Hook up symbol files to the Windows GN build.

Previously the GN Windows build specified the symbol file $pdbfile but this variable was never defined, so the command like would just say "/Fd" and the default one would be used.

This patch defines some per-target variables in the ninja file for the toolchain to use. The Windows toolchain uses these to construct C- and C++-specific pdb files (the MS tools can't share between these two) for the current target.

BUG=
R=scottmg@chromium.org

Review URL: https://codereview.chromium.org/406453002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@284137 0039d316-1c4b-4281-b951-d872f2087c98

build/toolchain/win/BUILD.gn

@@ -22,6 +22,11 @@ exec_script("setup_toolchain.py",
 stamp_command = "$python_path gyp-win-tool stamp \$out"
 copy_command = "$python_path gyp-win-tool recursive-mirror \$in \$out"
 
+# MSVC can't share PDB files between compilers compiling C and C++ files, so
+# we construct different names for each type.
+c_pdb_suffix = " /Fd\${target_out_dir}/\${target_name}_c.pdb"
+cc_pdb_suffix = " /Fd\${target_out_dir}/\${target_name}_cc.pdb"
+
 # 32-bit toolchain -------------------------------------------------------------
 
 toolchain("32") {
@@ -29,16 +34,16 @@ toolchain("32") {
   lib_prefix = ""
   lib_dir_prefix="/LIBPATH:"
 
-  cc_command = "ninja -t msvc -e environment.x86 -- cl.exe /nologo /showIncludes /FC @\$out.rsp /c \$in /Fo\$out /Fd\$pdbname"
+  cc_command = "ninja -t msvc -e environment.x86 -- cl.exe /nologo /showIncludes /FC @\$out.rsp /c \$in /Fo\$out"
   tool("cc") {
-    command = cc_command
+    command = cc_command + c_pdb_suffix
     description = "CC \$out"
     rspfile = "\$out.rsp"
     rspfile_content = "\$defines \$includes \$cflags \$cflags_c"
     depsformat = "msvc"
   }
   tool("cxx") {
-    command = cc_command  # Same as above
+    command = cc_command + cc_pdb_suffix
     description = "CXX \$out"
     rspfile = "\$out.rsp"
     rspfile_content = "\$defines \$includes \$cflags \$cflags_cc"
@@ -88,16 +93,16 @@ toolchain("64") {
   lib_prefix = ""
   lib_dir_prefix="/LIBPATH:"
 
-  cc_command = "ninja -t msvc -e environment.x64 -- cl.exe /nologo /showIncludes /FC @\$out.rsp /c \$in /Fo\$out /Fd\$pdbname"
+  cc_command = "ninja -t msvc -e environment.x64 -- cl.exe /nologo /showIncludes /FC @\$out.rsp /c \$in /Fo\$out"
   tool("cc") {
-    command = cc_command
+    command = cc_command + c_pdb_suffix
     description = "CC \$out"
     rspfile = "\$out.rsp"
     rspfile_content = "\$defines \$includes \$cflags \$cflags_c"
     depsformat = "msvc"
   }
   tool("cxx") {
-    command = cc_command  # Same as above
+    command = cc_command + cc_pdb_suffix
     description = "CXX \$out"
     rspfile = "\$out.rsp"
     rspfile_content = "\$defines \$includes \$cflags \$cflags_cc"

tools/gn/function_toolchain.cc

@@ -160,13 +160,14 @@ const char kTool_Help[] =
     "  given file type. See also \"gn help toolchain\".\n"
     "\n"
     "Command types:\n"
+    "\n"
     "  The following values may be passed to the tool() function for the type\n"
     "  of the command:\n"
     "\n"
     "  \"cc\", \"cxx\", \"objc\", \"objcxx\", \"asm\", \"alink\", \"solink\",\n"
     "  \"link\", \"stamp\", \"copy\"\n"
     "\n"
-    "Command flags:\n"
+    "Command flags\n"
     "\n"
     "  These variables may be specified in the { } block after the tool call.\n"
     "  They are passed directly to Ninja. See the ninja documentation for how\n"
@@ -188,7 +189,37 @@ const char kTool_Help[] =
     "  added to the link like with a \"-framework\" switch and the lib prefix\n"
     "  will be ignored.\n"
     "\n"
-    "Example:\n"
+    "Ninja variables available to tool invocations\n"
+    "\n"
+    "  When writing tool commands, you use the various built-in Ninja\n"
+    "  variables like \"$in\" and \"$out\" (note that the $ must be escaped\n"
+    "  for it to be passed to Ninja, so write \"\\$in\" in the command\n"
+    "  string).\n"
+    "\n"
+    "  GN defines the following variables for binary targets to access the\n"
+    "  various computed information needed for compiling:\n"
+    "\n"
+    "    - Compiler flags: \"cflags\", \"cflags_c\", \"cflags_cc\",\n"
+    "          \"cflags_objc\", \"cflags_objcc\"\n"
+    "\n"
+    "    - Linker flags: \"ldflags\", \"libs\"\n"
+    "\n"
+    "  GN sets these other variables with target information that can be\n"
+    "  used for computing names for supplimetary files:\n"
+    "\n"
+    "    - \"target_name\": The name of the current target with no\n"
+    "      path information. For example \"mylib\".\n"
+    "\n"
+    "    - \"target_out_dir\": The value of \"target_out_dir\" from the BUILD\n"
+    "      file for this target (see \"gn help target_out_dir\"), relative\n"
+    "      to the root build directory with no trailing slash.\n"
+    "\n"
+    "    - \"root_out_dir\": The value of \"root_out_dir\" from the BUILD\n"
+    "      file for this target (see \"gn help root_out_dir\"), relative\n"
+    "      to the root build directory with no trailing slash.\n"
+    "\n"
+    "Example\n"
+    "\n"
     "  toolchain(\"my_toolchain\") {\n"
     "    # Put these at the top to apply to all tools below.\n"
     "    lib_prefix = \"-l\"\n"

