update the slides for ep13

docs/videos.org

@@ -509,7 +509,8 @@ This framework allows for transforming a set of illegal operations to a set of l
 *** Rewrite Patterns
 *** Type Converter
 ** Full vs Partial Conversion
-* Episode 12 - Target code generation
+* DONE Episode 12 - Target code generation
+CLOSED: [2021-11-04 Thu 00:57]
 ** Updates:
 *** JIT work
 *** Emacs dev mode
@@ -561,3 +562,23 @@ and tries to =resolve= *undefined* symbols
 ** Let's look at some code
 ** Resources:
 - [[https://lwn.net/Articles/276782/][20 part linker essay]]
+* Episode 13 - Source Managers
+** FAQ:
+- What tools are you using?
+
+** Updates:
+- Still JIT
+- We're going to start the JIT discussion from next EP
+
+** Forgot to show case the code generation
+I didn't show it in action
+
+** What is a source manager
+- It owns and manages are the source buffers
+- All of our interactions with source files will happen though Source manager
+  - Including reading files
+  - Loading namespaces
+  - Including namespaces
+  - ...
+
+- LLVM provides a =SourceMgr= class that we're not using it

include/serene/source_mgr.h

@@ -42,7 +42,7 @@ class SereneContext;
 
 /// This class is quite similar to the `llvm::SourceMgr` in functionality. We
 /// even borrowed some of the code from the original implementation but removed
-/// a lot of code that ar irrelevant to us.
+/// a lot of code that were irrelevant to us.
 ///
 /// SouceMgr is responsible for finding a namespace in the `loadPaths` and read
 /// the content of the `.srn` (or any of the `DEFAULT_SUFFIX`) into a
@@ -80,7 +80,7 @@ private:
     /// dynamically based on the size of Buffer.
     mutable void *offsetCache = nullptr;
 
-    /// Look up a given \p Ptr in in the buffer, determining which line it came
+    /// Look up a given \p ptr in in the buffer, determining which line it came
     /// from.
     unsigned getLineNumber(const char *ptr) const;
     template <typename T>
@@ -103,7 +103,7 @@ private:
     SrcBuffer &operator=(const SrcBuffer &) = delete;
     ~SrcBuffer();
   };
-  using ErrorOrMemBufPtr = llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>;
+  using MemBufPtr = std::unique_ptr<llvm::MemoryBuffer>;
 
   /// This is all of the buffers that we are reading from.
   std::vector<SrcBuffer> buffers;
@@ -119,7 +119,7 @@ private:
   // a unique pointer to the memory buffer containing the content or an error.
   // In the success case it will put the path of the file into the \p
   // importedFile.
-  ErrorOrMemBufPtr findFileInLoadPath(const std::string &name,
+  MemBufPtr findFileInLoadPath(const std::string &name,
                                std::string &importedFile);
 
   bool isValidBufferID(unsigned i) const;
@@ -138,7 +138,7 @@ public:
   /// Set the `loadPaths` to the given \p dirs. `loadPaths` is a vector of
   /// directories that Serene will look in order to find a file that constains a
   /// namespace which it is looking for.
-  void setLoadPaths(const std::vector<std::string> &dirs) { loadPaths = dirs; }
+  void setLoadPaths(std::vector<std::string> &dirs) { loadPaths.swap(dirs); }
 
   /// Return a reference to a `SrcBuffer` with the given ID \p i.
   const SrcBuffer &getBufferInfo(unsigned i) const {

src/libserene/source_mgr.cpp

@@ -28,15 +28,16 @@
 #include "serene/namespace.h"
 #include "serene/reader/location.h"
 #include "serene/reader/reader.h"
-#include "serene/reader/semantics.h"
 #include "serene/utils.h"
 
