[src/trunk]: src/usr.bin/make make(1): clean up variable substitution in .for...

[rillig <rillig%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/6965ed6352ea
branches:  trunk
changeset: 956322:6965ed6352ea
user:      rillig <rillig%NetBSD.org@localhost>
date:      Mon Oct 26 07:33:48 2020 +0000

description:
make(1): clean up variable substitution in .for loops

The variable name cmd_cp was not really helpful for understanding the
code.

diffstat:

 usr.bin/make/for.c |  74 ++++++++++++++++++++++++++---------------------------
 1 files changed, 36 insertions(+), 38 deletions(-)

diffs (169 lines):

diff -r 0a035da2d8aa -r 6965ed6352ea usr.bin/make/for.c
--- a/usr.bin/make/for.c        Mon Oct 26 07:16:41 2020 +0000
+++ b/usr.bin/make/for.c        Mon Oct 26 07:33:48 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: for.c,v 1.109 2020/10/26 07:03:47 rillig Exp $ */
+/*     $NetBSD: for.c,v 1.110 2020/10/26 07:33:48 rillig Exp $ */
 
 /*
  * Copyright (c) 1992, The Regents of the University of California.
@@ -60,7 +60,7 @@
 #include    "make.h"
 
 /*     "@(#)for.c      8.1 (Berkeley) 6/6/93"  */
-MAKE_RCSID("$NetBSD: for.c,v 1.109 2020/10/26 07:03:47 rillig Exp $");
+MAKE_RCSID("$NetBSD: for.c,v 1.110 2020/10/26 07:33:48 rillig Exp $");
 
 /* The .for loop substitutes the items as ${:U<value>...}, which means
  * that characters that break this syntax must be backslash-escaped. */
@@ -326,8 +326,10 @@
     return 0;
 }
 
+/* While expanding the body of a .for loop, write the item in the ${:U...}
+ * expression, escaping characters as needed. See ApplyModifier_Defined. */
 static void
-for_substitute(Buffer *cmds, const char *item, char ech)
+Buf_AddEscaped(Buffer *cmds, const char *item, char ech)
 {
     ForEscapes escapes = GetEscapes(item);
     char ch;
@@ -360,71 +362,68 @@
 /* While expanding the body of a .for loop, replace expressions like
  * ${i}, ${i:...}, $(i) or $(i:...) with their ${:U...} expansion. */
 static void
-SubstVarLong(For *f, const char **inout_cp, const char **inout_cmd_cp, char ech)
+SubstVarLong(For *f, const char **pp, const char **inout_mark, char ech)
 {
     size_t i;
-    const char *cp = *inout_cp;
-    const char *cmd_cp = *inout_cmd_cp;
+    const char *p = *pp;
 
     for (i = 0; i < f->vars.len; i++) {
        ForVar *forVar = Vector_Get(&f->vars, i);
        char *var = forVar->name;
        size_t vlen = forVar->len;
 
-       /* XXX: undefined behavior for cp if vlen is longer than cp? */
-       if (memcmp(cp, var, vlen) != 0)
+       /* XXX: undefined behavior for p if vlen is longer than p? */
+       if (memcmp(p, var, vlen) != 0)
            continue;
        /* XXX: why test for backslash here? */
-       if (cp[vlen] != ':' && cp[vlen] != ech && cp[vlen] != '\\')
+       if (p[vlen] != ':' && p[vlen] != ech && p[vlen] != '\\')
            continue;
 
        /* Found a variable match. Replace with :U<value> */
-       Buf_AddBytesBetween(&f->curBody, cmd_cp, cp);
+       Buf_AddBytesBetween(&f->curBody, *inout_mark, p);
        Buf_AddStr(&f->curBody, ":U");
-       cp += vlen;
-       cmd_cp = cp;
-       for_substitute(&f->curBody, f->items.words[f->sub_next + i], ech);
+       Buf_AddEscaped(&f->curBody, f->items.words[f->sub_next + i], ech);
+
+       p += vlen;
+       *inout_mark = p;
        break;
     }
 
-    *inout_cp = cp;
-    *inout_cmd_cp = cmd_cp;
+    *pp = p;
 }
 
 /* While expanding the body of a .for loop, replace single-character
  * variable expressions like $i with their ${:U...} expansion. */
 static void
-SubstVarShort(For *f, char const ch,
-             const char **inout_cp, const char **input_cmd_cp)
+SubstVarShort(For *f, char const ch, const char **pp, const char **inout_mark)
 {
-    const char *cp = *inout_cp;
-    const char *cmd_cp = *input_cmd_cp;
+    const char *p = *pp;
     size_t i;
 
     /* Probably a single character name, ignore $$ and stupid ones. {*/
     if (!f->short_var || strchr("}):$", ch) != NULL) {
-       cp++;
-       *inout_cp = cp;
+       p++;
+       *pp = p;
        return;
     }
 
     for (i = 0; i < f->vars.len; i++) {
        ForVar *var = Vector_Get(&f->vars, i);
-       char *varname = var->name;
+       const char *varname = var->name;
        if (varname[0] != ch || varname[1] != '\0')
            continue;
 
        /* Found a variable match. Replace with ${:U<value>} */
-       Buf_AddBytesBetween(&f->curBody, cmd_cp, cp);
+       Buf_AddBytesBetween(&f->curBody, *inout_mark, p);
        Buf_AddStr(&f->curBody, "{:U");
-       cmd_cp = ++cp;
-       for_substitute(&f->curBody, f->items.words[f->sub_next + i], '}');
+       Buf_AddEscaped(&f->curBody, f->items.words[f->sub_next + i], '}');
        Buf_AddByte(&f->curBody, '}');
+
+       *inout_mark = ++p;
        break;
     }
 
-    *inout_cp = cp;
-    *input_cmd_cp = cmd_cp;
+    *pp = p;
 }
 
 /*
@@ -443,11 +442,10 @@
 ForIterate(void *v_arg, size_t *out_len)
 {
     For *f = v_arg;
-    const char *cp;
-    const char *cmd_cp;
+    const char *p;
+    const char *mark;          /* where the last replacement left off */
     const char *body_end;
     char *cmds_str;
-    size_t cmd_len;
 
     if (f->sub_next + f->vars.len > f->items.len) {
        /* No more iterations */
@@ -457,23 +455,23 @@
 
     Buf_Empty(&f->curBody);
 
-    cmd_cp = Buf_GetAll(&f->body, &cmd_len);
-    body_end = cmd_cp + cmd_len;
-    for (cp = cmd_cp; (cp = strchr(cp, '$')) != NULL;) {
+    mark = Buf_GetAll(&f->body, NULL);
+    body_end = mark + Buf_Len(&f->body);
+    for (p = mark; (p = strchr(p, '$')) != NULL;) {
        char ch, ech;
-       ch = *++cp;
+       ch = *++p;
        if ((ch == '(' && (ech = ')', 1)) || (ch == '{' && (ech = '}', 1))) {
-           cp++;
+           p++;
            /* Check variable name against the .for loop variables */
-           SubstVarLong(f, &cp, &cmd_cp, ech);
+           SubstVarLong(f, &p, &mark, ech);
            continue;
        }
        if (ch == '\0')
            break;
 
-       SubstVarShort(f, ch, &cp, &cmd_cp);
+       SubstVarShort(f, ch, &p, &mark);
     }
-    Buf_AddBytesBetween(&f->curBody, cmd_cp, body_end);
+    Buf_AddBytesBetween(&f->curBody, mark, body_end);
 
     *out_len = Buf_Len(&f->curBody);
     cmds_str = Buf_GetAll(&f->curBody, NULL);