[Clang][LLVM] Support for Fuchsia on ARM #163848
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This introduces the support for 32-bit ARM Fuchsia target which uses the aapcs-linux ABI defaulting to thumbv8a as the target.
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@llvm/pr-subscribers-llvm-ir @llvm/pr-subscribers-clang Author: Petr Hosek (petrhosek) ChangesThis introduces the support for 32-bit ARM Fuchsia target which uses the aapcs-linux ABI defaulting to thumbv8a as the target. Full diff: https://github.com/llvm/llvm-project/pull/163848.diff 10 Files Affected:
diff --git a/clang/lib/Basic/Targets.cpp b/clang/lib/Basic/Targets.cpp
index b7e8bad4f404b..f39c698b5d734 100644
--- a/clang/lib/Basic/Targets.cpp
+++ b/clang/lib/Basic/Targets.cpp
@@ -222,6 +222,8 @@ std::unique_ptr<TargetInfo> AllocateTarget(const llvm::Triple &Triple,
return std::make_unique<OHOSTargetInfo<ARMleTargetInfo>>(Triple, Opts);
case llvm::Triple::FreeBSD:
return std::make_unique<FreeBSDTargetInfo<ARMleTargetInfo>>(Triple, Opts);
+ case llvm::Triple::Fuchsia:
+ return std::make_unique<FuchsiaTargetInfo<ARMleTargetInfo>>(Triple, Opts);
case llvm::Triple::NetBSD:
return std::make_unique<NetBSDTargetInfo<ARMleTargetInfo>>(Triple, Opts);
case llvm::Triple::OpenBSD:
@@ -254,6 +256,8 @@ std::unique_ptr<TargetInfo> AllocateTarget(const llvm::Triple &Triple,
return std::make_unique<AppleMachOARMTargetInfo>(Triple, Opts);
switch (os) {
+ case llvm::Triple::Fuchsia:
+ return std::make_unique<FuchsiaTargetInfo<ARMbeTargetInfo>>(Triple, Opts);
case llvm::Triple::Linux:
return std::make_unique<LinuxTargetInfo<ARMbeTargetInfo>>(Triple, Opts);
case llvm::Triple::NetBSD:
diff --git a/clang/lib/Basic/Targets/ARM.cpp b/clang/lib/Basic/Targets/ARM.cpp
index 3de17d2c829f1..d00a3a453ed52 100644
--- a/clang/lib/Basic/Targets/ARM.cpp
+++ b/clang/lib/Basic/Targets/ARM.cpp
@@ -260,6 +260,7 @@ ARMTargetInfo::ARMTargetInfo(const llvm::Triple &Triple,
: TargetInfo(Triple), FPMath(FP_Default), IsAAPCS(true), LDREX(0),
HW_FP(0) {
bool IsFreeBSD = Triple.isOSFreeBSD();
+ bool IsFuchsia = Triple.isOSFuchsia();
bool IsOpenBSD = Triple.isOSOpenBSD();
bool IsNetBSD = Triple.isOSNetBSD();
bool IsHaiku = Triple.isOSHaiku();
@@ -332,7 +333,7 @@ ARMTargetInfo::ARMTargetInfo(const llvm::Triple &Triple,
default:
if (IsNetBSD)
setABI("apcs-gnu");
- else if (IsFreeBSD || IsOpenBSD || IsHaiku || IsOHOS)
+ else if (IsFreeBSD || IsFuchsia || IsOpenBSD || IsHaiku || IsOHOS)
setABI("aapcs-linux");
else
setABI("aapcs");
diff --git a/clang/lib/Driver/ToolChains/Arch/ARM.cpp b/clang/lib/Driver/ToolChains/Arch/ARM.cpp
index 954ecabe86836..61beb0455147d 100644
--- a/clang/lib/Driver/ToolChains/Arch/ARM.cpp
+++ b/clang/lib/Driver/ToolChains/Arch/ARM.cpp
@@ -290,6 +290,8 @@ void arm::setArchNameInTriple(const Driver &D, const ArgList &Args,
// Thumb2 is the default for V7 on Darwin.
(llvm::ARM::parseArchVersion(Suffix) == 7 &&
Triple.isOSBinFormatMachO()) ||
+ // Thumb2 is the default for Fuchsia.
