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authorH. Peter Anvin <hpa@zytor.com>2019-10-08 03:26:39 -0700
committerH. Peter Anvin <hpa@zytor.com>2019-10-08 03:26:39 -0700
commitc5717a8204b5fcd383cf9e0a237c4727feccb5bd (patch)
treed75e21bfc3c187da4e1e7b1c63cbb4a7c74c235a
parent1f82dffba7c35056b500051999076fdd1ee53ab0 (diff)
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preproc: %while ... %endwhile looploops
First user of the new loop infrastructure: a %while[n][cond] loop; supports anything that the %if/%elif directives support, too. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
-rw-r--r--asm/pptok.dat2
-rw-r--r--asm/preproc.c119
-rw-r--r--test/while.asm5
3 files changed, 97 insertions, 29 deletions
diff --git a/asm/pptok.dat b/asm/pptok.dat
index d2f361c8..8b90c5b2 100644
--- a/asm/pptok.dat
+++ b/asm/pptok.dat
@@ -39,6 +39,7 @@
# Condition stems. %if MUST BE FIRST in this list.
%if*
%elif*
+%while*
# Condition tests
*
@@ -99,3 +100,4 @@
%undefalias
%use
%warning
+%endwhile
diff --git a/asm/preproc.c b/asm/preproc.c
index c1c0cf86..e5126b77 100644
--- a/asm/preproc.c
+++ b/asm/preproc.c
@@ -271,7 +271,10 @@ struct MMacro {
Line *expansion;
mmcleanup_func cleanup; /* Cleanup function/loop type */
- uint64_t rep_cnt; /* Loop iterations left (%rep) */
+ union {
+ uint64_t rep_cnt;
+ enum preproc_token cond;
+ } loop;
struct mstk mstk; /* Macro expansion stack */
struct mstk dstk; /* Macro definitions stack */
@@ -3225,11 +3228,18 @@ static bool mmacro_cleanup(MMacro *m, bool emitting)
}
/*
- * End conditions of various loop types; also function as loop type identifiers
+ * End conditions of various loop types; also function as loop type identifiers.
+ * Note that for loop operations, *unlike macro expansions*, these are also called
+ * before the first time the loop body is emitted.
*/
static bool loop_end_rep(MMacro *m, bool emitting)
{
- return emitting && m->rep_cnt--;
+ return emitting && m->loop.rep_cnt--;
+}
+
+static bool loop_end_while(MMacro *m, bool emitting)
+{
+ return emitting && if_condition(dup_tlist(m->iline, NULL), m->loop.cond) == COND_IF_TRUE;
}
/**
@@ -3328,6 +3338,13 @@ static int do_directive(Token *tline, Token **output)
closer = PP_ENDREP;
goto is_opener;
+ CASE_PP_WHILE:
+ if (defining->name)
+ return NO_DIRECTIVE_FOUND;
+
+ closer = PP_ENDWHILE;
+ goto is_opener;
+
is_opener:
nasm_new(nd);
nd->next = nested_def;
@@ -3336,6 +3353,7 @@ static int do_directive(Token *tline, Token **output)
break;
case PP_ENDREP:
+ case PP_ENDWHILE:
if (defining->name)
return NO_DIRECTIVE_FOUND;
goto is_closer;
@@ -3964,6 +3982,39 @@ issue_error:
}
break;
+ CASE_PP_WHILE:
+ {
+ MMacro *tmp_defining;
+
+ nolist = false;
+ tline = skip_white(tline->next);
+ if (tok_type(tline, TOK_ID) && tline->len == 7 &&
+ !nasm_memicmp(tline->text.a, ".nolist", 7)) {
+ nolist = !list_option('f') || istk->nolist;
+ tline = skip_white(tline->next);
+ }
+
+ tmp_defining = defining;
+ nasm_new(defining);
+ defining->nolist = nolist;
+ defining->cleanup = loop_end_rep;
+ defining->loop.cond = i;
+ defining->iline = dup_tlist(tline, NULL);
+ defining->cleanup = loop_end_while;
