[clang-tidy] Fix a crash issue when clang-tidy runs with compilation database.

Summary:
The clang-tidy will trigger an assertion if it's not in the building directory.

TEST:
cd <llvm-repo>/
./build/bin/clang-tidy --checks=-*,modernize-use-nullptr -p build tools/clang/tools/extra/clang-tidy/ClangTidy.cpp

The crash issue is gone after applying this patch.

Fixes PR24834, PR26241

Reviewers: bkramer, alexfh

Subscribers: rizsotto.mailinglist, cfe-commits

Differential Revision: http://reviews.llvm.org/D17335

llvm-svn: 261991

2 files changed, 56 insertions, 0 deletions

diff --git a/clang-tools-extra/test/clang-tidy/Inputs/compilation-database/template.json b/clang-tools-extra/test/clang-tidy/Inputs/compilation-database/template.json
new file mode 100644
index 00000000000..74275d95372
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/Inputs/compilation-database/template.json
@@ -0,0 +1,32 @@
+[
+{
+  "directory": "test_dir/a",
+  "command": "clang++ -o test.o test_dir/a/a.cpp",
+  "file": "test_dir/a/a.cpp"
+},
+{
+  "directory": "test_dir/a",
+  "command": "clang++ -o test.o test_dir/a/b.cpp",
+  "file": "test_dir/a/b.cpp"
+},
+{
+  "directory": "test_dir/",
+  "command": "clang++ -o test.o test_dir/b/b.cpp",
+  "file": "test_dir/b/b.cpp"
+},
+{
+  "directory": "test_dir/b",
+  "command": "clang++ -o test.o ../b/c.cpp",
+  "file": "test_dir/b/c.cpp"
+},
+{
+  "directory": "test_dir/b",
+  "command": "clang++ -I../include -o test.o ../b/d.cpp",
+  "file": "test_dir/b/d.cpp"
+},
+{
+  "directory": "test_dir/",
+  "command": "clang++ -o test.o test_dir/b/not-exist.cpp",
+  "file": "test_dir/b/not-exist.cpp"
+}
+]
diff --git a/clang-tools-extra/test/clang-tidy/clang-tidy-run-with-database.cpp b/clang-tools-extra/test/clang-tidy/clang-tidy-run-with-database.cpp
new file mode 100644
index 00000000000..7304f0645ed
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/clang-tidy-run-with-database.cpp
@@ -0,0 +1,24 @@
+// REQUIRES: shell
+// RUN: mkdir -p %T/compilation-database-test/include
+// RUN: mkdir -p %T/compilation-database-test/a
+// RUN: mkdir -p %T/compilation-database-test/b
+// RUN: echo 'int *AA = 0;' > %T/compilation-database-test/a/a.cpp
+// RUN: echo 'int *AB = 0;' > %T/compilation-database-test/a/b.cpp
+// RUN: echo 'int *BB = 0;' > %T/compilation-database-test/b/b.cpp
+// RUN: echo 'int *BC = 0;' > %T/compilation-database-test/b/c.cpp
+// RUN: echo 'int *HP = 0;' > %T/compilation-database-test/include/header.h
+// RUN: echo '#include "header.h"' > %T/compilation-database-test/b/d.cpp
+// RUN: sed 's|test_dir|%T/compilation-database-test|g' %S/Inputs/compilation-database/template.json > %T/compile_commands.json
+// RUN: clang-tidy --checks=-*,modernize-use-nullptr -p %T %T/compilation-database-test/b/not-exist -header-filter=.*
+// RUN: clang-tidy --checks=-*,modernize-use-nullptr -p %T %T/compilation-database-test/a/a.cpp %T/compilation-database-test/a/b.cpp %T/compilation-database-test/b/b.cpp %T/compilation-database-test/b/c.cpp %T/compilation-database-test/b/d.cpp -header-filter=.* -fix
+// RUN: FileCheck -input-file=%T/compilation-database-test/a/a.cpp %s -check-prefix=CHECK-FIX1
+// RUN: FileCheck -input-file=%T/compilation-database-test/a/b.cpp %s -check-prefix=CHECK-FIX2
+// RUN: FileCheck -input-file=%T/compilation-database-test/b/b.cpp %s -check-prefix=CHECK-FIX3
+// RUN: FileCheck -input-file=%T/compilation-database-test/b/c.cpp %s -check-prefix=CHECK-FIX4
+// RUN: FileCheck -input-file=%T/compilation-database-test/include/header.h %s -check-prefix=CHECK-FIX5
+
+// CHECK-FIX1: int *AA = nullptr;
+// CHECK-FIX2: int *AB = nullptr;
+// CHECK-FIX3: int *BB = nullptr;
+// CHECK-FIX4: int *BC = nullptr;
+// CHECK-FIX5: int *HP = nullptr;