[.joined/src/trunk]: .joined/src/usr.bin/make make: clean up loadfile

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

details:   https://anonhg.NetBSD.org/.joined/src/rev/6c39f5979137
branches:  trunk
changeset: 359388:6c39f5979137
user:      rillig <rillig%NetBSD.org@localhost>
date:      Sat Jan 01 21:19:37 2022 +0000

description:
make: clean up loadfile

Do not reserve extra space "just in case a makefile does not end in
'\n'" since that doesn't happen often.

The assertion for 'buf.len <= buf.cap' was redundant.

No functional change.

diffstat:

 usr.bin/make/parse.c |  58 ++++++++-------------------------------------------
 1 files changed, 10 insertions(+), 48 deletions(-)

diffs (108 lines):

diff -r b2fd609803cd -r 6c39f5979137 usr.bin/make/parse.c
--- a/usr.bin/make/parse.c      Sat Jan 01 21:07:13 2022 +0000
+++ b/usr.bin/make/parse.c      Sat Jan 01 21:19:37 2022 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: parse.c,v 1.611 2022/01/01 21:04:15 rillig Exp $       */
+/*     $NetBSD: parse.c,v 1.612 2022/01/01 21:19:37 rillig Exp $       */
 
 /*
  * Copyright (c) 1988, 1989, 1990, 1993
@@ -110,7 +110,7 @@
 #include "pathnames.h"
 
 /*     "@(#)parse.c    8.3 (Berkeley) 3/19/94" */
-MAKE_RCSID("$NetBSD: parse.c,v 1.611 2022/01/01 21:04:15 rillig Exp $");
+MAKE_RCSID("$NetBSD: parse.c,v 1.612 2022/01/01 21:19:37 rillig Exp $");
 
 /* types and constants */
 
@@ -318,7 +318,7 @@
 /* file loader */
 
 struct loadedfile {
-       char *buf;              /* contents buffer */
+       char *buf;              /* contents buffer, not null-terminated */
        size_t len;             /* length of contents */
        bool used;              /* XXX: have we used the data yet */
 };
@@ -361,36 +361,6 @@
 }
 
 /*
- * Try to get the size of a file.
- */
-static bool
-load_getsize(int fd, size_t *ret)
-{
-       struct stat st;
-
-       if (fstat(fd, &st) < 0)
-               return false;
-
-       if (!S_ISREG(st.st_mode))
-               return false;
-
-       /*
-        * st_size is an off_t, which is 64 bits signed; *ret is
-        * size_t, which might be 32 bits unsigned or 64 bits
-        * unsigned. Rather than being elaborate, just punt on
-        * files that are more than 1 GiB. We should never
-        * see a makefile that size in practice.
-        *
-        * While we're at it reject negative sizes too, just in case.
-        */
-       if (st.st_size < 0 || st.st_size > 0x3fffffff)
-               return false;
-
-       *ret = (size_t)st.st_size;
-       return true;
-}
-
-/*
  * Read in a file.
  *
  * Until the path search logic can be moved under here instead of
@@ -404,28 +374,20 @@
 {
        ssize_t n;
        Buffer buf;
-       size_t filesize;
-
+       size_t bufSize;
+       struct stat st;
 
        if (path == NULL) {
                assert(fd == -1);
                fd = STDIN_FILENO;
        }
 
-       if (load_getsize(fd, &filesize)) {
-               /*
-                * Avoid resizing the buffer later for no reason.
-                *
-                * At the same time leave space for adding a final '\n',
-                * just in case it is missing in the file.
-                */
-               filesize++;
-       } else
-               filesize = 1024;
-       Buf_InitSize(&buf, filesize);
+       bufSize = fstat(fd, &st) == 0 && S_ISREG(st.st_mode) &&
+                 st.st_size >= 0 && st.st_size <= 0x3fffffff
+           ? (size_t)st.st_size : 1024;
+       Buf_InitSize(&buf, bufSize);
 
        for (;;) {
-               assert(buf.len <= buf.cap);
                if (buf.len == buf.cap) {
                        if (buf.cap > 0x1fffffff) {
                                errno = EFBIG;
@@ -462,7 +424,7 @@
        const IFile *entries;
        size_t i, n;
 
-       if (!(DEBUG(PARSE)))
+       if (!DEBUG(PARSE))
                return;
 
        entries = GetInclude(0);