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utils: Pass linker flags to the Swift flags #88758

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64 changes: 46 additions & 18 deletions utils/build.ps1
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Original file line number Diff line number Diff line change
Expand Up @@ -2105,6 +2105,22 @@ function Build-CMakeProject {
# Helper cmdlet to add linker flags with the appropriate handling based on
# the linker driver and CMake version.
function Convert-LinkerFlags([string[]]$Value) {
# CMake only passes CMAKE_EXE_LINKER_FLAGS to Swift executables starting
# with CMake 4.4, which CMP0214 set to NEW. CMAKE_SHARED_LINKER_FLAGS
# are passed to Swift shared libraries when CMP0157 is set to NEW, but
# only after CMake 3.30.
# To work around these issues, add the linker flags directly to
# CMAKE_Swift_FLAGS with the `-Xlinker` prefix, until CMake 4.4 is used to
# build the toolchain.
if ($UseSwift) {
$SwiftLinkerFlags = @()
foreach ($Flag in $Value) {
$SwiftLinkerFlags += "-Xlinker"
$SwiftLinkerFlags += $Flag
}
Add-FlagsDefine $Defines CMAKE_Swift_FLAGS $SwiftLinkerFlags
}

switch ($FlagHandling) {
CMP0181 {
$Value | ForEach-Object { "LINKER:$_" }
Expand Down Expand Up @@ -2237,21 +2253,31 @@ function Build-CMakeProject {
Add-FlagsDefine $Defines CMAKE_Swift_FLAGS $(& $SwiftCompiler.DebugFlags $DebugFormat)
} else {
Add-FlagsDefine $Defines CMAKE_Swift_FLAGS @("-gnone")
[string[]] $SwiftFlags = @();

$SwiftFlags += if ($SwiftSDK) {
@("-sdk", $SwiftSDK)
} else {
@()
}

$SwiftFlags += if ($DebugInfo) {
if ($DebugFormat -eq "dwarf") {
@("-g", "-debug-info-format=dwarf", "-use-ld=lld-link")
} else {
@("-g", "-debug-info-format=codeview")
}
} else {
@("-gnone")
}

if ($CMakePassesSwiftLinkerFlags) {
# CMake 3.30+ passes all linker flags to Swift as the linker driver,
# including those from the internal CMake modules files, without
# a `-Xlinker` prefix. This causes build failures as Swift cannot
# parse linker flags.
# Overwrite the release linker flags to be empty to avoid this.
# CMake 3.30+ passes CMAKE_SHARED_LINKER_FLAGS to Swift shared
# libraries (via CMP0157). CMake's MSVC platform files set
# release-config linker flags that the Swift driver doesn't
# understand. Clear them to prevent build failures.
Add-KeyValueIfNew $Defines CMAKE_EXE_LINKER_FLAGS_RELEASE ""
Add-KeyValueIfNew $Defines CMAKE_SHARED_LINKER_FLAGS_RELEASE ""
} else {
# Disable EnC as that introduces padding in the conformance tables
Add-FlagsDefine $Defines CMAKE_Swift_FLAGS @("-Xlinker", "/INCREMENTAL:NO")
# Swift requires COMDAT folding and de-duplication
Add-FlagsDefine $Defines CMAKE_Swift_FLAGS @("-Xlinker", "/OPT:REF", "-Xlinker", "/OPT:ICF")
}

Add-FlagsDefine $Defines CMAKE_Swift_FLAGS $SwiftCompiler.Flags
Expand All @@ -2260,6 +2286,8 @@ function Build-CMakeProject {
Add-FlagsDefine $Defines CMAKE_Swift_FLAGS_RELWITHDEBINFO "-O"
}

# Disable Edit-and-Continue as that introduces padding in the conformance tables.
# COMDAT folding and de-duplication are required by Swift.
Add-LinkerFlagsDefine $Defines @("/INCREMENTAL:NO", "/OPT:REF", "/OPT:ICF")
Add-SharedLinkerFlagsDefine $Defines @("/MANIFEST:NO")
Add-KeyValueIfNew $Defines CMAKE_USER_MAKE_RULES_OVERRIDE `
Expand All @@ -2273,16 +2301,16 @@ function Build-CMakeProject {
# is no need to set them explicitly above.
Add-KeyValueIfNew $Defines CMAKE_MSVC_DEBUG_INFORMATION_FORMAT Embedded
Add-KeyValueIfNew $Defines CMAKE_POLICY_DEFAULT_CMP0141 NEW
}

if ($DebugFormat -eq "dwarf" -and -not ($UseMSVCCompilers.Contains("C") -or $UseMSVCCompilers.Contains("CXX"))) {
# The linker flags are shared across every language, and these are
# `lld-link.exe` arguments, not `link.exe`.
# TODO: Investigate supporting fission with PE/COFF, this should
# avoid the `longsections` warning.
Add-LinkerFlagsDefine $Defines @("/DEBUG:DWARF", "/IGNORE:longsections")
} else {
Add-LinkerFlagsDefine $Defines @("/DEBUG")

# The linker flags are shared across every language, and `/IGNORE:longsections` is an
# `lld-link.exe` argument, not `link.exe`, so this can only be enabled when we use
# `lld-link.exe` for linking.
# TODO: Investigate supporting fission with PE/COFF, this should avoid this warning.
if ($DebugFormat -eq "dwarf" -and -not $UseMSVC) {
Add-LinkerFlagsDefine $Defines @("/IGNORE:longsections")
}
}
}
}
Expand Down