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BR 1239818 - handle multiple %else clauses

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Using multiple %else clauses or mixing %else and %elif
caused strange results.
Warn about it and produce sensible results.
This commit is contained in:
Victor van den Elzen 2008-09-18 13:51:36 +02:00
parent 9ef3017240
commit 3b404c0f6b
2 changed files with 138 additions and 37 deletions
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129
preproc.c
View file

@ -253,14 +253,15 @@ enum {
*/
COND_ELSE_TRUE, COND_ELSE_FALSE,
/*
* This state means that we're not emitting now, and also that
* nothing until %endif will be emitted at all. It's for use in
* two circumstances: (i) when we've had our moment of emission
* and have now started seeing %elifs, and (ii) when the
* condition construct in question is contained within a
* non-emitting branch of a larger condition construct.
* These states mean that we're not emitting now, and also that
* nothing until %endif will be emitted at all. COND_DONE is
* used when we've had our moment of emission
* and have now started seeing %elifs. COND_NEVER is used when
* the condition construct in question is contained within a
* non-emitting branch of a larger condition construct,
* or if there is an error.
*/
COND_NEVER
COND_DONE, COND_NEVER
};
#define emitting(x) ( (x) == COND_IF_TRUE || (x) == COND_ELSE_TRUE )
@ -398,6 +399,7 @@ static Token *expand_id(Token * tline);
static Context *get_ctx(const char *name, bool all_contexts);
static void make_tok_num(Token * tok, int64_t val);
static void error(int severity, const char *fmt, ...);
static void error_precond(int severity, const char *fmt, ...);
static void *new_Block(size_t size);
static void delete_Blocks(void);
static Token *new_Token(Token * next, enum pp_token_type type,
@ -2406,42 +2408,69 @@ static int do_directive(Token * tline)
CASE_PP_ELIF:
if (!istk->conds)
error(ERR_FATAL, "`%s': no matching `%%if'", pp_directives[i]);
if (emitting(istk->conds->state)
|| istk->conds->state == COND_NEVER)
istk->conds->state = COND_NEVER;
else {
/*
* IMPORTANT: In the case of %if, we will already have
* called expand_mmac_params(); however, if we're
* processing an %elif we must have been in a
* non-emitting mode, which would have inhibited
* the normal invocation of expand_mmac_params(). Therefore,
* we have to do it explicitly here.
*/
j = if_condition(expand_mmac_params(tline->next), i);
tline->next = NULL; /* it got freed */
istk->conds->state =
j < 0 ? COND_NEVER : j ? COND_IF_TRUE : COND_IF_FALSE;
switch(istk->conds->state) {
case COND_IF_TRUE:
istk->conds->state = COND_DONE;
break;
case COND_DONE:
case COND_NEVER:
break;
case COND_ELSE_TRUE:
case COND_ELSE_FALSE:
error_precond(ERR_WARNING, "`%%elif' after `%%else' ignored");
istk->conds->state = COND_NEVER;
break;
case COND_IF_FALSE:
/*
* IMPORTANT: In the case of %if, we will already have
* called expand_mmac_params(); however, if we're
* processing an %elif we must have been in a
* non-emitting mode, which would have inhibited
* the normal invocation of expand_mmac_params(). Therefore,
* we have to do it explicitly here.
*/
j = if_condition(expand_mmac_params(tline->next), i);
tline->next = NULL; /* it got freed */
istk->conds->state =
j < 0 ? COND_NEVER : j ? COND_IF_TRUE : COND_IF_FALSE;
break;
}
free_tlist(origline);
return DIRECTIVE_FOUND;
case PP_ELSE:
if (tline->next)
error(ERR_WARNING, "trailing garbage after `%%else' ignored");
error_precond(ERR_WARNING, "trailing garbage after `%%else' ignored");
if (!istk->conds)
error(ERR_FATAL, "`%%else': no matching `%%if'");
if (emitting(istk->conds->state)
|| istk->conds->state == COND_NEVER)
istk->conds->state = COND_ELSE_FALSE;
else
istk->conds->state = COND_ELSE_TRUE;
switch(istk->conds->state) {
case COND_IF_TRUE:
case COND_DONE:
istk->conds->state = COND_ELSE_FALSE;
break;
case COND_NEVER:
break;
case COND_IF_FALSE:
istk->conds->state = COND_ELSE_TRUE;
break;
case COND_ELSE_TRUE:
case COND_ELSE_FALSE:
error_precond(ERR_WARNING, "`%%else' after `%%else' ignored.");
istk->conds->state = COND_NEVER;
break;
}
free_tlist(origline);
return DIRECTIVE_FOUND;
case PP_ENDIF:
if (tline->next)
error(ERR_WARNING, "trailing garbage after `%%endif' ignored");
error_precond(ERR_WARNING, "trailing garbage after `%%endif' ignored");
if (!istk->conds)
error(ERR_FATAL, "`%%endif': no matching `%%if'");
cond = istk->conds;
@ -4115,6 +4144,20 @@ static int expand_mmacro(Token * tline)
return 1;
}
/* The function that actually does the error reporting */
static void verror(int severity, const char *fmt, va_list arg)
{
char buff[1024];
vsnprintf(buff, sizeof(buff), fmt, arg);
if (istk && istk->mstk && istk->mstk->name)
_error(severity | ERR_PASS1, "(%s:%d) %s", istk->mstk->name,
istk->mstk->lineno, buff);
else
_error(severity | ERR_PASS1, "%s", buff);
}
/*
* Since preprocessor always operate only on the line that didn't
* arrived yet, we should always use ERR_OFFBY1. Also since user
@ -4124,21 +4167,33 @@ static int expand_mmacro(Token * tline)
static void error(int severity, const char *fmt, ...)
{
va_list arg;
char buff[1024];
/* If we're in a dead branch of IF or something like it, ignore the error */
if (istk && istk->conds && !emitting(istk->conds->state))
return;
va_start(arg, fmt);
vsnprintf(buff, sizeof(buff), fmt, arg);
verror(severity, fmt, arg);
va_end(arg);
}
if (istk && istk->mstk && istk->mstk->name)
_error(severity | ERR_PASS1, "(%s:%d) %s", istk->mstk->name,
istk->mstk->lineno, buff);
else
_error(severity | ERR_PASS1, "%s", buff);
/*
* Because %else etc are evaluated in the state context
* of the previous branch, errors might get lost with error():
* %if 0 ... %else trailing garbage ... %endif
* So %else etc should report errors with this function.
*/
static void error_precond(int severity, const char *fmt, ...)
{
va_list arg;
/* Only ignore the error if it's really in a dead branch */
if (istk && istk->conds && istk->conds->state == COND_NEVER)
return;
va_start(arg, fmt);
verror(severity, fmt, arg);
va_end(arg);
}
static void

46
test/ifelse.asm Executable file
View file

@ -0,0 +1,46 @@
;Testname=ifelse; Arguments=-fbin -oifelse.bin; Files=.stdout .stderr ifelse.bin
;No problems -> db 3
%if 0
db 0
%elif 0 > 0
db 1
%elif 1 < 1
db 2
%else
db 3
%endif
;Garbage after else, elif after else -> db 5
%if 0
db 4
%else trailing garbage
db 5
%elif 1
db 6
%endif
;Garbage after endif ->
%if 0
db 7
%endif trailing garbage
;else after else -> db 9
%if 0
db 8
%else
db 9
%else
db 10
%endif
;Problem preprocessed out, no warning ->
%if 0
%if 1
db 11
%else
db 12
%else
db 13
%endif
%endif