[DebugInfo] Fully implement DWARF issue 180201.1 #149226
Merged
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Finish making LLVM's implementation of `DW_LNCT_LLVM_source` conform to the final accepted version of `DW_LNCT_source` from https://dwarfstd.org/issues/180201.1.html This is effectively a continuation of a few commits which have moved in this direction already, including: c9cb4fc [DebugInfo] Store optional DIFile::Source as pointer 87e22bd Allow for mixing source/no-source DIFiles in one CU This patch: * Teaches LLParser that there is a distinction between an empty and an absent "source:" field on DIFile. * Makes printing the "source:" field in AsmWriter conditional on it being present, instead of being conditional on it being non-empty. * Teaches MC to map an empty-but-present source field to "\n" (which is ambiguous, making the source strings "" and "\n" indistinguishable, but that's what the DWARF issue specifies). Add a test for round-tripping an empty source field through assembler/bitcode. Extend the test for the actual DWARF generation so it covers all of the cases (absent, present-but-empty, present-and-ambiguously-single-newline, present).
|
@llvm/pr-subscribers-debuginfo @llvm/pr-subscribers-llvm-ir Author: Scott Linder (slinder1) ChangesFinish making LLVM's implementation of This is effectively a continuation of a few commits which have moved in this direction already, including:
This patch:
Add a test for round-tripping an empty source field through assembler/bitcode. Extend the test for the actual DWARF generation so it covers all of the cases (absent, present-but-empty, present-and-ambiguously-single-newline, present). Full diff: https://github.com/llvm/llvm-project/pull/149226.diff 5 Files Affected:
diff --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp
index b7f6950f679ef..ebdac354179f2 100644
--- a/llvm/lib/AsmParser/LLParser.cpp
+++ b/llvm/lib/AsmParser/LLParser.cpp
@@ -4783,9 +4783,13 @@ struct MDField : public MDFieldImpl<Metadata *> {
};
struct MDStringField : public MDFieldImpl<MDString *> {
- bool AllowEmpty;
- MDStringField(bool AllowEmpty = true)
- : ImplTy(nullptr), AllowEmpty(AllowEmpty) {}
+ enum class EmptyIs {
+ Null, //< Allow empty input string, map to nullptr
+ Empty, //< Allow empty input string, map to an empty MDString
+ Error, //< Disallow empty string, map to an error
+ } EmptyIs;
+ MDStringField(enum EmptyIs EmptyIs = EmptyIs::Null)
+ : ImplTy(nullptr), EmptyIs(EmptyIs) {}
};
struct MDFieldList : public MDFieldImpl<SmallVector<Metadata *, 4>> {
@@ -5257,10 +5261,19 @@ bool LLParser::parseMDField(LocTy Loc, StringRef Name, MDStringField &Result) {
if (parseStringConstant(S))
return true;
- if (!Result.AllowEmpty && S.empty())
- return error(ValueLoc, "'" + Name + "' cannot be empty");
+ if (S.empty()) {
+ switch (Result.EmptyIs) {
+ case MDStringField::EmptyIs::Null:
+ Result.assign(nullptr);
+ return false;
+ case MDStringField::EmptyIs::Empty:
+ break;
+ case MDStringField::EmptyIs::Error:
+ return error(ValueLoc, "'" + Name + "' cannot be empty");
+ }
+ }
- Result.assign(S.empty() ? nullptr : MDString::get(Context, S));
+ Result.assign(MDString::get(Context, S));
return false;
}
@@ -5778,7 +5791,7 @@ bool LLParser::parseDIFile(MDNode *&Result, bool IsDistinct) {
REQUIRED(directory, MDStringField, ); \
OPTIONAL(checksumkind, ChecksumKindField, (DIFile::CSK_MD5)); \
OPTIONAL(checksum, MDStringField, ); \
- OPTIONAL(source, MDStringField, );
+ OPTIONAL(source, MDStringField, (MDStringField::EmptyIs::Empty));
PARSE_MD_FIELDS();
#undef VISIT_MD_FIELDS
@@ -6062,7 +6075,7 @@ bool LLParser::parseDITemplateValueParameter(MDNode *&Result, bool IsDistinct) {
/// declaration: !4, align: 8)
bool LLParser::parseDIGlobalVariable(MDNode *&Result, bool IsDistinct) {
#define VISIT_MD_FIELDS(OPTIONAL, REQUIRED) \
- OPTIONAL(name, MDStringField, (/* AllowEmpty */ false)); \
+ OPTIONAL(name, MDStringField, (MDStringField::EmptyIs::Error)); \
OPTIONAL(scope, MDField, ); \
OPTIONAL(linkageName, MDStringField, ); \
OPTIONAL(file, MDField, ); \
diff --git a/llvm/lib/IR/AsmWriter.cpp b/llvm/lib/IR/AsmWriter.cpp
index 145ef10f28f35..18d67f0c3a006 100644
--- a/llvm/lib/IR/AsmWriter.cpp
+++ b/llvm/lib/IR/AsmWriter.cpp
@@ -2398,8 +2398,9 @@ static void writeDIFile(raw_ostream &Out, const DIFile *N, AsmWriterContext &) {
// Print all values for checksum together, or not at all.
