Make the default triple optional by allowing an empty string

When building LLVM as a (potentially dynamic) library that can be linked against
by multiple compilers, the default triple is not really meaningful.
We allow to explicitely set it to an empty string when configuring LLVM.
In this case, said "target independent" tests in the test suite that are using
the default triple are disabled by matching the newly available feature
"default_triple".

Reviewers: probinson, echristo
Differential Revision: http://reviews.llvm.org/D12660

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 247775

1 files changed, 182 insertions, 0 deletions

diff --git a/llvm/test/DebugInfo/Generic/missing-abstract-variable.ll b/llvm/test/DebugInfo/Generic/missing-abstract-variable.ll
new file mode 100644
index 00000000000..0ebb5a28edc
--- /dev/null
+++ b/llvm/test/DebugInfo/Generic/missing-abstract-variable.ll
@@ -0,0 +1,182 @@
+; REQUIRES: object-emission
+
+; RUN: %llc_dwarf -O0 -filetype=obj < %s | llvm-dwarfdump -debug-dump=info - | FileCheck %s
+
+; The formal parameter 'b' for Function 'x' when inlined within 'a' is lost on
+; mips and powerpc64 (and on x86_64 at at least -O2). Presumably this is a
+; SelectionDAG issue (do mips/powerpc64 use FastISel?).
+; XFAIL: mips, powerpc64, s390x, sparc
+
+; Build from the following source with clang -O2.
+
+; The important details are that 'x's abstract definition is first built during
+; the definition of 'b', where the parameter to 'x' is constant and so 'x's 's'
+; variable is optimized away. No abstract definition DIE for 's' is constructed.
+; Then, during 'a' emission, the abstract DbgVariable for 's' is created, but
+; the abstract DIE isn't (since the abstract definition for 'b' is already
+; built). This results in 's' inlined in 'a' being emitted with its name, line,
+; file there, rather than referencing an abstract definition.
+
+; extern int t;
+;
+; void f(int);
+;
+; inline void x(bool b) {
+;   if (b) {
+;     int s = t;
+;     f(s);
+;   }
+;   f(0);
+; }
+;
+; void b() {
+;   x(false);
+; }
+;
+; void a(bool u) {
+;   x(u);
+; }
+
+; CHECK: [[X_DECL:.*]]: DW_TAG_subprogram
+; CHECK-NOT: DW_TAG
+; CHECK:   DW_AT_name {{.*}} "x"
+; CHECK-NOT: {{DW_TAG|NULL}}
+; CHECK:   DW_TAG_formal_parameter
+; CHECK-NOT: DW_TAG
+; CHECK:     DW_AT_name {{.*}} "b"
+; CHECK-NOT: {{DW_TAG|NULL}}
+; CHECK:       DW_TAG_lexical_block
+; CHECK-NOT: {{DW_TAG|NULL}}
+; CHECK:   DW_TAG_variable
+; CHECK-NOT: DW_TAG
+; CHECK:         DW_AT_name {{.*}} "s"
+
+; CHECK: DW_TAG_subprogram
+; CHECK-NOT: DW_TAG
+; CHECK:   DW_AT_name {{.*}} "b"
+; CHECK-NOT: {{DW_TAG|NULL}}
+; CHECK:   DW_TAG_inlined_subroutine
+; CHECK-NOT: DW_TAG
+; CHECK:     DW_AT_abstract_origin {{.*}} {[[X_DECL]]}
+; CHECK-NOT: {{DW_TAG|NULL}}
+; CHECK:     DW_TAG_formal_parameter
+; CHECK-NOT: DW_TAG
+; CHECK:       DW_AT_abstract_origin {{.*}} "b"
+; Notice 'x's local variable 's' is missing. Not necessarily a bug here,
+; since it's been optimized entirely away and it should be described in
+; abstract subprogram.
+; CHECK-NOT: DW_TAG
+; CHECK: NULL
+; CHECK-NOT: DW_TAG
+; CHECK: NULL
+
+; CHECK: DW_TAG_subprogram
+; CHECK-NOT: DW_TAG
+; CHECK:   DW_AT_name {{.*}} "a"
+; CHECK-NOT: {{DW_TAG|NULL}}
+; CHECK:   DW_TAG_formal_parameter
+; CHECK-NOT: {{DW_TAG|NULL}}
+; CHECK:   DW_TAG_inlined_subroutine
+; CHECK-NOT: DW_TAG
+; CHECK:     DW_AT_abstract_origin {{.*}} {[[X_DECL]]}
+; CHECK-NOT: {{DW_TAG|NULL}}
+; FIXME: This formal parameter goes missing at least at -O2 (& on
+; mips/powerpc), maybe before that. Perhaps SelectionDAG is to blame (and
+; fastisel succeeds).
+; CHECK:     DW_TAG_formal_parameter
+; CHECK-NOT: DW_TAG
+; CHECK:       DW_AT_abstract_origin {{.*}} "b"
+
+; CHECK-NOT: {{DW_TAG|NULL}}
+; CHECK:     DW_TAG_lexical_block
+; CHECK-NOT: {{DW_TAG|NULL}}
+; CHECK:       DW_TAG_variable
+; CHECK-NOT: DW_TAG
+; CHECK:         DW_AT_abstract_origin {{.*}} "s"
+
+@t = external global i32
+
+; Function Attrs: uwtable
+define void @_Z1bv() #0 {
+entry:
+  tail call void @llvm.dbg.value(metadata i1 false, i64 0, metadata !25, metadata !DIExpression()), !dbg !27
