Bug 1615245 - checker fopen-usage should ignore some gtest include files. r=froydnj

Differential Revision: https://phabricator.services.mozilla.com/D62997

--HG--
extra : moz-landing-system : lando

build/clang-plugin/CustomMatchers.h

@@ -126,11 +126,22 @@ AST_MATCHER(QualType, isFloat) { return Node->isRealFloatingType(); }
 /// This matcher will match locations in system headers.  This is adopted from
 /// isExpansionInSystemHeader in newer clangs, but modified in order to work
 /// with old clangs that we use on infra.
-AST_POLYMORPHIC_MATCHER(isInSystemHeader,                                      \
+AST_POLYMORPHIC_MATCHER(isInSystemHeader,
                         AST_POLYMORPHIC_SUPPORTED_TYPES(Decl, Stmt)) {
   return ASTIsInSystemHeader(Finder->getASTContext(), Node);
 }
 
+/// This matcher will match a file "gtest-port.h". The file contains
+/// known fopen usages that are OK.
+AST_MATCHER(CallExpr, isInWhitelistForFopenUsage) {
+  static const char Whitelist[] = "gtest-port.h";
+  SourceLocation Loc = Node.getBeginLoc();
+  StringRef FileName =
+      getFilename(Finder->getASTContext().getSourceManager(), Loc);
+
+  return llvm::sys::path::rbegin(FileName)->equals(Whitelist);
+}
+
 /// This matcher will match a list of files.  These files contain
 /// known NaN-testing expressions which we would like to whitelist.
 AST_MATCHER(BinaryOperator, isInWhitelistForNaNExpr) {

build/clang-plugin/FopenUsageChecker.cpp

@@ -50,7 +50,8 @@ void FopenUsageChecker::registerMatchers(MatchFinder *AstMatcher) {
                             hasIntegerParam(1), hasIntegerParam(2),
                             hasParamOfType(3, "LPSECURITY_ATTRIBUTES"),
                             hasIntegerParam(4), hasIntegerParam(5),
-                            hasParamOfType(6, "HANDLE"))))))))
+                            hasParamOfType(6, "HANDLE")))))),
+              unless(isInWhitelistForFopenUsage())))
           .bind("funcCall"),
       this);
 }