[src/trunk]: src/usr.bin/make make: use simpler code for handling .for loops

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

details:   https://anonhg.NetBSD.org/src/rev/4606a0e30feb
branches:  trunk
changeset: 359488:4606a0e30feb
user:      rillig <rillig%NetBSD.org@localhost>
date:      Fri Jan 07 20:04:49 2022 +0000

description:
make: use simpler code for handling .for loops

Since the body of a .for loop is scanned from start to end, there is no
need to remember the length of a variable name.

Using memcmp for comparing the variable name was probably overkill since
the variable names are usually very short, so rather compare them byte
by byte.

No functional change.

diffstat:

 usr.bin/make/for.c |  54 ++++++++++++++++++------------------------------------
 1 files changed, 18 insertions(+), 36 deletions(-)

diffs (135 lines):

diff -r 8173ed6222b0 -r 4606a0e30feb usr.bin/make/for.c
--- a/usr.bin/make/for.c        Fri Jan 07 19:30:17 2022 +0000
+++ b/usr.bin/make/for.c        Fri Jan 07 20:04:49 2022 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: for.c,v 1.154 2022/01/02 01:54:43 rillig Exp $ */
+/*     $NetBSD: for.c,v 1.155 2022/01/07 20:04:49 rillig Exp $ */
 
 /*
  * Copyright (c) 1992, The Regents of the University of California.
@@ -58,18 +58,12 @@
 #include "make.h"
 
 /*     "@(#)for.c      8.1 (Berkeley) 6/6/93"  */
-MAKE_RCSID("$NetBSD: for.c,v 1.154 2022/01/02 01:54:43 rillig Exp $");
-
+MAKE_RCSID("$NetBSD: for.c,v 1.155 2022/01/07 20:04:49 rillig Exp $");
 
-/* One of the variables to the left of the "in" in a .for loop. */
-typedef struct ForVar {
-       char *name;
-       size_t nameLen;
-} ForVar;
 
 typedef struct ForLoop {
        Buffer body;            /* Unexpanded body of the loop */
-       Vector /* of ForVar */ vars; /* Iteration variables */
+       Vector /* of 'char *' */ vars; /* Iteration variables */
        SubstringWords items;   /* Substitution items */
        unsigned int nextItem;  /* Where to continue iterating */
 } ForLoop;
@@ -85,7 +79,7 @@
        ForLoop *f = bmake_malloc(sizeof *f);
 
        Buf_Init(&f->body);
-       Vector_Init(&f->vars, sizeof(ForVar));
+       Vector_Init(&f->vars, sizeof(char *));
        SubstringWords_Init(&f->items);
        f->nextItem = 0;
 
@@ -97,10 +91,8 @@
 {
        Buf_Done(&f->body);
 
-       while (f->vars.len > 0) {
-               ForVar *var = Vector_Pop(&f->vars);
-               free(var->name);
-       }
+       while (f->vars.len > 0)
+               free(*(char **)Vector_Pop(&f->vars));
        Vector_Done(&f->vars);
 
        SubstringWords_Free(f->items);
@@ -108,14 +100,6 @@
        free(f);
 }
 
-static void
-ForLoop_AddVar(ForLoop *f, const char *name, size_t len)
-{
-       ForVar *var = Vector_Push(&f->vars);
-       var->name = bmake_strldup(name, len);
-       var->nameLen = len;
-}
-
 static bool
 ForLoop_ParseVarnames(ForLoop *f, const char **pp)
 {
@@ -142,7 +126,7 @@
                        break;
                }
 
-               ForLoop_AddVar(f, p, len);
+               *(char **)Vector_Push(&f->vars) = bmake_strldup(p, len);
                p += len;
        }
 
@@ -374,31 +358,29 @@
                     const char *end, char endc, const char **inout_mark)
 {
        size_t i;
-       const char *p = *pp;
+       const char *start = *pp;
+       const char **vars = Vector_Get(&f->vars, 0);
 
        for (i = 0; i < f->vars.len; i++) {
-               const ForVar *forVar = Vector_Get(&f->vars, i);
-               const char *varname = forVar->name;
-               size_t varnameLen = forVar->nameLen;
+               const char *p = start;
+               const char *varname = vars[i];
 
-               if (varnameLen >= (size_t)(end - p))
-                       continue;
-               if (memcmp(p, varname, varnameLen) != 0)
+               while (p < end && *varname != '\0' && *p == *varname)
+                       p++, varname++;
+               if (*varname != '\0')
                        continue;
                /* XXX: why test for backslash here? */
-               if (p[varnameLen] != ':' && p[varnameLen] != endc &&
-                   p[varnameLen] != '\\')
+               if (*p != ':' && *p != endc && *p != '\\')
                        continue;
 
                /*
                 * Found a variable match.  Skip over the variable name and
                 * instead add ':U<value>' to the current body.
                 */
-               Buf_AddBytesBetween(body, *inout_mark, p);
+               Buf_AddBytesBetween(body, *inout_mark, start);
                Buf_AddStr(body, ":U");
                Buf_AddEscaped(body, f->items.words[f->nextItem + i], endc);
 
-               p += varnameLen;
                *inout_mark = p;
                *pp = p;
                return;
@@ -414,7 +396,7 @@
                      const char *p, const char **inout_mark)
 {
        const char ch = *p;
-       const ForVar *vars;
+       const char **vars;
        size_t i;
 
        /* Skip $$ and stupid ones. */
@@ -423,7 +405,7 @@
 
        vars = Vector_Get(&f->vars, 0);
        for (i = 0; i < f->vars.len; i++) {
-               const char *varname = vars[i].name;
+               const char *varname = vars[i];
                if (varname[0] == ch && varname[1] == '\0')
                        goto found;
        }