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llvm-project/clang/test/CodeGen/attr-x86-interrupt.c

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[X86] Support 'interrupt' attribute for x86 This attribute may be attached to a function definition and instructs the backend to generate appropriate function entry/exit code so that it can be used directly as an interrupt handler. The IRET instruction, instead of the RET instruction, is used to return from interrupt or exception handlers. All registers, except for the EFLAGS register which is restored by the IRET instruction, are preserved by the compiler. Any interruptible-without-stack-switch code must be compiled with -mno-red-zone since interrupt handlers can and will, because of the hardware design, touch the red zone. interrupt handler must be declared with a mandatory pointer argument: struct interrupt_frame; __attribute__ ((interrupt)) void f (struct interrupt_frame *frame) { ... } and user must properly define the structure the pointer pointing to. exception handler: The exception handler is very similar to the interrupt handler with a different mandatory function signature: #ifdef __x86_64__ typedef unsigned long long int uword_t; #else typedef unsigned int uword_t; #endif struct interrupt_frame; __attribute__ ((interrupt)) void f (struct interrupt_frame *frame, uword_t error_code) { ... } and compiler pops the error code off stack before the IRET instruction. The exception handler should only be used for exceptions which push an error code and all other exceptions must use the interrupt handler. The system will crash if the wrong handler is used. Differential Revision: http://reviews.llvm.org/D15709 llvm-svn: 257867
2016-01-15 12:06:31 +08:00
// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu %s -emit-llvm -o - | FileCheck %s --check-prefix=X86_64_LINUX
// RUN: %clang_cc1 -triple i386-unknown-linux-gnu %s -emit-llvm -o - | FileCheck %s --check-prefix=X86_LINUX
// RUN: %clang_cc1 -triple x86_64-pc-win32 %s -emit-llvm -o - | FileCheck %s --check-prefix=X86_64_WIN
// RUN: %clang_cc1 -triple i386-pc-win32 %s -emit-llvm -o - | FileCheck %s --check-prefix=X86_WIN
// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnux32 %s -emit-llvm -o - | FileCheck %s --check-prefix=X86_64_LINUX
#ifdef __x86_64__
typedef __UINT64_TYPE__ uword;
#else
typedef __UINT32_TYPE__ uword;
#endif
__attribute__((interrupt)) void foo7(int *a, uword b) {}
__attribute__((interrupt)) void foo8(int *a) {}
Change some addUsedGlobal to addUsedOrCompilerUsedGlobal An global value in the `llvm.used` list does not have GC root semantics on ELF targets. This will be changed in a subsequent backend patch. Change some `llvm.used` in the ELF code path to use `llvm.compiler.used` to prevent undesired GC root semantics. Change one extern "C" alias (due to `__attribute__((used))` in extern "C") to use `llvm.compiler.used` on all targets. GNU ld has a rule "`__start_/__stop_` references from a live input section retain the associated C identifier name sections", which LLD may drop entirely (currently refined to exclude SHF_LINK_ORDER/SHF_GROUP) in a future release (the rule makes it clumsy to GC metadata sections; D96914 added a way to try the potential future behavior). For `llvm.used` global values defined in a C identifier name section, keep using `llvm.used` so that the future LLD change will not affect them. rnk kindly categorized the changes: ``` ObjC/blocks: this wants GC root semantics, since ObjC mainly runs on Mac. MS C++ ABI stuff: wants GC root semantics, no change OpenMP: unsure, but GC root semantics probably don't hurt CodeGenModule: affected in this patch to *not* use GC root semantics so that __attribute__((used)) behavior remains the same on ELF, plus two other minor use cases that don't want GC semantics Coverage: Probably want GC root semantics CGExpr.cpp: refers to LTO, wants GC root CGDeclCXX.cpp: one is MS ABI specific, so yes GC root, one is some other C++ init functionality, which should form GC roots (C++ initializers can have side effects and must run) CGDecl.cpp: Changed in this patch for __attribute__((used)) ``` Differential Revision: https://reviews.llvm.org/D97446
2021-02-27 02:42:07 +08:00
// X86_64_LINUX: @llvm.compiler.used = appending global [2 x i8*] [i8* bitcast (void (i32*, i64)* @foo7 to i8*), i8* bitcast (void (i32*)* @foo8 to i8*)], section "llvm.metadata"
[test] Add {{.*}} to make ELF tests immune to dso_local/dso_preemptable/(none) differences For a default visibility external linkage definition, dso_local is set for ELF -fno-pic/-fpie and COFF and Mach-O. Since default clang -cc1 for ELF is similar to -fpic ("PIC Level" is not set), this nuance causes unneeded binary format differences. To make emitted IR similar, ELF -cc1 -fpic will default to -fno-semantic-interposition, which sets dso_local for default visibility external linkage definitions. To make this flip smooth and enable future (dso_local as definition default), this patch replaces (function) `define ` with `define{{.*}} `, (variable/constant/alias) `= ` with `={{.*}} `, or inserts appropriate `{{.*}} `.
