Generate VS projects also for target dependencies.

tools/gn/docs/reference.md

 # GN Reference
 
 *This page is automatically generated from* `gn help --markdown all`.
 
 ## **\--args**: Specifies build arguments overrides.
 
 ```
   See "gn help buildargs" for an overview of how build arguments work.
 
   Most operations take a build directory. The build arguments are taken
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       "vs" - Visual Studio project/solution files.
              (default Visual Studio version: 2015)
       "vs2013" - Visual Studio 2013 project/solution files.
       "vs2015" - Visual Studio 2015 project/solution files.
       "xcode" - Xcode workspace/solution files.
       "qtcreator" - QtCreator project files.
 
   --filters=<path_prefixes>
       Semicolon-separated list of label patterns used to limit the set
       of generated projects (see "gn help label_pattern"). Only
-      matching targets will be included to the solution. Only used for
-      Visual Studio and Xcode.
+      matching targets and their dependencies will be included in the
+      solution. Only used for Visual Studio and Xcode.
 
 ```
 
 ### **Visual Studio Flags**
 
 ```
   --sln=<file_name>
       Override default sln file name ("all"). Solution file is written
       to the root build directory.
 
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       Lists all variants of the target //base:base (it may be referenced
       in multiple toolchains).
 
 
 ```
 ## **gn path <out_dir> <target_one> <target_two>**
 
 ```
   Finds paths of dependencies between two targets. Each unique path
   will be printed in one group, and groups will be separate by newlines.
-  The two targets can appear in either order: paths will be found going
-  in either direction.
+  The two targets can appear in either order (paths will be found going
+  in either direction).
 
   By default, a single path will be printed. If there is a path with
   only public dependencies, the shortest public path will be printed.
   Otherwise, the shortest path using either public or private
   dependencies will be printed. If --with-data is specified, data deps
   will also be considered. If there are multiple shortest paths, an
   arbitrary one will be selected.
 
 ```
 
+### **Interesting paths**
+
+```
+  In a large project, there can be 100's of millions of unique paths
+  between a very high level and a common low-level target. To make the
+  output more useful (and terminate in a reasonable time), GN will not
+  revisit sub-paths previously known to lead to the target.
+
+```
+
 ### **Options**
 
 ```
   --all
-     Prints all paths found rather than just the first one. Public paths
-     will be printed first in order of increasing length, followed by
-     non-public paths in order of increasing length.
+     Prints all "interesting" paths found rather than just the first
+     one. Public paths will be printed first in order of increasing
+     length, followed by non-public paths in order of increasing length.
 
   --public
      Considers only public paths. Can't be used with --with-data.
 
   --with-data
      Additionally follows data deps. Without this flag, only public and
      private linked deps will be followed. Can't be used with --public.
 
 ```
 
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     args = [ "-o", rebase_path(root_out_dir, root_build_dir) ]
   }
 
 
 ```
 ## **target_cpu**: The desired cpu architecture for the build.
 
 ```
   This value should be used to indicate the desired architecture for
   the primary objects of the build. It will match the cpu architecture
-  of the default toolchain.
+  of the default toolchain, but not necessarily the current toolchain.
 
   In many cases, this is the same as "host_cpu", but in the case
-  of cross-compiles, this can be set to something different. This 
-  value is different from "current_cpu" in that it can be referenced
-  from inside any toolchain. This value can also be ignored if it is
-  not needed or meaningful for a project.
+  of cross-compiles, this can be set to something different. This
+  value is different from "current_cpu" in that it does not change
+  based on the current toolchain. When writing rules, "current_cpu"
+  should be used rather than "target_cpu" most of the time.
 
   This value is not used internally by GN for any purpose, so it
   may be set to whatever value is needed for the build.
   GN defaults this value to the empty string ("") and the
   configuration files should set it to an appropriate value
   (e.g., setting it to the value of "host_cpu") if it is not
   overridden on the command line or in the args.gn file.
 
   Where practical, use one of the following list of common values:
 
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   (possibly on the static library target itself).
 
 ```
 
 ### **Multiple outputs**
 
 ```
   When a tool produces more than one output, only the first output
   is considered. For example, a shared library target may produce a
   .dll and a .lib file on Windows. Only the .dll file will be considered
-  a runtime dependency. This applies only to linker tools, scripts and
-  copy steps with multiple outputs will also get all outputs listed.
+  a runtime dependency. This applies only to linker tools. Scripts and
+  copy steps with multiple outputs will get all outputs listed.
 
 
 ```
 ## **How Source Expansion Works**
 
 ```
   Source expansion is used for the action_foreach and copy target types
   to map source file names to output file names or arguments.
 
   To perform source expansion in the outputs, GN maps every entry in the
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 **  \--root**: Explicitly specify source root.
 **  \--runtime-deps-list-file**: Save runtime dependencies for targets in file.
 **  \--script-executable**: Set the executable used to execute scripts.
 **  \--threads**: Specify number of worker threads.
 **  \--time**: Outputs a summary of how long everything took.
 **  \--tracelog**: Writes a Chrome-compatible trace log to the given file.
 **  -v**: Verbose logging.
 **  \--version**: Prints the GN version number and exits.
 
 ```