[libc-commits] [libc] [libc][WIP] support fully oot build (PR #101287)

Tue Jul 30 22:08:01 PDT 2024

llvmbot wrote:




@llvm/pr-subscribers-libc

Author: Schrodinger ZHU Yifan (SchrodingerZhu)

<details>
<summary>Changes</summary>

Fully OOT build along with SCUDO:
```
cmake ../libc -DLIBC_USE_NEW_HEADER_GEN=On -DLLVM_LIBC_FULL_BUILD=On -DLLVM_LIBC_FULL_BUILD=On -DLLVM_LIBC_INCLUDE_SCUDO=On -DCOMPILER_RT_BUILD_SCUDO_STANDALONE_WITH_LLVM_LIBC=On -DCOMPILER_RT_SCUDO_STANDALONE_BUILD_SHARED=Off -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_C_COMPILER=clang -DLLVM_LIBC_COMPILER_RT_PATH=../compiler-rt/ -DCOMPILER_RT_STANDALONE_BUILD=On -GNinja
```

Current facing the following problems:
```
[10/455] Building CXX object startup/linux/CMakeFiles/libc.startup.linux.do_start.dir/do_start.cpp.o
FAILED: startup/linux/CMakeFiles/libc.startup.linux.do_start.dir/do_start.cpp.o 
/usr/bin/clang++ -DLIBC_NAMESPACE=__llvm_libc -I/home/schrodinger/development/llvm-project/libc -isystem /home/schrodinger/development/llvm-project/build-2/include -std=gnu++17 -DLIBC_QSORT_IMPL=LIBC_QSORT_QUICK_SORT -ffreestanding -fno-builtin -fno-stack-protector -DLIBC_COPT_RAW_MUTEX_DEFAULT_SPIN_COUNT=100 -DLIBC_COPT_TIMEOUT_ENSURE_MONOTONICITY=1 -MD -MT startup/linux/CMakeFiles/libc.startup.linux.do_start.dir/do_start.cpp.o -MF startup/linux/CMakeFiles/libc.startup.linux.do_start.dir/do_start.cpp.o.d -o startup/linux/CMakeFiles/libc.startup.linux.do_start.dir/do_start.cpp.o -c /home/schrodinger/development/llvm-project/libc/startup/linux/do_start.cpp
In file included from /home/schrodinger/development/llvm-project/libc/startup/linux/do_start.cpp:13:
In file included from /home/schrodinger/development/llvm-project/libc/src/stdlib/atexit.h:12:
/home/schrodinger/development/llvm-project/libc/hdr/types/atexithandler_t.h:18:2: error: // type not available in overlay mode
   18 | #error // type not available in overlay mode
      |  ^
In file included from /home/schrodinger/development/llvm-project/libc/startup/linux/do_start.cpp:13:
/home/schrodinger/development/llvm-project/libc/src/stdlib/atexit.h:17:12: error: unknown type name '__atexithandler_t'
   17 | int atexit(__atexithandler_t);
      |            ^
/home/schrodinger/development/llvm-project/libc/startup/linux/do_start.cpp:136:3: error: no matching function for call to 'atexit'
  136 |   atexit([]() { cleanup_tls(tls.tp, tls.size); });
      |   ^~~~~~
/home/schrodinger/development/llvm-project/libc/src/stdlib/atexit.h:17:5: note: candidate function not viable: no known conversion from '(lambda at /home/schrodinger/development/llvm-project/libc/startup/linux/do_start.cpp:136:10)' to 'int' for 1st argument
   17 | int atexit(__atexithandler_t);
      |     ^
/home/schrodinger/development/llvm-project/libc/startup/linux/do_start.cpp:141:3: error: no matching function for call to 'atexit'
  141 |   atexit(&call_fini_array_callbacks);
      |   ^~~~~~
/home/schrodinger/development/llvm-project/libc/src/stdlib/atexit.h:17:5: note: candidate function not viable: no known conversion from 'void (*)()' to 'int' for 1st argument
   17 | int atexit(__atexithandler_t);
      |     ^
4 errors generated.
[12/455] Building CXX object src/__support/OSUtil/linux/CMakeFiles/libc.src.__support.OSUtil.linux.linux_util.dir/fcntl.cpp.o
FAILED: src/__support/OSUtil/linux/CMakeFiles/libc.src.__support.OSUtil.linux.linux_util.dir/fcntl.cpp.o 
/usr/bin/clang++ -DLIBC_NAMESPACE=__llvm_libc -I/home/schrodinger/development/llvm-project/libc -isystem /home/schrodinger/development/llvm-project/build-2/include -std=gnu++17 -DLIBC_QSORT_IMPL=LIBC_QSORT_QUICK_SORT -MD -MT src/__support/OSUtil/linux/CMakeFiles/libc.src.__support.OSUtil.linux.linux_util.dir/fcntl.cpp.o -MF src/__support/OSUtil/linux/CMakeFiles/libc.src.__support.OSUtil.linux.linux_util.dir/fcntl.cpp.o.d -o src/__support/OSUtil/linux/CMakeFiles/libc.src.__support.OSUtil.linux.linux_util.dir/fcntl.cpp.o -c /home/schrodinger/development/llvm-project/libc/src/__support/OSUtil/linux/fcntl.cpp
/home/schrodinger/development/llvm-project/libc/src/__support/OSUtil/linux/fcntl.cpp:41:20: error: variable has incomplete type 'struct flock64'
   41 |     struct fl
```