+  tail call void @_Z1fi(i32 0), !dbg !28
+  ret void, !dbg !29
+}
+
+; Function Attrs: uwtable
+define void @_Z1ab(i1 zeroext %u) #0 {
+entry:
+  tail call void @llvm.dbg.value(metadata i1 %u, i64 0, metadata !13, metadata !DIExpression()), !dbg !30
+  tail call void @llvm.dbg.value(metadata i1 %u, i64 0, metadata !31, metadata !DIExpression()), !dbg !33
+  br i1 %u, label %if.then.i, label %_Z1xb.exit, !dbg !34
+
+if.then.i:                                        ; preds = %entry
+  %0 = load i32, i32* @t, align 4, !dbg !35, !tbaa !36
+  tail call void @llvm.dbg.value(metadata i32 %0, i64 0, metadata !40, metadata !DIExpression()), !dbg !35
+  tail call void @_Z1fi(i32 %0), !dbg !41
+  br label %_Z1xb.exit, !dbg !42
+
+_Z1xb.exit:                                       ; preds = %entry, %if.then.i
+  tail call void @_Z1fi(i32 0), !dbg !43
+  ret void, !dbg !44
+}
+
+declare void @_Z1fi(i32) #1
+
+; Function Attrs: nounwind readnone
+declare void @llvm.dbg.value(metadata, i64, metadata, metadata) #2
+
+attributes #0 = { uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #2 = { nounwind readnone }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!21, !22}
+!llvm.ident = !{!23}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, producer: "clang version 3.5.0 ", isOptimized: true, emissionKind: 1, file: !1, enums: !2, retainedTypes: !2, subprograms: !3, globals: !2, imports: !2)
+!1 = !DIFile(filename: "missing-abstract-variables.cc", directory: "/tmp/dbginfo")
+!2 = !{}
+!3 = !{!4, !8, !14}
+!4 = distinct !DISubprogram(name: "b", linkageName: "_Z1bv", line: 13, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, scopeLine: 13, file: !1, scope: !5, type: !6, function: void ()* @_Z1bv, variables: !2)
+!5 = !DIFile(filename: "missing-abstract-variables.cc", directory: "/tmp/dbginfo")
+!6 = !DISubroutineType(types: !7)
+!7 = !{null}
+!8 = distinct !DISubprogram(name: "a", linkageName: "_Z1ab", line: 17, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, scopeLine: 17, file: !1, scope: !5, type: !9, function: void (i1)* @_Z1ab, variables: !12)
+!9 = !DISubroutineType(types: !10)
+!10 = !{null, !11}
+!11 = !DIBasicType(tag: DW_TAG_base_type, name: "bool", size: 8, align: 8, encoding: DW_ATE_boolean)
+!12 = !{!13}
+!13 = !DILocalVariable(name: "u", line: 17, arg: 1, scope: !8, file: !5, type: !11)
+!14 = distinct !DISubprogram(name: "x", linkageName: "_Z1xb", line: 5, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: true, scopeLine: 5, file: !1, scope: !5, type: !9, variables: !15)
+!15 = !{!16, !17}
+!16 = !DILocalVariable(name: "b", line: 5, arg: 1, scope: !14, file: !5, type: !11)
+!17 = !DILocalVariable(name: "s", line: 7, scope: !18, file: !5, type: !20)
+!18 = distinct !DILexicalBlock(line: 6, column: 0, file: !1, scope: !19)
+!19 = distinct !DILexicalBlock(line: 6, column: 0, file: !1, scope: !14)
+!20 = !DIBasicType(tag: DW_TAG_base_type, name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
+!21 = !{i32 2, !"Dwarf Version", i32 4}
+!22 = !{i32 2, !"Debug Info Version", i32 3}
+!23 = !{!"clang version 3.5.0 "}
+!24 = !{i1 false}
+!25 = !DILocalVariable(name: "b", line: 5, arg: 1, scope: !14, file: !5, type: !11)
+!26 = !DILocation(line: 14, scope: !4)
+!27 = !DILocation(line: 5, scope: !14, inlinedAt: !26)
+!28 = !DILocation(line: 10, scope: !14, inlinedAt: !26)
+!29 = !DILocation(line: 15, scope: !4)
+!30 = !DILocation(line: 17, scope: !8)
+!31 = !DILocalVariable(name: "b", line: 5, arg: 1, scope: !14, file: !5, type: !11)
+!32 = !DILocation(line: 18, scope: !8)
+!33 = !DILocation(line: 5, scope: !14, inlinedAt: !32)
+!34 = !DILocation(line: 6, scope: !19, inlinedAt: !32)
+!35 = !DILocation(line: 7, scope: !18, inlinedAt: !32)
+!36 = !{!37, !37, i64 0}
+!37 = !{!"int", !38, i64 0}
+!38 = !{!"omnipotent char", !39, i64 0}
+!39 = !{!"Simple C/C++ TBAA"}
+!40 = !DILocalVariable(name: "s", line: 7, scope: !18, file: !5, type: !20)
+!41 = !DILocation(line: 8, scope: !18, inlinedAt: !32)
+!42 = !DILocation(line: 9, scope: !18, inlinedAt: !32)
+!43 = !DILocation(line: 10, scope: !14, inlinedAt: !32)
+!44 = !DILocation(line: 19, scope: !8)