Propagate GN public shared libraries through shared libraries

tools/gn/variables.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "tools/gn/variables.h"
 
 namespace variables {
 
 // Built-in variables ----------------------------------------------------------
 
@@ skipping 301 matching lines @@
     "  2. Those set on the \"configs\" on the target in order that the\n" \
     "     configs appear in the list.\n" \
     "  3. Those set on the \"all_dependent_configs\" on the target in order\n" \
     "     that the configs appear in the list.\n" \
     "  4. Those set on the \"public_configs\" on the target in order that\n" \
     "     those configs appear in the list.\n" \
     "  5. all_dependent_configs pulled from dependencies, in the order of\n" \
     "     the \"deps\" list. This is done recursively. If a config appears\n" \
     "     more than once, only the first occurance will be used.\n" \
     "  6. public_configs pulled from dependencies, in the order of the\n" \
-    "     \"deps\" list. If a dependency has " \
-              "\"forward_dependent_configs_from\",\n" \
-    "     or are public dependencies, they will be applied recursively.\n"
+    "     \"deps\" list. If a dependency is public, they will be applied\n" \
+    "     recursively.\n"
 
 const char kAllDependentConfigs[] = "all_dependent_configs";
 const char kAllDependentConfigs_HelpShort[] =
     "all_dependent_configs: [label list] Configs to be forced on dependents.";
 const char kAllDependentConfigs_Help[] =
     "all_dependent_configs: Configs to be forced on dependents.\n"
     "\n"
     "  A list of config labels.\n"
     "\n"
     "  All targets depending on this one, and recursively, all targets\n"
@@ skipping 270 matching lines @@
     "  that can't be linked (like actions and groups) listed in \"deps\" will\n"
     "  be treated as \"data_deps\". Likewise, if the current target isn't\n"
     "  linkable, then all deps will be treated as \"data_deps\".\n"
     "\n"
     "  These dependencies are private in that it does not grant dependent\n"
     "  targets the ability to include headers from the dependency, and direct\n"
     "  dependent configs are not forwarded.\n"
     "\n"
     "  See also \"public_deps\" and \"data_deps\".\n";
 
+// TODO(brettw) remove this, deprecated.
 const char kForwardDependentConfigsFrom[] = "forward_dependent_configs_from";
 const char kForwardDependentConfigsFrom_HelpShort[] =
-    "forward_dependent_configs_from: [label list] Forward dependent's configs.";
+    "forward_dependent_configs_from: [label list] DEPRECATED.";
 const char kForwardDependentConfigsFrom_Help[] =
     "forward_dependent_configs_from\n"
     "\n"
     "  A list of target labels.\n"
     "\n"
+    "  DEPRECATED. Use public_deps instead which will have the same effect.\n"
+    "\n"
     "  Exposes the public_configs from a private dependent target as\n"
     "  public_configs of the current one. Each label in this list\n"
     "  must also be in the deps.\n"
     "\n"
     "  Generally you should use public_deps instead of this variable to\n"
     "  express the concept of exposing a dependency as part of a target's\n"
     "  public API. We're considering removing this variable.\n"
     "\n"
     "Discussion\n"
     "\n"
@@ skipping 267 matching lines @@
 const char kPublicDeps[] = "public_deps";
 const char kPublicDeps_HelpShort[] =
     "public_deps: [label list] Declare public dependencies.";
 const char kPublicDeps_Help[] =
     "public_deps: Declare public dependencies.\n"
     "\n"
     "  Public dependencies are like private dependencies (\"deps\") but\n"
     "  additionally express that the current target exposes the listed deps\n"
     "  as part of its public API.\n"
     "\n"
-    "  This has two ramifications:\n"
+    "  This has several ramifications:\n"
     "\n"
     "    - public_configs that are part of the dependency are forwarded\n"
-    "      to direct dependents (this is the same as using\n"
-    "      forward_dependent_configs_from).\n"
+    "      to direct dependents.\n"
     "\n"
-    "    - public headers in the dependency are usable by dependents\n"
+    "    - Public headers in the dependency are usable by dependents\n"
     "      (includes do not require a direct dependency or visibility).\n"
     "\n"
+    "    - If the current target is a shared library, other shared libraries\n"
+    "      that it publicly depends on (directly or indirectly) are\n"
+    "      propagated up the dependency tree to dependents for linking.\n"
+    "\n"
     "Discussion\n"
     "\n"
     "  Say you have three targets: A -> B -> C. C's visibility may allow\n"
     "  B to depend on it but not A. Normally, this would prevent A from\n"
     "  including any headers from C, and C's public_configs would apply\n"
     "  only to B.\n"
     "\n"
     "  If B lists C in its public_deps instead of regular deps, A will now\n"
     "  inherit C's public_configs and the ability to include C's public\n"
     "  headers.\n"
@@ skipping 182 matching lines @@
     INSERT_VARIABLE(Sources)
     INSERT_VARIABLE(Testonly)
     INSERT_VARIABLE(Visibility)
   }
   return info_map;
 }
 
 #undef INSERT_VARIABLE
 
 }  // namespace variables