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[ELF][CHERI] Rewrite exception-table test in LLVM IR
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This avoids one dependency on clang and will hopefully allow removing it
entirely soon. Ideally this would be written as an assembly test but
adding the right directives for EH tables is tedious, so I went for
IR instead.
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@arichardson
arichardson committed Sep 12, 2024
1 parent d2e741e commit 1355df3
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104 changes: 0 additions & 104 deletions lld/test/ELF/cheri/exception-table.cpp
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215 changes: 215 additions & 0 deletions lld/test/ELF/cheri/exception-table.ll
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Original file line number Diff line number Diff line change
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; RUN: %cheri_purecap_llc --relocation-model=pic < %s -filetype=obj -o %t.o
; RUN: llvm-readobj -r %t.o | FileCheck %s --check-prefix=MIPS-OBJ-RELOCS
; RUN: %riscv64_cheri_purecap_llc --relocation-model=pic < %s -filetype=obj -o %t-riscv64.o
; RUN: llvm-readobj -r %t-riscv64.o | FileCheck %s --check-prefix=RV64-OBJ-RELOCS
;; Should have two relocations against a local alias for _Z4testll
; MIPS-OBJ-RELOCS: Section ({{.+}}) .rela.gcc_except_table {
; MIPS-OBJ-RELOCS-NEXT: R_MIPS_CHERI_CAPABILITY/R_MIPS_NONE/R_MIPS_NONE .L_Z4testll$local 0x80
; MIPS-OBJ-RELOCS-NEXT: R_MIPS_CHERI_CAPABILITY/R_MIPS_NONE/R_MIPS_NONE .L_Z4testll$local 0x60
; MIPS-OBJ-RELOCS-NEXT: R_MIPS_CHERI_CAPABILITY/R_MIPS_NONE/R_MIPS_NONE .L_Z5test2ll$local 0x60
; MIPS-OBJ-RELOCS-NEXT: R_MIPS_PC32/R_MIPS_NONE/R_MIPS_NONE .L_ZTIl.DW.stub 0x0
; MIPS-OBJ-RELOCS-NEXT: }
; RV64-OBJ-RELOCS: Section ({{.+}}) .rela.gcc_except_table {
; RV64-OBJ-RELOCS-NEXT: R_RISCV_ADD32 - 0x0
; RV64-OBJ-RELOCS-NEXT: R_RISCV_SUB32 - 0x0
; RV64-OBJ-RELOCS-NEXT: R_RISCV_ADD32 - 0x0
; RV64-OBJ-RELOCS-NEXT: R_RISCV_SUB32 - 0x0
; RV64-OBJ-RELOCS-NEXT: R_RISCV_CHERI_CAPABILITY .L_Z4testll$local 0x5C
; RV64-OBJ-RELOCS-NEXT: R_RISCV_ADD32 - 0x0
; RV64-OBJ-RELOCS-NEXT: R_RISCV_SUB32 - 0x0
; RV64-OBJ-RELOCS-NEXT: R_RISCV_ADD32 - 0x0
; RV64-OBJ-RELOCS-NEXT: R_RISCV_SUB32 - 0x0
; RV64-OBJ-RELOCS-NEXT: R_RISCV_CHERI_CAPABILITY .L_Z4testll$local 0x48
; RV64-OBJ-RELOCS-NEXT: R_RISCV_ADD32 - 0x0
; RV64-OBJ-RELOCS-NEXT: R_RISCV_SUB32 - 0x0
; RV64-OBJ-RELOCS-NEXT: R_RISCV_ADD32 - 0x0
; RV64-OBJ-RELOCS-NEXT: R_RISCV_SUB32 - 0x0
; RV64-OBJ-RELOCS-NEXT: R_RISCV_ADD32 - 0x0
; RV64-OBJ-RELOCS-NEXT: R_RISCV_SUB32 - 0x0
; RV64-OBJ-RELOCS-NEXT: R_RISCV_ADD32 - 0x0
; RV64-OBJ-RELOCS-NEXT: R_RISCV_SUB32 - 0x0
; RV64-OBJ-RELOCS-NEXT: R_RISCV_CHERI_CAPABILITY .L_Z5test2ll$local 0x48
; RV64-OBJ-RELOCS-NEXT: R_RISCV_ADD32 - 0x0
; RV64-OBJ-RELOCS-NEXT: R_RISCV_SUB32 - 0x0
; RV64-OBJ-RELOCS-NEXT: R_RISCV_ADD32 - 0x0
; RV64-OBJ-RELOCS-NEXT: R_RISCV_SUB32 - 0x0
; RV64-OBJ-RELOCS-NEXT: R_RISCV_32_PCREL .L_ZTIl.DW.stub 0x0
; RV64-OBJ-RELOCS-NEXT: }