if (N->getChecksum())
Printer.printChecksum(*N->getChecksum());
- Printer.printString("source", N->getSource().value_or(StringRef()),
- /* ShouldSkipEmpty */ true);
+ if (N->getSource())
+ Printer.printString("source", *N->getSource(),
+ /* ShouldSkipEmpty */ false);
Out << ")";
}
diff --git a/llvm/lib/MC/MCDwarf.cpp b/llvm/lib/MC/MCDwarf.cpp
index b1dced7e2cda3..e7c0d37e8f99b 100644
--- a/llvm/lib/MC/MCDwarf.cpp
+++ b/llvm/lib/MC/MCDwarf.cpp
@@ -447,10 +447,17 @@ static void emitOneV5FileEntry(MCStreamer *MCOS, const MCDwarfFile &DwarfFile,
StringRef(reinterpret_cast<const char *>(Cksum.data()), Cksum.size()));
}
if (HasAnySource) {
+ // From https://dwarfstd.org/issues/180201.1.html
+ // * The value is an empty null-terminated string if no source is available
+ StringRef Source = DwarfFile.Source.value_or(StringRef());
+ // * If the source is available but is an empty file then the value is a
+ // null-terminated single "\n".
+ if (DwarfFile.Source && DwarfFile.Source->empty())
+ Source = "\n";
if (LineStr)
- LineStr->emitRef(MCOS, DwarfFile.Source.value_or(StringRef()));
+ LineStr->emitRef(MCOS, Source);
else {
- MCOS->emitBytes(DwarfFile.Source.value_or(StringRef())); // Source and...
+ MCOS->emitBytes(Source); // Source and...
MCOS->emitBytes(StringRef("\0", 1)); // its null terminator.
}
}
diff --git a/llvm/test/Assembler/difile-empty-source.ll b/llvm/test/Assembler/difile-empty-source.ll
new file mode 100644
index 0000000000000..11587d8f1afdc
--- /dev/null
+++ b/llvm/test/Assembler/difile-empty-source.ll
@@ -0,0 +1,12 @@
+; RUN: llvm-as < %s | llvm-dis | llvm-as | llvm-dis | FileCheck %s
+; RUN: verify-uselistorder
+
+; CHECK: !DIFile({{.*}}, source: "")
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!2, !3}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C11, file: !1, emissionKind: FullDebug)
+!1 = !DIFile(filename: "-", directory: "/", checksumkind: CSK_MD5, checksum: "d41d8cd98f00b204e9800998ecf8427e", source: "")
+!2 = !{i32 7, !"Dwarf Version", i32 5}
+!3 = !{i32 2, !"Debug Info Version", i32 3}
diff --git a/llvm/test/DebugInfo/Generic/mixed-source.ll b/llvm/test/DebugInfo/Generic/mixed-source.ll
index d5586f8fc5389..ee3598f1fdd13 100644
--- a/llvm/test/DebugInfo/Generic/mixed-source.ll
+++ b/llvm/test/DebugInfo/Generic/mixed-source.ll
@@ -5,36 +5,66 @@
; CHECK: include_directories[ 0] = "dir"
; CHECK-NEXT: file_names[ 0]:
+; CHECK-NEXT: name: "main.c"
+; CHECK-NEXT: dir_index: 0
+; CHECK-NOT: source:
+; CHECK-NEXT: file_names[ 1]:
; CHECK-NEXT: name: "foo.c"
; CHECK-NEXT: dir_index: 0
; CHECK-NEXT: source: "void foo() { }\n"
-; CHECK-NEXT: file_names[ 1]:
-; CHECK-NEXT: name: "bar.h"
+; CHECK-NEXT: file_names[ 2]:
+; CHECK-NEXT: name: "newline.h"
+; CHECK-NEXT: dir_index: 0
+; CHECK-NEXT: source: "\n"
+; CHECK-NEXT: file_names[ 3]:
+; CHECK-NEXT: name: "empty.h"
+; CHECK-NEXT: dir_index: 0
+; CHECK-NEXT: source: "\n"
+; CHECK-NEXT: file_names[ 4]:
+; CHECK-NEXT: name: "absent.h"
; CHECK-NEXT: dir_index: 0
; CHECK-NOT: source:
; Test that DIFiles mixing source and no-source within a DICompileUnit works.
