First cut at a tool to set status

AlisdairM · AlisdairM · commit 3c28f5a8b781 · 2014-02-20T07:31:43.000-05:00
After hacking around failing to make std::regex solve the parse
problem, resorted to an old-school search-and-replace algorithm.

Combined with the previous list-issues filtering program, this
should make it simple to change the state of issues en-masse
while preparing work pre- and post-meetings.
diff --git a/src/set_status.cpp b/src/set_status.cpp
@@ -0,0 +1,191 @@
+// This program reads all the issues in the issues directory passed as the first command line argument.
+// If all documents are successfully parsed, it will generate the standard LWG Issues List documents
+// for an ISO SC22 WG21 mailing.
+
+// Based on code originally donated by Howard Hinnant
+// Since modified by Alisdair Meredith
+
+// Note that this program requires a reasonably conformant C++11 compiler, supporting at least:
+//    auto
+//    lambda expressions
+//    brace-initialization
+//    range-based for loops
+//    raw string literals
+//    constexpr
+//    new function syntax (late specified return type)
+//    noexcept
+//    new type-alias syntax (using my_name = type)
+
+// Likewise, the following C++11 library facilities are used:
+//    to_string
+//    consistent overloading of 'char const *' and 'std::string'
+
+// Following the planned removal of (deprecated) bool post-increment operator, we now
+// require the following C++14 library facilities:
+//    exchange
+
+// The following C++14 features are being considered for future cleanup/refactoring:
+//    polymorphic lambdas
+//    string UDLs
+
+// The following TS features are also desirable
+//    filesystem
+//    string_view
+
+// Its coding style assumes a standard library optimized with move-semantics
+// The only known compiler to support all of this today is the experimental gcc trunk (4.6)
+
+// TODO
+// .  Better handling of TR "sections", and grouping of issues in "Clause X"
+// .  Sort the Revision comments in the same order as the 'Status' reports, rather than alphabetically
+// .  Lots of tidy and cleanup after merging the revision-generating tool
+// .  Refactor more common text
+// .  Split 'format' function and usage to that the issues vector can pass by const-ref in the common cases
+// .  Document the purpose amd contract on each function
+// Waiting on external fix for preserving file-dates
+// .  sort-by-last-modified-date should offer some filter or separation to see only the issues modified since the last meeting
+
+// Missing standard facilities that we work around
+// . Date
+// . Filesystem navigation
+
+// Missing standard library facilities that would probably not change this program
+// . XML parser
+
+// standard headers
+#include <fstream>
+#include <functional>
+#include <iostream>
+#include <iterator>
+#include <memory>
+#include <sstream>
+#include <stdexcept>
+#include <string>
+
+// platform headers - requires a Posix compatible platform
+// The hope is to replace all of this with the filesystem TS
+#include <dirent.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+// solution specific headers
+#include "issues.h"
+#include "sections.h"
+
+
+#if 0
+// Revisit this after AJM works out linker issues on his Mac
+#if 1
+// workaround until <experimental/filesystem> is widely available:
+##include <boost/filesystem.hpp>
+namespace std {
+namespace experimental {
+namespace filesystem {
+using namespace boost::filesystem;
+}
+}
+}
+#else
+#include <experimental/filesystem>
+#endif
+#endif
+
+struct bad_issue_file : std::runtime_error {
+   bad_issue_file(std::string const & filename, std::string const & error_message)
+      : runtime_error{"Error parsing issue file " + filename + ": " + error_message}
+      {
+   }
+};
+
+
+auto read_file_into_string(std::string const & filename) -> std::string {
+   // read a text file completely into memory, and return its contents as
+   // a 'string' for further manipulation.
+
+   std::ifstream infile{filename.c_str()};
+   if (!infile.is_open()) {
+      throw std::runtime_error{"Unable to open file " + filename};
+   }
+
+   std::istreambuf_iterator<char> first{infile}, last{};
+   return std::string {first, last};
+}
+
+// ============================================================================================================
+
+void check_is_directory(std::string const & directory) {
+   struct stat sb;
+   if (stat(directory.c_str(), &sb) != 0 or !S_ISDIR(sb.st_mode)) {
+      throw std::runtime_error(directory + " is not an existing directory");
+   }
+}
+
+int main(int argc, char const* argv[]) {
+   try {
+      bool trace_on{false};  // Will pick this up from the command line later
+
+      if (argc != 3) {
+         std::cerr << "Must specify exactly one issue, followed by its new status\n";
+         return -2;
+      }
+
+      int const issue_number = atoi(argv[1]);
+
+      std::string const new_status{argv[2]};
+  
+      std::string path;
+      char cwd[1024];
+      if (getcwd(cwd, sizeof(cwd)) == 0) {
+         std::cerr << "unable to getcwd\n";
+         return -3;
+      }
+      path = cwd;
+      if (path.back() != '/') { path.push_back('/'); }
+
+      check_is_directory(path);
+
+      std::string issue_file = std::string{"issue"} + argv[1] + ".xml";
+      auto const filename = path + "xml/" + issue_file;
+
+      auto issue_data = read_file_into_string(filename);
+
+      // find 'status' tag and replace it
+      auto k = issue_data.find("<issue num=\"");
+      if (k == std::string::npos) {
+         throw bad_issue_file{filename, "Unable to find issue number"};
+      }
+      k += sizeof("<issue num=\"") - 1;
+      auto l = issue_data.find('"', k);
+      if (l == std::string::npos) {
+         throw bad_issue_file{filename, "Corrupt issue number attribute"};
+      }
+      if (std::stod(issue_data.substr(k, k-l)) != issue_number) {
+         throw bad_issue_file{filename, "Issue number does not match filename"};
+      }
+
+      k = issue_data.find("status=\"");
+      if (k == std::string::npos) {
+         throw bad_issue_file{filename, "Unable to find issue status"};
+      }
+      k += sizeof("status=\"") - 1;
+      l = issue_data.find('"', k);
+      if (l == std::string::npos) {
+         throw bad_issue_file{filename, "Corrupt status attribute"};
+      }
+      issue_data.replace(k, l-k, new_status);
+
+      std::ofstream out_file{filename};
+      if (!out_file.is_open()) {
+         throw std::runtime_error{"Unable to re-open file " + filename};
+      }
+
+      out_file << issue_data;
+   }
+   catch(std::exception const & ex) {
+      std::cout << ex.what() << std::endl;
+      return -1;
+   }
+}
+
+
