refactor file reading

4 files changed, 29 insertions, 17 deletions

diff --git a/ninja.cc b/ninja.cc
index 5581bf9..7d9e25b 100644
--- a/ninja.cc
+++ b/ninja.cc
@@ -19,6 +19,12 @@ void usage() {
           );
 }
 
+struct RealFileReader : public ManifestParser::FileReader {
+  bool ReadFile(const string& path, string* content, string* err) {
+    return ::ReadFile(path, content, err) == 0;
+  }
+};
+
 int main(int argc, char** argv) {
   const char* input_file = "build.ninja";
 
@@ -41,7 +47,8 @@ int main(int argc, char** argv) {
   }
 
   State state;
-  ManifestParser parser(&state);
+  RealFileReader file_reader;
+  ManifestParser parser(&state, &file_reader);
   string err;
   if (!parser.Load(input_file, &err)) {
     fprintf(stderr, "error loading '%s': %s\n", input_file, err.c_str());
diff --git a/ninja.h b/ninja.h
index 66aa807..4fd790f 100644
--- a/ninja.h
+++ b/ninja.h
@@ -11,6 +11,8 @@ using namespace std;
 
 #include "eval_env.h"
 
+int ReadFile(const string& path, string* contents, string* err);
+
 struct DiskInterface {
   // stat() a file, returning the mtime, or 0 if missing and -1 on other errors.
   virtual int Stat(const string& path) = 0;
diff --git a/ninja_jumble.cc b/ninja_jumble.cc
index e9da25e..fa0023f 100644
--- a/ninja_jumble.cc
+++ b/ninja_jumble.cc
@@ -8,26 +8,26 @@
 #include <stdio.h>
 #include <string.h>
 
-string ReadFile(const string& path, string* err) {
+int ReadFile(const string& path, string* contents, string* err) {
   FILE* f = fopen(path.c_str(), "r");
   if (!f) {
-    if (errno != ENOENT)
-      err->assign(strerror(errno));
-    return "";
+    err->assign(strerror(errno));
+    return -errno;
   }
 
-  string text;
   char buf[64 << 10];
   size_t len;
   while ((len = fread(buf, 1, sizeof(buf), f)) > 0) {
-    text.append(buf, len);
+    contents->append(buf, len);
   }
   if (ferror(f)) {
-    err->assign(strerror(errno));
-    text = "";
+    err->assign(strerror(errno));  // XXX errno?
+    contents->clear();
+    fclose(f);
+    return -errno;
   }
   fclose(f);
-  return text;
+  return 0;
 }
 
 int RealDiskInterface::Stat(const string& path) {
@@ -70,7 +70,13 @@ bool DiskInterface::MakeDirs(const string& path) {
 }
 
 string RealDiskInterface::ReadFile(const string& path, string* err) {
-  return ::ReadFile(path, err);
+  string contents;
+  int ret = ::ReadFile(path, &contents, err);
+  if (ret == -ENOENT) {
+    // Swallow ENOENT.
+    err->clear();
+  }
+  return contents;
 }
 
 bool RealDiskInterface::MakeDir(const string& path) {
diff --git a/parsers.cc b/parsers.cc
index 497b0dc..d9b236c 100644
--- a/parsers.cc
+++ b/parsers.cc
@@ -208,14 +208,11 @@ bool MakefileParser::Parse(const string& input, string* err) {
   return true;
 }
 
-// XXX refactor.
-extern string ReadFile(const string& path, string* err);
-
 bool ManifestParser::Load(const string& filename, string* err) {
-  string input = ReadFile(filename, err);
-  if (!err->empty())
+  string contents;
+  if (!file_reader_->ReadFile(filename, &contents, err))
     return false;
-  return Parse(input, err);
+  return Parse(contents, err);
 }
 
 bool ManifestParser::Parse(const string& input, string* err) {