-define dso_local void @foo() !dbg !5 {
+define dso_local void @foo() !dbg !6 {
ret void, !dbg !7
}
-define dso_local void @bar() !dbg !6 {
- ret void, !dbg !8
+define dso_local void @newline() !dbg !9 {
+ ret void, !dbg !10
}
-!llvm.dbg.cu = !{!4}
+define dso_local void @empty() !dbg !12 {
+ ret void, !dbg !13
+}
+
+define dso_local void @absent() !dbg !15 {
+ ret void, !dbg !16
+}
+
+!llvm.dbg.cu = !{!2}
!llvm.module.flags = !{!0, !1}
!0 = !{i32 2, !"Dwarf Version", i32 5}
!1 = !{i32 2, !"Debug Info Version", i32 3}
-!2 = !DIFile(filename: "foo.c", directory: "dir", source: "void foo() { }\0A")
-!3 = !DIFile(filename: "bar.h", directory: "dir")
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, emissionKind: FullDebug, file: !4)
+!3 = !DISubroutineType(types: !{})
+!4 = !DIFile(filename: "main.c", directory: "dir")
+
+!5 = !DIFile(filename: "foo.c", directory: "dir", source: "void foo() { }\0A")
+!6 = distinct !DISubprogram(name: "foo", file: !5, line: 1, type: !3, scopeLine: 1, spFlags: DISPFlagDefinition, unit: !2)
+!7 = !DILocation(line: 1, scope: !6)
+
+!8 = !DIFile(filename: "newline.h", directory: "dir", source: "\0A")
+!9 = distinct !DISubprogram(name: "newline", file: !8, line: 1, type: !3, scopeLine: 1, spFlags: DISPFlagDefinition, unit: !2)
+!10 = !DILocation(line: 1, scope: !9)
+
+!11 = !DIFile(filename: "empty.h", directory: "dir", source: "")
+!12 = distinct !DISubprogram(name: "empty", file: !11, line: 1, type: !3, scopeLine: 1, spFlags: DISPFlagDefinition, unit: !2)
+!13 = !DILocation(line: 1, scope: !12)
-!4 = distinct !DICompileUnit(language: DW_LANG_C99, emissionKind: FullDebug, file: !2)
-!5 = distinct !DISubprogram(name: "foo", file: !2, line: 1, type: !9, scopeLine: 1, spFlags: DISPFlagDefinition, unit: !4)
-!6 = distinct !DISubprogram(name: "bar", file: !3, line: 1, type: !9, scopeLine: 1, spFlags: DISPFlagDefinition, unit: !4)
-!7 = !DILocation(line: 1, scope: !5)
-!8 = !DILocation(line: 1, scope: !6)
-!9 = !DISubroutineType(types: !{})
+!14 = !DIFile(filename: "absent.h", directory: "dir")
+!15 = distinct !DISubprogram(name: "absent", file: !14, line: 1, type: !3, scopeLine: 1, spFlags: DISPFlagDefinition, unit: !2)
+!16 = !DILocation(line: 1, scope: !15)
|
|
@llvm/pr-subscribers-mc Author: Scott Linder (slinder1) ChangesFinish making LLVM's implementation of This is effectively a continuation of a few commits which have moved in this direction already, including:
This patch:
Add a test for round-tripping an empty source field through assembler/bitcode. Extend the test for the actual DWARF generation so it covers all of the cases (absent, present-but-empty, present-and-ambiguously-single-newline, present). Full diff: https://github.com/llvm/llvm-project/pull/149226.diff 5 Files Affected:
diff --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp
index b7f6950f679ef..ebdac354179f2 100644
--- a/llvm/lib/AsmParser/LLParser.cpp
+++ b/llvm/lib/AsmParser/LLParser.cpp
@@ -4783,9 +4783,13 @@ struct MDField : public MDFieldImpl<Metadata *> {
};
struct MDStringField : public MDFieldImpl<MDString *> {
- bool AllowEmpty;
- MDStringField(bool AllowEmpty = true)
- : ImplTy(nullptr), AllowEmpty(AllowEmpty) {}
