[PATCH] D59135: Add check for matching HeaderFilter before emitting Diagnostic

[Thorsten via Phabricator via cfe-commits]

thorsten-klein added a comment.

Hello @alexfh ,
Let me extend your example

  $ cat a.cc 
  #include "b.h"
  #include "d.h"
  int main(){check(nullptr);}
  $ cat b.h 
  #include "c.h"
  inline void b() { c(/*y=*/42); }
  $ cat c.h 
  void c(int x);
  $ cat d.h 
  inline char* check(char* buffer)
  {
  	*buffer++=1; // Should be clang-analyzer-core.NullDereference
  	return buffer;
  }

Now an additional warning is found and shown (=not suppressed):

  $ clang-tidy -checks=-*,clang-*,bugprone-argument-comment a.cc --
  2 warnings generated.
  /home/default/Temp/clang-tidy-test/d.h:3:11: warning: Dereference of null pointer [clang-analyzer-core.NullDereference]
          *buffer++=1; // Should be clang-analyzer-core.NullDereference
                   ^
  /home/default/Temp/clang-tidy-test/a.cc:3:12: note: Calling 'check'
  int main(){check(0);}
             ^
  /home/default/Temp/clang-tidy-test/d.h:3:3: note: Null pointer value stored to 'buffer'
          *buffer++=1; // Should be clang-analyzer-core.NullDereference
           ^
  /home/default/Temp/clang-tidy-test/d.h:3:11: note: Dereference of null pointer
          *buffer++=1; // Should be clang-analyzer-core.NullDereference
                   ^
  Suppressed 1 warnings (1 in non-user code).
  Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.

**How can I use -header-filter now?**

With -header-filter=b.h clang-tidy shows both warnings:

  $ clang-tidy -checks=-*,clang-*,bugprone-argument-comment a.cc -header-filter=b.h --
  2 warnings generated.
  /home/default/Temp/clang-tidy-test/b.h:2:21: warning: argument name 'y' in comment does not match parameter name 'x' [bugprone-argument-comment]
  inline void b() { c(/*y=*/42); }
                      ^~~~~~
                      /*x=*/
  /home/default/Temp/clang-tidy-test/c.h:1:12: note: 'x' declared here
  void c(int x);
             ^
  /home/default/Temp/clang-tidy-test/d.h:3:11: warning: Dereference of null pointer [clang-analyzer-core.NullDereference]
          *buffer++=1; // Should be clang-analyzer-core.NullDereference
                   ^
  /home/default/Temp/clang-tidy-test/a.cc:3:12: note: Calling 'check'
  int main(){check(0);}
             ^
  /home/default/Temp/clang-tidy-test/d.h:3:3: note: Null pointer value stored to 'buffer'
          *buffer++=1; // Should be clang-analyzer-core.NullDereference
           ^
  /home/default/Temp/clang-tidy-test/d.h:3:11: note: Dereference of null pointer
          *buffer++=1; // Should be clang-analyzer-core.NullDereference
                   ^

With -header-filter=c.h clang-tidy shows both warnings:

  $ clang-tidy -checks=-*,clang-*,bugprone-argument-comment a.cc -header-filter=c.h --
  2 warnings generated.
  /home/default/Temp/clang-tidy-test/b.h:2:21: warning: argument name 'y' in comment does not match parameter name 'x' [bugprone-argument-comment]
  inline void b() { c(/*y=*/42); }
                      ^~~~~~
                      /*x=*/
  /home/default/Temp/clang-tidy-test/c.h:1:12: note: 'x' declared here
  void c(int x);
             ^
  /home/default/Temp/clang-tidy-test/d.h:3:11: warning: Dereference of null pointer [clang-analyzer-core.NullDereference]
          *buffer++=1; // Should be clang-analyzer-core.NullDereference
                   ^
  /home/default/Temp/clang-tidy-test/a.cc:3:12: note: Calling 'check'
  int main(){check(0);}
             ^
  /home/default/Temp/clang-tidy-test/d.h:3:3: note: Null pointer value stored to 'buffer'
          *buffer++=1; // Should be clang-analyzer-core.NullDereference
           ^
  /home/default/Temp/clang-tidy-test/d.h:3:11: note: Dereference of null pointer
          *buffer++=1; // Should be clang-analyzer-core.NullDereference
                   ^

With -header-filter=c.h clang-tidy shows both warnings:

  $ clang-tidy -checks=-*,clang-*,bugprone-argument-comment a.cc -header-filter=d.h --
  2 warnings generated.
  /home/default/Temp/clang-tidy-test/d.h:3:11: warning: Dereference of null pointer [clang-analyzer-core.NullDereference]
          *buffer++=1; // Should be clang-analyzer-core.NullDereference
                   ^
  /home/default/Temp/clang-tidy-test/a.cc:3:12: note: Calling 'check'
  int main(){check(nullptr);}
             ^
  /home/default/Temp/clang-tidy-test/d.h:3:3: note: Null pointer value stored to 'buffer'
          *buffer++=1; // Should be clang-analyzer-core.NullDereference
           ^
  /home/default/Temp/clang-tidy-test/d.h:3:11: note: Dereference of null pointer
          *buffer++=1; // Should be clang-analyzer-core.NullDereference
                   ^
  Suppressed 1 warnings (1 in non-user code).
  Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.

How can I suppress warning for my header file //**d.h**// so that only warning from //**b.h**// is shown?


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  https://reviews.llvm.org/D59135/new/

https://reviews.llvm.org/D59135