[clang] [Clang][OpenCL][AMDGPU] Allow a kernel to call another kernel (PR #115821)

[John McCall via cfe-commits]

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@@ -1780,6 +1786,15 @@ void CXXNameMangler::mangleDeviceStubName(const IdentifierInfo *II) {
       << II->getName();
 }
 
+void CXXNameMangler::mangleOCLDeviceStubName(const IdentifierInfo *II) {
+  // <source-name> ::= <positive length number> __clang_ocl_kern_imp_
+  // <identifier> <number> ::= [n] <non-negative decimal integer> <identifier>
+  // ::= <unqualified source code identifier>
+  StringRef OCLDeviceStubNamePrefix = "__clang_ocl_kern_imp_";
+  Out << II->getLength() + OCLDeviceStubNamePrefix.size() - 1
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rjmccall wrote:

Why the `- 1`?

https://github.com/llvm/llvm-project/pull/115821