Module Name: src
Committed By: rillig
Date: Fri Jul 31 19:50:44 UTC 2020
Modified Files:
src/usr.bin/make: dir.c
Log Message:
make(1): refactor DirExpandCurly
Separating the low-level parts into small functions reduces the need for
summarizing comments between the code lines.
Using a consistent naming scheme for the variables and expressive names
makes the code easier to understand. The number of variables has
increased from 7 to 11, their clearer names compensate for that, plus
the fact that they come in triples (x, x_end, x_len). Placing the
variables into appropriate registers and eliminating memory access is
left as an exercise to the compiler.
To generate a diff of this commit:
cvs rdiff -u -r1.79 -r1.80 src/usr.bin/make/dir.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/usr.bin/make/dir.c
diff -u src/usr.bin/make/dir.c:1.79 src/usr.bin/make/dir.c:1.80
--- src/usr.bin/make/dir.c:1.79 Fri Jul 31 19:06:33 2020
+++ src/usr.bin/make/dir.c Fri Jul 31 19:50:44 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: dir.c,v 1.79 2020/07/31 19:06:33 rillig Exp $ */
+/* $NetBSD: dir.c,v 1.80 2020/07/31 19:50:44 rillig Exp $ */
/*
* Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
@@ -70,14 +70,14 @@
*/
#ifndef MAKE_NATIVE
-static char rcsid[] = "$NetBSD: dir.c,v 1.79 2020/07/31 19:06:33 rillig Exp $";
+static char rcsid[] = "$NetBSD: dir.c,v 1.80 2020/07/31 19:50:44 rillig Exp $";
#else
#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)dir.c 8.2 (Berkeley) 1/2/94";
#else
-__RCSID("$NetBSD: dir.c,v 1.79 2020/07/31 19:06:33 rillig Exp $");
+__RCSID("$NetBSD: dir.c,v 1.80 2020/07/31 19:50:44 rillig Exp $");
#endif
#endif /* not lint */
#endif
@@ -647,6 +647,62 @@ DirMatchFiles(const char *pattern, Path
return 0;
}
+static const char *
+closing_brace(const char *p)
+{
+ int nest = 0;
+ while (*p != '\0' && !(*p == '}' && nest == 0)) {
+ if (*p == '{')
+ nest++;
+ if (*p == '}')
+ nest--;
+ p++;
+ }
+ return p;
+}
+
+static const char *
+separator_comma(const char *p)
+{
+ int nest = 0;
+ while (*p != '\0' && !((*p == '}' || *p == ',') && nest == 0)) {
+ if (*p == '{')
+ nest++;
+ if (*p == '}')
+ nest--;
+ p++;
+ }
+ return p;
+}
+
+static Boolean
+contains_wildcard(const char *p)
+{
+ for (; *p != '\0'; p++) {
+ switch(*p) {
+ case '*':
+ case '?':
+ case '{':
+ case '[':
+ return TRUE;
+ }
+ }
+ return FALSE;
+}
+
+static char *
+concat3(const char *a, size_t a_len, const char *b, size_t b_len,
+ const char *c, size_t c_len)
+{
+ size_t s_len = a_len + b_len + c_len;
+ char *s = bmake_malloc(s_len + 1);
+ memcpy(s, a, a_len);
+ memcpy(s + a_len, b, b_len);
+ memcpy(s + a_len + b_len, c, c_len);
+ s[s_len] = '\0';
+ return s;
+}
+
/*-
*-----------------------------------------------------------------------
* DirExpandCurly --
@@ -672,103 +728,51 @@ DirMatchFiles(const char *pattern, Path
static void
DirExpandCurly(const char *word, const char *brace, Lst path, Lst expansions)
{
- const char *end; /* Character after the closing brace */
- const char *cp; /* Current position in brace clause */
- const char *start; /* Start of current piece of brace clause */
- int bracelevel; /* Number of braces we've seen. If we see a
- * right brace when this is 0, we've hit the
- * end of the clause. */
- char *file; /* Current expansion */
- int otherLen; /* The length of the other pieces of the
- * expansion (chars before and after the
- * clause in 'word') */
- char *cp2; /* Pointer for checking for wildcards in
- * expansion before calling Dir_Expand */
+ /* Split the word into prefix '{' middle '}' suffix. */
- start = brace+1;
+ const char *middle = brace + 1;
+ const char *middle_end = closing_brace(middle);
+ size_t middle_len = (size_t)(middle_end - middle);
- /*
- * Find the end of the brace clause first, being wary of nested brace
- * clauses.
