Treat bad values passed to --images as a fatal error

If an option is passed to --images that is either a non-existent path or
a folder with no images matching the supported types, assume this is
an error and exit, so they can supply a valid path instead.

Share code between DM and nanobench in SkCommonFlags.

nanobench now behaves more like DM - it will check a directory for
images that match the supported extensions.

GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1611323004

Review URL: https://codereview.chromium.org/1611323004

2 files changed, 61 insertions, 2 deletions

diff --git a/tools/flags/SkCommonFlags.cpp b/tools/flags/SkCommonFlags.cpp
index 2d5a855bf7..e6d269b9e2 100644
--- a/tools/flags/SkCommonFlags.cpp
+++ b/tools/flags/SkCommonFlags.cpp
@@ -6,6 +6,7 @@
  */
 
 #include "SkCommonFlags.h"
+#include "SkOSFile.h"
 
 DEFINE_bool(cpu, true, "master switch for running CPU-bound work.");
 
@@ -14,7 +15,8 @@ DEFINE_bool(dryRun, false,
 
 DEFINE_bool(gpu, true, "master switch for running GPU-bound work.");
 
-DEFINE_string(images, "", "Directory of images to decode.");
+DEFINE_string(images, "", "List of images and/or directories to decode. A directory with no images"
+                          " is treated as a fatal error.");
 
 DEFINE_string2(match, m, nullptr,
                "[~][^]substring[$] [...] of GM name to run.\n"
@@ -47,5 +49,46 @@ DEFINE_string(key, "",
               "Space-separated key/value pairs to add to JSON identifying this builder.");
 DEFINE_string(properties, "",
               "Space-separated key/value pairs to add to JSON identifying this run.");
-
 DEFINE_bool2(pre_log, p, false, "Log before running each test. May be incomprehensible when threading");
+
+bool CollectImages(SkTArray<SkString>* output) {
+    SkASSERT(output);
+
+    static const char* const exts[] = {
+        "bmp", "gif", "jpg", "jpeg", "png", "webp", "ktx", "astc", "wbmp", "ico",
+        "BMP", "GIF", "JPG", "JPEG", "PNG", "WEBP", "KTX", "ASTC", "WBMP", "ICO",
+#ifdef SK_CODEC_DECODES_RAW
+        "arw", "cr2", "dng", "nef", "nrw", "orf", "raf", "rw2", "pef", "srw",
+        "ARW", "CR2", "DNG", "NEF", "NRW", "ORF", "RAF", "RW2", "PEF", "SRW",
+#endif
+    };
+
+    for (int i = 0; i < FLAGS_images.count(); ++i) {
+        const char* flag = FLAGS_images[i];
+        if (!sk_exists(flag)) {
+            SkDebugf("%s does not exist!\n", flag);
+            return false;
+        }
+
+        if (sk_isdir(flag)) {
+            // If the value passed in is a directory, add all the images
+            bool foundAnImage = false;
+            for (const char* ext : exts) {
+                SkOSFile::Iter it(flag, ext);
+                SkString file;
+                while (it.next(&file)) {
+                    foundAnImage = true;
+                    output->push_back() = SkOSPath::Join(flag, file.c_str());
+                }
+            }
+            if (!foundAnImage) {
+                SkDebugf("No supported images found in %s!\n", flag);
+                return false;
+            }
+        } else {
+            // Also add the value if it is a single image
+            output->push_back() = flag;
+        }
+    }
+    return true;
+}
diff --git a/tools/flags/SkCommonFlags.h b/tools/flags/SkCommonFlags.h
index 127d37328e..8e00e7516c 100644
--- a/tools/flags/SkCommonFlags.h
+++ b/tools/flags/SkCommonFlags.h
@@ -9,6 +9,8 @@
 #define SK_COMMON_FLAGS_H
 
 #include "SkCommandLineFlags.h"
+#include "SkTArray.h"
+#include "SkString.h"
 
 DECLARE_bool(cpu);
 DECLARE_bool(dryRun);
@@ -30,4 +32,18 @@ DECLARE_bool(pre_log);
 DECLARE_string(key);
 DECLARE_string(properties);
 
+/**
+ *  Helper to assist in collecting image paths from --images.
+ *
+ *  Populates an array of strings with paths to images to test.
+ *
+ *  Returns true if each argument to --images is meaningful:
+ *  - If the file/directory does not exist, return false.
+ *  - If a directory passed to --images does not have any supported images (based on file
+ *  type), return false.
+ *  - If a file is passed to --images, assume the user is deliberately testing this image,
+ *  regardless of file type.
+ */
+bool CollectImages(SkTArray<SkString>*);
+
 #endif