tools/gn/ninja_binary_target_writer.cc

@@ -125,7 +125,16 @@ void NinjaBinaryTargetWriter::WriteCompilerVars() {
 
 #undef WRITE_FLAGS
 
+  // Write some variables about the target for the toolchain definition to use.
+  out_ << "target_name = " << target_->label().name() << std::endl;
+  out_ << "target_out_dir = ";
+  path_output_.WriteDir(out_, helper_.GetTargetOutputDir(target_),
+                        PathOutput::DIR_NO_LAST_SLASH);
   out_ << std::endl;
+  out_ << "root_out_dir = ";
+  path_output_.WriteDir(out_, target_->settings()->toolchain_output_subdir(),
+                        PathOutput::DIR_NO_LAST_SLASH);
+  out_ << std::endl << std::endl;
 }
 
 void NinjaBinaryTargetWriter::WriteSources(

tools/gn/path_output.cc

@@ -75,6 +75,32 @@ void PathOutput::WriteFile(std::ostream& out, const OutputFile& file) const {
   EscapeStringToStream(out, file.value(), options_);
 }
 
+void PathOutput::WriteDir(std::ostream& out,
+                          const OutputFile& file,
+                          DirSlashEnding slash_ending) const {
+  DCHECK(file.value().empty() ||
+         file.value()[file.value().size() - 1] == '/');
+
+  switch (slash_ending) {
+    case DIR_INCLUDE_LAST_SLASH:
+      EscapeStringToStream(out, file.value(), options_);
+      break;
+    case DIR_NO_LAST_SLASH:
+      if (!file.value().empty() &&
+          file.value()[file.value().size() - 1] == '/') {
+        // Trim trailing slash.
+        EscapeStringToStream(
+            out,
+            base::StringPiece(file.value().data(), file.value().size() - 1),
+            options_);
+      } else {
+        // Doesn't end with a slash, write the whole thing.
+        EscapeStringToStream(out, file.value(), options_);
+      }
+      break;
+  }
+}
+
 void PathOutput::WriteFile(std::ostream& out,
                            const base::FilePath& file) const {
   // Assume native file paths are always absolute.

tools/gn/path_output.h

@@ -49,10 +49,16 @@ class PathOutput {
   void WriteFile(std::ostream& out, const SourceFile& file) const;
   void WriteFile(std::ostream& out, const OutputFile& file) const;
   void WriteFile(std::ostream& out, const base::FilePath& file) const;
+
+  // This variant assumes the dir ends in a trailing slash or is empty.
   void WriteDir(std::ostream& out,
                 const SourceDir& dir,
                 DirSlashEnding slash_ending) const;
 
+  void WriteDir(std::ostream& out,
+                const OutputFile& file,
+                DirSlashEnding slash_ending) const;
+
   // Backend for WriteFile and WriteDir. This appends the given file or
   // directory string to the file.
   void WritePathStr(std::ostream& out, const base::StringPiece& str) const;

tools/gn/path_output_unittest.cc

@@ -5,6 +5,7 @@
 #include <sstream>
 
 #include "testing/gtest/include/gtest/gtest.h"
+#include "tools/gn/output_file.h"
 #include "tools/gn/path_output.h"
 #include "tools/gn/source_dir.h"
 #include "tools/gn/source_file.h"
@@ -213,8 +214,6 @@ TEST(PathOutput, WriteDir) {
     // Output inside current dir.
     {
       std::ostringstream out;
-
-
       writer.WriteDir(out, SourceDir("//out/Debug/"),
                       PathOutput::DIR_INCLUDE_LAST_SLASH);
       EXPECT_EQ("./", out.str());
@@ -237,6 +236,26 @@ TEST(PathOutput, WriteDir) {
                       PathOutput::DIR_NO_LAST_SLASH);
       EXPECT_EQ("foo", out.str());
     }
+
+    // WriteDir using an OutputFile.
+    {
+      std::ostringstream out;
+      writer.WriteDir(out, OutputFile("foo/"),
+                      PathOutput::DIR_INCLUDE_LAST_SLASH);
+      EXPECT_EQ("foo/", out.str());
+    }
+    {
+      std::ostringstream out;
+      writer.WriteDir(out, OutputFile("foo/"),
+                      PathOutput::DIR_NO_LAST_SLASH);
+      EXPECT_EQ("foo", out.str());
+    }
+    {
+      std::ostringstream out;
+      writer.WriteDir(out, OutputFile(),
+                      PathOutput::DIR_INCLUDE_LAST_SLASH);
+      EXPECT_EQ("", out.str());
+    }
   }
   {
     // Empty build dir writer.

tools/gn/variables.cc

@@ -216,7 +216,7 @@ const char kTargetOutDir[] = "target_out_dir";
 const char kTargetOutDir_HelpShort[] =
     "target_out_dir: [string] Directory for target output files.";
 const char kTargetOutDir_Help[] =
-    "target_out_dir: [string] Directory for target output files."
+    "target_out_dir: [string] Directory for target output files.\n"
     "\n"
     "  Absolute path to the target's generated file directory. If your\n"
     "  current target is in \"//tools/doom_melon\" then this value might be\n"