;; This should work with both -z text and -z notext
;; Check that .gcc_except_table ends up in the relro section and the relocations are correct
; RUN: ld.lld -shared %t.o -o %t.so -z notext
; RUN: llvm-readelf -r --section-mapping --sections --program-headers --cap-relocs %t.so | FileCheck %s --check-prefixes=HEADERS,MIPS-RELOCS
; RUN: ld.lld -shared %t.o -o %t.so -z text
; RUN: llvm-readelf -r --section-mapping %t.so
; RUN: llvm-readelf -r --section-mapping --sections --program-headers --cap-relocs %t.so | FileCheck %s --check-prefixes=HEADERS,MIPS-RELOCS

; HEADERS-LABEL: There are 10 program headers, starting at
; HEADERS-EMPTY:
; HEADERS-NEXT: Program Headers:
; HEADERS-NEXT: Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align
; HEADERS-NEXT: PHDR 0x{{.+}} 0x{{.+}} 0x{{.+}} 0x{{.+}} 0x{{.+}} R 0x8
; HEADERS-NEXT: LOAD 0x{{.+}} 0x{{.+}} 0x{{.+}} 0x{{.+}} 0x{{.+}} R 0x10000
; HEADERS-NEXT: LOAD 0x{{.+}} 0x{{.+}} 0x{{.+}} 0x{{.+}} 0x{{.+}} R E 0x10000
; HEADERS-NEXT: LOAD 0x{{.+}} 0x{{.+}} 0x{{.+}} 0x{{.+}} 0x{{.+}} RW 0x10000
; HEADERS-NEXT: LOAD 0x{{.+}} 0x{{.+}} 0x{{.+}} 0x{{.+}} 0x{{.+}} RW 0x10000
; HEADERS-NEXT: DYNAMIC 0x{{.+}} 0x{{.+}} 0x{{.+}} 0x{{.+}} 0x{{.+}} R 0x8
; HEADERS-NEXT: GNU_RELRO 0x{{.+}} 0x{{.+}} 0x{{.+}} 0x{{.+}} 0x{{.+}} R 0x1
; HEADERS-NEXT: GNU_STACK 0x{{.+}} 0x{{.+}} 0x{{.+}} 0x{{.+}} 0x{{.+}} RW 0x0
; HEADERS-NEXT: OPTIONS 0x{{.+}} 0x{{.+}} 0x{{.+}} 0x{{.+}} 0x{{.+}} R 0x8
; HEADERS-NEXT: ABIFLAGS 0x{{.+}} 0x{{.+}} 0x{{.+}} 0x{{.+}} 0x{{.+}} R 0x8
; HEADERS-EMPTY:
; HEADERS-NEXT: Section to Segment mapping:
; HEADERS-NEXT: Segment Sections...
; HEADERS-NEXT: 00
; HEADERS-NEXT: 01 .MIPS.abiflags .MIPS.options .dynsym .hash .dynamic .dynstr .rel.dyn .rel.plt .eh_frame __cap_relocs {{$}}
; HEADERS-NEXT: 02 .text
; HEADERS-NEXT: 03 .gcc_except_table
; HEADERS-NEXT: 04 .data .captable .got
; HEADERS-NEXT: 05 .dynamic
; HEADERS-NEXT: 06 .gcc_except_table
; HEADERS-NEXT: 07
; HEADERS-NEXT: 08 .MIPS.options
; HEADERS-NEXT: 09 .MIPS.abiflags
; HEADERS-NEXT: None .bss .mdebug.abi64 .pdr .comment .symtab .shstrtab .strtab

