diff --git a/experimental/sktext/tests/UnicodeText.cpp b/experimental/sktext/tests/UnicodeText.cpp
index 7cdc1dd4bb..c00a5a92c3 100644
--- a/experimental/sktext/tests/UnicodeText.cpp
+++ b/experimental/sktext/tests/UnicodeText.cpp
@@ -63,26 +63,26 @@ UNIX_ONLY_TEST(SkText_UnicodeText_Flags, reporter) {
     auto lineBreak = utf16.find_first_of(u"\n");
     for (size_t i = 0; i < unicodeText16.getText16().size(); ++i) {
         if (i == lineBreak) {
-            REPORTER_ASSERT(reporter, unicodeText16.hasProperty(i, CodeUnitFlags::kHardLineBreakBefore), "Pos16 %d should point to hard line break\n", lineBreak);
-            REPORTER_ASSERT(reporter, unicodeText8 .hasProperty(i, CodeUnitFlags::kHardLineBreakBefore), "Pos8 %d should point to hard line break\n", lineBreak);
+            REPORTER_ASSERT(reporter, unicodeText16.hasProperty(i, CodeUnitFlags::kHardLineBreakBefore), "Pos16 %zu should point to hard line break\n", lineBreak);
+            REPORTER_ASSERT(reporter, unicodeText8 .hasProperty(i, CodeUnitFlags::kHardLineBreakBefore), "Pos8 %zu should point to hard line break\n", lineBreak);
         } else {
-            REPORTER_ASSERT(reporter, unicodeText16.hasProperty(i, CodeUnitFlags::kGraphemeStart), "Pos16 %d should be a grapheme start\n", i);
-            REPORTER_ASSERT(reporter, unicodeText8 .hasProperty(i, CodeUnitFlags::kGraphemeStart), "Pos8 %d should be a grapheme start\n", i);
+            REPORTER_ASSERT(reporter, unicodeText16.hasProperty(i, CodeUnitFlags::kGraphemeStart), "Pos16 %zu should be a grapheme start\n", i);
+            REPORTER_ASSERT(reporter, unicodeText8 .hasProperty(i, CodeUnitFlags::kGraphemeStart), "Pos8 %zu should be a grapheme start\n", i);
         }
     }
 
     auto space1 = utf16.find_first_of(u" ");
     auto space2 = utf16.find_last_of(u" ");
 
-    REPORTER_ASSERT(reporter, unicodeText16.hasProperty(space1, CodeUnitFlags::kPartOfWhiteSpace), "Pos16 %d should be a part of whitespaces\n", space1);
-    REPORTER_ASSERT(reporter, unicodeText16.hasProperty(space1 + 1, CodeUnitFlags::kSoftLineBreakBefore), "Pos16 %d should have soft line break before\n", space1 + 1);
-    REPORTER_ASSERT(reporter, unicodeText16.hasProperty(space2, CodeUnitFlags::kPartOfWhiteSpace), "Pos16 %d should be a part of whitespaces\n", space2);
-    REPORTER_ASSERT(reporter, unicodeText16.hasProperty(space2 + 1, CodeUnitFlags::kSoftLineBreakBefore), "Pos16 %d should have soft line break before\n", space2 + 1);
+    REPORTER_ASSERT(reporter, unicodeText16.hasProperty(space1, CodeUnitFlags::kPartOfWhiteSpace), "Pos16 %zu should be a part of whitespaces\n", space1);
+    REPORTER_ASSERT(reporter, unicodeText16.hasProperty(space1 + 1, CodeUnitFlags::kSoftLineBreakBefore), "Pos16 %zu should have soft line break before\n", space1 + 1);
+    REPORTER_ASSERT(reporter, unicodeText16.hasProperty(space2, CodeUnitFlags::kPartOfWhiteSpace), "Pos16 %zu should be a part of whitespaces\n", space2);
+    REPORTER_ASSERT(reporter, unicodeText16.hasProperty(space2 + 1, CodeUnitFlags::kSoftLineBreakBefore), "Pos16 %zu should have soft line break before\n", space2 + 1);
 
