[clang-tidy] Preserve comments and preprocessor directives when simplifying boolean expressions

This changeset still emits the diagnostic that the expression could be simplified, but it doesn't generate any fix-its that would lose comments or preprocessor directives within the text that would be replaced.

Fixes PR25842

Reviewers: alexfh

Subscribers: xazax.hun, cfe-commits

Patch by Richard Thomson! (+a naming style fix)

Differential Revision: http://reviews.llvm.org/D15737

llvm-svn: 256492

1 files changed, 24 insertions, 0 deletions

diff --git a/clang-tools-extra/test/clang-tidy/readability-simplify-bool-expr.cpp b/clang-tools-extra/test/clang-tidy/readability-simplify-bool-expr.cpp
index 58cb416f37f..e3276103ded 100644
--- a/clang-tools-extra/test/clang-tidy/readability-simplify-bool-expr.cpp
+++ b/clang-tools-extra/test/clang-tidy/readability-simplify-bool-expr.cpp
@@ -871,3 +871,27 @@ bool negated_null_pointer_condition(int *p4) {
 }
 // CHECK-MESSAGES: :[[@LINE-5]]:12: warning: {{.*}} in conditional return
 // CHECK-FIXES: return p4 != nullptr;{{$}}
+
+bool comments_in_the_middle(bool b) {
+  if (b) {
+    return true;
+  } else {
+    // something wicked this way comes
+    return false;
+  }
+}
+// CHECK-MESSAGES: :[[@LINE-6]]:12: warning: {{.*}} in conditional return
+// CHECK-FIXES: {{^}}  if (b) {
+// CHECK-FIXES: // something wicked this way comes{{$}}
+
+bool preprocessor_in_the_middle(bool b) {
+  if (b) {
+    return true;
+  } else {
+#define SOMETHING_WICKED false
+    return false;
+  }
+}
+// CHECK-MESSAGES: :[[@LINE-6]]:12: warning: {{.*}} in conditional return
+// CHECK-FIXES: {{^}}  if (b) {
+// CHECK-FIXES: {{^}}#define SOMETHING_WICKED false