commit cb7fb90525997f131eeeaa7fafb19b52dfdb189c
author Daniel Hosseinian <dhoss@chromium.org> Wed Jan 15 19:10:38 2020 +0000
committer Chromium commit bot <commit-bot@chromium.org> Wed Jan 15 19:10:38 2020 +0000
tree f922b191aba4269b9d6c742f9735f047a2147767
parent de6595c714420b8d355c07649e70b6212c7e141e

Update pdfium_diff printf messages to use the current binary name

The usage messages were confusing as they used image_diff instead of
pdfium_diff as the binary name.

Changes some static consts to constexprs along the way.

Change-Id: I6df02eb6ad4e2ed057c058218b78e155d02b2d00
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/64870
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Daniel Hosseinian <dhoss@chromium.org>

testing/image_diff/image_diff.cpp

diff --git a/testing/image_diff/image_diff.cpp b/testing/image_diff/image_diff.cpp
index a102a36..c8f9caf 100644
--- a/testing/image_diff/image_diff.cpp
+++ b/testing/image_diff/image_diff.cpp
@@ -20,6 +20,7 @@
 
 #include "core/fxcrt/fx_memory.h"
 #include "testing/image_diff/image_diff_png.h"
+#include "testing/utils/path_service.h"
 #include "third_party/base/logging.h"
 #include "third_party/base/numerics/safe_conversions.h"
 
@@ -28,13 +29,13 @@
 #endif
 
 // Return codes used by this utility.
-static const int kStatusSame = 0;
-static const int kStatusDifferent = 1;
-static const int kStatusError = 2;
+constexpr int kStatusSame = 0;
+constexpr int kStatusDifferent = 1;
+constexpr int kStatusError = 2;
 
 // Color codes.
-static const uint32_t RGBA_RED = 0x000000ff;
-static const uint32_t RGBA_ALPHA = 0xff000000;
+constexpr uint32_t RGBA_RED = 0x000000ff;
+constexpr uint32_t RGBA_ALPHA = 0xff000000;
 
 class Image {
  public:
@@ -193,22 +194,24 @@
   return CalculateDifferencePercentage(actual, pixels_different);
 }
 
-void PrintHelp() {
+void PrintHelp(const std::string& binary_name) {
   fprintf(
       stderr,
       "Usage:\n"
-      "  image_diff OPTIONS <compare file> <reference file>\n"
+      "  %s OPTIONS <compare file> <reference file>\n"
       "    Compares two files on disk, returning 0 when they are the same;\n"
       "    Passing \"--histogram\" additionally calculates a diff of the\n"
       "    RGBA value histograms. (which is resistant to shifts in layout)\n"
       "    Passing \"--reverse-byte-order\" additionally assumes the compare\n"
       "    file has BGRA byte ordering.\n"
-      "  image_diff --diff <compare file> <reference file> <output file>\n"
+      "  %s --diff <compare file> <reference file> <output file>\n"
       "    Compares two files on disk, outputs an image that visualizes the\n"
-      "    difference to <output file>\n");
+      "    difference to <output file>\n",
+      binary_name.c_str(), binary_name.c_str());
 }
 
-int CompareImages(const std::string& file1,
+int CompareImages(const std::string& binary_name,
+                  const std::string& file1,
                   const std::string& file2,
                   bool compare_histograms,
                   bool reverse_byte_order) {
@@ -220,11 +223,13 @@
           ? actual_image.CreateFromFilenameWithReverseByteOrder(file1)
           : actual_image.CreateFromFilename(file1);
   if (!actual_load_result) {
-    fprintf(stderr, "image_diff: Unable to open file \"%s\"\n", file1.c_str());
+    fprintf(stderr, "%s: Unable to open file \"%s\"\n", binary_name.c_str(),
+            file1.c_str());
     return kStatusError;
   }
   if (!baseline_image.CreateFromFilename(file2)) {
-    fprintf(stderr, "image_diff: Unable to open file \"%s\"\n", file2.c_str());
+    fprintf(stderr, "%s: Unable to open file \"%s\"\n", binary_name.c_str(),
+            file2.c_str());
     return kStatusError;
   }
 
@@ -275,18 +280,21 @@
   return same;
 }
 
-int DiffImages(const std::string& file1,
+int DiffImages(const std::string& binary_name,
+               const std::string& file1,
                const std::string& file2,
                const std::string& out_file) {
   Image actual_image;
   Image baseline_image;
 
   if (!actual_image.CreateFromFilename(file1)) {
-    fprintf(stderr, "image_diff: Unable to open file \"%s\"\n", file1.c_str());
+    fprintf(stderr, "%s: Unable to open file \"%s\"\n", binary_name.c_str(),
+            file1.c_str());
     return kStatusError;
   }
   if (!baseline_image.CreateFromFilename(file2)) {
-    fprintf(stderr, "image_diff: Unable to open file \"%s\"\n", file2.c_str());
+    fprintf(stderr, "%s: Unable to open file \"%s\"\n", binary_name.c_str(),
+            file2.c_str());
     return kStatusError;
   }
 
@@ -322,6 +330,10 @@
   std::string filename2;
   std::string diff_filename;
 
+  // Strip the path from the first arg
+  const char* last_separator = strrchr(argv[0], PATH_SEPARATOR);
+  std::string binary_name = last_separator ? last_separator + 1 : argv[0];
+
   int i;
   for (i = 1; i < argc; ++i) {
     const char* arg = argv[i];
@@ -344,12 +356,13 @@
 
   if (produce_diff_image) {
     if (!diff_filename.empty()) {
-      return DiffImages(filename1, filename2, diff_filename);
+      return DiffImages(binary_name, filename1, filename2, diff_filename);
     }
   } else if (!filename2.empty()) {
-    return CompareImages(filename1, filename2, histograms, reverse_byte_order);
+    return CompareImages(binary_name, filename1, filename2, histograms,
+                         reverse_byte_order);
   }
 
-  PrintHelp();
+  PrintHelp(binary_name);
   return kStatusError;
 }