2020-12-31 16:27:11 +08:00
// X86_64_LINUX: define{{.*}} x86_intrcc void @foo7(i32* byval(i32) %{{.+}}, i64 %{{.+}})
// X86_64_LINUX: define{{.*}} x86_intrcc void @foo8(i32* byval(i32) %{{.+}})
Resolved Bug 26414. https://llvm.org/bugs/show_bug.cgi?id=26414 Since interrupt handler must be returned with iret, tail call can't be used. Differential Revision: http://reviews.llvm.org/D17853 llvm-svn: 262830
2016-03-07 22:22:46 +08:00
// X86_64_LINUX: "disable-tail-calls"="true"
// X86_64_LINUX-NOT: "disable-tail-calls"="false"
Change some addUsedGlobal to addUsedOrCompilerUsedGlobal An global value in the `llvm.used` list does not have GC root semantics on ELF targets. This will be changed in a subsequent backend patch. Change some `llvm.used` in the ELF code path to use `llvm.compiler.used` to prevent undesired GC root semantics. Change one extern "C" alias (due to `__attribute__((used))` in extern "C") to use `llvm.compiler.used` on all targets. GNU ld has a rule "`__start_/__stop_` references from a live input section retain the associated C identifier name sections", which LLD may drop entirely (currently refined to exclude SHF_LINK_ORDER/SHF_GROUP) in a future release (the rule makes it clumsy to GC metadata sections; D96914 added a way to try the potential future behavior). For `llvm.used` global values defined in a C identifier name section, keep using `llvm.used` so that the future LLD change will not affect them. rnk kindly categorized the changes: ``` ObjC/blocks: this wants GC root semantics, since ObjC mainly runs on Mac. MS C++ ABI stuff: wants GC root semantics, no change OpenMP: unsure, but GC root semantics probably don't hurt CodeGenModule: affected in this patch to *not* use GC root semantics so that __attribute__((used)) behavior remains the same on ELF, plus two other minor use cases that don't want GC semantics Coverage: Probably want GC root semantics CGExpr.cpp: refers to LTO, wants GC root CGDeclCXX.cpp: one is MS ABI specific, so yes GC root, one is some other C++ init functionality, which should form GC roots (C++ initializers can have side effects and must run) CGDecl.cpp: Changed in this patch for __attribute__((used)) ``` Differential Revision: https://reviews.llvm.org/D97446
2021-02-27 02:42:07 +08:00
// X86_LINUX: @llvm.compiler.used = appending global [2 x i8*] [i8* bitcast (void (i32*, i32)* @foo7 to i8*), i8* bitcast (void (i32*)* @foo8 to i8*)], section "llvm.metadata"
[test] Add {{.*}} to make ELF tests immune to dso_local/dso_preemptable/(none) differences For a default visibility external linkage definition, dso_local is set for ELF -fno-pic/-fpie and COFF and Mach-O. Since default clang -cc1 for ELF is similar to -fpic ("PIC Level" is not set), this nuance causes unneeded binary format differences. To make emitted IR similar, ELF -cc1 -fpic will default to -fno-semantic-interposition, which sets dso_local for default visibility external linkage definitions. To make this flip smooth and enable future (dso_local as definition default), this patch replaces (function) `define ` with `define{{.*}} `, (variable/constant/alias) `= ` with `={{.*}} `, or inserts appropriate `{{.*}} `.
