Make 3c -verify an error for now. (#519)

PR #488 made `3c -verify` cover only the compiler diagnostics, but none
of our regression tests actually use that functionality. Instead, one
regression test (macro_function_call) used `3c -verify` to try to test
the absence of 3C warnings, and we were unaware that the test wasn't
testing what it was supposed to. I think it's best to make `3c -verify`
an error for now so we don't make that mistake again.

Author: mattmccutchen-cci

clang/lib/3C/3C.cpp

@@ -186,6 +186,13 @@ _3CInterface::_3CInterface(const struct _3COptions &CCopt,
 
   ConstraintsBuilt = false;
 
+  if (VerifyDiagnosticOutput) {
+    errs() << "3C initialization error: Diagnostic verification is currently "
+              "unsupported.\n";
+    Failed = true;
+    return;
+  }
+
   if (OutputPostfix != "-" && !OutputDir.empty()) {
     errs() << "3C initialization error: Cannot use both -output-postfix and "
               "-output-dir\n";
@@ -287,6 +294,9 @@ bool _3CInterface::parseASTs() {
 
   auto *Tool = new ClangTool(*CurrCompDB, SourceFiles);
   Tool->appendArgumentsAdjuster(getIgnoreCheckedPointerAdjuster());
+  // NOTE: This code is currently unreachable because VerifyDiagnosticOutput is
+  // rejected in the _3CInterface constructor.
+  //
   // TODO: This currently only enables compiler diagnostic verification.
   // see https://github.com/correctcomputation/checkedc-clang/issues/425
   // for status.

clang/test/3C/macro_function_call.c

@@ -1,9 +1,9 @@
 // RUN: rm -rf %t*
-// RUN: 3c -base-dir=%S -verify -alltypes -addcr %s -- | FileCheck -match-full-lines -check-prefixes="CHECK_ALL","CHECK" %s
-// RUN: 3c -base-dir=%S -verify -addcr %s -- | FileCheck -match-full-lines -check-prefixes="CHECK_NOALL","CHECK" %s
-// RUN: 3c -base-dir=%S -verify -alltypes -addcr %s -- | %clang -c -fcheckedc-extension -x c -o /dev/null -
-// RUN: 3c -base-dir=%S -verify -alltypes -output-dir=%t.checked %s --
-// RUN: 3c -base-dir=%t.checked -verify  -alltypes %t.checked/macro_function_call.c -- | diff %t.checked/macro_function_call.c -
+// RUN: 3c -base-dir=%S -alltypes -addcr %s -- | FileCheck -match-full-lines -check-prefixes="CHECK_ALL","CHECK" %s
+// RUN: 3c -base-dir=%S -addcr %s -- | FileCheck -match-full-lines -check-prefixes="CHECK_NOALL","CHECK" %s
+// RUN: 3c -base-dir=%S -alltypes -addcr %s -- | %clang -c -fcheckedc-extension -x c -o /dev/null -
+// RUN: 3c -base-dir=%S -alltypes -output-dir=%t.checked %s --
+// RUN: 3c -base-dir=%t.checked -alltypes %t.checked/macro_function_call.c -- | diff %t.checked/macro_function_call.c -
 
 // Test fix for https://github.com/correctcomputation/checkedc-clang/issues/439
 // We cannot insert casts on function calls inside macros, so constraints must
@@ -12,6 +12,13 @@
 
 // 3C emits a warning if it fails inserting a cast. Ensure the test fails if
 // this happens.
+//
+// NOTICE: This part of the test is disabled (the -verify option has been
+// removed from the 3c RUN commands) until we have a replacement for the
+// diagnostic verifier
+// (https://github.com/correctcomputation/checkedc-clang/issues/503).
+// TODO: Re-enable it when we do.
+//
 // expected-no-diagnostics
 
 // Unsafe call in macro. This would require an _Assume_bounds_cast, but we