[libc-commits] [libc] [libc] Add hooks for extra options in running hermetic tests (PR #147931)

[William Huynh via libc-commits]

https://github.com/saturn691 created https://github.com/llvm/llvm-project/pull/147931

These hooks are required downstream in order to run hermetic tests. I'm not too sure about the specifics about this PR, it's quite rough, but if you're happy we can get started with hermetic testing downstream.

Closes #145349. This is the final PR to get minimal functionality.

>From aa3b5ef27245f35afd1e7a3717d6282ff2be1c0c Mon Sep 17 00:00:00 2001
From: William Huynh <William.Huynh at arm.com>
Date: Thu, 10 Jul 2025 11:09:22 +0100
Subject: [PATCH] [libc] Add hooks for extra options in running hermetic tests

---
 libc/cmake/modules/LLVMLibCTestRules.cmake | 25 +++++++++++++++++-----
 1 file changed, 20 insertions(+), 5 deletions(-)

diff --git a/libc/cmake/modules/LLVMLibCTestRules.cmake b/libc/cmake/modules/LLVMLibCTestRules.cmake
index 1cd09816e223f..739fd6639a976 100644
--- a/libc/cmake/modules/LLVMLibCTestRules.cmake
+++ b/libc/cmake/modules/LLVMLibCTestRules.cmake
@@ -288,7 +288,9 @@ function(create_libc_unittest fq_target_name)
   target_include_directories(${fq_build_target_name} SYSTEM PRIVATE ${LIBC_INCLUDE_DIR})
   target_include_directories(${fq_build_target_name} PRIVATE ${LIBC_SOURCE_DIR})
   target_compile_options(${fq_build_target_name} PRIVATE ${compile_options})
-  target_link_options(${fq_build_target_name} PRIVATE ${link_options})
+  
+  string(REPLACE " " ";" EXTRA_LINK_OPTIONS "${LIBC_TEST_EXTRA_LINK_OPTIONS}")
+  target_link_options(${fq_build_target_name} PRIVATE ${link_options} ${EXTRA_LINK_OPTIONS})
 
   if(NOT LIBC_UNITTEST_CXX_STANDARD)
     set(LIBC_UNITTEST_CXX_STANDARD ${CMAKE_CXX_STANDARD})
@@ -580,7 +582,9 @@ function(add_integration_test test_name)
       -march=${LIBC_GPU_TARGET_ARCHITECTURE} -nostdlib -static
       "--cuda-path=${LIBC_CUDA_ROOT}")
   elseif(LIBC_CC_SUPPORTS_NOSTDLIBPP)
-    target_link_options(${fq_build_target_name} PRIVATE -nolibc -nostartfiles -nostdlib++ -static)
+    string(REPLACE " " ";" EXTRA_LINK_OPTIONS "${LIBC_TEST_EXTRA_LINK_OPTIONS}")
+    target_link_options(${fq_build_target_name} PRIVATE
+      -nolibc -nostartfiles -nostdlib++ -static ${EXTRA_LINK_OPTIONS})
   else()
     # Older version of gcc does not support `nostdlib++` flag.  We use
     # `nostdlib` and link against libgcc_s, which cannot be linked statically.
@@ -774,7 +778,9 @@ function(add_libc_hermetic test_name)
       -march=${LIBC_GPU_TARGET_ARCHITECTURE} -nostdlib -static
       "--cuda-path=${LIBC_CUDA_ROOT}")
   elseif(LIBC_CC_SUPPORTS_NOSTDLIBPP)
-    target_link_options(${fq_build_target_name} PRIVATE -nolibc -nostartfiles -nostdlib++ -static)
+    string(REPLACE " " ";" EXTRA_LINK_OPTIONS "${LIBC_TEST_EXTRA_LINK_OPTIONS}")
+    target_link_options(${fq_build_target_name} PRIVATE 
+      -nolibc -nostartfiles -nostdlib++ -static ${EXTRA_LINK_OPTIONS})
   else()
     # Older version of gcc does not support `nostdlib++` flag.  We use
     # `nostdlib` and link against libgcc_s, which cannot be linked statically.
@@ -809,9 +815,16 @@ function(add_libc_hermetic test_name)
   endif()
 
   if(NOT HERMETIC_TEST_NO_RUN_POSTBUILD)
-    set(test_cmd ${HERMETIC_TEST_ENV}
+    if (LIBC_TEST_CMD)
+      # In the form of "<command> binary=@BINARY@", e.g. "qemu-system-arm -loader$<COMMA>file=@BINARY@"
+      string(REPLACE "@BINARY@" "$<TARGET_FILE:${fq_build_target_name}>" test_cmd_parsed ${LIBC_TEST_CMD})
+      string(REPLACE " " ";" test_cmd "${test_cmd_parsed}")
+    else()
+      set(test_cmd ${HERMETIC_TEST_ENV}
         $<$<BOOL:${LIBC_TARGET_OS_IS_GPU}>:${gpu_loader_exe}> ${CMAKE_CROSSCOMPILING_EMULATOR} ${HERMETIC_TEST_LOADER_ARGS}
         $<TARGET_FILE:${fq_build_target_name}> ${HERMETIC_TEST_ARGS})
+    endif()
+
     add_custom_target(
       ${fq_target_name}
       DEPENDS ${fq_target_name}.__cmd__
@@ -863,7 +876,9 @@ function(add_libc_test test_name)
       # Tests like the file tests perform file operations on disk file. If we
       # don't chain up the unit test and hermetic test, then those tests will
       # step on each other's files.
-      add_dependencies(${fq_test_name}.__hermetic__ ${fq_test_name}.__unit__)
+      if(NOT LIBC_TEST_HERMETIC_ONLY)
+        add_dependencies(${fq_test_name}.__hermetic__ ${fq_test_name}.__unit__)
+      endif()
     endif()
   endif()
 endfunction(add_libc_test)