[clang-tidy] Fix relative path in header-filter.

Summary:
Clang-tidy supports output diagnostics from header files if user
specifies --header-filter. But it can't handle relative path well.
For example, the folder structure of a project is:

```
// a.h is in /src/a/a.h

// b.h is in /src/b/b.h
...

// c.cpp is in /src/c.cpp

```

Now, we set --header-filter as --header-filter=/a/. That means we only
want to check header files under /src/a/ path, and ignore header files
uder /src/b/ path, but in current implementation, clang-tidy will check
/src/b/b.h also, because the name of b.h used in clang-tidy is
/src/a/../b/b.h.

This change tries to fix this issue.

Reviewers: alexfh, hokein, aaron.ballman, gribozavr

Reviewed By: gribozavr

Subscribers: MyDeveloperDay, xazax.hun, cfe-commits

Tags: #clang, #clang-tools-extra

Differential Revision: https://reviews.llvm.org/D67501

Patch by Yubo Xie.

llvm-svn: 372388

clang-tools-extra/clang-tidy/ClangTidyDiagnosticConsumer.cpp

@@ -551,7 +551,9 @@ void ClangTidyDiagnosticConsumer::checkFilters(SourceLocation Location,
     return;
   }
 
-  StringRef FileName(File->getName());
+  StringRef FileName = File->tryGetRealPathName();
+  if (FileName.empty())
+    FileName = File->getName();
   LastErrorRelatesToUserCode = LastErrorRelatesToUserCode ||
                                Sources.isInMainFile(Location) ||
                                getHeaderFilter()->match(FileName);

clang-tools-extra/test/clang-tidy/Inputs/file-filter/subfolder_a/header_a.h

@@ -0,0 +1,3 @@
+#include "../subfolder_b/header_b.h"
+
+class SA { SA(int); };

clang-tools-extra/test/clang-tidy/Inputs/file-filter/subfolder_b/header_b.h

@@ -0,0 +1 @@
+class SB { SB(int); };

clang-tools-extra/test/clang-tidy/Inputs/file-filter/subfolder_c/header_c.h

@@ -0,0 +1 @@
+class SC { SC(int); };

clang-tools-extra/test/clang-tidy/file-filter.cpp

@@ -9,6 +9,12 @@
 //       file-filter\header*.h due to code order between '/' and '\\'.
 // RUN: clang-tidy -checks='-*,google-explicit-constructor' -header-filter='.*' -system-headers %s -- -I %S/Inputs/file-filter/system/.. -isystem %S/Inputs/file-filter/system 2>&1 | FileCheck --check-prefix=CHECK4 %s
 // RUN: clang-tidy -checks='-*,google-explicit-constructor' -header-filter='.*' -system-headers -quiet %s -- -I %S/Inputs/file-filter/system/.. -isystem %S/Inputs/file-filter/system 2>&1 | FileCheck --check-prefix=CHECK4-QUIET %s
+// RUN: clang-tidy -checks='-*,google-explicit-constructor' -header-filter='subfolder_a' %s -- -I %S/Inputs/file-filter -isystem %S/Inputs/file-filter/system 2>&1 | FileCheck --check-prefix=CHECK5 %s
+// RUN: clang-tidy -checks='-*,google-explicit-constructor' -header-filter='subfolder_a' -quiet %s -- -I %S/Inputs/file-filter -isystem %S/Inputs/file-filter/system 2>&1 | FileCheck --check-prefix=CHECK5-QUIET %s
+// RUN: clang-tidy -checks='-*,google-explicit-constructor' -header-filter='subfolder_b' %s -- -I %S/Inputs/file-filter -isystem %S/Inputs/file-filter/system 2>&1 | FileCheck --check-prefix=CHECK6 %s
+// RUN: clang-tidy -checks='-*,google-explicit-constructor' -header-filter='subfolder_b' -quiet %s -- -I %S/Inputs/file-filter -isystem %S/Inputs/file-filter/system 2>&1 | FileCheck --check-prefix=CHECK6-QUIET %s
+// RUN: clang-tidy -checks='-*,google-explicit-constructor' -header-filter='subfolder_c' %s -- -I %S/Inputs/file-filter -isystem %S/Inputs/file-filter/system 2>&1 | FileCheck --check-prefix=CHECK7 %s
+// RUN: clang-tidy -checks='-*,google-explicit-constructor' -header-filter='subfolder_c' -quiet %s -- -I %S/Inputs/file-filter -isystem %S/Inputs/file-filter/system 2>&1 | FileCheck --check-prefix=CHECK7-QUIET %s
 
