Sema: further enhance explanation of why expr is evaluated at comptime

4 files changed, 65 insertions, 2 deletions

diff --git a/test/cases/compile_errors/condition_comptime_reason_explained.zig b/test/cases/compile_errors/condition_comptime_reason_explained.zig
new file mode 100644
index 0000000000..332ae8afc8
--- /dev/null
+++ b/test/cases/compile_errors/condition_comptime_reason_explained.zig
@@ -0,0 +1,48 @@
+const S = struct {
+    fnPtr: fn () void,
+};
+fn bar() void {}
+fn baz() void {}
+var runtime: bool = true;
+fn ifExpr() S {
+    if (runtime) {
+        return .{
+            .fnPtr = bar,
+        };
+    } else {
+        return .{
+            .fnPtr = baz,
+        };
+    }
+}
+pub export fn entry1() void {
+    _ = ifExpr();
+}
+fn switchExpr() S {
+    switch (runtime) {
+        true => return .{
+            .fnPtr = bar,
+        },
+        false => return .{
+            .fnPtr = baz,
+        },
+    }
+}
+pub export fn entry2() void {
+    _ = switchExpr();
+}
+
+// error
+// backend=stage2
+// target=native
+//
+// :8:9: error: unable to resolve comptime value
+// :8:9: note: condition in comptime branch must be comptime-known
+// :7:13: note: expression is evaluated at comptime because the function returns a comptime-only type 'tmp.S'
+// :2:12: note: struct requires comptime because of this field
+// :2:12: note: use '*const fn() void' for a function pointer type
+// :19:15: note: called from here
+// :22:13: error: unable to resolve comptime value
+// :22:13: note: condition in comptime switch must be comptime-known
+// :21:17: note: expression is evaluated at comptime because the function returns a comptime-only type 'tmp.S'
+// :32:19: note: called from here
diff --git a/test/cases/compile_errors/explain_why_fn_is_called_at_comptime.zig b/test/cases/compile_errors/explain_why_fn_is_called_at_comptime.zig
index d19ab31617..83d5d7e33f 100644
--- a/test/cases/compile_errors/explain_why_fn_is_called_at_comptime.zig
+++ b/test/cases/compile_errors/explain_why_fn_is_called_at_comptime.zig
@@ -18,6 +18,6 @@ pub export fn entry() void {
 //
 // :12:13: error: unable to resolve comptime value
 // :12:13: note: argument to function being called at comptime must be comptime-known
-// :7:25: note: function is being called at comptime because it returns a comptime-only type 'tmp.S'
+// :7:25: note: expression is evaluated at comptime because the function returns a comptime-only type 'tmp.S'
 // :2:12: note: struct requires comptime because of this field
 // :2:12: note: use '*const fn() void' for a function pointer type
diff --git a/test/cases/compile_errors/explain_why_generic_fn_is_called_at_comptime.zig b/test/cases/compile_errors/explain_why_generic_fn_is_called_at_comptime.zig
index 36aeb40479..701241a403 100644
--- a/test/cases/compile_errors/explain_why_generic_fn_is_called_at_comptime.zig
+++ b/test/cases/compile_errors/explain_why_generic_fn_is_called_at_comptime.zig
@@ -19,4 +19,4 @@ pub export fn entry() void {
 //
 // :14:13: error: unable to resolve comptime value
 // :14:13: note: argument to function being called at comptime must be comptime-known
-// :9:38: note: generic function is instantiated with a comptime-only return type
+// :9:38: note: expression is evaluated at comptime because the generic function was instantiated with a comptime-only return type
diff --git a/test/cases/compile_errors/unable_to_evaluate_expr_inside_cimport.zig b/test/cases/compile_errors/unable_to_evaluate_expr_inside_cimport.zig
new file mode 100644
index 0000000000..9460a58993
--- /dev/null
+++ b/test/cases/compile_errors/unable_to_evaluate_expr_inside_cimport.zig
@@ -0,0 +1,15 @@
+const c = @cImport({
+    _ = 1 + foo;
+});
+extern var foo: i32;
+export fn entry() void {
+    _ = c;
+}
+
+// error
+// backend=llvm
+// target=native
+//
+// :2:11: error: unable to evaluate comptime expression
+// :2:13: note: operation is runtime due to this operand
+// :1:11: note: expression is evaluated at comptime because it is inside a @cImport