; RUN: opt -passes=bpf-preserve-static-offset -mtriple=bpf-pc-linux -S -o - %s 2>&1 | FileCheck %s ; ; If load offset is not a constant bpf-preserve-static-offset should report a ; warning and remove preserve.static.offset call. ; ; Source: ; #define __ctx __attribute__((preserve_static_offset)) ; ; struct foo { ; int a[7]; ; } __ctx; ; ; extern void consume(int); ; ; void bar(struct foo *p, unsigned long i) { ; consume(p->a[i]); ; } ; ; Compilation flag: ; clang -cc1 -O2 -debug-info-kind=line-tables-only -triple bpf \ ; -S -emit-llvm -disable-llvm-passes -o - \ ; | opt -passes=function(sroa) -S -o - ; CHECK: warning: some-file.c:10:11: in function bar void (ptr, i64): ; CHECK-SAME: Non-constant offset in access to a field of a type marked with ; CHECK-SAME: preserve_static_offset might be rejected by BPF verifier %struct.foo = type { [7 x i32] } ; Function Attrs: nounwind define dso_local void @bar(ptr noundef %p, i64 noundef %i) #0 !dbg !5 { entry: %0 = call ptr @llvm.preserve.static.offset(ptr %p), !dbg !8 %a = getelementptr inbounds %struct.foo, ptr %0, i32 0, i32 0, !dbg !8 %arrayidx = getelementptr inbounds [7 x i32], ptr %a, i64 0, i64 %i, !dbg !9 %1 = load i32, ptr %arrayidx, align 4, !dbg !9, !tbaa !10 call void @consume(i32 noundef %1), !dbg !14 ret void, !dbg !15 } ; CHECK: define dso_local void @bar(ptr noundef %[[p:.*]], i64 noundef %[[i:.*]]) ; CHECK: %[[a:.*]] = getelementptr inbounds %struct.foo, ptr %[[p]], i32 0, i32 0, !dbg ; CHECK-NEXT: %[[arrayidx:.*]] = getelementptr inbounds [7 x i32], ptr %[[a]], i64 0, i64 %[[i]], !dbg ; CHECK-NEXT: %[[v5:.*]] = load i32, ptr %[[arrayidx]], align 4, !dbg {{.*}}, !tbaa ; CHECK-NEXT: call void @consume(i32 noundef %[[v5]]), !dbg declare void @consume(i32 noundef) #1 ; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none) declare ptr @llvm.preserve.static.offset(ptr readnone) #2 attributes #0 = { nounwind "no-trapping-math"="true" "stack-protector-buffer-size"="8" } attributes #1 = { "no-trapping-math"="true" "stack-protector-buffer-size"="8" } attributes #2 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) } !llvm.dbg.cu = !{!0} !llvm.module.flags = !{!2, !3} !llvm.ident = !{!4} !0 = distinct !DICompileUnit(language: DW_LANG_C11, file: !1, producer: "clang", isOptimized: true, runtimeVersion: 0, emissionKind: LineTablesOnly, splitDebugInlining: false, nameTableKind: None) !1 = !DIFile(filename: "some-file.c", directory: "/some/dir/") !2 = !{i32 2, !"Debug Info Version", i32 3} !3 = !{i32 1, !"wchar_size", i32 4} !4 = !{!"clang"} !5 = distinct !DISubprogram(name: "bar", scope: !1, file: !1, line: 9, type: !6, scopeLine: 9, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0) !6 = !DISubroutineType(types: !7) !7 = !{} !8 = !DILocation(line: 10, column: 14, scope: !5) !9 = !DILocation(line: 10, column: 11, scope: !5) !10 = !{!11, !11, i64 0} !11 = !{!"int", !12, i64 0} !12 = !{!"omnipotent char", !13, i64 0} !13 = !{!"Simple C/C++ TBAA"} !14 = !DILocation(line: 10, column: 3, scope: !5) !15 = !DILocation(line: 11, column: 1, scope: !5)