GNU make and NetBSD's bmake (which is also used by FreeBSD)
support this.
This is based on the implementation from bmake.
Index: usr.bin/make/config.h
===================================================================
RCS file: /cvs/src/usr.bin/make/config.h,v
retrieving revision 1.20
diff -u -p -u -r1.20 config.h
--- usr.bin/make/config.h 18 Oct 2014 07:50:06 -0000 1.20
+++ usr.bin/make/config.h 8 Nov 2015 20:17:13 -0000
@@ -64,6 +64,12 @@
#define SYSVVARSUB
/*
+ * GMAKEEXPORT
+ * Recognize gmake like variable export directives [export <VAR>=<VALUE>]
+ */
+#define GMAKEEXPORT
+
+/*
* SUNSHCMD
* Recognize SunOS and Solaris:
* VAR :sh= CMD # Assign VAR to the command substitution of CMD
@@ -94,6 +100,11 @@
#else
#define DOFEATURE_SYSVVARSUB 0
#endif
+#ifdef GMAKEEXPORT
+#define DOFEATURE_GMAKEEXPORT FEATURE_GMAKEEXPORT
+#else
+#define DOFEATURE_GMAKEEXPORT 0
+#endif
#ifdef SUNSHCMD
#define DOFEATURE_SUNSHCMD FEATURE_SUNSHCMD
#else
@@ -101,7 +112,10 @@
#endif
#ifndef DEFAULT_FEATURES
-#define DEFAULT_FEATURES (FEATURE_UPPERLOWER | DOFEATURE_SYSVVARSUB |
DOFEATURE_SYSVINCLUDE | DOFEATURE_SUNSHCMD | FEATURE_RECVARS |
FEATURE_CONDINCLUDE)
+#define DEFAULT_FEATURES (FEATURE_UPPERLOWER | DOFEATURE_SYSVVARSUB | \
+ DOFEATURE_SYSVINCLUDE | DOFEATURE_SUNSHCMD | \
+ FEATURE_RECVARS | FEATURE_CONDINCLUDE | \
+ DOFEATURE_GMAKEEXPORT)
#endif
#define FEATURES(x) ((DEFAULT_FEATURES & (x)) != 0)
@@ -116,6 +130,7 @@
#define FEATURE_CONDINCLUDE 256
#define FEATURE_ASSIGN 512
#define FEATURE_EXECMOD 1024
+#define FEATURE_GMAKEEXPORT 2048
/*
* There are several places where expandable buffers are used (parse.c and
Index: usr.bin/make/parse.c
===================================================================
RCS file: /cvs/src/usr.bin/make/parse.c,v
retrieving revision 1.112
diff -u -p -u -r1.112 parse.c
--- usr.bin/make/parse.c 23 Jan 2015 22:35:57 -0000 1.112
+++ usr.bin/make/parse.c 8 Nov 2015 20:17:13 -0000
@@ -151,6 +151,7 @@ static bool lookup_bsd_include(const cha
static void lookup_sysv_style_include(const char *, const char *, bool);
static void lookup_sysv_include(const char *, const char *);
static void lookup_conditional_include(const char *, const char *);
+static void handle_gmake_export(char *, const char *);
static bool parse_as_special_line(Buffer, Buffer, const char *);
static unsigned int parse_operator(const char **);
@@ -1226,6 +1227,28 @@ lookup_conditional_include(const char *f
lookup_sysv_style_include(file, directive, false);
}
+static void
+handle_gmake_export(char *line, const char *directive)
+{
+ char *variable = line;
+ char *value;
+
+ while (isspace((unsigned char)*variable))
+ variable++;
+
+ for (value = variable; *value && *value != '='; value++)
+ continue;
+
+ if (*value != '=') {
+ Parse_Error(PARSE_FATAL,
+ "Variable/Value missing from \"%s\"", directive);
+ return;
+ }
+ *value++ = '\0';
+
+ value = Var_Subst(value, NULL, false);
+ setenv(variable, value, 1);
+}
/***
*** BSD-specific . constructs
@@ -1469,6 +1492,13 @@ parse_as_special_line(Buffer buf, Buffer
ISSPACE(line[8]) &&
strchr(line, ':') == NULL) {
lookup_conditional_include(line+8, "-include");
+ return true;
+ }
+ if (FEATURES(FEATURE_GMAKEEXPORT) &&
+ strncmp(line, "export", 6) == 0 &&
+ ISSPACE(line[6]) &&
+ strchr(line, ':') == NULL) {
+ handle_gmake_export((char *)line+6, "export");
return true;
}
return false;
Index: usr.bin/make/make.1
===================================================================
RCS file: /cvs/src/usr.bin/make/make.1,v
retrieving revision 1.120
diff -u -p -u -r1.120 make.1
--- usr.bin/make/make.1 13 Mar 2015 19:58:41 -0000 1.120
+++ usr.bin/make/make.1 8 Nov 2015 20:17:13 -0000
@@ -974,6 +974,14 @@ in
.At V
variable substitutions is not mandated by POSIX, though it is
fairly common.
+.Pp
+The
+.Ic export
+directive can be used to export a variable to the environment,
+using the syntax:
+.Bd -unfilled -offset indent
+.Ic export Ar NAME Ns = Ns Ar value
+.Ed
.Sh INCLUDE STATEMENTS, CONDITIONALS AND FOR LOOPS
Makefile inclusion, conditional structures and for loops reminiscent
of the C programming language are provided in
--
Carlin
