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Fix LTO build #712

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Merged
alexcrichton merged 1 commit into from
Jan 23, 2026
Merged

Fix LTO build #712

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6 changes: 6 additions & 0 deletions .github/workflows/main.yml
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Original file line number Diff line number Diff line change
Expand Up @@ -144,6 +144,12 @@ jobs:
test: true
args: -DMALLOC=emmalloc

- name: Test LTO
os: ubuntu-24.04
clang_version: 19
test: true
args: -DLTO=full -DTARGET_TRIPLE=wasm32-wasip2 -DCHECK_SYMBOLS=OFF

steps:
- uses: actions/checkout@v4.1.7
with:
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2 changes: 2 additions & 0 deletions CMakeLists.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -119,8 +119,10 @@ if(LTO)
set(SYSROOT_LIB ${SYSROOT_LIB}/llvm-lto/${clang_version})
if(LTO STREQUAL "thin")
add_compile_options(-flto=thin)
add_link_options(-flto=thin)
elseif(LTO STREQUAL "full")
add_compile_options(-flto)
add_link_options(-flto)
else()
message(FATAL_ERROR "Unknown LTO mode: ${LTO}")
endif()
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32 changes: 17 additions & 15 deletions libc-bottom-half/CMakeLists.txt
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Expand Up @@ -195,21 +195,23 @@ foreach(file crt/crt1-command.c
clang_format_target(${stem})
target_link_libraries(${stem} PRIVATE musl-top-half-interface)
set_pic(${stem})
target_compile_options(${stem} PRIVATE -fvisibility=default)
target_compile_options(${stem} PRIVATE -fvisibility=default -fno-lto)
endforeach()

set(crt_sysroot ${SYSROOT}/lib/${TARGET_TRIPLE})

# crt1-reactor.o is a straight copy of what CMake produces
add_custom_command(
OUTPUT ${SYSROOT_LIB}/crt1-reactor.o
COMMAND ${CMAKE_COMMAND} -E copy $<TARGET_OBJECTS:crt1-reactor> ${SYSROOT_LIB}/crt1-reactor.o
OUTPUT ${crt_sysroot}/crt1-reactor.o
COMMAND ${CMAKE_COMMAND} -E copy $<TARGET_OBJECTS:crt1-reactor> ${crt_sysroot}/crt1-reactor.o
DEPENDS crt1-reactor $<TARGET_OBJECTS:crt1-reactor>
)

if (WASI STREQUAL "p1")
# wasip1: crt1-command.o is a straight copy of what CMake produces
add_custom_command(
OUTPUT ${SYSROOT_LIB}/crt1-command.o
COMMAND ${CMAKE_COMMAND} -E copy $<TARGET_OBJECTS:crt1-command> ${SYSROOT_LIB}/crt1-command.o
OUTPUT ${crt_sysroot}/crt1-command.o
COMMAND ${CMAKE_COMMAND} -E copy $<TARGET_OBJECTS:crt1-command> ${crt_sysroot}/crt1-command.o
DEPENDS crt1-command $<TARGET_OBJECTS:crt1-command>
)
elseif (WASI STREQUAL "p2")
Expand All @@ -232,24 +234,24 @@ elseif (WASI STREQUAL "p2")
# please feel free to open an issue or a PR and maintainers can work with you
# on getting that integrated.
add_custom_command(
OUTPUT ${SYSROOT_LIB}/crt1-command.o
OUTPUT ${crt_sysroot}/crt1-command.o
COMMAND
${wasm_tools} component embed
${wasip2_wit_dir}
$<TARGET_OBJECTS:crt1-command>
--world wasi:cli/command@0.2.0
-o ${SYSROOT_LIB}/crt1-command.o
-o ${crt_sysroot}/crt1-command.o
DEPENDS crt1-command wasip2-wits $<TARGET_OBJECTS:crt1-command> wasm-tools
)
elseif (WASI STREQUAL "p3")
add_custom_command(
OUTPUT ${SYSROOT_LIB}/crt1-command.o
OUTPUT ${crt_sysroot}/crt1-command.o
COMMAND
${wasm_tools} component embed
${wasip3_wit_dir}
$<TARGET_OBJECTS:crt1-command>
--world wasi:cli/command@0.3.0-rc-2025-09-16
-o ${SYSROOT_LIB}/crt1-command.o
-o ${crt_sysroot}/crt1-command.o
DEPENDS crt1-command wasip3-wits $<TARGET_OBJECTS:crt1-command> wasm-tools
)
else()
Expand All @@ -259,15 +261,15 @@ endif()
# Provide a plain crt1.o for toolchain compatibility, identical to
# `crt1-command.c`
add_custom_command(
OUTPUT ${SYSROOT_LIB}/crt1.o
COMMAND ${CMAKE_COMMAND} -E copy ${SYSROOT_LIB}/crt1-command.o ${SYSROOT_LIB}/crt1.o
DEPENDS ${SYSROOT_LIB}/crt1-command.o
OUTPUT ${crt_sysroot}/crt1.o
COMMAND ${CMAKE_COMMAND} -E copy ${crt_sysroot}/crt1-command.o ${crt_sysroot}/crt1.o
DEPENDS ${crt_sysroot}/crt1-command.o
)

add_custom_target(sysroot-startup-objects
DEPENDS
${SYSROOT_LIB}/crt1-reactor.o
${SYSROOT_LIB}/crt1-command.o
${SYSROOT_LIB}/crt1.o
${crt_sysroot}/crt1-reactor.o
${crt_sysroot}/crt1-command.o
${crt_sysroot}/crt1.o
)
add_dependencies(sysroot sysroot-startup-objects)
3 changes: 3 additions & 0 deletions test/CMakeLists.txt
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Expand Up @@ -193,6 +193,9 @@ if (MALLOC STREQUAL "emmalloc")
set_tests_properties(libc_test_functional_search_hsearch.wasm PROPERTIES WILL_FAIL TRUE)
endif()
add_libc_test(functional/search_insque.c)
if (LTO STREQUAL "full")
set_tests_properties(libc_test_functional_search_insque.wasm PROPERTIES WILL_FAIL TRUE)
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@yamt yamt Jan 13, 2026

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can you add a link to a bug report?

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@alexcrichton alexcrichton Jan 13, 2026

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I don't have a bug report to link to. This repository does not control the source of this test, nor does this repository have WASI-specific source for insque and other functions. (I barely know what those functions are). If you'd like to open an issue I'd be happy to link it here.

endif()
add_libc_test(functional/search_lsearch.c)
add_libc_test(functional/search_tsearch.c)
add_libc_test(functional/snprintf.c)
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