+ Triple.isOSFuchsia() ||
// FIXME: this is invalid for WindowsCE
Triple.isOSWindows();
@@ -452,6 +454,9 @@ arm::FloatABI arm::getDefaultFloatABI(const llvm::Triple &Triple) {
case llvm::Triple::OpenBSD:
return FloatABI::SoftFP;
+ case llvm::Triple::Fuchsia:
+ return FloatABI::Hard;
+
default:
if (Triple.isOHOSFamily())
return FloatABI::Soft;
diff --git a/clang/test/Driver/arm-abi.c b/clang/test/Driver/arm-abi.c
index 139456cf98e14..b89b969858acb 100644
--- a/clang/test/Driver/arm-abi.c
+++ b/clang/test/Driver/arm-abi.c
@@ -31,6 +31,8 @@
// FreeBSD / OpenBSD default to aapcs-linux
// RUN: %clang -target arm--freebsd- %s -### -o %t.o 2>&1 \
// RUN: | FileCheck -check-prefix=CHECK-AAPCS-LINUX %s
+// RUN: %clang -target arm--fuchsia- %s -### -o %t.o 2>&1 \
+// RUN: | FileCheck -check-prefix=CHECK-AAPCS-LINUX %s
// RUN: %clang -target arm--openbsd- %s -### -o %t.o 2>&1 \
// RUN: | FileCheck -check-prefix=CHECK-AAPCS-LINUX %s
// RUN: %clang -target arm--haiku- %s -### -o %t.o 2>&1 \
diff --git a/clang/test/Driver/fuchsia.c b/clang/test/Driver/fuchsia.c
index cf92f85040901..3fb2a94124cd1 100644
--- a/clang/test/Driver/fuchsia.c
+++ b/clang/test/Driver/fuchsia.c
@@ -2,6 +2,10 @@
// RUN: -resource-dir=%S/Inputs/resource_dir_with_per_target_subdir \
// RUN: --sysroot=%S/platform -fuse-ld=ld 2>&1 \
// RUN: | FileCheck -check-prefixes=CHECK,CHECK-X86_64 %s
+// RUN: %clang -### %s --target=arm-unknown-fuchsia \
+// RUN: -resource-dir=%S/Inputs/resource_dir_with_per_target_subdir \
+// RUN: --sysroot=%S/platform -fuse-ld=ld 2>&1 \
+// RUN: | FileCheck -check-prefixes=CHECK,CHECK-ARMV8A %s
// RUN: %clang -### %s --target=aarch64-unknown-fuchsia \
// RUN: -resource-dir=%S/Inputs/resource_dir_with_per_target_subdir \
// RUN: --sysroot=%S/platform -fuse-ld=ld 2>&1 \
@@ -14,6 +18,10 @@
// RUN: -resource-dir=%S/Inputs/resource_dir_with_per_target_subdir \
// RUN: --sysroot=%S/platform -fuse-ld=ld 2>&1 \
// RUN: | FileCheck -check-prefixes=CHECK,CHECK-X86_64 %s
+// RUN: %clang -### %s --target=arm-fuchsia \
+// RUN: -resource-dir=%S/Inputs/resource_dir_with_per_target_subdir \
+// RUN: --sysroot=%S/platform -fuse-ld=ld 2>&1 \
+// RUN: | FileCheck -check-prefixes=CHECK,CHECK-ARMV8A %s
// RUN: %clang -### %s --target=aarch64-fuchsia \
// RUN: -resource-dir=%S/Inputs/resource_dir_with_per_target_subdir \
// RUN: --sysroot=%S/platform -fuse-ld=ld 2>&1 \
@@ -24,6 +32,7 @@
// RUN: | FileCheck -check-prefixes=CHECK,CHECK-RISCV64 %s
// CHECK: "-cc1"
// CHECK-X86_64: "-triple" "x86_64-unknown-fuchsia"
+// CHECK-ARMV8A: "-triple" "thumbv8a-unknown-fuchsia"
// CHECK-AARCH64: "-triple" "aarch64-unknown-fuchsia"
// CHECK-RISCV64: "-triple" "riscv64-unknown-fuchsia"
// CHECK: "-funwind-tables=2"
diff --git a/llvm/include/llvm/IR/RuntimeLibcalls.h b/llvm/include/llvm/IR/RuntimeLibcalls.h
index 307cc662d2022..ef359830041f5 100644
--- a/llvm/include/llvm/IR/RuntimeLibcalls.h
+++ b/llvm/include/llvm/IR/RuntimeLibcalls.h
@@ -238,7 +238,7 @@ struct RuntimeLibcallsInfo {
static bool hasAEABILibcalls(const Triple &TT) {
return TT.isTargetAEABI() || TT.isTargetGNUAEABI() ||
- TT.isTargetMuslAEABI() || TT.isAndroid();
+ TT.isTargetMuslAEABI() || TT.isOSFuchsia() || TT.isAndroid();
}
LLVM_READONLY
diff --git a/llvm/include/llvm/TargetParser/Triple.h b/llvm/include/llvm/TargetParser/Triple.h
index dc8cd86d2a69a..555533f9b5a09 100644
--- a/llvm/include/llvm/TargetParser/Triple.h
+++ b/llvm/include/llvm/TargetParser/Triple.h
@@ -935,7 +935,8 @@ class Triple {
