Add ability to ignore directories via command line

For ClazyStandalone it's with --ignore-dirs.
For clazy it's via the CLAZY_IGNORE_DIRS env variable.

Both take a regexp, to make it similar to clang-tidy.

BUG: 397885

6 files changed, 53 insertions, 17 deletions

diff --git a/src/Clazy.cpp b/src/Clazy.cpp
index d000ab4f..7b7dda18 100644
--- a/src/Clazy.cpp
+++ b/src/Clazy.cpp
@@ -189,11 +189,11 @@ std::unique_ptr<clang::ASTConsumer> ClazyASTAction::CreateASTConsumer(CompilerIn
     return std::unique_ptr<clang::ASTConsumer>(astConsumer.release());
 }
 
-static std::string getHeaderFilterEnv()
+static std::string getEnvVariable(const char *name)
 {
-    const char *headerFilter = getenv("CLAZY_HEADER_FILTER");
-    if (headerFilter)
-        return headerFilter;
+    const char *result = getenv(name);
+    if (result)
+        return result;
     else return std::string();
 }
 
@@ -205,7 +205,7 @@ bool ClazyASTAction::ParseArgs(const CompilerInstance &ci, const std::vector<std
     std::vector<std::string> args = args_;
 
     if (parseArgument("help", args)) {
-        m_context = new ClazyContext(ci, getHeaderFilterEnv(), ClazyContext::ClazyOption_None);
+        m_context = new ClazyContext(ci, getEnvVariable("CLAZY_HEADER_FILTER"), getEnvVariable("CLAZY_IGNORE_DIRS"), ClazyContext::ClazyOption_None);
         PrintHelp(llvm::errs());
         return true;
     }
@@ -238,7 +238,7 @@ bool ClazyASTAction::ParseArgs(const CompilerInstance &ci, const std::vector<std
     if (parseArgument("ignore-included-files", args))
         m_options |= ClazyContext::ClazyOption_IgnoreIncludedFiles;
 
-    m_context = new ClazyContext(ci, /*headerFilter=*/ "", m_options);
+    m_context = new ClazyContext(ci, /*headerFilter=*/ "", /*ignoreDirs=*/ "", m_options);
 
     // This argument is for debugging purposes
     const bool dbgPrintRequestedChecks = parseArgument("print-requested-checks", args);
@@ -343,18 +343,19 @@ void ClazyASTAction::PrintHelp(llvm::raw_ostream &ros) const
     ros << "FixIts are experimental and rewrite your code therefore only one FixIt is allowed per build.\nSpecifying a list of different FixIts is not supported.\nBackup your code before running them.\n";
 }
 
-ClazyStandaloneASTAction::ClazyStandaloneASTAction(const string &checkList, const string &headerFilter,
+ClazyStandaloneASTAction::ClazyStandaloneASTAction(const string &checkList, const string &headerFilter, const string &ignoreDirs,
                                                    ClazyContext::ClazyOptions options)
     : clang::ASTFrontendAction()
     , m_checkList(checkList.empty() ? "level1" : checkList)
-    , m_headerFilter(headerFilter.empty() ? getHeaderFilterEnv() : headerFilter)
+    , m_headerFilter(headerFilter.empty() ? getEnvVariable("CLAZY_HEADER_FILTER") : headerFilter)
+    , m_ignoreDirs(ignoreDirs.empty() ? getEnvVariable("CLAZY_IGNORE_DIRS") : ignoreDirs)
     , m_options(options)
 {
 }
 
 unique_ptr<ASTConsumer> ClazyStandaloneASTAction::CreateASTConsumer(CompilerInstance &ci, llvm::StringRef)
 {
-    auto context = new ClazyContext(ci, m_headerFilter, m_options);
+    auto context = new ClazyContext(ci, m_headerFilter, m_ignoreDirs, m_options);
     auto astConsumer = new ClazyASTConsumer(context);
 
     auto cm = CheckManager::instance();
diff --git a/src/Clazy.h b/src/Clazy.h
index 12497f0d..b126e221 100644
--- a/src/Clazy.h
+++ b/src/Clazy.h
@@ -73,12 +73,14 @@ class ClazyStandaloneASTAction : public clang::ASTFrontendAction
 public:
     explicit ClazyStandaloneASTAction(const std::string &checkList,
                                       const std::string &headerFilter,
+                                      const std::string &ignoreDirs,
                                       ClazyContext::ClazyOptions = ClazyContext::ClazyOption_None);
 protected:
     std::unique_ptr<clang::ASTConsumer> CreateASTConsumer(clang::CompilerInstance &ci, llvm::StringRef) override;
 private:
     const std::string m_checkList;
     const std::string m_headerFilter;
+    const std::string m_ignoreDirs;
     const ClazyContext::ClazyOptions m_options;
 };
 
diff --git a/src/ClazyContext.cpp b/src/ClazyContext.cpp
index b0467a49..4d4ecd82 100644
--- a/src/ClazyContext.cpp
+++ b/src/ClazyContext.cpp
@@ -50,7 +50,7 @@ public:
 };
 