-    REPORTER_ASSERT(reporter, unicodeText8 .hasProperty(space1, CodeUnitFlags::kPartOfWhiteSpace), "Pos8 %d should be a part of whitespaces\n", space1);
-    REPORTER_ASSERT(reporter, unicodeText8 .hasProperty(space1 + 1, CodeUnitFlags::kSoftLineBreakBefore), "Pos8 %d should have soft line break before\n", space1 + 1);
-    REPORTER_ASSERT(reporter, unicodeText8 .hasProperty(space2, CodeUnitFlags::kPartOfWhiteSpace), "Pos8 %d should be a part of whitespaces\n", space2);
-    REPORTER_ASSERT(reporter, unicodeText8 .hasProperty(space2 + 1, CodeUnitFlags::kSoftLineBreakBefore), "Pos8 %d should have soft line break before\n", space2 + 1);
+    REPORTER_ASSERT(reporter, unicodeText8 .hasProperty(space1, CodeUnitFlags::kPartOfWhiteSpace), "Pos8 %zu should be a part of whitespaces\n", space1);
+    REPORTER_ASSERT(reporter, unicodeText8 .hasProperty(space1 + 1, CodeUnitFlags::kSoftLineBreakBefore), "Pos8 %zu should have soft line break before\n", space1 + 1);
+    REPORTER_ASSERT(reporter, unicodeText8 .hasProperty(space2, CodeUnitFlags::kPartOfWhiteSpace), "Pos8 %zu should be a part of whitespaces\n", space2);
+    REPORTER_ASSERT(reporter, unicodeText8 .hasProperty(space2 + 1, CodeUnitFlags::kSoftLineBreakBefore), "Pos8 %zu should have soft line break before\n", space2 + 1);
 }
 
 // TODO: Test RTL text
diff --git a/modules/skparagraph/tests/SkParagraphTest.cpp b/modules/skparagraph/tests/SkParagraphTest.cpp
index 51d65fb8e0..6e2d643a0f 100644
--- a/modules/skparagraph/tests/SkParagraphTest.cpp
+++ b/modules/skparagraph/tests/SkParagraphTest.cpp
@@ -2041,13 +2041,13 @@ UNIX_ONLY_TEST(SkParagraph_JustifyRTLNewLine, reporter) {
     // All lines should be justified to the width of the paragraph
     // except for #0 (new line) and #5 (the last one)
     for (auto& line : impl->lines()) {
-        auto num = &line - impl->lines().data();
+        ptrdiff_t num = &line - impl->lines().data();
         if (num == 0 || num == 5) {
             REPORTER_ASSERT(reporter, line.width() < TestCanvasWidth - 100);
         } else {
             REPORTER_ASSERT(reporter,
                             SkScalarNearlyEqual(line.width(), TestCanvasWidth - 100, EPSILON100),
-                            "#%d: %f <= %f\n", num, line.width(), TestCanvasWidth - 100);
+                            "#%zd: %f <= %d\n", num, line.width(), TestCanvasWidth - 100);
         }
     }
 }
diff --git a/tests/AnimatedImageTest.cpp b/tests/AnimatedImageTest.cpp
index 91c6606f18..707e0e754a 100644
--- a/tests/AnimatedImageTest.cpp
+++ b/tests/AnimatedImageTest.cpp
@@ -76,7 +76,7 @@ DEF_TEST(AnimatedImage_rotation, r) {
 
             auto bounds = animatedImage->getBounds();
             if (bounds != expectedBounds) {
-                ERRORF(r, "Mismatched bounds for %", file);
+                ERRORF(r, "Mismatched bounds for %s", file);
                 bounds.dump();
             }
         }
diff --git a/tests/BackendAllocationTest.cpp b/tests/BackendAllocationTest.cpp
index 9a4ec28f7b..f89742e3e5 100644
--- a/tests/BackendAllocationTest.cpp
+++ b/tests/BackendAllocationTest.cpp
@@ -52,7 +52,7 @@ void test_wrapping(GrDirectContext* dContext,
     sk_sp<ManagedBackendTexture> mbet = create(dContext, mipMapped, renderable);
     if (!mbet) {
         ERRORF(reporter, "Couldn't create backendTexture for grColorType %d renderable %s\n",
-               grColorType,
+               (int)grColorType,
                GrRenderable::kYes == renderable ? "yes" : "no");
         return;
     }
@@ -285,7 +285,8 @@ static void check_base_readbacks(GrDirectContext* dContext,
         GrColorInfo info(colorType, kUnpremul_SkAlphaType, nullptr);
         auto surfaceContext = dContext->priv().makeSC(readView, info);
         if (!surfaceContext) {
-            ERRORF(reporter, "Could not create surface context for colorType: %d\n", colorType);
+            ERRORF(reporter, "Could not create surface context for colorType: %d\n",
+                   (int)colorType);
         }
 
