svn commit: r352074 - head/sys/ddb
Conrad Meyer
cem at FreeBSD.org
Mon Sep 9 16:31:15 UTC 2019
Author: cem
Date: Mon Sep 9 16:31:14 2019
New Revision: 352074
URL: https://svnweb.freebsd.org/changeset/base/352074
Log:
ddb(4): Enhance lexer functionality for specialized commands
Add a db_read_token_flags() variant of db_read_token() with configurable
parameters.
Allow specifying an explicit radix for tNUMBER lexing. It overrides the
default inference and db_radix setting.
Also provide the option of yielding any lexed whitespace (tWSPACE) (instead
of ignoring it). This is useful for whitespace-sensitive CS_OWN commands.
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D21459
Modified:
head/sys/ddb/db_lex.c
head/sys/ddb/db_lex.h
Modified: head/sys/ddb/db_lex.c
==============================================================================
--- head/sys/ddb/db_lex.c Mon Sep 9 16:25:09 2019 (r352073)
+++ head/sys/ddb/db_lex.c Mon Sep 9 16:31:14 2019 (r352074)
@@ -38,6 +38,7 @@ __FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/libkern.h>
+#include <sys/lock.h>
#include <ddb/ddb.h>
#include <ddb/db_lex.h>
@@ -45,7 +46,7 @@ __FBSDID("$FreeBSD$");
static char db_line[DB_MAXLINE];
static char * db_lp, *db_endlp;
-static int db_lex(void);
+static int db_lex(int);
static void db_flush_line(void);
static int db_read_char(void);
static void db_unread_char(int);
@@ -124,23 +125,24 @@ db_unread_char(c)
static int db_look_token = 0;
void
-db_unread_token(t)
- int t;
+db_unread_token(int t)
{
db_look_token = t;
}
int
-db_read_token()
+db_read_token_flags(int flags)
{
int t;
+ MPASS((flags & ~(DRT_VALID_FLAGS_MASK)) == 0);
+
if (db_look_token) {
t = db_look_token;
db_look_token = 0;
}
else
- t = db_lex();
+ t = db_lex(flags);
return (t);
}
@@ -158,22 +160,46 @@ db_flush_lex(void)
}
static int
-db_lex(void)
+db_lex(int flags)
{
- int c;
+ int c, n, radix_mode;
+ bool lex_wspace;
+ switch (flags & DRT_RADIX_MASK) {
+ case DRT_DEFAULT_RADIX:
+ radix_mode = -1;
+ break;
+ case DRT_OCTAL:
+ radix_mode = 8;
+ break;
+ case DRT_DECIMAL:
+ radix_mode = 10;
+ break;
+ case DRT_HEXADECIMAL:
+ radix_mode = 16;
+ break;
+ }
+
+ lex_wspace = ((flags & DRT_WSPACE) != 0);
+
c = db_read_char();
- while (c <= ' ' || c > '~') {
+ for (n = 0; c <= ' ' || c > '~'; n++) {
if (c == '\n' || c == -1)
return (tEOL);
c = db_read_char();
}
+ if (lex_wspace && n != 0) {
+ db_unread_char(c);
+ return (tWSPACE);
+ }
if (c >= '0' && c <= '9') {
/* number */
int r, digit = 0;
- if (c > '0')
+ if (radix_mode != -1)
+ r = radix_mode;
+ else if (c > '0')
r = db_radix;
else {
c = db_read_char();
Modified: head/sys/ddb/db_lex.h
==============================================================================
--- head/sys/ddb/db_lex.h Mon Sep 9 16:25:09 2019 (r352073)
+++ head/sys/ddb/db_lex.h Mon Sep 9 16:31:14 2019 (r352074)
@@ -38,13 +38,51 @@
/*
* Lexical analyzer.
*/
+
+/*
+ * Options and flags can configure db_read_token() => db_lex() behavior.
+ *
+ * When a radix other than DRT_DEFAULT_RADIX is used, it overrides
+ * auto-detection, as well as the user-specified db_radix, in db_lex() of
+ * 'tNUMBER' tokens.
+ */
+enum {
+ /* Infer or use db_radix using the old logic. */
+ DRT_DEFAULT_RADIX = 0,
+ /* The following set an explicit base for tNUMBER lex. */
+ DRT_OCTAL,
+ DRT_DECIMAL,
+ DRT_HEXADECIMAL,
+};
+#define DRT_RADIX_MASK 0x3
+/*
+ * Flag bit powers of two for db_read_token_flags.
+ * The low 2 bits are reserved for radix selection.
+ */
+enum {
+ _DRT_WSPACE = 2,
+};
+#ifndef BIT
+#define BIT(n) (1ull << (n))
+#endif
+enum {
+ DRT_WSPACE = BIT(_DRT_WSPACE),
+};
+#define DRT_VALID_FLAGS_MASK ((int)DRT_RADIX_MASK | DRT_WSPACE)
+
void db_flush_lex(void);
char *db_get_line(void);
void db_inject_line(const char *command);
int db_read_line(void);
-int db_read_token(void);
+int db_read_token_flags(int);
void db_unread_token(int t);
+static inline int
+db_read_token(void)
+{
+ return (db_read_token_flags(0));
+}
+
extern db_expr_t db_tok_number;
#define TOK_STRING_SIZE 120
extern char db_tok_string[TOK_STRING_SIZE];
@@ -84,5 +122,6 @@ extern char db_tok_string[TOK_STRING_SIZE];
#define tSTRING 32
#define tQUESTION 33
#define tBIT_NOT 34
+#define tWSPACE 35
#endif /* !_DDB_DB_LEX_H_ */
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