zig

commit 1708da2c710bd5fa84167ed4abc7ec79438c9be4 (tree)
parent b2c2b4d0630716fa6a61ec27df26c5253f2de5b0
Author: Kendall Condon <goon.pri.low@gmail.com>
Date:   Sun, 22 Mar 2026 18:00:51 -0400

libfuzzer: fix SkipZigTest with new inputs

It is now ignored for inputs from the corpus to ensure the filesystem
and process corpus stay in sync. For other (nondeterministic) inputs the
input builder is now reset.

Diffstat:
M
lib/fuzzer.zig
 | 
25
+++++++++++++++++++++++--

1 file changed, 23 insertions(+), 2 deletions(-)
diff --git a/lib/fuzzer.zig b/lib/fuzzer.zig
@@ -594,6 +594,21 @@ const Fuzzer = struct {
                 b.smithed_len = 4;
                 return input;
             }
+
+            pub fn reset(b: *Builder) void {
+                const uid_slices = b.uid_slices.entries.slice();
+                for (uid_slices.items(.key), uid_slices.items(.value)) |uid, *uid_data| {
+                    switch (uid.kind) {
+                        .int => uid_data.ints.deinit(gpa),
+                        .bytes => uid_data.bytes.deinit(gpa),
+                    }
+                }
+                b.uid_slices.clearRetainingCapacity();
+                b.total_ints = 0;
+                b.total_bytes = 0;
+                b.weighted_len = 0;
+                b.smithed_len = 4;
+            }
         };
     };
 
@@ -876,7 +891,14 @@ const Fuzzer = struct {
         // * The test has changed and a previous corpus input is being used
         // * An input provided by the test results in it
         // * The test is non-deterministic
-        if (f.runBytes(bytes, .bytes_fresh)) return;
+        if (f.runBytes(bytes, .bytes_fresh) and
+            modify_fs_corpus // The input is not from the filesystem.
+            // This is required to ensure the filesystem and process corpus are the same.
+        ) {
+            f.input_builder.reset();
+            f.corpus_pos = @enumFromInt(0);
+            return;
+        }
         f.req_values = f.input_builder.total_ints + f.input_builder.total_bytes;
         f.req_bytes = @intCast(f.input_builder.bytes_table.items.len);
         var input = f.input_builder.build();
@@ -1859,7 +1881,6 @@ const MemoryMappedInput = struct {
     /// Invalidates item pointers if more space is required.
     pub fn appendLittleInt(l: *MemoryMappedInput, T: type, x: T) void {
         l.ensureUnusedCapacity(@sizeOf(T));
-        //std.log.debug("{} {} {}", .{ l.writeSlice().len, l.len, @sizeOf(T) });
         l.writeSlice()[4 + l.len ..][0..@sizeOf(T)].* = @bitCast(mem.nativeToLittle(T, x));
         l.len += @sizeOf(T);
         l.writeLen();