         if (!surfaceContext->readPixels(dContext, actual, {0, 0})) {
@@ -293,7 +294,7 @@ static void check_base_readbacks(GrDirectContext* dContext,
             // arbitrary colorType
 #if 0
             ERRORF(reporter, "Couldn't readback from SurfaceContext for colorType: %d\n",
-                   colorType);
+                   (int)colorType);
 #endif
         } else {
             auto name = SkStringPrintf("%s::readPixels",
diff --git a/tests/CodecTest.cpp b/tests/CodecTest.cpp
index f2fa0b7c5c..cd55b14754 100644
--- a/tests/CodecTest.cpp
+++ b/tests/CodecTest.cpp
@@ -1683,7 +1683,7 @@ DEF_TEST(Codec_webp_rowsDecoded, r) {
     sk_sp<SkData> subset = SkData::MakeSubset(data.get(), 0, truncatedSize);
     std::unique_ptr<SkCodec> codec = SkCodec::MakeFromData(std::move(subset));
     if (!codec) {
-        ERRORF(r, "Failed to create a codec for %s truncated to only %lu bytes",
+        ERRORF(r, "Failed to create a codec for %s truncated to only %zu bytes",
                path, truncatedSize);
         return;
     }
diff --git a/tests/EmptyPathTest.cpp b/tests/EmptyPathTest.cpp
index 06c3cea752..38b819b357 100644
--- a/tests/EmptyPathTest.cpp
+++ b/tests/EmptyPathTest.cpp
@@ -49,7 +49,7 @@ static void drawAndTest(skiatest::Reporter* reporter, const SkPath& path,
         ERRORF(reporter, "%s style[%d] cap[%d] join[%d] antialias[%d]"
                " filltype[%d] ptcount[%d]", str, paint.getStyle(),
                paint.getStrokeCap(), paint.getStrokeJoin(),
-               paint.isAntiAlias(), path.getFillType(), path.countPoints());
+               paint.isAntiAlias(), (int)path.getFillType(), path.countPoints());
 // uncomment this if you want to step in to see the failure
 //        canvas.drawPath(path, p);
     }
diff --git a/tests/GrClipStackTest.cpp b/tests/GrClipStackTest.cpp
index b0cb2764aa..0acfd5103b 100644
--- a/tests/GrClipStackTest.cpp
+++ b/tests/GrClipStackTest.cpp
@@ -379,7 +379,7 @@ void TestCase::run(const std::vector<int>& order,
         matchedElements += found ? 1 : 0;
     }
     REPORTER_ASSERT(reporter, matchedElements == fExpectedElements.size(),
-                    "%s, did not match all expected elements: expected %d but matched only %d",
+                    "%s, did not match all expected elements: expected %zu but matched only %zu",
                     name.c_str(), fExpectedElements.size(), matchedElements);
 
     // Validate restoration behavior
@@ -388,7 +388,8 @@ void TestCase::run(const std::vector<int>& order,
         cs.restore();
         REPORTER_ASSERT(reporter, cs.clipState() == oldState,
                         "%s, restoring an empty save record should not change clip state: "
-                        "expected %d but got %d", (int) oldState, (int) cs.clipState());
+                        "expected %d but got %d",
+                        name.c_str(), (int) oldState, (int) cs.clipState());
     } else if (policy != SavePolicy::kNever) {
         int restoreCount = policy == SavePolicy::kAtStart ? 1 : (int) order.size();
         for (int i = 0; i < restoreCount; ++i) {
@@ -397,7 +398,7 @@ void TestCase::run(const std::vector<int>& order,
         // Should be wide open if everything is restored to base state
         REPORTER_ASSERT(reporter, cs.clipState() == ClipStack::ClipState::kWideOpen,
                         "%s, restore should make stack become wide-open, not %d",
-                        (int) cs.clipState());
+                        name.c_str(), (int) cs.clipState());
     }
 }
 