+ enum class EmptyIs {
+ Null, //< Allow empty input string, map to nullptr
+ Empty, //< Allow empty input string, map to an empty MDString
+ Error, //< Disallow empty string, map to an error
+ } EmptyIs;
+ MDStringField(enum EmptyIs EmptyIs = EmptyIs::Null)
+ : ImplTy(nullptr), EmptyIs(EmptyIs) {}
};
struct MDFieldList : public MDFieldImpl<SmallVector<Metadata *, 4>> {
@@ -5257,10 +5261,19 @@ bool LLParser::parseMDField(LocTy Loc, StringRef Name, MDStringField &Result) {
if (parseStringConstant(S))
return true;
- if (!Result.AllowEmpty && S.empty())
- return error(ValueLoc, "'" + Name + "' cannot be empty");
+ if (S.empty()) {
+ switch (Result.EmptyIs) {
+ case MDStringField::EmptyIs::Null:
+ Result.assign(nullptr);
+ return false;
+ case MDStringField::EmptyIs::Empty:
+ break;
+ case MDStringField::EmptyIs::Error:
+ return error(ValueLoc, "'" + Name + "' cannot be empty");
+ }
+ }
- Result.assign(S.empty() ? nullptr : MDString::get(Context, S));
+ Result.assign(MDString::get(Context, S));
return false;
}
@@ -5778,7 +5791,7 @@ bool LLParser::parseDIFile(MDNode *&Result, bool IsDistinct) {
REQUIRED(directory, MDStringField, ); \
OPTIONAL(checksumkind, ChecksumKindField, (DIFile::CSK_MD5)); \
OPTIONAL(checksum, MDStringField, ); \
- OPTIONAL(source, MDStringField, );
+ OPTIONAL(source, MDStringField, (MDStringField::EmptyIs::Empty));
PARSE_MD_FIELDS();
#undef VISIT_MD_FIELDS
@@ -6062,7 +6075,7 @@ bool LLParser::parseDITemplateValueParameter(MDNode *&Result, bool IsDistinct) {
/// declaration: !4, align: 8)
bool LLParser::parseDIGlobalVariable(MDNode *&Result, bool IsDistinct) {
#define VISIT_MD_FIELDS(OPTIONAL, REQUIRED) \
- OPTIONAL(name, MDStringField, (/* AllowEmpty */ false)); \
+ OPTIONAL(name, MDStringField, (MDStringField::EmptyIs::Error)); \
OPTIONAL(scope, MDField, ); \
OPTIONAL(linkageName, MDStringField, ); \
OPTIONAL(file, MDField, ); \
diff --git a/llvm/lib/IR/AsmWriter.cpp b/llvm/lib/IR/AsmWriter.cpp
index 145ef10f28f35..18d67f0c3a006 100644
--- a/llvm/lib/IR/AsmWriter.cpp
+++ b/llvm/lib/IR/AsmWriter.cpp
@@ -2398,8 +2398,9 @@ static void writeDIFile(raw_ostream &Out, const DIFile *N, AsmWriterContext &) {
// Print all values for checksum together, or not at all.
if (N->getChecksum())
Printer.printChecksum(*N->getChecksum());
- Printer.printString("source", N->getSource().value_or(StringRef()),
- /* ShouldSkipEmpty */ true);
+ if (N->getSource())
+ Printer.printString("source", *N->getSource(),
+ /* ShouldSkipEmpty */ false);
Out << ")";
}
diff --git a/llvm/lib/MC/MCDwarf.cpp b/llvm/lib/MC/MCDwarf.cpp
index b1dced7e2cda3..e7c0d37e8f99b 100644
--- a/llvm/lib/MC/MCDwarf.cpp
+++ b/llvm/lib/MC/MCDwarf.cpp
@@ -447,10 +447,17 @@ static void emitOneV5FileEntry(MCStreamer *MCOS, const MCDwarfFile &DwarfFile,
StringRef(reinterpret_cast<const char *>(Cksum.data()), Cksum.size()));
}
if (HasAnySource) {
+ // From https://dwarfstd.org/issues/180201.1.html
+ // * The value is an empty null-terminated string if no source is available
+ StringRef Source = DwarfFile.Source.value_or(StringRef());
+ // * If the source is available but is an empty file then the value is a
+ // null-terminated single "\n".
