Guard against most unintentionally ephemeral SkAutoFoo instantiations.

include/core/SkTSearch.h

Index: include/core/SkTSearch.h
diff --git a/include/core/SkTSearch.h b/include/core/SkTSearch.h
index a4e4994ef378b2b14a39c1da2daa601c35677f71..3493996656a0466889c1b2a569034a84970ba830 100644
--- a/include/core/SkTSearch.h
+++ b/include/core/SkTSearch.h
@@ -11,6 +11,7 @@
 #define SkTSearch_DEFINED
 
 #include "SkTypes.h"
+#include <ctype.h>
 
 /**
  *  All of the SkTSearch variants want to return the index (0...N-1) of the
@@ -125,8 +126,39 @@ int SkStrLCSearch(const char*const* base, int count, const char target[],
 */
 class SkAutoAsciiToLC {
 public:
-    SkAutoAsciiToLC(const char str[], size_t len = (size_t)-1);
-    ~SkAutoAsciiToLC();
+    SkAutoAsciiToLC(const char str[], size_t len = (size_t)-1) {

[reed1, 2013/11/15 18:20:12]

Not sure I agree with this one.

1. This class does *not* perform its magic in its destructor as the AutoFoo guys
do, but it is used to access its lc() method. Seems less likely a caller would
make this mistake, and certainly it would not lead to any bug, unlike the Auto
guys.

2. The macro seems to force us to inline the code, which is overkill/bloaty for
this guy imho.

[mtklein, 2013/11/15 18:28:14]

Reverted.

+        // see if we need to compute the length
+        if ((long)len < 0) {
+            len = strlen(str);
+        }
+        fLength = len;
+
+        // assign lc to our preallocated storage if len is small enough, or allocate
+        // it on the heap
+        char*   lc;
+        if (len <= STORAGE) {
+            lc = fStorage;
+        } else {
+            lc = (char*)sk_malloc_throw(len + 1);
+        }
+        fLC = lc;
+
+        // convert any asii to lower-case. we let non-ascii (utf8) chars pass
+        // through unchanged
+        for (int i = (int)(len - 1); i >= 0; --i) {
+            int c = str[i];
+            if ((c & 0x80) == 0) {   // is just ascii
+                c = tolower(c);
+            }
+            lc[i] = c;
+        }
+        lc[len] = 0;
+    }
+    ~SkAutoAsciiToLC() {
+        if (fLC != fStorage) {
+            sk_free(fLC);
+        }
+    }
 
     const char* lc() const { return fLC; }
     size_t      length() const { return fLength; }
@@ -139,6 +171,7 @@ private:
     };
     char    fStorage[STORAGE+1];
 };
+#define SkAutoAsciiToLC(...) SK_REQUIRE_LOCAL_VAR(SkAutoAsciiToLC)
 
 // Helper when calling qsort with a compare proc that has typed its arguments
 #define SkCastForQSort(compare) reinterpret_cast<int (*)(const void*, const void*)>(compare)