getEnvironment() == Triple::GNUEABIHF ||
getEnvironment() == Triple::GNUEABIHFT64 ||
getEnvironment() == Triple::OpenHOS ||
- getEnvironment() == Triple::MuslEABIHF || isAndroid()) &&
+ getEnvironment() == Triple::MuslEABIHF ||
+ isAndroid() || isOSFuchsia()) &&
isOSBinFormatELF() && !isOSNetBSD();
}
diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp
index 67ea2dd3df792..2a117cedc9a96 100644
--- a/llvm/lib/Target/ARM/ARMISelLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp
@@ -1089,7 +1089,7 @@ ARMTargetLowering::ARMTargetLowering(const TargetMachine &TM_,
// Register based DivRem for AEABI (RTABI 4.2)
if (TT.isTargetAEABI() || TT.isAndroid() || TT.isTargetGNUAEABI() ||
- TT.isTargetMuslAEABI() || TT.isOSWindows()) {
+ TT.isTargetMuslAEABI() || TT.isOSFuchsia() || TT.isOSWindows()) {
setOperationAction(ISD::SREM, MVT::i64, Custom);
setOperationAction(ISD::UREM, MVT::i64, Custom);
HasStandaloneRem = false;
@@ -20574,7 +20574,7 @@ static TargetLowering::ArgListTy getDivRemArgList(
SDValue ARMTargetLowering::LowerDivRem(SDValue Op, SelectionDAG &DAG) const {
assert((Subtarget->isTargetAEABI() || Subtarget->isTargetAndroid() ||
Subtarget->isTargetGNUAEABI() || Subtarget->isTargetMuslAEABI() ||
- Subtarget->isTargetWindows()) &&
+ Subtarget->isTargetFuchsia() || Subtarget->isTargetWindows()) &&
"Register-based DivRem lowering only");
unsigned Opcode = Op->getOpcode();
assert((Opcode == ISD::SDIVREM || Opcode == ISD::UDIVREM) &&
diff --git a/llvm/lib/Target/ARM/ARMSubtarget.h b/llvm/lib/Target/ARM/ARMSubtarget.h
index b2d368e0ca175..4a0883cc662e7 100644
--- a/llvm/lib/Target/ARM/ARMSubtarget.h
+++ b/llvm/lib/Target/ARM/ARMSubtarget.h
@@ -343,6 +343,7 @@ class ARMSubtarget : public ARMGenSubtargetInfo {
bool isTargetWatchOS() const { return TargetTriple.isWatchOS(); }
bool isTargetWatchABI() const { return TargetTriple.isWatchABI(); }
bool isTargetDriverKit() const { return TargetTriple.isDriverKit(); }
+ bool isTargetFuchsia() const { return TargetTriple.isOSFuchsia(); }
bool isTargetLinux() const { return TargetTriple.isOSLinux(); }
bool isTargetNetBSD() const { return TargetTriple.isOSNetBSD(); }
bool isTargetWindows() const { return TargetTriple.isOSWindows(); }
diff --git a/llvm/lib/TargetParser/ARMTargetParser.cpp b/llvm/lib/TargetParser/ARMTargetParser.cpp
index 08944e6148a00..5e62562932508 100644
--- a/llvm/lib/TargetParser/ARMTargetParser.cpp
+++ b/llvm/lib/TargetParser/ARMTargetParser.cpp
@@ -567,8 +567,8 @@ StringRef ARM::computeDefaultTargetABI(const Triple &TT) {
default:
if (TT.isOSNetBSD())
return "apcs-gnu";
- if (TT.isOSFreeBSD() || TT.isOSOpenBSD() || TT.isOSHaiku() ||
- TT.isOHOSFamily())
+ if (TT.isOSFreeBSD() || TT.isOSFuchsia() || TT.isOSOpenBSD() ||
+ TT.isOSHaiku() || TT.isOHOSFamily())
return "aapcs-linux";
return "aapcs";
}
@@ -648,6 +648,8 @@ StringRef ARM::getARMCPUForArch(const llvm::Triple &Triple, StringRef MArch) {
}
case llvm::Triple::OpenBSD:
return "cortex-a8";
+ case llvm::Triple::Fuchsia:
+ return "cortex-a53";
default:
switch (Triple.getEnvironment()) {
case llvm::Triple::EABIHF:
|
|
✅ With the latest revision this PR passed the C/C++ code formatter. |
| case llvm::Triple::OpenBSD: | ||
| return FloatABI::SoftFP; | ||
|
|
||
| case llvm::Triple::Fuchsia: |
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I'm wondering about this. It seems like it shouldn't be needed because the default case should already derive it correctly from Triple.getEnvironment().
