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(variable_expand): Rewrote computed variable name and substitution

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reference handling to be simpler.  First expand the entire text between the
parens if it contains any $s, then examine the result of that for
subtitution references and do no further expansion while parsing them.
This commit is contained in:
Roland McGrath 1995-01-15 15:32:37 +00:00
parent 7879457545
commit e167e0a3c2
1 changed files with 94 additions and 112 deletions
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206
expand.c
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@ -1,5 +1,5 @@
/* Variable expansion functions for GNU Make.
Copyright (C) 1988, 1989, 1991, 1992, 1993 Free Software Foundation, Inc.
Copyright (C) 1988, 89, 91, 92, 93, 95 Free Software Foundation, Inc.
This file is part of GNU Make.
GNU Make is free software; you can redistribute it and/or modify
@ -197,9 +197,9 @@ variable_expand (line)
char openparen = *p;
char closeparen = (openparen == '(') ? ')' : '}';
register char *beg = p + 1;
int free_beg = 0;
char *op, *begp;
char *end;
char *colon = 0;
char *end, *colon;
op = o;
begp = p;
@ -213,10 +213,18 @@ variable_expand (line)
/* Is there a variable reference inside the parens or braces?
If so, expand it before expanding the entire reference. */
p1 = index (beg, closeparen);
end = index (beg, closeparen);
if (end == 0)
{
/* Unterminated variable reference. */
if (reading_filename != 0)
makefile_fatal (reading_filename, *reading_lineno_ptr,
"unterminated variable reference");
else
fatal ("unterminated variable reference");
}
p1 = lindex (beg, end, '$');
if (p1 != 0)
p1 = lindex (beg, p1, '$');
if (p1 != 0 && lindex (beg, p1, ':') == 0)
{
/* BEG now points past the opening paren or brace.
Count parens or braces until it is matched. */
@ -227,133 +235,107 @@ variable_expand (line)
++count;
else if (*p == closeparen && --count < 0)
break;
else if (colon == 0 && count == 0 && *p == ':')
/* Record where we found a colon, which
indicates a substitution reference.
We want to expand the text before the
reference only. */
colon = p;
}
/* If COUNT is >= 0, there were unmatched opening parens
or braces, so we go to the simple case of a variable name
such as `$($(a)'. */
if (count < 0)
{
char *name = expand_argument (beg, colon == 0 ? p : colon);
unsigned int namelen = strlen (name);
if (colon == 0)
{
/* This is a simple reference to the expanded name. */
o = reference_variable (o, name, namelen);
free (name);
break;
}
else
{
/* This is a substitution reference to the expanded
name. We replace the pending text with a copy
containing the expanded name in place of the
original name, and then fall through to
the normal substitution reference code below. */
unsigned int restlen = strlen (colon) + 1;
beg = (char *) alloca (namelen + restlen);
bcopy (name, beg, namelen);
bcopy (colon, &beg[namelen], restlen);
/* Point COLON into the new copy. */
colon = &beg[namelen];
}
beg = expand_argument (beg, p); /* Expand the name. */
free_beg = 1; /* Remember to free BEG when finished. */
end = index (beg, '\0');
}
}
else
/* Advance P to the end of this reference. After we are
finished expanding this one, P will be incremented to
continue the scan. */
p = end;
/* This is not a reference to a built-in function and
it does not contain any variable references inside.
There are several things it could be. */
any variable references inside are now expanded.
Is the resultant text a substitution reference? */
if (colon == 0)
colon = index (beg, ':');
if (colon != 0 && lindex (beg, colon, closeparen) == 0)
colon = index (beg, ':');
if (colon != 0)
{
/* This is a substitution reference: $(FOO:A=B). */
int count;
/* This looks like a substitution reference: $(FOO:A=B). */
char *subst_beg, *subst_end, *replace_beg, *replace_end;
v = lookup_variable (beg, colon - beg);
if (v == 0)
warn_undefined (beg, colon - beg);
subst_beg = colon + 1;
count = 0;
for (p = subst_beg; *p != '\0'; ++p)
subst_end = index (subst_beg, '=');
if (subst_end == 0)
/* There is no = in sight. Punt on the substitution
reference and treat this as a variable name containing
a colon, in the code below. */
colon = 0;
else
{
if (*p == openparen)
++count;
else if (*p == closeparen)
--count;
else if (*p == '=' && count <= 0)
break;
replace_beg = subst_end + 1;
replace_end = end;
/* Extract the variable name before the colon
and look up that variable. */
v = lookup_variable (beg, colon - beg);
if (v == 0)
warn_undefined (beg, colon - beg);
if (v != 0 && *v->value != '\0')
{
char *value = (v->recursive ? recursively_expand (v)
: v->value);
char *pattern, *percent;
if (free_beg)
{
*subst_end = '\0';
pattern = subst_beg;
}
else
{
pattern = alloca (subst_end - subst_beg + 1);
bcopy (subst_beg, pattern, subst_end - subst_beg);
pattern[subst_end - subst_beg] = '\0';
}
percent = find_percent (pattern);
if (percent != 0)
{
char *replace;
if (free_beg)
{
*replace_end = '\0';
replace = replace_beg;
}
else
{
replace = alloca (replace_end - replace_beg
+ 1);
bcopy (replace_beg, replace,
replace_end - replace_beg);
replace[replace_end - replace_beg] = '\0';
}
o = patsubst_expand (o, value, pattern, replace,
percent, (char *) 0);
}
else
o = subst_expand (o, value,
pattern, replace_beg,
strlen (pattern),
end - replace_beg,
0, 1);
if (v->recursive)
free (value);
}
}
if (count > 0)
/* There were unmatched opening parens. */
return initialize_variable_output ();
subst_end = p;
replace_beg = p + 1;
count = 0;
for (p = replace_beg; *p != '\0'; ++p)
{
if (*p == openparen)
++count;
else if (*p == closeparen && --count < 0)
break;
}
if (count > 0)
/* There were unmatched opening parens. */
return initialize_variable_output ();
end = p;
replace_end = p;
p = expand_argument (subst_beg, subst_end);
p1 = expand_argument (replace_beg, replace_end);
if (v != 0 && *v->value != '\0')
{
char *value = (v->recursive ? recursively_expand (v)
: v->value);
char *percent = find_percent (p);
if (percent != 0)
o = patsubst_expand (o, value, p, p1,
percent, (char *) 0);
else
o = subst_expand (o, value,
p, p1, strlen (p), strlen (p1),
0, 1);
if (v->recursive)
free (value);
}
free (p);
free (p1);
}
/* No, this must be an ordinary variable reference. */
else
{
/* Look up the value of the variable. */
end = index (beg, closeparen);
if (end == 0)
{
/* Unterminated variable reference. */
if (reading_filename != 0)
makefile_fatal (reading_filename, *reading_lineno_ptr,
"unterminated variable reference");
else
fatal ("unterminated variable reference");
}
if (colon == 0)
/* This is an ordinary variable reference.
Look up the value of the variable. */
o = reference_variable (o, beg, end - beg);
}
/* Advance p past the variable reference to resume scan. */
p = end;
if (free_beg)
free (beg);
}
break;