 @@ -1,14 +1,14 @@
-/*	$NetBSD: make.h,v 1.176 2020/10/30 07:19:30 rillig Exp $	*/
+/*	$NetBSD: make.h,v 1.177 2020/10/30 17:10:48 rillig Exp $	*/
 /*
  * Copyright (c) 1988, 1989, 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
+ *
  * This code is derived from software contributed to Berkeley by
  * Adam de Boor.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
 @@ -354,27 +354,27 @@ typedef struct GNode {
     int unmade_cohorts;
     /* Pointer to the first instance of a '::' node; only set when on a
      * cohorts list */
     struct GNode *centurion;
     /* Last time (sequence number) we tried to make this node */
     unsigned int checked_seqno;
     /* The "local" variables that are specific to this target and this target
      * only, such as $@, $<, $?.
+     *
      * Also used for the global variable scopes VAR_GLOBAL, VAR_CMDLINE,
      * VAR_INTERNAL, which contain variables with arbitrary names. */
-    HashTable context;
+    HashTable /* of Var pointer */ context;
     /* The commands to be given to a shell to create this target. */
     StringList *commands;
     /* Suffix for the node (determined by Suff_FindDeps and opaque to everyone
      * but the Suff module) */
     struct Suff *suffix;
     /* filename where the GNode got defined */
     const char *fname;
     /* line number where the GNode got defined */
     int lineno;
 } GNode;

 @@ -1,14 +1,14 @@
-/*	$NetBSD: var.c,v 1.604 2020/10/30 16:54:38 rillig Exp $	*/
+/*	$NetBSD: var.c,v 1.605 2020/10/30 17:10:48 rillig Exp $	*/
 /*
  * Copyright (c) 1988, 1989, 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
+ *
  * This code is derived from software contributed to Berkeley by
  * Adam de Boor.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
 @@ -119,27 +119,27 @@
 #include    <sys/types.h>
 #include    <regex.h>
 #endif
 #include    <inttypes.h>
 #include    <limits.h>
 #include    <time.h>
 #include    "make.h"
 #include    "dir.h"
 #include    "job.h"
 #include    "metachar.h"
 /*	"@(#)var.c	8.3 (Berkeley) 3/19/94" */
-MAKE_RCSID("$NetBSD: var.c,v 1.604 2020/10/30 16:54:38 rillig Exp $");
+MAKE_RCSID("$NetBSD: var.c,v 1.605 2020/10/30 17:10:48 rillig Exp $");
 #define VAR_DEBUG1(fmt, arg1) DEBUG1(VAR, fmt, arg1)
 #define VAR_DEBUG2(fmt, arg1, arg2) DEBUG2(VAR, fmt, arg1, arg2)
 #define VAR_DEBUG3(fmt, arg1, arg2, arg3) DEBUG3(VAR, fmt, arg1, arg2, arg3)
 #define VAR_DEBUG4(fmt, arg1, arg2, arg3, arg4) DEBUG4(VAR, fmt, arg1, arg2, arg3, arg4)
 ENUM_FLAGS_RTTI_3(VarEvalFlags,
 		  VARE_UNDEFERR, VARE_WANTRES, VARE_ASSIGN);
 /*
  * This lets us tell if we have replaced the original environ
  * (which we cannot free).
  */
 @@ -338,66 +338,60 @@ CanonicalVarname(const char *name)
+    }
     /* GNU make has an additional alias $^ == ${.ALLSRC}. */
     return name;
+}
 static Var *
 GNode_FindVar(GNode *ctxt, const char *varname, unsigned int hash)
+{
     return HashTable_FindValueHash(&ctxt->context, varname, hash);
+}
-/*-
+/* Find the variable in the context, and maybe in other contexts as well.
  *-----------------------------------------------------------------------
  * VarFind --
  *	Find the given variable in the given context and any other contexts
  *	indicated.
+ *
  * Input:
  *	name		name to find
- *	ctxt		context in which to find it
+ *	ctxt		context in which to look first
- *	elsewhere	to look in other contexts as well
+ *	elsewhere	TRUE to look in other contexts as well
+ *
  * Results:
- *	A pointer to the structure describing the desired variable or
+ *	The found variable, or NULL if the variable does not exist.
- *	NULL if the variable does not exist.
+ *	If the variable is an environment variable, it must be freed using
- *-----------------------------------------------------------------------
+ *	VarFreeEnv after use.
  */
 static Var *
 VarFind(const char *name, GNode *ctxt, Boolean elsewhere)
+{
     Var *var;
     unsigned int nameHash;
     /*
      * If the variable name begins with a '.', it could very well be one of
      * the local ones.  We check the name against all the local variables
      * and substitute the short version in for 'name' if it matches one of
      * them.
