GN: Add logging for the location of an invocation.

I was working on the Windows build and having problems finding why a file was loaded that shouldn't have been. This adds the source of the invocation to the verbose logging so you can find this information.

I removed an assert which caused a debug assertion for random punctuation and isn't harmful (a real error will be reported).

I moved the location-to-string conversion code into the location class so I can share it for my new logging command, and moved a bunch of other logging functions to the new .cc file.

BUG=288991
R=scottmg@chromium.org

Review URL: https://codereview.chromium.org/23532076

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@223469 0039d316-1c4b-4281-b951-d872f2087c98

7 files changed, 99 insertions, 52 deletions

diff --git a/tools/gn/BUILD.gn b/tools/gn/BUILD.gn
index a887696..c34e977 100644
--- a/tools/gn/BUILD.gn
+++ b/tools/gn/BUILD.gn
@@ -61,6 +61,7 @@ static_library("gn_lib") {
     "item_tree.h",
     "label.cc",
     "label.h",
+    "location.cc",
     "location.h",
     "ninja_binary_target_writer.cc",
     "ninja_binary_target_writer.h",
diff --git a/tools/gn/err.cc b/tools/gn/err.cc
index 326f5b3..5db3c42 100644
--- a/tools/gn/err.cc
+++ b/tools/gn/err.cc
@@ -161,21 +161,13 @@ void Err::InternalPrintToStdout(bool is_sub_err) const {
 
   // File name and location.
   const InputFile* input_file = location_.file();
-  std::string loc_str;
-  if (input_file) {
-    std::string name;
-    if (input_file->friendly_name().empty())
-      name = input_file->name().value();
-    else
-      name = input_file->friendly_name();
-
+  std::string loc_str = location_.Describe(true);
+  if (!loc_str.empty()) {
     if (is_sub_err)
-      loc_str = "See ";
+      loc_str.insert(0, "See ");
     else
-      loc_str = "at ";
-    loc_str += name + ": " +
-        base::IntToString(location_.line_number()) + ":" +
-        base::IntToString(location_.char_offset()) + ": ";
+      loc_str.insert(0, "at ");
+    loc_str.append(": ");
   }
   OutputString(loc_str + message_ + "\n");
 
diff --git a/tools/gn/gn.gyp b/tools/gn/gn.gyp
index 65b525b..82fa7f7 100644
--- a/tools/gn/gn.gyp
+++ b/tools/gn/gn.gyp
@@ -71,6 +71,7 @@
         'item_tree.h',
         'label.cc',
         'label.h',
+        'location.cc',
         'location.h',
         'ninja_binary_target_writer.cc',
         'ninja_binary_target_writer.h',
diff --git a/tools/gn/input_file_manager.cc b/tools/gn/input_file_manager.cc
index 7a009e46..1b55ea4 100644
--- a/tools/gn/input_file_manager.cc
+++ b/tools/gn/input_file_manager.cc
@@ -194,8 +194,12 @@ bool InputFileManager::LoadFile(const LocationRange& origin,
                                 Err* err) {
   // Do all of this stuff outside the lock. We should not give out file
   // pointers until the read is complete.
-  if (g_scheduler->verbose_logging())
-    g_scheduler->Log("Loading", name.value());
+  if (g_scheduler->verbose_logging()) {
+    std::string logmsg = name.value();
+    if (origin.begin().file())
+      logmsg += " (referenced from " + origin.begin().Describe(false) + ")";
+    g_scheduler->Log("Loading", logmsg);
+  }
 