+ if (DwarfFile.Source && DwarfFile.Source->empty())
+ Source = "\n";
if (LineStr)
- LineStr->emitRef(MCOS, DwarfFile.Source.value_or(StringRef()));
+ LineStr->emitRef(MCOS, Source);
else {
- MCOS->emitBytes(DwarfFile.Source.value_or(StringRef())); // Source and...
+ MCOS->emitBytes(Source); // Source and...
MCOS->emitBytes(StringRef("\0", 1)); // its null terminator.
}
}
diff --git a/llvm/test/Assembler/difile-empty-source.ll b/llvm/test/Assembler/difile-empty-source.ll
new file mode 100644
index 0000000000000..11587d8f1afdc
--- /dev/null
+++ b/llvm/test/Assembler/difile-empty-source.ll
@@ -0,0 +1,12 @@
+; RUN: llvm-as < %s | llvm-dis | llvm-as | llvm-dis | FileCheck %s
+; RUN: verify-uselistorder
+
+; CHECK: !DIFile({{.*}}, source: "")
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!2, !3}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C11, file: !1, emissionKind: FullDebug)
+!1 = !DIFile(filename: "-", directory: "/", checksumkind: CSK_MD5, checksum: "d41d8cd98f00b204e9800998ecf8427e", source: "")
+!2 = !{i32 7, !"Dwarf Version", i32 5}
+!3 = !{i32 2, !"Debug Info Version", i32 3}
diff --git a/llvm/test/DebugInfo/Generic/mixed-source.ll b/llvm/test/DebugInfo/Generic/mixed-source.ll
index d5586f8fc5389..ee3598f1fdd13 100644
--- a/llvm/test/DebugInfo/Generic/mixed-source.ll
+++ b/llvm/test/DebugInfo/Generic/mixed-source.ll
@@ -5,36 +5,66 @@
; CHECK: include_directories[ 0] = "dir"
; CHECK-NEXT: file_names[ 0]:
+; CHECK-NEXT: name: "main.c"
+; CHECK-NEXT: dir_index: 0
+; CHECK-NOT: source:
+; CHECK-NEXT: file_names[ 1]:
; CHECK-NEXT: name: "foo.c"
; CHECK-NEXT: dir_index: 0
; CHECK-NEXT: source: "void foo() { }\n"
-; CHECK-NEXT: file_names[ 1]:
-; CHECK-NEXT: name: "bar.h"
+; CHECK-NEXT: file_names[ 2]:
+; CHECK-NEXT: name: "newline.h"
+; CHECK-NEXT: dir_index: 0
+; CHECK-NEXT: source: "\n"
+; CHECK-NEXT: file_names[ 3]:
+; CHECK-NEXT: name: "empty.h"
+; CHECK-NEXT: dir_index: 0
+; CHECK-NEXT: source: "\n"
+; CHECK-NEXT: file_names[ 4]:
+; CHECK-NEXT: name: "absent.h"
; CHECK-NEXT: dir_index: 0
; CHECK-NOT: source:
; Test that DIFiles mixing source and no-source within a DICompileUnit works.