 ClazyContext::ClazyContext(const clang::CompilerInstance &compiler,
-                           const string &headerFilter, ClazyOptions opts)
+                           const string &headerFilter, const string &ignoreDirs, ClazyOptions opts)
     : ci(compiler)
     , astContext(ci.getASTContext())
     , sm(ci.getSourceManager())
@@ -61,6 +61,9 @@ ClazyContext::ClazyContext(const clang::CompilerInstance &compiler,
     if (!headerFilter.empty())
         headerFilterRegex = std::unique_ptr<llvm::Regex>(new llvm::Regex(headerFilter));
 
+    if (!ignoreDirs.empty())
+        ignoreDirsRegex = std::unique_ptr<llvm::Regex>(new llvm::Regex(ignoreDirs));
+
     const char *fixitsEnv = getenv("CLAZY_FIXIT");
     allFixitsEnabled = (options & ClazyOption_AllFixitsEnabled);
     if (!allFixitsEnabled && fixitsEnv) {
diff --git a/src/ClazyContext.h b/src/ClazyContext.h
index dab85fef..608e86b4 100644
--- a/src/ClazyContext.h
+++ b/src/ClazyContext.h
@@ -67,6 +67,7 @@ public:
 
     explicit ClazyContext(const clang::CompilerInstance &ci,
                           const std::string &headerFilter,
+                          const std::string &ignoreDirs,
                           ClazyOptions = ClazyOption_None);
     ~ClazyContext();
 
@@ -110,18 +111,42 @@ public:
         return clazy::contains(extraOptions, optionName);
     }
 
-    bool isHeaderFilteredOut(clang::SourceLocation loc) const
+    bool fileMatchesLoc(const std::unique_ptr<llvm::Regex> &regex, clang::SourceLocation loc,  const clang::FileEntry **file) const
     {
+        if (!regex)
+            return false;
+
+        if (!(*file)) {
+            clang::FileID fid = sm.getDecomposedExpansionLoc(loc).first;
+            *file = sm.getFileEntryForID(fid);
+            if (!(*file)) {
+                return false;
+            }
+        }
+
+        StringRef fileName((*file)->getName());
+        return regex->match(fileName);
+    }
+
+    bool shouldIgnoreFile(clang::SourceLocation loc) const
+    {
+        // 1. Process the regexp that excludes files
+        const clang::FileEntry *file = nullptr;
+        if (ignoreDirsRegex) {
+            const bool matches = fileMatchesLoc(ignoreDirsRegex, loc, &file);
+            if (matches)
+                return true;
+        }
+
+        // 2. Process the regexp that includes files. Has lower priority.
         if (!headerFilterRegex || isMainFile(loc))
             return false;
 
-        clang::FileID fid = sm.getDecomposedExpansionLoc(loc).first;
-        const clang::FileEntry *file = sm.getFileEntryForID(fid);
+        const bool matches = fileMatchesLoc(headerFilterRegex, loc, &file);
         if (!file)
             return false;
 
-        StringRef fileName(file->getName());
-        return !headerFilterRegex->match(fileName);
+        return !matches;
     }
 
     bool isMainFile(clang::SourceLocation loc) const
@@ -156,6 +181,7 @@ public:
     clang::CXXMethodDecl *lastMethodDecl = nullptr;
     clang::Decl *lastDecl = nullptr;
     std::unique_ptr<llvm::Regex> headerFilterRegex;
+    std::unique_ptr<llvm::Regex> ignoreDirsRegex;
 };
 
 #endif
diff --git a/src/ClazyStandaloneMain.cpp b/src/ClazyStandaloneMain.cpp
index 39fcd9ae..697091e6 100644
--- a/src/ClazyStandaloneMain.cpp
+++ b/src/ClazyStandaloneMain.cpp
@@ -65,6 +65,10 @@ from the main file of each translation unit are
 always displayed.)"),
                               cl::init(""), cl::cat(s_clazyCategory));
 
+static cl::opt<std::string> s_ignoreDirs("ignore-dirs", cl::desc(R"(Regular expression matching the names of the
+directories for which diagnostics should never be emitted. Useful for ignoring 3rdparty code.)"),
+                              cl::init(""), cl::cat(s_clazyCategory));
+
 static cl::extrahelp s_commonHelp(CommonOptionsParser::HelpMessage);
 
 class ClazyToolActionFactory : public clang::tooling::FrontendActionFactory
@@ -97,7 +101,7 @@ public:
         if (s_ignoreIncludedFiles.getValue())
             options |= ClazyContext::ClazyOption_IgnoreIncludedFiles;
 
-        return new ClazyStandaloneASTAction(s_checks.getValue(), s_headerFilter.getValue(), options);
+        return new ClazyStandaloneASTAction(s_checks.getValue(), s_headerFilter.getValue(), s_ignoreDirs.getValue(), options);
     }
 };
 
diff --git a/src/checkbase.cpp b/src/checkbase.cpp
index cc64cd50..955411ce 100644
--- a/src/checkbase.cpp
+++ b/src/checkbase.cpp
@@ -152,7 +152,7 @@ void CheckBase::emitWarning(clang::SourceLocation loc, std::string error,
     if (m_context->suppressionManager.isSuppressed(m_name, loc, sm(), lo()))
         return;
 
-    if (m_context->isHeaderFilteredOut(loc))
+    if (m_context->shouldIgnoreFile(loc))
         return;
 
     if (loc.isMacroID()) {