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[Nasm-cvs] BR 1239818 - handle multiple %else clauses
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From: Victor v. d. E. <vic...@gm...> - 2008-09-18 11:54:15
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Date: Thu, 18 Sep 2008 13:51:36 +0200
Using multiple %else clauses or mixing %else and %elif
caused strange results.
Warn about it and produce sensible results.
---
preproc.c | 129 +++++++++++++++++++++++++++++++++++++++----------------
test/ifelse.asm | 46 +++++++++++++++++++
2 files changed, 138 insertions(+), 37 deletions(-)
create mode 100755 test/ifelse.asm
diff --git a/preproc.c b/preproc.c
index 99e8928..b98a61b 100644
--- a/preproc.c
+++ b/preproc.c
@@ -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
diff --git a/test/ifelse.asm b/test/ifelse.asm
new file mode 100755
index 0000000..b450287
--- /dev/null
+++ b/test/ifelse.asm
@@ -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
--
1.5.5.1
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