 #include "header1.h"
 // CHECK-NOT: warning:
@@ -19,6 +25,12 @@
 // CHECK3-QUIET-NOT: warning:
 // CHECK4: header1.h:1:12: warning: single-argument constructors
 // CHECK4-QUIET: header1.h:1:12: warning: single-argument constructors
+// CHECK5-NOT: warning:
+// CHECK5-QUIET-NOT: warning:
+// CHECK6-NOT: warning:
+// CHECK6-QUIET-NOT: warning:
+// CHECK7-NOT: warning:
+// CHECK7-QUIET-NOT: warning:
 
 #include "header2.h"
 // CHECK-NOT: warning:
@@ -29,6 +41,44 @@
 // CHECK3-QUIET: header2.h:1:12: warning: single-argument constructors
 // CHECK4: header2.h:1:12: warning: single-argument constructors
 // CHECK4-QUIET: header2.h:1:12: warning: single-argument constructors
+// CHECK5-NOT: warning:
+// CHECK5-QUIET-NOT: warning:
+// CHECK6-NOT: warning:
+// CHECK6-QUIET-NOT: warning:
+// CHECK7-NOT: warning:
+// CHECK7-QUIET-NOT: warning:
+
+#include "subfolder_a/header_a.h"
+// CHECK-NOT: warning:
+// CHECK-QUIET-NOT: warning:
+// CHECK2: header_b.h:1:12: warning: single-argument constructors must be marked explicit
+// CHECK2-QUIET: header_b.h:1:12: warning: single-argument constructors must be marked explicit
+// CHECK3-NOT: warning:
+// CHECK3-QUIET-NOT: warning:
+// CHECK4: header_b.h:1:12: warning: single-argument constructors must be marked explicit
+// CHECK4-QUIET: header_b.h:1:12: warning: single-argument constructors must be marked explicit
+// CHECK5: header_a.h:3:12: warning: single-argument constructors must be marked explicit
+// CHECK5-QUIET: header_a.h:3:12: warning: single-argument constructors must be marked explicit
+// CHECK6: header_b.h:1:12: warning: single-argument constructors must be marked explicit
+// CHECK6-QUIET: header_b.h:1:12: warning: single-argument constructors must be marked explicit
+// CHECK7-NOT: warning:
+// CHECK7-QUIET-NOT: warning:
+
+#include "subfolder_c/header_c.h"
+// CHECK-NOT: warning:
+// CHECK-QUIET-NOT: warning:
+// CHECK2: header_c.h:1:12: warning: single-argument constructors must be marked explicit
+// CHECK2-QUIET: header_c.h:1:12: warning: single-argument constructors must be marked explicit
+// CHECK3-NOT: warning:
+// CHECK3-QUIET-NOT: warning:
+// CHECK4: header_c.h:1:12: warning: single-argument constructors must be marked explicit
+// CHECK4-QUIET: header_c.h:1:12: warning: single-argument constructors must be marked explicit
+// CHECK5-NOT: warning:
+// CHECK5-QUIET-NOT: warning:
+// CHECK6-NOT: warning:
+// CHECK6-QUIET-NOT: warning:
+// CHECK7: header_c.h:1:12: warning: single-argument constructors must be marked explicit
+// CHECK7-QUIET: header_c.h:1:12: warning: single-argument constructors must be marked explicit
 
