From fca0b26275a82c480a5286c281834dad6887b410 Mon Sep 17 00:00:00 2001
From: Michael Forney <mforney@mforney.org>
Date: Mon, 15 Apr 2019 01:11:08 -0700
Subject: Handle static sub-initializers

---
 qbe.c                                | 25 +++++++++++++++++--------
 tests/initializer-replace-local.c    | 10 ++++++++++
 tests/initializer-replace-local.qbe  | 22 ++++++++++++++++++++++
 tests/initializer-replace-static.c   |  6 ++++++
 tests/initializer-replace-static.qbe |  1 +
 tests/initializer-replace.c          | 10 ----------
 tests/initializer-replace.qbe        | 22 ----------------------
 7 files changed, 56 insertions(+), 40 deletions(-)
 create mode 100644 tests/initializer-replace-local.c
 create mode 100644 tests/initializer-replace-local.qbe
 create mode 100644 tests/initializer-replace-static.c
 create mode 100644 tests/initializer-replace-static.qbe
 delete mode 100644 tests/initializer-replace.c
 delete mode 100644 tests/initializer-replace.qbe

diff --git a/qbe.c b/qbe.c
index 7130002..0d14949 100644
--- a/qbe.c
+++ b/qbe.c
@@ -1234,15 +1234,24 @@ emitdata(struct decl *d, struct init *init)
 	emitvalue(d->value);
 	printf(" = align %d { ", d->align);
 
-	for (; init; init = init->next) {
-		if (init->start < offset)  /* XXX: sub-initializer may overlap */
-			continue;
-		if (offset < init->start)
-			printf("z %" PRIu64 ", ", init->start - offset);
-		printf("%c ", init->expr->type->kind == TYPEARRAY ? init->expr->type->base->repr->ext : init->expr->type->repr->ext);
-		dataitem(init->expr, init->end - init->start);
+	while (init) {
+		cur = init;
+		while (init = init->next, init && init->start < cur->end) {
+			/*
+			XXX: Currently, if multiple union members are
+			initialized, these assertions may not hold.
+			(https://todo.sr.ht/~mcf/cc-issues/38)
+			*/
+			assert(cur->expr->kind == EXPRSTRING);
+			assert(init->expr->kind == EXPRCONST);
+			cur->expr->string.data[init->start - cur->start] = init->expr->constant.i;
+		}
+		if (offset < cur->start)
+			printf("z %" PRIu64 ", ", cur->start - offset);
+		printf("%c ", cur->expr->type->kind == TYPEARRAY ? cur->expr->type->base->repr->ext : cur->expr->type->repr->ext);
+		dataitem(cur->expr, cur->end - cur->start);
 		fputs(", ", stdout);
-		offset = init->end;
+		offset = cur->end;
 	}
 	assert(offset <= d->type->size);
 	if (offset < d->type->size)
diff --git a/tests/initializer-replace-local.c b/tests/initializer-replace-local.c
new file mode 100644
index 0000000..8b93ef2
--- /dev/null
+++ b/tests/initializer-replace-local.c
@@ -0,0 +1,10 @@
+void f(void) {
+	struct {
+		char s[6];
+	} x = {
+		.s[0] = 'x',
+		.s[4] = 'y',
+		.s = "hello",
+		.s[1] = 'a',
+	};
+}
diff --git a/tests/initializer-replace-local.qbe b/tests/initializer-replace-local.qbe
new file mode 100644
index 0000000..72ad90a
--- /dev/null
+++ b/tests/initializer-replace-local.qbe
@@ -0,0 +1,22 @@
+export
+function $f() {
+@start.1
+	%.1 =l alloc4 6
+@body.2
+	%.2 =l add %.1, 0
+	storeb 104, %.2
+	%.3 =l add %.1, 1
+	storeb 101, %.3
+	%.4 =l add %.1, 2
+	storeb 108, %.4
+	%.5 =l add %.1, 3
+	storeb 108, %.5
+	%.6 =l add %.1, 4
+	storeb 111, %.6
+	%.7 =l add %.1, 1
+	%.8 =w copy 97
+	storeb %.8, %.7
+	%.9 =l add %.1, 5
+	storeb 0, %.9
+	ret
+}
diff --git a/tests/initializer-replace-static.c b/tests/initializer-replace-static.c
new file mode 100644
index 0000000..c1fa376
--- /dev/null
+++ b/tests/initializer-replace-static.c
@@ -0,0 +1,6 @@
+struct {
+	char s[6];
+} x = {
+	.s = "hello",
+	.s[1] = 'a',
+};
diff --git a/tests/initializer-replace-static.qbe b/tests/initializer-replace-static.qbe
new file mode 100644
index 0000000..18b774e
--- /dev/null
+++ b/tests/initializer-replace-static.qbe
@@ -0,0 +1 @@
+export data $x = align 1 { b "hallo", z 1, }
diff --git a/tests/initializer-replace.c b/tests/initializer-replace.c
deleted file mode 100644
index 8b93ef2..0000000
--- a/tests/initializer-replace.c
+++ /dev/null
@@ -1,10 +0,0 @@
-void f(void) {
-	struct {
-		char s[6];
-	} x = {
-		.s[0] = 'x',
-		.s[4] = 'y',
-		.s = "hello",
-		.s[1] = 'a',
-	};
-}
diff --git a/tests/initializer-replace.qbe b/tests/initializer-replace.qbe
deleted file mode 100644
index 72ad90a..0000000
--- a/tests/initializer-replace.qbe
+++ /dev/null
@@ -1,22 +0,0 @@
-export
-function $f() {
-@start.1
-	%.1 =l alloc4 6
-@body.2
-	%.2 =l add %.1, 0
-	storeb 104, %.2
-	%.3 =l add %.1, 1
-	storeb 101, %.3
-	%.4 =l add %.1, 2
-	storeb 108, %.4
-	%.5 =l add %.1, 3
-	storeb 108, %.5
-	%.6 =l add %.1, 4
-	storeb 111, %.6
-	%.7 =l add %.1, 1
-	%.8 =w copy 97
-	storeb %.8, %.7
-	%.9 =l add %.1, 5
-	storeb 0, %.9
-	ret
-}
-- 
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