Auto merge of rust-lang#1035 - fitzgen:csmith-tweaks, r=pepyakin

Csmith tweaks

r? @e00E or @emilio or @pepyakin whoever wants to get here first ;)

Author: bors-servo

.gitignore

@@ -11,3 +11,6 @@ ir.png
 
 # Output of the --dump-preprocessed-input flag.
 __bindgen.*
+
+# Generated by C-Smith
+csmith-fuzzing/platform.info

csmith-fuzzing/driver.py

@@ -1,33 +1,94 @@
-from subprocess import run, DEVNULL, PIPE
+import os, sys
+from subprocess import run, SubprocessError, DEVNULL, PIPE
+from tempfile import NamedTemporaryFile
 
 csmith_command = [
-        "csmith",
-        "--no-checksum",
-        "--nomain",
-        "--max-block-size", "1",
-        "--max-block-depth", "1",
-        "--output", "generated.h"]
+    "csmith",
+    "--no-checksum",
+    "--nomain",
+    "--max-block-size", "1",
+    "--max-block-depth", "1",
+]
 
-bindgen_command = ["bindgen", "generated.h"]
+def cat(path, title=None):
+    if not title:
+        title = path
+    print("-------------------- {} --------------------".format(title))
+    run(["cat", path])
 
-if __name__ == "__main__":
-    print("Bindgen fuzzing with csmith.")
-    print(
-        "This script will write to generated.h, bindgen_stdout, bindgen_stderr and platform.info . "
-        "These files can be deleted after running.")
+def run_logged(cmd):
+    with NamedTemporaryFile() as stdout, NamedTemporaryFile() as stderr:
+        result = run(cmd, stdin=DEVNULL, stdout=stdout, stderr=stderr)
+        if result.returncode != 0:
+            print()
+            print("Error: '{}' exited with code {}".format(" ".join(cmd), result.returncode))
+            cat(stdout.name, title="stdout")
+            cat(stdout.name, title="stderr")
+        return result
+
+def run_bindgen(input, output):
+    return run_logged([
+        "bindgen",
+        "--with-derive-partialeq",
+        "--with-derive-eq",
+        "-o", output.name,
+        input.name,
+        "--",
+        "-I", os.path.abspath(os.path.dirname(sys.argv[0])),
+    ])
+
+def run_rustc(output, test):
+    return run_logged([
+        "rustc",
+        "--crate-type", "lib",
+        "--test",
+        output.name,
+        "-o", test.name,
+    ])
+
+def main():
+    print("Fuzzing `bindgen` with C-Smith...\n")
 
     iterations = 0
     while True:
         print("\rIteration: {}".format(iterations), end="", flush=True)
 
-        run(csmith_command, stdin=DEVNULL, stdout=DEVNULL, stderr=DEVNULL)
-        with open("bindgen_stdout", "wb") as stdout, open("bindgen_stdout", "wb") as stderr:
-            result = run(bindgen_command, stdin=DEVNULL, stdout=stdout, stderr=stderr)
-            if result.returncode != 0:
-                print()
-                print(
-                    "Error: bindgen existed with non zero exit code {} when ran on generated.h . "
-                    "You can find its output in bindgen_stoud and bindgen_stderr."
-                    .format(result.returncode))
-                exit()
+        input = NamedTemporaryFile(delete=False, prefix="input-", suffix=".h")
+        input.close()
+        result = run_logged(csmith_command + ["-o", input.name])
+        if result.returncode != 0:
+            exit(1)
+
+        output = NamedTemporaryFile(delete=False, prefix="output-", suffix=".rs")
+        output.close()
+        result = run_bindgen(input, output)
+        if result.returncode != 0:
+            cat(input.name)
+            cat(output.name)
+            exit(1)
+
+        test = NamedTemporaryFile(delete=False, prefix="test-")
+        test.close()
+        result = run_rustc(output, test)
+        if result.returncode != 0:
+            cat(input.name)
+            cat(output.name)
+            exit(1)
+
+        result = run_logged([test.name])
+        if result.returncode != 0:
+            cat(input.name)
+            cat(output.name)
+            exit(1)
+
+        os.remove(input.name)
+        os.remove(output.name)
+        os.remove(test.name)
+
         iterations += 1
+
+if __name__ == "__main__":
+    try:
+        main()
+    except KeyboardInterrupt:
+        exit()