From c5ce18591f9cf3fd9b6658a8844fa1039f425e2f Mon Sep 17 00:00:00 2001
From: Bill Currie <bill@taniwha.org>
Date: Sat, 15 Feb 2020 17:24:53 +0900
Subject: [PATCH] Catch and warn demotion of double in assignments

---
 tools/qfcc/source/expr_assign.c             |  4 ++++
 tools/qfcc/test/Makefile.am                 | 10 +++++++++-
 tools/qfcc/test/double-demote-float-linit.r |  6 ++++++
 tools/qfcc/test/double-demote-int-linit.r   |  6 ++++++
 4 files changed, 25 insertions(+), 1 deletion(-)
 create mode 100644 tools/qfcc/test/double-demote-float-linit.r
 create mode 100644 tools/qfcc/test/double-demote-int-linit.r

diff --git a/tools/qfcc/source/expr_assign.c b/tools/qfcc/source/expr_assign.c
index 1797f7677..600c6140a 100644
--- a/tools/qfcc/source/expr_assign.c
+++ b/tools/qfcc/source/expr_assign.c
@@ -151,6 +151,10 @@ check_types_compatible (expr_t *dst, expr_t *src)
 
 	if (type_assignable (dst_type, src_type)) {
 		if (is_scalar (dst_type) && is_scalar (src_type)) {
+			if (is_double (src_type)) {
+				warning (dst, "assignment of double to %s (use a cast)\n",
+						 dst_type->name);
+			}
 			// the types are different but cast-compatible
 			expr_t     *new = cast_expr (dst_type, src);
 			// the cast was a no-op, so the types are compatible at the
diff --git a/tools/qfcc/test/Makefile.am b/tools/qfcc/test/Makefile.am
index 32e5cd5ec..1d3d9de9c 100644
--- a/tools/qfcc/test/Makefile.am
+++ b/tools/qfcc/test/Makefile.am
@@ -61,8 +61,10 @@ test_progs_dat=\
 fail_progs_dat=
 
 test_build_errors=\
-	double-demote-int.r \
 	double-demote-float.r \
+	double-demote-float-linit.r \
+	double-demote-int.r \
+	double-demote-int-linit.r \
 	double-int-compare.r \
 	double-float-compare.r
 
@@ -161,6 +163,12 @@ double-demote-int.run$(EXEEXT): double-demote-int.r Makefile build-compile-fail-
 double-demote-float.run$(EXEEXT): double-demote-float.r Makefile build-compile-fail-run
 	$(srcdir)/build-compile-fail-run $@ $(QFCC) $(QCFLAGS) $<
 
+double-demote-int-linit.run$(EXEEXT): double-demote-int-linit.r Makefile build-compile-fail-run
+	$(srcdir)/build-compile-fail-run $@ $(QFCC) $(QCFLAGS) $<
+
+double-demote-float-linit.run$(EXEEXT): double-demote-float-linit.r Makefile build-compile-fail-run
+	$(srcdir)/build-compile-fail-run $@ $(QFCC) $(QCFLAGS) $<
+
 double-int-compare.run$(EXEEXT): double-int-compare.r Makefile build-compile-fail-run
 	$(srcdir)/build-compile-fail-run $@ $(QFCC) $(QCFLAGS) $<
 
diff --git a/tools/qfcc/test/double-demote-float-linit.r b/tools/qfcc/test/double-demote-float-linit.r
new file mode 100644
index 000000000..796b2040f
--- /dev/null
+++ b/tools/qfcc/test/double-demote-float-linit.r
@@ -0,0 +1,6 @@
+double a;
+int main ()
+{
+	float b = a;
+	return 1;	// test fails if compile succeeds
+}
diff --git a/tools/qfcc/test/double-demote-int-linit.r b/tools/qfcc/test/double-demote-int-linit.r
new file mode 100644
index 000000000..3a206f4b5
--- /dev/null
+++ b/tools/qfcc/test/double-demote-int-linit.r
@@ -0,0 +1,6 @@
+double a;
+int main ()
+{
+	int b = a;
+	return 1;	// test fails if compile succeeds
+}