---
Full diff: https://github.com/llvm/llvm-project/pull/101287.diff


2 Files Affected:

- (modified) libc/CMakeLists.txt (+18-13) 
- (modified) libc/newhdrgen/yaml_to_classes.py (+1-1) 


``````````diff

diff --git a/libc/CMakeLists.txt b/libc/CMakeLists.txt
index 1ce3bdf53b525..2b15d124abb79 100644
--- a/libc/CMakeLists.txt
+++ b/libc/CMakeLists.txt
@@ -1,6 +1,8 @@
 cmake_minimum_required(VERSION 3.20.0)
 set(LLVM_SUBPROJECT_TITLE "libc")
 
+include(CheckCXXCompilerFlag)
+
 # Include LLVM's cmake policies.
 if(NOT DEFINED LLVM_COMMON_CMAKE_UTILS)
   set(LLVM_COMMON_CMAKE_UTILS ${CMAKE_CURRENT_SOURCE_DIR}/../cmake)
@@ -53,18 +55,19 @@ set(LIBC_NAMESPACE ${default_namespace}
 
 add_subdirectory(newhdrgen)
 
-
-if(LLVM_LIBC_FULL_BUILD OR LLVM_LIBC_GPU_BUILD)
-  if(NOT LIBC_HDRGEN_EXE)
-    # We need to set up hdrgen first since other targets depend on it.
-    add_subdirectory(utils/LibcTableGenUtil)
-    add_subdirectory(utils/HdrGen)
-    # Calling add_tablegen sets variables like LIBC_TABLEGEN_EXE in
-    # PARENT_SCOPE which get lost until saved in the cache.
-    set(LIBC_TABLEGEN_EXE "${LIBC_TABLEGEN_EXE}" CACHE INTERNAL "")
-    set(LIBC_TABLEGEN_TARGET "${LIBC_TABLEGEN_TARGET}" CACHE INTERNAL "")
-  else()
-    message(STATUS "Will use ${LIBC_HDRGEN_EXE} for libc header generation.")
+if(NOT LIBC_USE_NEW_HEADER_GEN)
+  if(LLVM_LIBC_FULL_BUILD OR LLVM_LIBC_GPU_BUILD)
+    if(NOT LIBC_HDRGEN_EXE)
+      # We need to set up hdrgen first since other targets depend on it.
+      add_subdirectory(utils/LibcTableGenUtil)
+      add_subdirectory(utils/HdrGen)
+      # Calling add_tablegen sets variables like LIBC_TABLEGEN_EXE in
+      # PARENT_SCOPE which get lost until saved in the cache.
+      set(LIBC_TABLEGEN_EXE "${LIBC_TABLEGEN_EXE}" CACHE INTERNAL "")
+      set(LIBC_TABLEGEN_TARGET "${LIBC_TABLEGEN_TARGET}" CACHE INTERNAL "")
+    else()
+      message(STATUS "Will use ${LIBC_HDRGEN_EXE} for libc header generation.")
+    endif()
   endif()
 endif()
 # We will build the GPU utilities if we are not doing a runtimes build.
@@ -327,7 +330,9 @@ endif()
 
 option(LLVM_LIBC_INCLUDE_SCUDO "Include the SCUDO standalone as the allocator for LLVM libc" OFF)
 if(LLVM_LIBC_INCLUDE_SCUDO)
-  if (NOT ("compiler-rt" IN_LIST LLVM_ENABLE_PROJECTS OR "compiler-rt" IN_LIST LLVM_ENABLE_RUNTIMES))
+  if (LLVM_LIBC_COMPILER_RT_PATH)
+    add_subdirectory(${LLVM_LIBC_COMPILER_RT_PATH} ${CMAKE_CURRENT_BINARY_DIR}/compiler-rt)
+  elseif(NOT ("compiler-rt" IN_LIST LLVM_ENABLE_PROJECTS OR "compiler-rt" IN_LIST LLVM_ENABLE_RUNTIMES))
     message(FATAL_ERROR "SCUDO cannot be included without adding compiler-rt to LLVM_ENABLE_PROJECTS or LLVM_ENABLE_RUNTIMES")
   endif()
 endif()
diff --git a/libc/newhdrgen/yaml_to_classes.py b/libc/newhdrgen/yaml_to_classes.py
old mode 100644
new mode 100755
index d3bdfde2e2a22..9d3593a1bafc1
--- a/libc/newhdrgen/yaml_to_classes.py
+++ b/libc/newhdrgen/yaml_to_classes.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # ===- Generate headers for libc functions  -------------------*- python -*--==#
 #

``````````

</details>


https://github.com/llvm/llvm-project/pull/101287
