Fix g++ -pedantic warnings

src/IceGlobalContext.cpp

Index: src/IceGlobalContext.cpp
diff --git a/src/IceGlobalContext.cpp b/src/IceGlobalContext.cpp
index ab63b4cda6bd878b4bcc89fd0eae600fa92fcbb9..e47b67f62cafeb7fce8ddd4a557956ac1f0c5b37 100644
--- a/src/IceGlobalContext.cpp
+++ b/src/IceGlobalContext.cpp
@@ -99,9 +99,11 @@ IceString GlobalContext::mangleName(const IceString &Name) const {
     return Name;
 
   unsigned PrefixLength = getTestPrefix().length();
-  char NameBase[1 + Name.length()];
+  llvm::OwningArrayPtr<char> NameBaseOwner(new char[1 + Name.length()]);

[JF, 2014/05/23 16:45:22]

Ew. VLAs aren't that evil in this context... What was the issue, just a VLA
warning? Can you allocate a statically-sized array that's realistically smaller
than any name?

[Jim Stichnoth, 2014/05/23 18:26:45]

I don't know what the maximum identifier length is (509?), but can't you make
the input string to mangleName() arbitrarily long just by embedding something
within an arbitrary nesting of namespaces?

Also, maximum-length arrays, ick.

Since it's a silly issue to start with, and it's isolated to this one function
that is just used for testing, I've rolled back the VLA-related changes and we
can revisit if the Mac bots complain.

+  char *NameBase = NameBaseOwner.get();
   const size_t BufLen = 30 + Name.length() + PrefixLength;
-  char NewName[BufLen];
+  llvm::OwningArrayPtr<char> NewNameOwner(new char[BufLen]);
+  char *NewName = NewNameOwner.get();
   uint32_t BaseLength = 0; // using uint32_t due to sscanf format string
 
   int ItemsParsed = sscanf(Name.c_str(), "_ZN%s", NameBase);
@@ -128,8 +130,10 @@ IceString GlobalContext::mangleName(const IceString &Name) const {
     // Transform _Z3barIabcExyz ==> _ZN6Prefix3barIabcEExyz
     //                                ^^^^^^^^         ^
     // (splice in "N6Prefix", and insert "E" after "3barIabcE")
-    char OrigName[Name.length()];
-    char OrigSuffix[Name.length()];
+    llvm::OwningArrayPtr<char> OrigNameOwner(new char[Name.length()]);
+    char *OrigName = OrigNameOwner.get();
+    llvm::OwningArrayPtr<char> OrigSuffixOwner(new char[Name.length()]);
+    char *OrigSuffix = OrigSuffixOwner.get();
     uint32_t ActualBaseLength = BaseLength;
     if (NameBase[ActualBaseLength] == 'I') {
       ++ActualBaseLength;