Disable dtor inlining for clang-tidy

LLVM r328258 turned on a feature called temporary dtor inlining by
default for all of C++ in clang-tidy. This feature appears to be
somewhat over-aggressive when objects are being passed by value. For
example, given:

void foo(std::unique_ptr<int> i);

void bar() {
  auto x = std::make_unique<int>();
  int *i = x.get();
  foo(std::move(x));
  *i = 99;
}

...clang-tidy will complain about `*i = 99;` being a definite
use-after-free. This is incorrect, however: `foo` could stash the
`unique_ptr` it's given in a global, or a class member, or ...

Until upstream fixes this bug, it's probably best to keep this disabled.

Bug: None
Test: Ran the analyzer across Android locally. Nothing broke; number of
complaints dropped significantly.

Change-Id: I806c7ead34b61f4a88a7e6ec1c94751836a21e70

1 files changed, 15 insertions, 3 deletions

diff --git a/cc/tidy.go b/cc/tidy.go
index 8ca94efc..491cc22d 100644
--- a/cc/tidy.go
+++ b/cc/tidy.go
@@ -83,9 +83,21 @@ func (tidy *tidyFeature) flags(ctx ModuleContext, flags Flags) Flags {
 		flags.TidyFlags = append(flags.TidyFlags, "-extra-arg-before=-fno-caret-diagnostics")
 	}
 
-	// We might be using the static analyzer through clang tidy.
-	// https://bugs.llvm.org/show_bug.cgi?id=32914
-	flags.TidyFlags = append(flags.TidyFlags, "-extra-arg-before=-D__clang_analyzer__")
+	extraArgFlags := []string{
+		// We might be using the static analyzer through clang tidy.
+		// https://bugs.llvm.org/show_bug.cgi?id=32914
+		"-D__clang_analyzer__",
+
+		// A recent change in clang-tidy (r328258) enabled destructor inlining, which
+		// appears to cause a number of false positives. Until that's resolved, this turns
+		// off the effects of r328258.
+		// https://bugs.llvm.org/show_bug.cgi?id=37459
+		"-Xclang", "-analyzer-config", "-Xclang", "c++-temp-dtor-inlining=false",
+	}
+
+	for _, f := range extraArgFlags {
+		flags.TidyFlags = append(flags.TidyFlags, "-extra-arg-before="+f)
+	}
 
 	tidyChecks := "-checks="
 	if checks := ctx.Config().TidyChecks(); len(checks) > 0 {