[flang] Search for #include "file" in right directory

Make the #include "file" preprocessing directive begin its
search in the same directory as the file containing the directive,
as other preprocessors and our Fortran INCLUDE statement do.

Avoid current working directory for all source files after the original.

Differential Revision: https://reviews.llvm.org/D95388

1 files changed, 4 insertions, 6 deletions

diff --git a/flang/lib/Parser/source.cpp b/flang/lib/Parser/source.cpp
index 11cd591..3fbbf78 100644
--- a/flang/lib/Parser/source.cpp
+++ b/flang/lib/Parser/source.cpp
@@ -56,9 +56,9 @@ std::string DirectoryName(std::string path) {
   return pathBuf.str().str();
 }
 
-std::string LocateSourceFile(
-    std::string name, const std::vector<std::string> &searchPath) {
-  if (name.empty() || name == "-" || llvm::sys::path::is_absolute(name)) {
+std::optional<std::string> LocateSourceFile(
+    std::string name, const std::list<std::string> &searchPath) {
+  if (name == "-" || llvm::sys::path::is_absolute(name)) {
     return name;
   }
   for (const std::string &dir : searchPath) {
@@ -70,7 +70,7 @@ std::string LocateSourceFile(
       return path.str().str();
     }
   }
-  return name;
+  return std::nullopt;
 }
 
 std::size_t RemoveCarriageReturns(llvm::MutableArrayRef<char> buf) {
@@ -123,7 +123,6 @@ bool SourceFile::Open(std::string path, llvm::raw_ostream &error) {
 bool SourceFile::ReadStandardInput(llvm::raw_ostream &error) {
   Close();
   path_ = "standard input";
-
   auto buf_or = llvm::MemoryBuffer::getSTDIN();
   if (!buf_or) {
     auto err = buf_or.getError();
@@ -146,7 +145,6 @@ void SourceFile::ReadFile() {
       auto tmp_buf{llvm::WritableMemoryBuffer::getNewUninitMemBuffer(
           content().size() + 1)};
       llvm::copy(content(), tmp_buf->getBufferStart());
-      Close();
       buf_ = std::move(tmp_buf);
     }
     buf_end_++;