      */
     name = CanonicalVarname(name);
     nameHash = Hash_Hash(name);
-    /*
+    /* First look for the variable in the given context. */
      * First look for the variable in the given context. If it's not there,
      * look for it in VAR_CMDLINE, VAR_GLOBAL and the environment, in that order,
      * depending on the FIND_* flags in 'flags'
      */
     var = GNode_FindVar(ctxt, name, nameHash);
     if (!elsewhere)
 	return var;
     /* The variable was not found in the given context.  Now look for it in
      * the other contexts as well. */
     if (var == NULL && ctxt != VAR_CMDLINE)
 	var = GNode_FindVar(VAR_CMDLINE, name, nameHash);
     if (!opts.checkEnvFirst && var == NULL && ctxt != VAR_GLOBAL) {
 	var = GNode_FindVar(VAR_GLOBAL, name, nameHash);
 	if (var == NULL && ctxt != VAR_INTERNAL) {
 	    /* VAR_INTERNAL is subordinate to VAR_GLOBAL */
 	    var = GNode_FindVar(VAR_INTERNAL, name, nameHash);
+	}
+    }
     if (var == NULL) {
 	char *env;
 @@ -410,65 +404,62 @@ VarFind(const char *name, GNode *ctxt, B
 	if (opts.checkEnvFirst && ctxt != VAR_GLOBAL) {
 	    var = GNode_FindVar(VAR_GLOBAL, name, nameHash);
 	    if (var == NULL && ctxt != VAR_INTERNAL)
 		var = GNode_FindVar(VAR_INTERNAL, name, nameHash);
 	    return var;
+	}
 	return NULL;
+    }
     return var;
+}
-/*-
+/* If the variable is an environment variable, free it.
  *-----------------------------------------------------------------------
  * VarFreeEnv  --
  *	If the variable is an environment variable, free it
+ *
  * Input:
  *	v		the variable
- *	destroy		true if the value buffer should be destroyed.
+ *	freeValue	true if the variable value should be freed as well
+ *
  * Results:
  *	TRUE if it is an environment variable, FALSE otherwise.
  *-----------------------------------------------------------------------
  */
 static Boolean
-VarFreeEnv(Var *v, Boolean destroy)
+VarFreeEnv(Var *v, Boolean freeValue)
+{
     if (!(v->flags & VAR_FROM_ENV))
 	return FALSE;
     free(v->name_freeIt);
-    Buf_Destroy(&v->val, destroy);
+    Buf_Destroy(&v->val, freeValue);
     free(v);
     return TRUE;
+}
 /* Add a new variable of the given name and value to the given context.
  * The name and val arguments are duplicated so they may safely be freed. */
 static void
 VarAdd(const char *name, const char *val, GNode *ctxt, VarSet_Flags flags)
+{
     HashEntry *he = HashTable_CreateEntry(&ctxt->context, name, NULL);
-    Var *v = VarNew(he->key, NULL, val,
+    Var *v = VarNew(he->key /* aliased */, NULL, val,
 		    flags & VAR_SET_READONLY ? VAR_READONLY : 0);
     HashEntry_Set(he, v);
     if (!(ctxt->flags & INTERNAL)) {
 	VAR_DEBUG3("%s:%s = %s\n", ctxt->name, name, val);
+    }
+}
-/* Remove a variable from a context, freeing the Var structure as well. */
+/* Remove a variable from a context, freeing all related memory as well. */
 void
 Var_Delete(const char *name, GNode *ctxt)
+{
     char *name_freeIt = NULL;
     HashEntry *he;
     if (strchr(name, '$') != NULL) {
 	(void)Var_Subst(name, VAR_GLOBAL, VARE_WANTRES, &name_freeIt);
 	/* TODO: handle errors */
 	name = name_freeIt;
+    }
     he = HashTable_FindEntry(&ctxt->context, name);
     VAR_DEBUG3("%s:delete %s%s\n",
 @@ -533,64 +524,65 @@ Var_Export1(const char *name, VarExportF
     v = VarFind(name, VAR_GLOBAL, 0);
     if (v == NULL)
 	return FALSE;
     if (!parent && (v->flags & VAR_EXPORTED) && !(v->flags & VAR_REEXPORT))
 	return FALSE;		/* nothing to do */
     val = Buf_GetAll(&v->val, NULL);
     if (!(flags & VAR_EXPORT_LITERAL) && strchr(val, '$') != NULL) {
 	char *expr;
 	if (parent) {
 	    /*
-	     * Flag this as something we need to re-export.
+	     * Flag the variable as something we need to re-export.
 	     * No point actually exporting it now though,
-	     * the child can do it at the last minute.
+	     * the child process can do it at the last minute.
 	     */
 	    v->flags |= VAR_EXPORTED | VAR_REEXPORT;
 	    return TRUE;
+	}
 	if (v->flags & VAR_IN_USE) {
 	    /*
 	     * We recursed while exporting in a child.
 	     * This isn't going to end well, just skip it.
 	     */
 	    return FALSE;
+	}
 	expr = str_concat3("${", name, "}");
 	(void)Var_Subst(expr, VAR_GLOBAL, VARE_WANTRES, &val);
 	/* TODO: handle errors */
 	setenv(name, val, 1);
 	free(val);
 	free(expr);
     } else {
 	if (parent)
 	    v->flags &= ~(unsigned)VAR_REEXPORT;	/* once will do */
 	if (parent || !(v->flags & VAR_EXPORTED))
 	    setenv(name, val, 1);
+    }
     /*
      * This is so Var_Set knows to call Var_Export again...
      */
     if (parent) {
 	v->flags |= VAR_EXPORTED;
+    }
     return TRUE;
+}
 /*
- * This gets called from our children.
+ * This gets called from our child processes.
  */
 void
 Var_ExportVars(void)
+{
     char *val;
     /*
      * Several make's support this sort of mechanism for tracking
      * recursion - but each uses a different name.
      * We allow the makefiles to update MAKELEVEL and ensure
      * children see a correctly incremented value.
      */
     char tmp[BUFSIZ];