a flag to indicate this circumstance.

1 files changed, 9 insertions, 7 deletions

diff --git a/miscutils/make.c b/miscutils/make.c
index 02da3611c..deb04ec88 100644
--- a/miscutils/make.c
+++ b/miscutils/make.c
@@ -226,8 +226,9 @@ struct macro {
 };
 
 // Flags passed to setmacro()
-#define M_IMMEDIATE  8          // immediate-expansion macro is being defined
-#define M_VALID     16          // assert macro name is valid
+#define M_IMMEDIATE  0x08       // immediate-expansion macro is being defined
+#define M_VALID      0x10       // assert macro name is valid
+#define M_ENVIRON    0x20       // macro imported from environment
 
 // Constants for PRAGMA.  Order must match strings in set_pragma().
 enum {
@@ -781,9 +782,10 @@ setmacro(const char *name, const char *val, int level)
 {
         struct macro *mp;
         bool valid = level & M_VALID;
+        bool from_env = level & M_ENVIRON;
         bool immediate = level & M_IMMEDIATE;
 
-        level &= ~(M_IMMEDIATE | M_VALID);
+        level &= ~(M_IMMEDIATE | M_VALID | M_ENVIRON);
         mp = getmp(name);
         if (mp) {
                 // Don't replace existing macro from a lower level
@@ -798,7 +800,7 @@ setmacro(const char *name, const char *val, int level)
 
                 if (!valid && !is_valid_macro(name)) {
                         // Silently drop invalid names from the environment
-                        if (level == 3)
+                        if (from_env)
                                 return;
 #if ENABLE_FEATURE_MAKE_POSIX
                         error("invalid macro name '%s'%s", name,
@@ -2843,9 +2845,9 @@ process_macros(char **argv, int level)
 
                 /* We want to process _most_ macro assignments.
                  * There are exceptions for particular values from the
-                 * environment (level 3). */
+                 * environment. */
                 idx = index_in_strings(SPECIAL_MACROS, *argv);
-                if (!(level == 3 &&
+                if (!((level & M_ENVIRON) &&
                                 (idx == MAKEFLAGS || idx == SHELL ||
                                         (idx == CURDIR && !useenv && !POSIX_2017)))) {
                         if (colon) {
@@ -3084,7 +3086,7 @@ int make_main(int argc UNUSED_PARAM, char **argv)
         }
 
         // Process macro definitions from the environment
-        process_macros(environ, 3);
+        process_macros(environ, 3 | M_ENVIRON);
 
         // Update MAKEFLAGS and environment
         update_makeflags();