 #include <system_error>
 
+#include <llvm/Support/Error.h>
 #include <llvm/Support/FormatVariadic.h>
 #include <llvm/Support/Locale.h>
 #include <llvm/Support/MemoryBufferRef.h>
 #include <llvm/Support/Path.h>
+#include <llvm/Support/raw_ostream.h>
 #include <mlir/Support/LogicalResult.h>
 
 namespace serene {
@@ -55,27 +56,30 @@ bool SourceMgr::isValidBufferID(unsigned i) const {
   return i != 0 && i <= buffers.size();
 };
 
-SourceMgr::ErrorOrMemBufPtr
-SourceMgr::findFileInLoadPath(const std::string &name,
+SourceMgr::MemBufPtr SourceMgr::findFileInLoadPath(const std::string &name,
                                                    std::string &importedFile) {
 
   auto path = convertNamespaceToPath(name);
-  // TODO: Fix this to enqueue a proper error instead
-  ErrorOrMemBufPtr newBufOrErr(
-      std::make_error_code(std::errc::no_such_file_or_directory));
 
   // If the file didn't exist directly, see if it's in an include path.
-  for (unsigned i = 0, e = loadPaths.size(); i != e && !newBufOrErr; ++i) {
+  for (unsigned i = 0, e = loadPaths.size(); i != e; ++i) {
 
     // TODO: Ugh, Udgly, fix this using llvm::sys::path functions
     importedFile = loadPaths[i] + llvm::sys::path::get_separator().data() +
                    path + "." + DEFAULT_SUFFIX;
 
     SMGR_LOG("Try to load the ns from: " + importedFile);
-    newBufOrErr = llvm::MemoryBuffer::getFile(importedFile);
+    auto newBufOrErr = llvm::MemoryBuffer::getFile(importedFile);
+
+    if (auto err = newBufOrErr.getError()) {
+      llvm::consumeError(llvm::errorCodeToError(err));
+      continue;
     }
 
-  return newBufOrErr;
+    return std::move(*newBufOrErr);
+  }
+
+  return nullptr;
 };
 
 MaybeNS SourceMgr::readNamespace(SereneContext &ctx, std::string name,
@@ -83,16 +87,16 @@ MaybeNS SourceMgr::readNamespace(SereneContext &ctx, std::string name,
   std::string importedFile;
 
   SMGR_LOG("Attempt to load namespace: " + name);
-  ErrorOrMemBufPtr newBufOrErr(findFileInLoadPath(name, importedFile));
+  MemBufPtr newBufOrErr(findFileInLoadPath(name, importedFile));
 
-  if (!newBufOrErr) {
+  if (newBufOrErr == nullptr) {
     auto msg = llvm::formatv("Couldn't find namespace '{0}'", name);
     auto err = errors::makeErrorTree(importLoc, errors::NSLoadError,
                                      llvm::StringRef(msg));
     return MaybeNS::error(err);
   }
 
-  auto bufferId = AddNewSourceBuffer(std::move(*newBufOrErr), importLoc);
+  auto bufferId = AddNewSourceBuffer(std::move(newBufOrErr), importLoc);
 
   UNUSED(nsTable.insert_or_assign(name, bufferId));
 

src/serenec/serenec.cpp

@@ -249,11 +249,11 @@ int dumpAsObject(Namespace &ns) {
     //     failCommand.front().second->Print(llvm::errs(), "\n", false);
     //   }
     // }
-
+  }
   return 0;
-  };
+};
 
-  int main(int argc, char *argv[]) {
+int main(int argc, char *argv[]) {
   initCompiler();
   registerSereneCLOptions();
 
@@ -267,8 +267,7 @@ int dumpAsObject(Namespace &ns) {
   // TODO: handle the outputDir by not forcing it. it should be
   //       default to the current working dir
   if (outputDir == "-") {
-      llvm::errs()
-          << "Error: The build directory is not set. Did you forget to "
+    llvm::errs() << "Error: The build directory is not set. Did you forget to "
                     "use '-b'?\n";
     return 1;
   }
@@ -392,4 +391,4 @@ int dumpAsObject(Namespace &ns) {
   }
 
   return 0;
-  }
+}