2020-12-31 16:27:11 +08:00
// X86_LINUX: define{{.*}} x86_intrcc void @foo7(i32* byval(i32) %{{.+}}, i32 %{{.+}})
// X86_LINUX: define{{.*}} x86_intrcc void @foo8(i32* byval(i32) %{{.+}})
Resolved Bug 26414. https://llvm.org/bugs/show_bug.cgi?id=26414 Since interrupt handler must be returned with iret, tail call can't be used. Differential Revision: http://reviews.llvm.org/D17853 llvm-svn: 262830
2016-03-07 22:22:46 +08:00
// X86_LINUX: "disable-tail-calls"="true"
// X86_LINUX-NOT: "disable-tail-calls"="false"
[X86] Support 'interrupt' attribute for x86 This attribute may be attached to a function definition and instructs the backend to generate appropriate function entry/exit code so that it can be used directly as an interrupt handler. The IRET instruction, instead of the RET instruction, is used to return from interrupt or exception handlers. All registers, except for the EFLAGS register which is restored by the IRET instruction, are preserved by the compiler. Any interruptible-without-stack-switch code must be compiled with -mno-red-zone since interrupt handlers can and will, because of the hardware design, touch the red zone. interrupt handler must be declared with a mandatory pointer argument: struct interrupt_frame; __attribute__ ((interrupt)) void f (struct interrupt_frame *frame) { ... } and user must properly define the structure the pointer pointing to. exception handler: The exception handler is very similar to the interrupt handler with a different mandatory function signature: #ifdef __x86_64__ typedef unsigned long long int uword_t; #else typedef unsigned int uword_t; #endif struct interrupt_frame; __attribute__ ((interrupt)) void f (struct interrupt_frame *frame, uword_t error_code) { ... } and compiler pops the error code off stack before the IRET instruction. The exception handler should only be used for exceptions which push an error code and all other exceptions must use the interrupt handler. The system will crash if the wrong handler is used. Differential Revision: http://reviews.llvm.org/D15709 llvm-svn: 257867
2016-01-15 12:06:31 +08:00
// X86_64_WIN: @llvm.used = appending global [2 x i8*] [i8* bitcast (void (i32*, i64)* @foo7 to i8*), i8* bitcast (void (i32*)* @foo8 to i8*)], section "llvm.metadata"
clang: Add byval on x86_intrcc parameter 0 This will allow removing the special case treatment of the parameter and avoid depending on the pointer's element type.
2020-12-15 05:13:29 +08:00
// X86_64_WIN: define dso_local x86_intrcc void @foo7(i32* byval(i32) %{{.+}}, i64 %{{.+}})
// X86_64_WIN: define dso_local x86_intrcc void @foo8(i32* byval(i32) %{{.+}})
// X86_64_WIN: "disable-tail-calls"="true"
// X86_64_WIN-NOT: "disable-tail-calls"="false"
[X86] Support 'interrupt' attribute for x86 This attribute may be attached to a function definition and instructs the backend to generate appropriate function entry/exit code so that it can be used directly as an interrupt handler. The IRET instruction, instead of the RET instruction, is used to return from interrupt or exception handlers. All registers, except for the EFLAGS register which is restored by the IRET instruction, are preserved by the compiler. Any interruptible-without-stack-switch code must be compiled with -mno-red-zone since interrupt handlers can and will, because of the hardware design, touch the red zone. interrupt handler must be declared with a mandatory pointer argument: struct interrupt_frame; __attribute__ ((interrupt)) void f (struct interrupt_frame *frame) { ... } and user must properly define the structure the pointer pointing to. exception handler: The exception handler is very similar to the interrupt handler with a different mandatory function signature: #ifdef __x86_64__ typedef unsigned long long int uword_t; #else typedef unsigned int uword_t; #endif struct interrupt_frame; __attribute__ ((interrupt)) void f (struct interrupt_frame *frame, uword_t error_code) { ... } and compiler pops the error code off stack before the IRET instruction. The exception handler should only be used for exceptions which push an error code and all other exceptions must use the interrupt handler. The system will crash if the wrong handler is used. Differential Revision: http://reviews.llvm.org/D15709 llvm-svn: 257867
2016-01-15 12:06:31 +08:00
// X86_WIN: @llvm.used = appending global [2 x i8*] [i8* bitcast (void (i32*, i32)* @foo7 to i8*), i8* bitcast (void (i32*)* @foo8 to i8*)], section "llvm.metadata"
clang: Add byval on x86_intrcc parameter 0 This will allow removing the special case treatment of the parameter and avoid depending on the pointer's element type.
2020-12-15 05:13:29 +08:00
// X86_WIN: define dso_local x86_intrcc void @foo7(i32* byval(i32) %{{.+}}, i32 %{{.+}})
// X86_WIN: define dso_local x86_intrcc void @foo8(i32* byval(i32) %{{.+}})
// X86_WIN: "disable-tail-calls"="true"
// X86_WIN-NOT: "disable-tail-calls"="false"