zig

commit 73d3fb9883c1d89fd1460a18f186a1737613bfbc (tree)
parent 6261c1373168b265047db5704d9d0fd5f2e458f2
Author: Andrew Kelley <andrew@ziglang.org>
Date:   Thu, 27 Apr 2023 14:01:16 -0700

C backend: fix ptr comparison of array ptrs when one is null-terminated

Diffstat:
M
src/codegen/c.zig
 | 
2
+-
M
test/behavior.zig
 | 
1
+
A
test/behavior/memcpy.zig
 | 
44
++++++++++++++++++++++++++++++++++++++++++++
M
test/behavior/memset.zig
 | 
21
---------------------

4 files changed, 46 insertions(+), 22 deletions(-)
diff --git a/src/codegen/c.zig b/src/codegen/c.zig
@@ -3858,7 +3858,7 @@ fn airCmpOp(
     try reap(f, inst, &.{ data.lhs, data.rhs });
 
     const rhs_ty = f.air.typeOf(data.rhs);
-    const need_cast = lhs_ty.isSinglePointer() != rhs_ty.isSinglePointer();
+    const need_cast = lhs_ty.isSinglePointer() or rhs_ty.isSinglePointer();
     const writer = f.object.writer();
     const local = try f.allocLocal(inst, inst_ty);
     const v = try Vectorize.start(f, inst, writer, lhs_ty);
diff --git a/test/behavior.zig b/test/behavior.zig
@@ -177,6 +177,7 @@ test {
     _ = @import("behavior/math.zig");
     _ = @import("behavior/maximum_minimum.zig");
     _ = @import("behavior/member_func.zig");
+    _ = @import("behavior/memcpy.zig");
     _ = @import("behavior/memset.zig");
     _ = @import("behavior/merge_error_sets.zig");
     _ = @import("behavior/muladd.zig");
diff --git a/test/behavior/memcpy.zig b/test/behavior/memcpy.zig
@@ -0,0 +1,44 @@
+const std = @import("std");
+const builtin = @import("builtin");
+const expect = std.testing.expect;
+
+test "memcpy and memset intrinsics" {
+    if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
+
+    try testMemcpyMemset();
+    try comptime testMemcpyMemset();
+}
+
+fn testMemcpyMemset() !void {
+    var foo: [20]u8 = undefined;
+    var bar: [20]u8 = undefined;
+
+    @memset(&foo, 'A');
+    @memcpy(&bar, &foo);
+
+    try expect(bar[0] == 'A');
+    try expect(bar[11] == 'A');
+    try expect(bar[19] == 'A');
+}
+
+test "@memcpy with both operands single-ptr-to-array, one is null-terminated" {
+    if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest;
+
+    try testMemcpyBothSinglePtrArrayOneIsNullTerminated();
+    try comptime testMemcpyBothSinglePtrArrayOneIsNullTerminated();
+}
+
+fn testMemcpyBothSinglePtrArrayOneIsNullTerminated() !void {
+    var buf: [100]u8 = undefined;
+    const suffix = "hello";
+    @memcpy(buf[buf.len - suffix.len ..], suffix);
+    try expect(buf[95] == 'h');
+    try expect(buf[96] == 'e');
+    try expect(buf[97] == 'l');
+    try expect(buf[98] == 'l');
+    try expect(buf[99] == 'o');
+}
diff --git a/test/behavior/memset.zig b/test/behavior/memset.zig
@@ -142,24 +142,3 @@ test "memset with large array element, comptime known" {
     for (buf[3]) |elem| try expect(elem == 0);
     for (buf[4]) |elem| try expect(elem == 0);
 }
-
-test "memcpy and memset intrinsics" {
-    if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
-    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
-    if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
-
-    try testMemcpyMemset();
-    try comptime testMemcpyMemset();
-}
-
-fn testMemcpyMemset() !void {
-    var foo: [20]u8 = undefined;
-    var bar: [20]u8 = undefined;
-
-    @memset(&foo, 'A');
-    @memcpy(&bar, &foo);
-
-    try expect(bar[0] == 'A');
-    try expect(bar[11] == 'A');
-    try expect(bar[19] == 'A');
-}