Disable tail calls inside Simple GM functions.

gm/gm.h

Index: gm/gm.h
diff --git a/gm/gm.h b/gm/gm.h
index e00a650f3352b241b6bccc628f9cda6068028a58..6fe59c2726ad6353ff6a8014bd0d90bb3e1d8235 100644
--- a/gm/gm.h
+++ b/gm/gm.h
@@ -34,10 +34,20 @@ struct GrContextOptions;
     DEF_SIMPLE_GM_BG_NAME(NAME, CANVAS, W, H, SK_ColorWHITE, SkString(#NAME))
 #define DEF_SIMPLE_GM_BG(NAME, CANVAS, W, H, BGCOLOR)\
     DEF_SIMPLE_GM_BG_NAME(NAME, CANVAS, W, H, BGCOLOR, SkString(#NAME))
-#define DEF_SIMPLE_GM_BG_NAME(NAME, CANVAS, W, H, BGCOLOR, NAME_STR)         \
-    static void SK_MACRO_CONCAT(NAME, _GM)(SkCanvas * CANVAS);               \
-    DEF_GM(return new skiagm::SimpleGM(NAME_STR, SK_MACRO_CONCAT(NAME, _GM), \
-                                       SkISize::Make(W, H), BGCOLOR);)       \
+
+// Disable tail calls in Simple GM functions to make sure they appear on any stack trace.
+#if defined(__clang__)
+    #define DISABLE_TAIL_CALLS __attribute__((optnone))
+#elif defined(__GNUC__)
+    #define DISABLE_TAIL_CALLS __attribute__((optimize("-O1")))
+#else
+    #define DISABLE_TAIL_CALLS /*TODO: MSVC*/
+#endif
+
+#define DEF_SIMPLE_GM_BG_NAME(NAME, CANVAS, W, H, BGCOLOR, NAME_STR)              \
+    static void DISABLE_TAIL_CALLS SK_MACRO_CONCAT(NAME, _GM)(SkCanvas * CANVAS); \
+    DEF_GM(return new skiagm::SimpleGM(NAME_STR, SK_MACRO_CONCAT(NAME, _GM),      \
+                                       SkISize::Make(W, H), BGCOLOR);)            \
     void SK_MACRO_CONCAT(NAME, _GM)(SkCanvas * CANVAS)
 
 namespace skiagm {