[clang-tidy] Fix bugprone-argument-comment bug: negative literal number is not checked.

Summary:
For example:
```
void foo(int a);
foo(-2);
```
should be fixed as:
```
foo(/*a=*/-2);
```
This change tries to fix this issue.

Reviewers: alexfh, hokein, aaron.ballman

Reviewed By: alexfh, aaron.ballman

Subscribers: xazax.hun, cfe-commits

Tags: #clang, #clang-tools-extra

Patch by Yubo Xie.

Differential Revision: https://reviews.llvm.org/D67084

llvm-svn: 371072

2 files changed, 22 insertions, 1 deletions

diff --git a/clang-tools-extra/clang-tidy/bugprone/ArgumentCommentCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/ArgumentCommentCheck.cpp
index 07219f9c724..968333ce15e 100644
--- a/clang-tools-extra/clang-tidy/bugprone/ArgumentCommentCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/ArgumentCommentCheck.cpp
@@ -230,9 +230,11 @@ static const FunctionDecl *resolveMocks(const FunctionDecl *Func) {
 // Given the argument type and the options determine if we should
 // be adding an argument comment.
 bool ArgumentCommentCheck::shouldAddComment(const Expr *Arg) const {
+  Arg = Arg->IgnoreImpCasts();
+  if (isa<UnaryOperator>(Arg))
+    Arg = cast<UnaryOperator>(Arg)->getSubExpr();
   if (Arg->getExprLoc().isMacroID())
     return false;
-  Arg = Arg->IgnoreImpCasts();
   return (CommentBoolLiterals && isa<CXXBoolLiteralExpr>(Arg)) ||
          (CommentIntegerLiterals && isa<IntegerLiteral>(Arg)) ||
          (CommentFloatLiterals && isa<FloatingLiteral>(Arg)) ||
diff --git a/clang-tools-extra/test/clang-tidy/bugprone-argument-comment-literals.cpp b/clang-tools-extra/test/clang-tidy/bugprone-argument-comment-literals.cpp
index 79ae4c45103..ac2cdc8f563 100644
--- a/clang-tools-extra/test/clang-tidy/bugprone-argument-comment-literals.cpp
+++ b/clang-tools-extra/test/clang-tidy/bugprone-argument-comment-literals.cpp
@@ -69,18 +69,29 @@ void test() {
   // CHECK-MESSAGES: [[@LINE-1]]:9: warning: argument comment missing for literal argument 'fabc' [bugprone-argument-comment]
   // CHECK-FIXES: a.foo(/*fabc=*/1.0f);
 
+  a.foo(-1.0f);
+  // CHECK-MESSAGES: [[@LINE-1]]:9: warning: argument comment missing for literal argument 'fabc' [bugprone-argument-comment]
+  // CHECK-FIXES: a.foo(/*fabc=*/-1.0f);
+
   a.foo(1.0);
   // CHECK-MESSAGES: [[@LINE-1]]:9: warning: argument comment missing for literal argument 'dabc' [bugprone-argument-comment]
   // CHECK-FIXES: a.foo(/*dabc=*/1.0);
 
+  a.foo(-1.0);
+  // CHECK-MESSAGES: [[@LINE-1]]:9: warning: argument comment missing for literal argument 'dabc' [bugprone-argument-comment]
+  // CHECK-FIXES: a.foo(/*dabc=*/-1.0);
+
   int val3 = 10;
   a.foo(val3);
+  a.foo(-val3);
 
   float val4 = 10.0;
   a.foo(val4);
+  a.foo(-val4);
 
   double val5 = 10.0;
   a.foo(val5);
+  a.foo(-val5);
 
   a.foo("Hello World");
   // CHECK-MESSAGES: [[@LINE-1]]:9: warning: argument comment missing for literal argument 'strabc' [bugprone-argument-comment]
@@ -98,14 +109,22 @@ void test() {
   // CHECK-MESSAGES: [[@LINE-1]]:9: warning: argument comment missing for literal argument 'dabc' [bugprone-argument-comment]
   // CHECK-FIXES: a.foo(/*dabc=*/402.0_km);
 
+  a.foo(-402.0_km);
+  // CHECK-MESSAGES: [[@LINE-1]]:9: warning: argument comment missing for literal argument 'dabc' [bugprone-argument-comment]
+  // CHECK-FIXES: a.foo(/*dabc=*/-402.0_km);
+
   a.foo('A');
   // CHECK-MESSAGES: [[@LINE-1]]:9: warning: argument comment missing for literal argument 'chabc' [bugprone-argument-comment]
   // CHECK-FIXES: a.foo(/*chabc=*/'A');
 
   g(FOO);
+  g(-FOO);
   h(1.0f);
   // CHECK-MESSAGES: [[@LINE-1]]:5: warning: argument comment missing for literal argument 'b' [bugprone-argument-comment]
   // CHECK-FIXES: h(/*b=*/1.0f);
+  h(-1.0f);
+  // CHECK-MESSAGES: [[@LINE-1]]:5: warning: argument comment missing for literal argument 'b' [bugprone-argument-comment]
+  // CHECK-FIXES: h(/*b=*/-1.0f);
   i(__FILE__);
 
   j(1, X(1), X(1));