[libcxx] Enable '-fdelayed-template-parsing' for clang-cl libcxx tests

[zeroomega]

This patch enables '-fdelayed-template-parsing' in clang-cl based libcxx
tests. This flag was disabled by default in PR#69431, which causes this
test to fail.

[llvmbot]

@llvm/pr-subscribers-libcxx

Author: Haowei (zeroomega)

Changes

This patch enables '-fdelayed-template-parsing' in clang-cl based libcxx
tests. This flag was disabled by default in PR#69431, which causes this
test to fail.

---

Full diff: https://github.com/llvm/llvm-project/pull/70092.diff

2 Files Affected:

• (modified) libcxx/test/configs/llvm-libc++-shared-clangcl.cfg.in (+1-1)
• (modified) libcxx/test/configs/llvm-libc++-static-clangcl.cfg.in (+3-1)

diff --git a/libcxx/test/configs/llvm-libc++-shared-clangcl.cfg.in b/libcxx/test/configs/llvm-libc++-shared-clangcl.cfg.in
index 50d28eb67c77b78..829f41cd5607c59 100644
--- a/libcxx/test/configs/llvm-libc++-shared-clangcl.cfg.in
+++ b/libcxx/test/configs/llvm-libc++-shared-clangcl.cfg.in
@@ -5,7 +5,7 @@ lit_config.load_config(config, '@CMAKE_CURRENT_BINARY_DIR@/cmake-bridge.cfg')
 
 config.substitutions.append(('%{flags}', '--driver-mode=g++'))
 config.substitutions.append(('%{compile_flags}',
-    '-fms-runtime-lib=' + config.fms_runtime_lib + ' -nostdinc++ -I %{include} -I %{target-include} -I %{libcxx}/test/support -D_CRT_SECURE_NO_WARNINGS -D_CRT_NONSTDC_NO_WARNINGS -D_CRT_STDIO_ISO_WIDE_SPECIFIERS -DNOMINMAX' + config.dbg_include
+    '-fms-runtime-lib=' + config.fms_runtime_lib + ' -fdelayed-template-parsing' + ' -nostdinc++ -I %{include} -I %{target-include} -I %{libcxx}/test/support -D_CRT_SECURE_NO_WARNINGS -D_CRT_NONSTDC_NO_WARNINGS -D_CRT_STDIO_ISO_WIDE_SPECIFIERS -DNOMINMAX' + config.dbg_include
 ))
 config.substitutions.append(('%{link_flags}',
     '-nostdlib -L %{lib} -lc++ -l' + config.cxx_lib
diff --git a/libcxx/test/configs/llvm-libc++-static-clangcl.cfg.in b/libcxx/test/configs/llvm-libc++-static-clangcl.cfg.in
index 4baaad765a92d38..8c643081d8c152c 100644
--- a/libcxx/test/configs/llvm-libc++-static-clangcl.cfg.in
+++ b/libcxx/test/configs/llvm-libc++-static-clangcl.cfg.in
@@ -4,8 +4,10 @@
 lit_config.load_config(config, '@CMAKE_CURRENT_BINARY_DIR@/cmake-bridge.cfg')
 
 config.substitutions.append(('%{flags}', '--driver-mode=g++'))
+# clang-cl by default disabled '-fdelayed-template-parsing'. Explicitly enable
+# it here for tests.
 config.substitutions.append(('%{compile_flags}',
-    '-fms-runtime-lib=' + config.fms_runtime_lib + ' -nostdinc++ -I %{include} -I %{target-include} -I %{libcxx}/test/support -D_CRT_SECURE_NO_WARNINGS -D_CRT_NONSTDC_NO_WARNINGS -D_CRT_STDIO_ISO_WIDE_SPECIFIERS -DNOMINMAX' + config.dbg_include
+    '-fms-runtime-lib=' + config.fms_runtime_lib + ' -fdelayed-template-parsing' + ' -nostdinc++ -I %{include} -I %{target-include} -I %{libcxx}/test/support -D_CRT_SECURE_NO_WARNINGS -D_CRT_NONSTDC_NO_WARNINGS -D_CRT_STDIO_ISO_WIDE_SPECIFIERS -DNOMINMAX' + config.dbg_include
 ))
 config.substitutions.append(('%{link_flags}',
     '-nostdlib -L %{lib} -llibc++ -l' + config.cxx_lib

[EricWF]

If I recall correctly -fdelayed-template-parsing puts the compiler into a non-conforming mode. And MSVC now defaults to -fno-delayed-template-parsing now.

Does libc++ want to support a non-conforming, legacy, MSVC extension?

[petrhosek]

In #69431 @ChuanqiXu9 suggested enabling -fdelayed-template-parsing to address the failing issues although I think it'd be better to address the issues. I think that addressing #70223 should be fairly straightforward but I don't know about #70225.

[EricWF]

Since there's already an issue for the failure, I would be OK XFAIL'ing the failing test. Would you like me to send the PR?

[ldionne]

Since there's already an issue for the failure, I would be OK XFAIL'ing the failing test. Would you like me to send the PR?

Yeah, same here. I would rather not be building the tests with non-standard arguments.

[petrhosek]

I sent #70422 which XFAIL's the affected tests.

[ldionne]

Thanks @petrhosek, I'll close this then.