   // Read.
   base::FilePath primary_path = build_settings->GetFullPath(name);
diff --git a/tools/gn/location.cc b/tools/gn/location.cc
new file mode 100644
index 0000000..61f22b5
--- /dev/null
+++ b/tools/gn/location.cc
@@ -0,0 +1,73 @@
+// 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/location.h"
+
+#include "base/logging.h"
+#include "base/strings/string_number_conversions.h"
+#include "tools/gn/input_file.h"
+
+Location::Location()
+    : file_(NULL),
+      line_number_(-1),
+      char_offset_(-1) {
+}
+
+Location::Location(const InputFile* file, int line_number, int char_offset)
+    : file_(file),
+      line_number_(line_number),
+      char_offset_(char_offset) {
+}
+
+bool Location::operator==(const Location& other) const {
+  return other.file_ == file_ &&
+         other.line_number_ == line_number_ &&
+         other.char_offset_ == char_offset_;
+}
+
+bool Location::operator!=(const Location& other) const {
+  return !operator==(other);
+}
+
+bool Location::operator<(const Location& other) const {
+  DCHECK(file_ == other.file_);
+  if (line_number_ != other.line_number_)
+    return line_number_ < other.line_number_;
+  return char_offset_ < other.char_offset_;
+}
+
+std::string Location::Describe(bool include_char_offset) const {
+  if (!file_)
+    return std::string();
+
+  std::string ret;
+  if (file_->friendly_name().empty())
+    ret = file_->name().value();
+  else
+    ret = file_->friendly_name();
+
+  ret += ":";
+  ret += base::IntToString(line_number_);
+  if (include_char_offset) {
+    ret += ":";
+    ret += base::IntToString(char_offset_);
+  }
+  return ret;
+}
+
+LocationRange::LocationRange() {
+}
+
+LocationRange::LocationRange(const Location& begin, const Location& end)
+    : begin_(begin),
+      end_(end) {
+  DCHECK(begin_.file() == end_.file());
+}
+
+LocationRange LocationRange::Union(const LocationRange& other) const {
+  DCHECK(begin_.file() == other.begin_.file());
+  return LocationRange(
+      begin_ < other.begin_ ? begin_ : other.begin_,
+      end_ < other.end_ ? other.end_ : end_);
+}
diff --git a/tools/gn/location.h b/tools/gn/location.h
index 2055125..aad3960 100644
--- a/tools/gn/location.h
+++ b/tools/gn/location.h
@@ -5,42 +5,28 @@
 #ifndef TOOLS_GN_LOCATION_H_
 #define TOOLS_GN_LOCATION_H_
 
-#include <algorithm>
-
-#include "base/logging.h"
+#include <string>
 
 class InputFile;
 
 // Represents a place in a source file. Used for error reporting.
 class Location {
  public:
-  Location()
-      : file_(NULL),
-        line_number_(-1),
-        char_offset_(-1) {
-  }
-  Location(const InputFile* file, int line_number, int char_offset)
-      : file_(file),
-        line_number_(line_number),
-        char_offset_(char_offset) {
-  }
+  Location();
+  Location(const InputFile* file, int line_number, int char_offset);
 
   const InputFile* file() const { return file_; }
   int line_number() const { return line_number_; }
   int char_offset() const { return char_offset_; }
 
-  bool operator==(const Location& other) const {
-    return other.file_ == file_ &&
-           other.line_number_ == line_number_ &&
-           other.char_offset_ == char_offset_;
-  }
+  bool operator==(const Location& other) const;
+  bool operator!=(const Location& other) const;
+  bool operator<(const Location& other) const;
 
-  bool operator<(const Location& other) const {
-    DCHECK(file_ == other.file_);
-    if (line_number_ != other.line_number_)
-      return line_number_ < other.line_number_;
-    return char_offset_ < other.char_offset_;
-  }
+  // Returns a string with the file, line, and (optionally) the character
+  // offset for this location. If this location is null, returns an empty
+  // string.
+  std::string Describe(bool include_char_offset) const;
 
  private:
   const InputFile* file_;  // Null when unset.
@@ -52,22 +38,13 @@ class Location {
 // The end is exclusive i.e. [begin, end)
 class LocationRange {
  public:
-  LocationRange() {}
-  LocationRange(const Location& begin, const Location& end)
-      : begin_(begin),
-        end_(end) {
-    DCHECK(begin_.file() == end_.file());
-  }
+  LocationRange();
+  LocationRange(const Location& begin, const Location& end);
 
   const Location& begin() const { return begin_; }
   const Location& end() const { return end_; }
 
-  LocationRange Union(const LocationRange& other) const {
-    DCHECK(begin_.file() == other.begin_.file());
-    return LocationRange(
-        begin_ < other.begin_ ? begin_ : other.begin_,
-        end_ < other.end_ ? other.end_ : end_);
-  }
+  LocationRange Union(const LocationRange& other) const;
 
  private:
   Location begin_;
diff --git a/tools/gn/tokenizer.cc b/tools/gn/tokenizer.cc
index 6771927..8acabdb 100644
--- a/tools/gn/tokenizer.cc
+++ b/tools/gn/tokenizer.cc
@@ -64,7 +64,6 @@ Token::Type GetSpecificOperatorType(base::StringPiece value) {
     return Token::BOOLEAN_OR;
   if (value == "!")
     return Token::BANG;
-  NOTREACHED();
   return Token::INVALID;
 }