 #include <system-header.h>
 // CHECK-NOT: warning:
@@ -39,6 +89,12 @@
 // CHECK3-QUIET-NOT: warning:
 // CHECK4: system-header.h:1:12: warning: single-argument constructors
 // CHECK4-QUIET: system-header.h:1:12: warning: single-argument constructors
+// CHECK5-NOT: warning:
+// CHECK5-QUIET-NOT: warning:
+// CHECK6-NOT: warning:
+// CHECK6-QUIET-NOT: warning:
+// CHECK7-NOT: warning:
+// CHECK7-QUIET-NOT: warning:
 
 class A { A(int); };
 // CHECK: :[[@LINE-1]]:11: warning: single-argument constructors
@@ -49,6 +105,12 @@ class A { A(int); };
 // CHECK3-QUIET: :[[@LINE-6]]:11: warning: single-argument constructors
 // CHECK4: :[[@LINE-7]]:11: warning: single-argument constructors
 // CHECK4-QUIET: :[[@LINE-8]]:11: warning: single-argument constructors
+// CHECK5: :[[@LINE-9]]:11: warning: single-argument constructors
+// CHECK5-QUIET: :[[@LINE-10]]:11: warning: single-argument constructors
+// CHECK6: :[[@LINE-11]]:11: warning: single-argument constructors
+// CHECK6-QUIET: :[[@LINE-12]]:11: warning: single-argument constructors
+// CHECK7: :[[@LINE-13]]:11: warning: single-argument constructors
+// CHECK7-QUIET: :[[@LINE-14]]:11: warning: single-argument constructors
 
 // CHECK-NOT: warning:
 // CHECK-QUIET-NOT: warning:
@@ -58,16 +120,31 @@ class A { A(int); };
 // CHECK3-QUIET-NOT: warning:
 // CHECK4-NOT: warning:
 // CHECK4-QUIET-NOT: warning:
+// CHECK5-NOT: warning:
+// CHECK5-QUIET-NOT: warning:
+// CHECK6-NOT: warning:
+// CHECK6-QUIET-NOT: warning:
+// CHECK7-NOT: warning:
+// CHECK7-QUIET-NOT: warning:
 
-// CHECK: Suppressed 3 warnings (3 in non-user code)
+// CHECK: Suppressed 6 warnings (6 in non-user code)
 // CHECK: Use -header-filter=.* to display errors from all non-system headers.
 // CHECK-QUIET-NOT: Suppressed
 // CHECK2: Suppressed 1 warnings (1 in non-user code)
 // CHECK2: Use -header-filter=.* {{.*}}
 // CHECK2-QUIET-NOT: Suppressed
-// CHECK3: Suppressed 2 warnings (2 in non-user code)
+// CHECK3: Suppressed 5 warnings (5 in non-user code)
 // CHECK3: Use -header-filter=.* {{.*}}
 // CHECK3-QUIET-NOT: Suppressed
 // CHECK4-NOT: Suppressed {{.*}} warnings
 // CHECK4-NOT: Use -header-filter=.* {{.*}}
 // CHECK4-QUIET-NOT: Suppressed
+// CHECK5: Suppressed 5 warnings (5 in non-user code)
+// CHECK5: Use -header-filter=.* to display errors from all non-system headers.
+// CHECK5-QUIET-NOT: Suppressed
+// CHECK6: Suppressed 5 warnings (5 in non-user code)
+// CHECK6: Use -header-filter=.* to display errors from all non-system headers.
+// CHECK6-QUIET-NOT: Suppressed
+// CHECK7: Suppressed 5 warnings (5 in non-user code)
+// CHECK7: Use -header-filter=.* to display errors from all non-system headers.
+// CHECK7-QUIET-NOT: Suppressed