But that's because I'm assuming that it should be GNUEABIHF, as it is in the most-similar existing target, arm*-linux-gnueabihf. In looking through what that's used for, it's frankly hard to tell. There are few checks for it directly. Things like isTargetEHABICompatible() definitely need to come up true, but I'm not sure what getEnvironment() value we have, and many of them are matched there.
Then there's isTargetGNUAEABI(), and isGNUEnvironment(). Those are tested in a bunch of places. Most of those we want to match what GNUEABIHF would give us. But in a few we might not (glibc-specific assumptions).
We can probably iterate to get all these corners right. But we'll probably need to actually investigate each use proactively and get the knobs right for the Fuchsia context rather than only tweak things as problems arise.
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For Fuchsia, on other architectures we don't specify any environment and I felt that requiring environment only for ARM (i.e. using arm-fuchsia-gnueabihf) would be inconsistent. Furthermore, as you pointed out, there are also place where GNUEABIHF behavior is likely undesirable for Fuchsia so I decide to instead directly conditionalize this and other places on OS rather than environment. I do expect we might need to another pass to make sure we get the right behavior, but at least for the initial version this change should be sufficient.
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Oh, I didn't realize that this "environment" was tied to the normalized triple text itself. I agree, we want the maximal triple to be something like armv8-unknown-fuchsia at most and canonically would tell people to just use --target=arm-fuchsia for sure. I just meant that it seemed likely that more actual choices would match what ::GNUEABIHF is used for than not, at a guess. (We are going for pretty much the armv7-linux-gnueabihf ABI in terms of most things: ISA support, code-gen details, C-visible core ABI issues, though armv8+... for -march and some differences in libc ABI expectations.)
| if (IsNetBSD) | ||
| setABI("apcs-gnu"); | ||
| else if (IsFreeBSD || IsOpenBSD || IsHaiku || IsOHOS) | ||
| else if (IsFreeBSD || IsFuchsia || IsOpenBSD || IsHaiku || IsOHOS) |
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I haven't actually been able to discern how aapcs-linux actually differs from aapcs or aapcs-vfp.
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The resources I found when researching this is https://wiki.debian.org/ArmEabiPort and https://kanj.github.io/elfs/book/armMusl/cross-tools/abi.html and according to those the only difference is enum size: aapcs defines enums to be a variable sized type, while with aapcs-linux they are always ints (4 bytes).
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Ah right, that is the default for -fshort-enum IOW. I don't know why Linux long ago diverged from the clearly-published AAPCS on this, but for us matching Linux ABIs for this sort of detail (things likely relevant to porting code from arm-linux distinct from direct OS dependencies) is more important than published standards or CPU vendor's recommendations. It would be nice if the code made it easier to discover that aapcs-linux means aapcs + -fshort-enum.
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It's especially notable if not only the glibc-based Linux configurations, but musl, android, etc. are also still doing -fshort-enum / aapcs-linux then there is no question that Fuchsia wants to follow them all. If e.g. Android differed from -gnueabihf on this then we might consider whether to align with one or the other.
3 participants
This introduces the support for 32-bit ARM Fuchsia target which uses the aapcs-linux ABI defaulting to thumbv8a as the target.