+ defining->mstk = istk->mstk;
+ defining->dstk.mstk = tmp_defining;
+ defining->dstk.mmac = tmp_defining ? tmp_defining->dstk.mmac : NULL;
+ src_get(&defining->xline, &defining->fname);
+ break;
+ }
+
+ case PP_ENDWHILE:
+ if (!defining || defining->cleanup != loop_end_while) {
+ nasm_nonfatal("`%s': no matching `%%while'", dname);
+ goto done;
+ }
+ goto end_loop;
+
case PP_REP:
{
MMacro *tmp_defining;
@@ -4016,7 +4067,7 @@ issue_error:
nasm_new(defining);
defining->nolist = nolist;
defining->cleanup = loop_end_rep;
- defining->rep_cnt = count;
+ defining->loop.rep_cnt = count;
defining->mstk = istk->mstk;
defining->dstk.mstk = tmp_defining;
defining->dstk.mmac = tmp_defining ? tmp_defining->dstk.mmac : NULL;
@@ -4029,31 +4080,41 @@ issue_error:
nasm_nonfatal("`%%endrep': no matching `%%rep'");
goto done;
}
-
- /*
- * Now we have a "macro" defined - although it has no name
- * and we won't be entering it in the hash tables - we must
- * push a macro-end marker for it on to istk->expansion.
- * After that, it will take care of propagating itself (a
- * macro-end marker line for a macro which is really a %rep
- * block will cause the macro to be re-expanded, complete
- * with another macro-end marker to ensure the process
- * continues) until the whole expansion is forcibly removed
- * from istk->expansion by a %exitrep.
- */
- nasm_new(l);
- l->next = istk->expansion;
- l->finishes = defining;
- l->first = NULL;
- istk->expansion = l;
-
- istk->mstk.mstk = defining;
- if (defining->rep_cnt == 0)
- istk->popping = defining; /* XXX: just skip this crap at this point */
-
- lfmt->uplevel(defining->nolist ? LIST_MACRO_NOLIST : LIST_MACRO, 0);
- defining = defining->dstk.mstk;
+ goto end_loop;
+
+ end_loop:
+ {
+ MMacro *d = defining;
+
+ /*
+ * Now we have a "macro" defined - although it has no name
+ * and we won't be entering it in the hash tables - we must
+ * push a macro-end marker for it on to istk->expansion.
+ * After that, it will take care of propagating itself (a
+ * macro-end marker line for a macro which is really a loop
+ * block will cause the macro to be re-expanded, complete
+ * with another macro-end marker to ensure the process
+ * continues) until the loop terminates.
+ */
+
+ defining = d->dstk.mstk;
+ lfmt->uplevel(d->nolist ? LIST_MACRO_NOLIST : LIST_MACRO, 0);
+
+ /* Are we going to execute at least one iteration? */
+ if (d->cleanup(d, true)) {
+ /* Add to expansion */
+ nasm_new(l);
+ l->next = istk->expansion;
+ l->finishes = d;
+ l->first = NULL;
+ istk->expansion = l;
+ istk->mstk.mstk = d;
+ } else {
+ /* Zero iterations, just discard everything */
+ free_mmacro(d);
+ }
break;
+ }
case PP_EXITREP:
{
@@ -6461,7 +6522,7 @@ static void pp_cleanup_pass(void)
nasm_nonfatal("end of file while still defining macro `%s'",
defining->name);
} else {
- nasm_nonfatal("end of file while still in %%rep");
+ nasm_nonfatal("end of file while still in loop body");
}
free_mmacro(defining);
diff --git a/test/while.asm b/test/while.asm
new file mode 100644
index 00000000..9b835066
--- /dev/null
+++ b/test/while.asm
@@ -0,0 +1,5 @@
+%assign i 1
+%while i
+ dq i
+ %assign i i << 1
+%endwhile