- */
- for (end = start, bracelevel = 0; *end != '\0'; end++) {
- if (*end == '{') {
- bracelevel++;
- } else if (*end == '}' && bracelevel-- == 0) {
- break;
- }
+ if (DEBUG(DIR)) {
+ fprintf(debug_file, "%s: word=\"%s\" middle=\"%.*s\"\n",
+ __func__, word, (int)middle_len, middle);
}
- if (DEBUG(DIR))
- fprintf(debug_file, "%s: word=\"%s\" start=\"%s\" end=\"%s\"\n",
- __func__, word, start, end);
- if (*end == '\0') {
- Error("Unterminated {} clause \"%s\"", start);
+ if (*middle_end == '\0') {
+ Error("Unterminated {} clause \"%s\"", middle);
return;
}
- end++;
- otherLen = brace - word + strlen(end);
+ const char *prefix = word;
+ size_t prefix_len = (size_t)(brace - prefix);
+ const char *suffix = middle_end + 1;
+ size_t suffix_len = strlen(suffix);
+
+ /* Split the middle into pieces, separated by commas. */
+
+ const char *piece = middle;
+ while (piece < middle_end) {
+ const char *piece_end = separator_comma(piece);
+ size_t piece_len = (size_t)(piece_end - piece);
- for (cp = start; cp < end; cp++) {
- /*
- * Find the end of this piece of the clause.
- */
- bracelevel = 0;
- while (*cp != '\0') {
- if ((*cp == ',' || *cp == '}') && bracelevel == 0)
- break;
- if (*cp == '{')
- bracelevel++;
- if (*cp == '}')
- bracelevel--;
- cp++;
- }
- /*
- * Allocate room for the combination and install the three pieces.
- */
- file = bmake_malloc(otherLen + cp - start + 1);
- char *fileend = file;
- if (brace != word) {
- memcpy(file, word, brace - word);
- fileend += brace - word;
- }
- if (cp != start) {
- memcpy(fileend, start, cp - start);
- fileend += cp - start;
- }
- strcpy(fileend, end);
- if (DEBUG(DIR))
- fprintf(debug_file, "%s: \"%.*s\" + \"%.*s\" + \"%s\" = \"%s\"\n",
- __func__, (int)(brace - word), word, (int)(cp - start), start,
- end, file);
+ char *file = concat3(prefix, prefix_len, piece, piece_len,
+ suffix, suffix_len);
- /*
- * See if the result has any wildcards in it. If we find one, call
- * Dir_Expand right away, telling it to place the result on our list
- * of expansions.
- */
- for (cp2 = file; *cp2 != '\0'; cp2++) {
- switch(*cp2) {
- case '*':
- case '?':
- case '{':
- case '[':
- Dir_Expand(file, path, expansions);
- goto next;
- }
+ if (DEBUG(DIR)) {
+ fprintf(debug_file, "%s: \"%.*s\" + \"%.*s\" + \"%s\" = \"%s\"\n",
+ __func__, (int)prefix_len, prefix, (int)piece_len, piece,
+ suffix, file);
}
- if (*cp2 == '\0') {
- /*
- * Hit the end w/o finding any wildcards, so stick the expansion
- * on the end of the list.
- */
- (void)Lst_AtEnd(expansions, file);
- } else {
- next:
+
+ if (contains_wildcard(file)) {
+ Dir_Expand(file, path, expansions);
free(file);
+ } else {
+ (void)Lst_AtEnd(expansions, file);
}
- start = cp+1;
+
+ piece = piece_end + 1; /* skip over the comma or closing brace */
}
}