; MIPS-RELOCS-LABEL: Relocation section '.rel.dyn' {{.+}} contains 2 entries:
; MIPS-RELOCS-NEXT: Offset Info Type Symbol's Value Symbol's Name
; MIPS-RELOCS-NEXT: R_MIPS_CHERI_CAPABILITY/R_MIPS_NONE/R_MIPS_NONE 0000000000000000 _ZTIl
; MIPS-RELOCS-NEXT: R_MIPS_CHERI_CAPABILITY/R_MIPS_NONE/R_MIPS_NONE 0000000000000000 __gxx_personality_v0
; MIPS-RELOCS-EMPTY:
; MIPS-RELOCS-NEXT: Relocation section '.rel.plt' at offset {{.+}} contains 3 entries:
; MIPS-RELOCS-NEXT: Offset Info Type Symbol's Value Symbol's Name
; MIPS-RELOCS-NEXT: R_MIPS_CHERI_CAPABILITY_CALL/R_MIPS_NONE/R_MIPS_NONE 0000000000000000 _Z11external_fnl
; MIPS-RELOCS-NEXT: R_MIPS_CHERI_CAPABILITY_CALL/R_MIPS_NONE/R_MIPS_NONE 0000000000000000 __cxa_begin_catch
; MIPS-RELOCS-NEXT: R_MIPS_CHERI_CAPABILITY_CALL/R_MIPS_NONE/R_MIPS_NONE 0000000000000000 __cxa_end_catch

;; Local relocations for exception handling:
; MIPS-RELOCS-NEXT: CHERI __cap_relocs [
; MIPS-RELOCS-NEXT: 0x02{{.+}} Base: 0x1{{.+}} (.L_Z4testll$local+128) Length: 160 Perms: Function
; MIPS-RELOCS-NEXT: 0x02{{.+}} Base: 0x1{{.+}} (.L_Z4testll$local+96) Length: 160 Perms: Function
; MIPS-RELOCS-NEXT: 0x02{{.+}} Base: 0x1{{.+}} (.L_Z5test2ll$local+96) Length: 168 Perms: Function
; MIPS-RELOCS-NEXT: ]

;; Should also emit __cap_relocs for RISC-V:
; RUN: ld.lld -shared %t-riscv64.o -o %t.so
; RUN: llvm-readelf -r --cap-relocs %t.so | FileCheck %s --check-prefixes=RV64-RELOCS
; RV64-RELOCS: CHERI __cap_relocs [
; RV64-RELOCS-NEXT: 0x002{{.+}} Base: 0x1{{.+}} (.L_Z4testll$local+92) Length: 116 Perms: Function
; RV64-RELOCS-NEXT: 0x002{{.+}} Base: 0x1{{.+}} (.L_Z4testll$local+72) Length: 116 Perms: Function
; RV64-RELOCS-NEXT: 0x002{{.+}} Base: 0x1{{.+}} (.L_Z5test2ll$local+72) Length: 124 Perms: Function
; RV64-RELOCS-NEXT: ]

; IR was generated from the following code:
; long external_fn(long arg);
;
; long test(long arg, long arg2) {
; long a = 0;
; long b = 0;
; try {
; a = external_fn(arg);
; } catch (...) {
; return -1;
; }
; try {
; b = external_fn(arg2);
; } catch (...) {
; return a;
; }
; return a + b;
; }
;
; long test2(long arg, long arg2) {
; try {
; return external_fn(arg) - external_fn(arg2);
; } catch (long &err) {
; return err;
; } catch (...) {
; return -1;
; }
; }