-define dso_local void @foo() !dbg !5 {
+define dso_local void @foo() !dbg !6 {
ret void, !dbg !7
}
-define dso_local void @bar() !dbg !6 {
- ret void, !dbg !8
+define dso_local void @newline() !dbg !9 {
+ ret void, !dbg !10
}
-!llvm.dbg.cu = !{!4}
+define dso_local void @empty() !dbg !12 {
+ ret void, !dbg !13
+}
+
+define dso_local void @absent() !dbg !15 {
+ ret void, !dbg !16
+}
+
+!llvm.dbg.cu = !{!2}
!llvm.module.flags = !{!0, !1}
!0 = !{i32 2, !"Dwarf Version", i32 5}
!1 = !{i32 2, !"Debug Info Version", i32 3}
-!2 = !DIFile(filename: "foo.c", directory: "dir", source: "void foo() { }\0A")
-!3 = !DIFile(filename: "bar.h", directory: "dir")
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, emissionKind: FullDebug, file: !4)
+!3 = !DISubroutineType(types: !{})
+!4 = !DIFile(filename: "main.c", directory: "dir")
+
+!5 = !DIFile(filename: "foo.c", directory: "dir", source: "void foo() { }\0A")
+!6 = distinct !DISubprogram(name: "foo", file: !5, line: 1, type: !3, scopeLine: 1, spFlags: DISPFlagDefinition, unit: !2)
+!7 = !DILocation(line: 1, scope: !6)
+
+!8 = !DIFile(filename: "newline.h", directory: "dir", source: "\0A")
+!9 = distinct !DISubprogram(name: "newline", file: !8, line: 1, type: !3, scopeLine: 1, spFlags: DISPFlagDefinition, unit: !2)
+!10 = !DILocation(line: 1, scope: !9)
+
+!11 = !DIFile(filename: "empty.h", directory: "dir", source: "")
+!12 = distinct !DISubprogram(name: "empty", file: !11, line: 1, type: !3, scopeLine: 1, spFlags: DISPFlagDefinition, unit: !2)
+!13 = !DILocation(line: 1, scope: !12)
-!4 = distinct !DICompileUnit(language: DW_LANG_C99, emissionKind: FullDebug, file: !2)
-!5 = distinct !DISubprogram(name: "foo", file: !2, line: 1, type: !9, scopeLine: 1, spFlags: DISPFlagDefinition, unit: !4)
-!6 = distinct !DISubprogram(name: "bar", file: !3, line: 1, type: !9, scopeLine: 1, spFlags: DISPFlagDefinition, unit: !4)
-!7 = !DILocation(line: 1, scope: !5)
-!8 = !DILocation(line: 1, scope: !6)
-!9 = !DISubroutineType(types: !{})
+!14 = !DIFile(filename: "absent.h", directory: "dir")
+!15 = distinct !DISubprogram(name: "absent", file: !14, line: 1, type: !3, scopeLine: 1, spFlags: DISPFlagDefinition, unit: !2)
+!16 = !DILocation(line: 1, scope: !15)
|
|
Not really knowledgeable for reviewing DWARF changes |
|
This broadly LGTM; it'd be great if someone with more context looks at it too. (The empty-string versus "\n" ambiguity is awkward; but it's also explicit in the spec, so presumably there's a reason for doing it). |
I remember the topic, although not the precise reasoning; had something to do with how a toolchain might generate source on the fly. Some languages mandate that source ends with a newline, or something along those lines. |
|
I agree the ambiguity isn't ideal, but the cases where I could imagine it being an issue seem unlikely to come up in practice. Thinking about this just now, if one includes a checksum alongside the embedded source it seems like it is actually enough to disambiguate it. The consumer can compare against the "null" hash digest, e.g. |
mahesh-attarde
pushed a commit
to mahesh-attarde/llvm-project
that referenced
this pull request
Jul 28, 2025
Finish making LLVM's implementation of `DW_LNCT_LLVM_source` conform to the final accepted version of `DW_LNCT_source` from https://dwarfstd.org/issues/180201.1.html This is effectively a continuation of a few commits which have moved in this direction already, including: * c9cb4fc [DebugInfo] Store optional DIFile::Source as pointer * 87e22bd Allow for mixing source/no-source DIFiles in one CU This patch: * Teaches LLParser that there is a distinction between an empty and an absent "source:" field on DIFile. * Makes printing the "source:" field in AsmWriter conditional on it being present, instead of being conditional on it being non-empty. * Teaches MC to map an empty-but-present source field to "\n" (which is ambiguous, making the source strings "" and "\n" indistinguishable, but that's what the DWARF issue specifies). Add a test for round-tripping an empty source field through assembler/bitcode. Extend the test for the actual DWARF generation so it covers all of the cases (absent, present-but-empty, present-and-ambiguously-single-newline, present).
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Finish making LLVM's implementation of
DW_LNCT_LLVM_sourceconform to the final accepted version ofDW_LNCT_sourcefromhttps://dwarfstd.org/issues/180201.1.html
This is effectively a continuation of a few commits which have moved in this direction already, including:
This patch:
Add a test for round-tripping an empty source field through assembler/bitcode.
Extend the test for the actual DWARF generation so it covers all of the cases (absent, present-but-empty, present-and-ambiguously-single-newline, present).