Module Name: src
Committed By: rillig
Date: Fri Nov 13 07:52:04 UTC 2020
Modified Files:
src/usr.bin/make: cond.c
Log Message:
make(1): use bitset for IfState
Previously, the individual IfStates contained redundant information,
which was apparent in the documentation. This led to expressions like
(state > ELSE_ACTIVE) that are hard to read since the reader has to look
up the order of the enum.
To avoid this, the state of an '.if' block is now encoded using a bitset,
encoding the properties of each state directly. This replaces the
previous (state > ELSE_ACTIVE) with !(state & IFS_ACTIVE), which is
easier to understand.
No change in behavior.
To generate a diff of this commit:
cvs rdiff -u -r1.212 -r1.213 src/usr.bin/make/cond.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/cond.c
diff -u src/usr.bin/make/cond.c:1.212 src/usr.bin/make/cond.c:1.213
--- src/usr.bin/make/cond.c:1.212 Fri Nov 13 07:35:27 2020
+++ src/usr.bin/make/cond.c Fri Nov 13 07:52:03 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: cond.c,v 1.212 2020/11/13 07:35:27 rillig Exp $ */
+/* $NetBSD: cond.c,v 1.213 2020/11/13 07:52:03 rillig Exp $ */
/*
* Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
@@ -94,7 +94,7 @@
#include "dir.h"
/* "@(#)cond.c 8.2 (Berkeley) 1/2/94" */
-MAKE_RCSID("$NetBSD: cond.c,v 1.212 2020/11/13 07:35:27 rillig Exp $");
+MAKE_RCSID("$NetBSD: cond.c,v 1.213 2020/11/13 07:52:03 rillig Exp $");
/*
* The parsing of conditional expressions is based on this grammar:
@@ -1092,26 +1092,18 @@ Cond_EvalLine(const char *const line)
{
typedef enum IfState {
- /* The previous <cond> evaluated to TRUE. The lines following this
- * condition are interpreted. */
- IF_ACTIVE,
-
- /* The previous '.else' evaluated to TRUE. The lines following this
- * condition are interpreted. The only difference to IF_ACTIVE is
- * that no other '.else' may follow. */
- ELSE_ACTIVE,
-
- /* All of the previous <cond> evaluated to FALSE. Still searching
- * for an '.elif' or an 'else' that evaluates to TRUE. */
- SEARCH_FOR_ELIF,
-
- /* One of the previous <cond> evaluated to TRUE. There was no '.else'
- * yet. */
- SKIP_TO_ELSE,
-
- /* One of the previous <cond> evaluated to TRUE, and '.else' was
- * already seen. No other '.else' may follow. */
- SKIP_TO_ENDIF
+ /* None of the previous <cond> evaluated to TRUE. */
+ IFS_INITIAL = 0,
+
+ /* The previous <cond> evaluated to TRUE.
+ * The lines following this condition are interpreted. */
+ IFS_ACTIVE = 1 << 0,
+
+ /* The previous directive was an '.else'. */
+ IFS_SEEN_ELSE = 1 << 1,
+
+ /* One of the previous <cond> evaluated to TRUE. */
+ IFS_WAS_ACTIVE = 1 << 2
} IfState;
@@ -1126,7 +1118,7 @@ Cond_EvalLine(const char *const line)
if (cond_states == NULL) {
cond_states = bmake_malloc(cond_states_cap * sizeof *cond_states);
- cond_states[0] = IF_ACTIVE;
+ cond_states[0] = IFS_ACTIVE;
}
p++; /* skip the leading '.' */
@@ -1136,8 +1128,8 @@ Cond_EvalLine(const char *const line)
if (p[0] == 'e') {
if (p[1] != 'l') {
if (!is_token(p + 1, "ndif", 4)) {
- /* Unknown directive. It might still be a transformation
- * rule like '.elisp.scm', therefore no error message here. */
+ /* Unknown directive. It might still be a transformation
+ * rule like '.elisp.scm', therefore no error message here. */
return COND_INVALID;
}
@@ -1151,7 +1143,7 @@ Cond_EvalLine(const char *const line)
/* Return state for previous conditional */
cond_depth--;
- return cond_states[cond_depth] <= ELSE_ACTIVE
+ return cond_states[cond_depth] & IFS_ACTIVE
? COND_PARSE : COND_SKIP;
}
@@ -1167,15 +1159,16 @@ Cond_EvalLine(const char *const line)
}
state = cond_states[cond_depth];
- if (state == SEARCH_FOR_ELIF) {
- state = ELSE_ACTIVE;
+ if (state == IFS_INITIAL) {
+ state = IFS_ACTIVE | IFS_SEEN_ELSE;
} else {
- if (state == ELSE_ACTIVE || state == SKIP_TO_ENDIF)
+ if (state & IFS_SEEN_ELSE)
Parse_Error(PARSE_WARNING, "extra else");
- state = SKIP_TO_ENDIF;
+ state = IFS_WAS_ACTIVE | IFS_SEEN_ELSE;
}
cond_states[cond_depth] = state;
- return state <= ELSE_ACTIVE ? COND_PARSE : COND_SKIP;
+
+ return state & IFS_ACTIVE ? COND_PARSE : COND_SKIP;
}
/* Assume for now it is an elif */
isElif = TRUE;
@@ -1215,14 +1208,13 @@ Cond_EvalLine(const char *const line)
return COND_PARSE;
}
state = cond_states[cond_depth];
- if (state == SKIP_TO_ENDIF || state == ELSE_ACTIVE) {
+ if (state & IFS_SEEN_ELSE) {
Parse_Error(PARSE_WARNING, "extra elif");
- cond_states[cond_depth] = SKIP_TO_ENDIF;
+ cond_states[cond_depth] = IFS_WAS_ACTIVE | IFS_SEEN_ELSE;
return COND_SKIP;
}
- if (state != SEARCH_FOR_ELIF) {
- /* Either just finished the 'true' block, or already SKIP_TO_ELSE */
- cond_states[cond_depth] = SKIP_TO_ELSE;
+ if (state != IFS_INITIAL) {
+ cond_states[cond_depth] = IFS_WAS_ACTIVE;
return COND_SKIP;
}
} else {
@@ -1239,9 +1231,9 @@ Cond_EvalLine(const char *const line)
}
state = cond_states[cond_depth];
cond_depth++;
- if (state > ELSE_ACTIVE) {
+ if (!(state & IFS_ACTIVE)) {
/* If we aren't parsing the data, treat as always false */
- cond_states[cond_depth] = SKIP_TO_ELSE;
+ cond_states[cond_depth] = IFS_WAS_ACTIVE;
return COND_SKIP;
}
}
@@ -1250,15 +1242,16 @@ Cond_EvalLine(const char *const line)
if (CondEvalExpression(ifp, p, &value, TRUE, TRUE) == COND_INVALID) {
/* Syntax error in conditional, error message already output. */
/* Skip everything to matching .endif */
- cond_states[cond_depth] = SKIP_TO_ELSE;
+ /* XXX: An extra '.else' is not detected in this case. */
+ cond_states[cond_depth] = IFS_WAS_ACTIVE;
return COND_SKIP;
}
if (!value) {
- cond_states[cond_depth] = SEARCH_FOR_ELIF;
+ cond_states[cond_depth] = IFS_INITIAL;
return COND_SKIP;
}
- cond_states[cond_depth] = IF_ACTIVE;
+ cond_states[cond_depth] = IFS_ACTIVE;
return COND_PARSE;
}