@_ZTIl = external dso_local addrspace(200) constant ptr addrspace(200)

define dso_local noundef i64 @_Z4testll(i64 noundef %arg, i64 noundef %arg2) local_unnamed_addr addrspace(200) uwtable personality ptr addrspace(200) @__gxx_personality_v0 {
entry:
%call = invoke noundef i64 @_Z11external_fnl(i64 noundef %arg)
to label %invoke.cont unwind label %lpad

invoke.cont:
%call3 = invoke noundef i64 @_Z11external_fnl(i64 noundef %arg2)
to label %invoke.cont2 unwind label %lpad1

lpad:
%0 = landingpad { ptr addrspace(200), i32 }
catch ptr addrspace(200) null
%1 = extractvalue { ptr addrspace(200), i32 } %0, 0
%2 = tail call ptr addrspace(200) @__cxa_begin_catch(ptr addrspace(200) %1) nounwind
tail call void @__cxa_end_catch()
br label %cleanup

invoke.cont2:
%add = add nsw i64 %call3, %call
br label %cleanup

lpad1:
%3 = landingpad { ptr addrspace(200), i32 }
catch ptr addrspace(200) null
%4 = extractvalue { ptr addrspace(200), i32 } %3, 0
%5 = tail call ptr addrspace(200) @__cxa_begin_catch(ptr addrspace(200) %4) nounwind
tail call void @__cxa_end_catch()
br label %cleanup

cleanup:
%retval.0 = phi i64 [ %add, %invoke.cont2 ], [ %call, %lpad1 ], [ -1, %lpad ]
ret i64 %retval.0
}

declare dso_local noundef i64 @_Z11external_fnl(i64 noundef) local_unnamed_addr addrspace(200)

declare dso_local i32 @__gxx_personality_v0(...) addrspace(200)

declare dso_local ptr addrspace(200) @__cxa_begin_catch(ptr addrspace(200)) local_unnamed_addr addrspace(200)

declare dso_local void @__cxa_end_catch() local_unnamed_addr addrspace(200)

; Function Attrs: mustprogress uwtable
define dso_local noundef i64 @_Z5test2ll(i64 noundef %arg, i64 noundef %arg2) local_unnamed_addr addrspace(200) #0 personality ptr addrspace(200) @__gxx_personality_v0 {
entry:
%call = invoke noundef i64 @_Z11external_fnl(i64 noundef %arg)
to label %invoke.cont unwind label %lpad

invoke.cont:
%call2 = invoke noundef i64 @_Z11external_fnl(i64 noundef %arg2)
to label %invoke.cont1 unwind label %lpad

invoke.cont1:
%sub = sub nsw i64 %call, %call2
br label %return

lpad:
%0 = landingpad { ptr addrspace(200), i32 }
catch ptr addrspace(200) @_ZTIl
catch ptr addrspace(200) null
%1 = extractvalue { ptr addrspace(200), i32 } %0, 0
%2 = extractvalue { ptr addrspace(200), i32 } %0, 1
%3 = tail call i32 @llvm.eh.typeid.for(ptr addrspacecast (ptr addrspace(200) @_ZTIl to ptr)) nounwind
%matches = icmp eq i32 %2, %3
%4 = tail call ptr addrspace(200) @__cxa_begin_catch(ptr addrspace(200) %1) nounwind
br i1 %matches, label %catch3, label %catch

catch3:
%5 = load i64, ptr addrspace(200) %4, align 8
tail call void @__cxa_end_catch() nounwind
br label %return

catch:
tail call void @__cxa_end_catch()
br label %return

return:
%retval.0 = phi i64 [ %sub, %invoke.cont1 ], [ %5, %catch3 ], [ -1, %catch ]
ret i64 %retval.0
}

declare i32 @llvm.eh.typeid.for(ptr) addrspace(200)
3 changes: 2 additions & 1 deletion lld/test/ELF/cheri/lit.local.cfg
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Original file line number Diff line number Diff line change
Expand Up @@ -26,7 +26,8 @@ config.lld = lit.util.which('ld.lld', config.llvm_tools_dir)
# These substitutions rely on %clang, etc. so must come before even if clang isn't found
add_sub('%clang_link_purecap ', '%cheri_purecap_clang ' +
'-fuse-ld=' + config.lld + ' -nostdlib -Wl,-melf64btsmip_cheri_fbsd ')
local_llvm_config.add_cheri_tool_substitutions(['llvm-mc'])
local_llvm_config.use_llvm_tool("llc")
local_llvm_config.add_cheri_tool_substitutions(['llvm-mc', 'llc'])
local_llvm_config.use_clang(required=False)
if config.clang:
if lit_config.debug:
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