Re-commit "llvm-isel-fuzzer: Handle a subset of backend flags in the exec name"

Here we add a secondary option parser to llvm-isel-fuzzer (and provide
it for use with other fuzzers). With this, you can copy the fuzzer to
a name like llvm-isel-fuzzer=aarch64-gisel for a fuzzer that fuzzer
AArch64 with GlobalISel enabled, or fuzzer=x86_64 to fuzz x86, with no
flags required. This should be useful for running these in OSS-Fuzz.

Note that this handrolls a subset of cl::opts to recognize, rather
than embedding a complete command parser for argv[0]. If we find we
really need the flexibility of handling arbitrary options at some
point we can rethink this.

This re-applies 315545 using "=" instead of ":" as a separator for
arguments.

llvm-svn: 315557

1 files changed, 2 insertions, 1 deletions

diff --git a/llvm/tools/llvm-isel-fuzzer/llvm-isel-fuzzer.cpp b/llvm/tools/llvm-isel-fuzzer/llvm-isel-fuzzer.cpp
index 314acdb5087..9b39483c1aa 100644
--- a/llvm/tools/llvm-isel-fuzzer/llvm-isel-fuzzer.cpp
+++ b/llvm/tools/llvm-isel-fuzzer/llvm-isel-fuzzer.cpp
@@ -150,11 +150,12 @@ extern "C" LLVM_ATTRIBUTE_USED int LLVMFuzzerInitialize(int *argc,
   InitializeAllAsmPrinters();
   InitializeAllAsmParsers();
 
+  handleExecNameEncodedBEOpts(*argv[0]);
   parseFuzzerCLOpts(*argc, *argv);
 
   if (TargetTriple.empty()) {
     errs() << *argv[0] << ": -mtriple must be specified\n";
-    return 1;
+    exit(1);
   }
 
   Triple TheTriple = Triple(Triple::normalize(TargetTriple));