Limit the set of Visual Studio projects generated by GN

tools/gn/visual_studio_writer.cc

Index: tools/gn/visual_studio_writer.cc
diff --git a/tools/gn/visual_studio_writer.cc b/tools/gn/visual_studio_writer.cc
index 7748fbe19df46326e53f19630d2b23ee04b7f568..27fbb8d9d1fedd2e1162dccc53f64c7e8e771f88 100644
--- a/tools/gn/visual_studio_writer.cc
+++ b/tools/gn/visual_studio_writer.cc
@@ -11,6 +11,7 @@
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "tools/gn/builder.h"
@@ -214,6 +215,8 @@ VisualStudioWriter::~VisualStudioWriter() {
 bool VisualStudioWriter::RunAndWriteFiles(const BuildSettings* build_settings,
                                           Builder* builder,
                                           Version version,
+                                          const std::string& sln_name,
+                                          const std::string& dir_filters,
                                           Err* err) {
   std::vector<const Target*> targets = builder->GetAllResolvedTargets();
 
@@ -221,6 +224,27 @@ bool VisualStudioWriter::RunAndWriteFiles(const BuildSettings* build_settings,
   writer.projects_.reserve(targets.size());
   writer.folders_.reserve(targets.size());
 
+  std::vector<std::string> filters;
+  if (!dir_filters.empty()) {
+    filters = base::SplitString(dir_filters, ";", base::TRIM_WHITESPACE,
+                                base::SPLIT_WANT_NONEMPTY);
+
+    // Git Bash and other MSYS shells convert POSIX paths before passing them to
+    // native Windows programs. Leading slash is trimmed in paths like
+    // "//chrome" or "/c:/foo" making them "/chrome" and "c:/foo". Convert such
+    // paths back to GN format so filters can be compared to other GN paths.
+    // See: http://www.mingw.org/wiki/Posix_path_conversion
+    for (std::string& filter : filters) {
+      if (filter.size() > 1 &&
+          (filter[0] == '/' &&

[brettw, 2016/02/24 22:11:26]

This seems complicated and isn't something we do anywhere else. My idea is to do
this the same way we handle the build dirs (which allow you to specify
"//foo/bar" GN paths if you want): it will also resolve paths relative to the
current directory. You can see in Setup::FillBuildDir how this works.

Also, GN has this "LabelPattern" concept that is used on various places. I think
it would be advantageous to use this rather than rolling custom prefix matching
for this case, just for consistency. You can see in
ResolveTargetsFromCommandLinePattern in commands.cc an example.

Putting this together, I think your command line would look like
  --filters="//base/*;chrome/*"
(you can see you can omit the leading slashes assuming the current directory is
"src", which should solve the MSVS problem).

[Tomasz Moniuszko, 2016/02/25 13:28:20]

Many thanks for this hint. I was thinking about using string pattern from base
before. I missed label pattern and it seems it's exactly what we want. It works
perfectly.

+               !(filter[1] == '/' ||
+                 filter.size() > 2 && base::IsAsciiAlpha(filter[1]) &&
+                     filter[2] == ':') ||
+           base::IsAsciiAlpha(filter[0]) && filter[1] == ':'))
+        filter = '/' + filter;
+    }
+  }
+
   for (const Target* target : targets) {
     // Skip actions and groups.
     if (target->output_type() == Target::GROUP ||
@@ -230,6 +254,19 @@ bool VisualStudioWriter::RunAndWriteFiles(const BuildSettings* build_settings,
       continue;
     }
 
+    if (!filters.empty()) {
+      bool exclude = true;
+      for (const std::string& filter : filters) {
+        if (base::StartsWith(target->label().dir().value(), filter,
+                             base::CompareCase::SENSITIVE)) {
+          exclude = false;
+          break;
+        }
+      }
+      if (exclude)
+        continue;
+    }
+
     if (!writer.WriteProjectFiles(target, err))
       return false;
   }
@@ -247,7 +284,7 @@ bool VisualStudioWriter::RunAndWriteFiles(const BuildSettings* build_settings,
             });
 
   writer.ResolveSolutionFolders();
-  return writer.WriteSolutionFile(err);
+  return writer.WriteSolutionFile(sln_name, err);
 }
 
 bool VisualStudioWriter::WriteProjectFiles(const Target* target, Err* err) {
@@ -579,9 +616,11 @@ void VisualStudioWriter::WriteFiltersFileContents(std::ostream& out,
   project.Text(files_out.str());
 }
 
-bool VisualStudioWriter::WriteSolutionFile(Err* err) {
+bool VisualStudioWriter::WriteSolutionFile(const std::string& sln_name,
+                                           Err* err) {
+  std::string name = sln_name.empty() ? "all" : sln_name;
   SourceFile sln_file = build_settings_->build_dir().ResolveRelativeFile(
-      Value(nullptr, "all.sln"), err);
+      Value(nullptr, name + ".sln"), err);
   if (sln_file.is_null())
     return false;
 
@@ -694,7 +733,8 @@ void VisualStudioWriter::ResolveSolutionFolders() {
           else if (root_folder_path_[i] != folder_path[i])
             break;
         }
-        if (i == max_common_length)
+        if (i == max_common_length &&
+            (i == folder_path.size() || IsSlash(folder_path[i])))
           common_prefix_len = max_common_length;
         if (common_prefix_len < root_folder_path_.size()) {
           if (IsSlash(root_folder_path_[common_prefix_len - 1]))