[clang] [clang][ssaf] Implement Entity Linker CLI and patching for JSON Format (PR #184713)

[Aviral Goel via cfe-commits]

================
@@ -0,0 +1,17 @@
+// Test the --time/-t flag of ssaf-linker.
+
+// RUN: rm -rf %t
+// RUN: mkdir -p %t
+
+// RUN: ssaf-linker --time %S/Inputs/tu-1.json %S/Inputs/tu-2.json -o %t/lu-1+2.json 2>&1 \
+// RUN:           | FileCheck %s --match-full-lines
+// CHECK:      ===-------------------------------------------------------------------------===
+// CHECK-NEXT: {{[ ]+}}SSAF Linker
+// CHECK-NEXT: ===-------------------------------------------------------------------------===
+// CHECK-NEXT:   Total Execution Time: {{[0-9.]+}} seconds ({{[0-9.]+}} wall clock)
----------------
aviralg wrote:

Nothing stops us from changing the output of time format later on and updating the test along with it.
At the same time, I don't see an alternative to the current design. We use the standard LLVM approach to timing which provides us user/system/wall clock time split between the different conceptual steps of linking.

https://github.com/llvm/llvm-project/pull/184713