diff --git a/tests/ImageFilterTest.cpp b/tests/ImageFilterTest.cpp
index d58a00497f..b73fde9f40 100644
--- a/tests/ImageFilterTest.cpp
+++ b/tests/ImageFilterTest.cpp
@@ -490,8 +490,8 @@ static void test_cropRects(skiatest::Reporter* reporter, GrRecordingContext* rCo
         SkImageFilter_Base::Context ctx(SkMatrix::I(), SkIRect::MakeWH(100, 100), nullptr,
                                         kN32_SkColorType, nullptr, srcImg.get());
         sk_sp<SkSpecialImage> resultImg(as_IFB(filter)->filterImage(ctx).imageAndOffset(&offset));
-        REPORTER_ASSERT(reporter, resultImg, filters.getName(i));
-        REPORTER_ASSERT(reporter, offset.fX == 20 && offset.fY == 30, filters.getName(i));
+        REPORTER_ASSERT(reporter, resultImg, "%s", filters.getName(i));
+        REPORTER_ASSERT(reporter, offset.fX == 20 && offset.fY == 30, "%s", filters.getName(i));
     }
 }
 
@@ -809,7 +809,7 @@ DEF_TEST(ImageFilterDrawTiled, reporter) {
             }
 
             if (!ToolUtils::equal_pixels(untiledResult, tiledResult)) {
-                REPORTER_ASSERT(reporter, false, filters.getName(i));
+                ERRORF(reporter, "%s", filters.getName(i));
                 break;
             }
         }
diff --git a/tests/ProcessorTest.cpp b/tests/ProcessorTest.cpp
index d4e6ab8294..b7b5fe20fb 100644
--- a/tests/ProcessorTest.cpp
+++ b/tests/ProcessorTest.cpp
@@ -740,13 +740,13 @@ DEF_GPUTEST_FOR_GL_RENDERING_CONTEXTS(ProcessorOptimizationValidationTest, repor
 
                 // Print first failing pixel's details.
                 if (!coverageMessage.isEmpty()) {
-                    ERRORF(reporter, coverageMessage.c_str());
+                    ERRORF(reporter, "%s", coverageMessage.c_str());
                 }
                 if (!constMessage.isEmpty()) {
-                    ERRORF(reporter, constMessage.c_str());
+                    ERRORF(reporter, "%s", constMessage.c_str());
                 }
                 if (!opaqueMessage.isEmpty()) {
-                    ERRORF(reporter, opaqueMessage.c_str());
+                    ERRORF(reporter, "%s", opaqueMessage.c_str());
                 }
 
                 if (!loggedFirstFailure) {
diff --git a/tests/RecordingXfermodeTest.cpp b/tests/RecordingXfermodeTest.cpp
index 9dad24e0d1..ecd59a2667 100644
--- a/tests/RecordingXfermodeTest.cpp
+++ b/tests/RecordingXfermodeTest.cpp
@@ -171,6 +171,6 @@ DEF_TEST(SkRecordingAccuracyXfermode, reporter) {
     }
 
 #if !FINEGRAIN
-    REPORTER_ASSERT(reporter, 0 == numErrors, errors.c_str());
+    REPORTER_ASSERT(reporter, 0 == numErrors, "%s", errors.c_str());
 #endif
 }
diff --git a/tests/Skbug6653.cpp b/tests/Skbug6653.cpp
index 769c177524..388463481c 100644
--- a/tests/Skbug6653.cpp
+++ b/tests/Skbug6653.cpp
@@ -90,7 +90,7 @@ static void test_bug_6653(GrDirectContext* dContext,
             }
         }
 
