harec

commit b2f81197761d64a5f53d95fe4b38bfffd67b7591
parent b201f877a1bb6fad5beae7a7d4ebce450ddbfff8
Author: Drew DeVault <sir@cmpwn.com>
Date:   Sun, 14 Feb 2021 10:54:11 -0500

qtype: fix tagged unions with middle zero types

If we have a type which, after sorting, looks like this:

	(nonzero | void | nonzero)

qtype would have bunged up the last type.

Diffstat:
M
src/emit.c
 | 
22
++++++++++++++++++++--
M
src/qtype.c
 | 
9
++++++++-
M
src/types.c
 | 
1
+

3 files changed, 29 insertions(+), 3 deletions(-)
diff --git a/src/emit.c b/src/emit.c
@@ -1,8 +1,10 @@
 #include <assert.h>
 #include <ctype.h>
+#include <stdlib.h>
 #include <stdio.h>
 #include "emit.h"
 #include "qbe.h"
+#include "typedef.h"
 
 static void
 emit_qtype(const struct qbe_type *type, bool aggr, FILE *out)
@@ -29,10 +31,26 @@ emit_qtype(const struct qbe_type *type, bool aggr, FILE *out)
 	}
 }
 
+static char *
+gen_typename(const struct type *type)
+{
+	size_t sz = 0;
+	char *ptr = NULL;
+	FILE *f = open_memstream(&ptr, &sz);
+	emit_type(type, f);
+	fclose(f);
+	return ptr;
+}
+
 static void
-emit_type(const struct qbe_def *def, FILE *out)
+qemit_type(const struct qbe_def *def, FILE *out)
 {
 	assert(def->kind == Q_TYPE);
+	if (def->type.base) {
+		char *tn = gen_typename(def->type.base);
+		fprintf(out, "# %s\n", tn);
+		free(tn);
+	}
 	fprintf(out, "type :%s =", def->name);
 	if (def->type.align != (size_t)-1) {
 		fprintf(out, " align %zu", def->type.align);
@@ -310,7 +328,7 @@ emit_def(struct qbe_def *def, FILE *out)
 {
 	switch (def->kind) {
 	case Q_TYPE:
-		emit_type(def, out);
+		qemit_type(def, out);
 		break;
 	case Q_FUNC:
 		emit_func(def, out);
diff --git a/src/qtype.c b/src/qtype.c
@@ -1,5 +1,6 @@
 #include <assert.h>
 #include <stdbool.h>
+#include <stdlib.h>
 #include <stdio.h>
 #include "gen.h"
 #include "qbe.h"
@@ -121,15 +122,21 @@ tagged_qtype(struct gen_context *ctx, const struct type *type)
 	def->type.size = type->size - type->align;
 
 	struct qbe_field *field = &def->type.fields;
+	struct qbe_field **next = &field->next;
 	for (const struct type_tagged_union *tu = &type->tagged;
 			tu; tu = tu->next) {
 		if (tu->type->size == 0) {
+			if (!tu->next && *next) {
+				free(*next);
+				*next = NULL;
+			}
 			continue;
 		}
 		field->type = qtype_for_type(ctx, tu->type, true);
 		field->count = 1;
-		if (tu->next && tu->next->type->size != 0) {
+		if (tu->next) {
 			field->next = xcalloc(1, sizeof(struct qbe_field));
+			next = &field->next;
 			field = field->next;
 		}
 	}
diff --git a/src/types.c b/src/types.c
@@ -407,6 +407,7 @@ type_hash(const struct type *type)
 				tuple; tuple = tuple->next) {
 			hash = fnv1a_u32(hash, type_hash(tuple->type));
 		}
+		break;
 	}
 	return hash;
 }