-        REPORTER_ASSERT(reporter, match, label);
+        REPORTER_ASSERT(reporter, match, "%s", label);
     }
 }
 
diff --git a/tests/StreamTest.cpp b/tests/StreamTest.cpp
index 49d2005287..cd821aff59 100644
--- a/tests/StreamTest.cpp
+++ b/tests/StreamTest.cpp
@@ -506,7 +506,7 @@ DEF_TEST(FILEStreamWithOffset, r) {
     const size_t size = stream1.getLength();
     const size_t middle = size / 2;
     if (!stream1.seek(middle)) {
-        ERRORF(r, "Could not seek SkFILEStream to %lu out of %lu", middle, size);
+        ERRORF(r, "Could not seek SkFILEStream to %zu out of %zu", middle, size);
         return;
     }
     REPORTER_ASSERT(r, stream1.getPosition() == middle);
@@ -518,7 +518,7 @@ DEF_TEST(FILEStreamWithOffset, r) {
     }
 
     if (fseek(file, (long) middle, SEEK_SET) != 0) {
-        ERRORF(r, "Could not fseek FILE to %lu out of %lu", middle, size);
+        ERRORF(r, "Could not fseek FILE to %zu out of %zu", middle, size);
         return;
     }
     SkFILEStream stream2(file);
diff --git a/tests/Test.h b/tests/Test.h
index 4a732f117c..87b3372938 100644
--- a/tests/Test.h
+++ b/tests/Test.h
@@ -165,24 +165,16 @@ private:
 
 }  // namespace skiatest
 
-static inline SkString reporter_string() { return {}; }
-/// Prevent security warnings when using a non-literal string i.e. not a format string.
-static inline SkString reporter_string(const char* s) { return SkString(s); }
-template<typename... Args>
-static inline SkString reporter_string(const char* fmt, Args... args)  {
-    return SkStringPrintf(fmt, std::forward<Args>(args)...);
-}
-
-#define REPORTER_ASSERT(r, cond, ...)                               \
-    do {                                                            \
-        if (!(cond)) {                                              \
-            REPORT_FAILURE(r, #cond, reporter_string(__VA_ARGS__)); \
-        }                                                           \
+#define REPORTER_ASSERT(r, cond, ...)                              \
+    do {                                                           \
+        if (!(cond)) {                                             \
+            REPORT_FAILURE(r, #cond, SkStringPrintf(__VA_ARGS__)); \
+        }                                                          \
     } while (0)
 
-#define ERRORF(r, ...)                                       \
-    do {                                                     \
-        REPORT_FAILURE(r, "", reporter_string(__VA_ARGS__)); \
+#define ERRORF(r, ...)                                      \
+    do {                                                    \
+        REPORT_FAILURE(r, "", SkStringPrintf(__VA_ARGS__)); \
     } while (0)
 
 #define INFOF(REPORTER, ...)         \
diff --git a/tests/VkYcbcrSamplerTest.cpp b/tests/VkYcbcrSamplerTest.cpp
index cb14e8d873..998446b92d 100644
--- a/tests/VkYcbcrSamplerTest.cpp
+++ b/tests/VkYcbcrSamplerTest.cpp
@@ -99,17 +99,17 @@ DEF_GPUTEST(VkYCbcrSampler_DrawImageWithYcbcrSampler, reporter, options) {
 
             int r = readbackData[(y * kImageWidth + x) * 4];
             if (abs(r - expectedR) > kColorTolerance) {
-                ERRORF(reporter, "R should be %d, but is %d at (%d, %d)", expectedR, r, x, y);
+                ERRORF(reporter, "R should be %d, but is %d at (%zu, %zu)", expectedR, r, x, y);
             }
 
             int g = readbackData[(y * kImageWidth + x) * 4 + 1];
             if (abs(g - expectedG) > kColorTolerance) {
-                ERRORF(reporter, "G should be %d, but is %d at (%d, %d)", expectedG, g, x, y);
+                ERRORF(reporter, "G should be %d, but is %d at (%zu, %zu)", expectedG, g, x, y);
             }
 
             int b = readbackData[(y * kImageWidth + x) * 4 + 2];
             if (abs(b - expectedB) > kColorTolerance) {
-                ERRORF(reporter, "B should be %d, but is %d at (%d, %d)", expectedB, b, x, y);
+                ERRORF(reporter, "B should be %d, but is %d at (%zu, %zu)", expectedB, b, x, y);
             }
         }
     }