[clang-tools-extra] 4cb5e43 - [clangd] Show size, offset and padding for bit fields on hover
Sam McCall via cfe-commits
cfe-commits at lists.llvm.org
Mon Jun 5 09:04:03 PDT 2023
Author: SR_team
Date: 2023-06-05T17:52:34+02:00
New Revision: 4cb5e436ae713579cfee00cfc8e516cf965b91e9
URL: https://github.com/llvm/llvm-project/commit/4cb5e436ae713579cfee00cfc8e516cf965b91e9
DIFF: https://github.com/llvm/llvm-project/commit/4cb5e436ae713579cfee00cfc8e516cf965b91e9.diff
LOG: [clangd] Show size, offset and padding for bit fields on hover
Examle:
```
struct test {
char a;
char b : 3;
char c : 5;
int d;
int e : 27;
};
```
{F27617774}
{F27617776}
{F27617777}
{F27617780}
Reviewed By: sammccall
Differential Revision: https://reviews.llvm.org/D151128
Added:
Modified:
clang-tools-extra/clangd/Hover.cpp
clang-tools-extra/clangd/Hover.h
clang-tools-extra/clangd/unittests/HoverTests.cpp
Removed:
################################################################################
diff --git a/clang-tools-extra/clangd/Hover.cpp b/clang-tools-extra/clangd/Hover.cpp
index d1f6f3a7b06c0..0ae70dd121ebf 100644
--- a/clang-tools-extra/clangd/Hover.cpp
+++ b/clang-tools-extra/clangd/Hover.cpp
@@ -866,7 +866,7 @@ HoverInfo getStringLiteralContents(const StringLiteral *SL,
HoverInfo HI;
HI.Name = "string-literal";
- HI.Size = (SL->getLength() + 1) * SL->getCharByteWidth();
+ HI.Size = (SL->getLength() + 1) * SL->getCharByteWidth() * 8;
HI.Type = SL->getType().getAsString(PP).c_str();
return HI;
@@ -1000,7 +1000,7 @@ void addLayoutInfo(const NamedDecl &ND, HoverInfo &HI) {
const auto &Ctx = ND.getASTContext();
if (auto *RD = llvm::dyn_cast<RecordDecl>(&ND)) {
if (auto Size = Ctx.getTypeSizeInCharsIfKnown(RD->getTypeForDecl()))
- HI.Size = Size->getQuantity();
+ HI.Size = Size->getQuantity() * 8;
return;
}
@@ -1008,25 +1008,26 @@ void addLayoutInfo(const NamedDecl &ND, HoverInfo &HI) {
const auto *Record = FD->getParent();
if (Record)
Record = Record->getDefinition();
- if (Record && !Record->isInvalidDecl() && !Record->isDependentType() &&
- !FD->isBitField()) {
+ if (Record && !Record->isInvalidDecl() && !Record->isDependentType()) {
const ASTRecordLayout &Layout = Ctx.getASTRecordLayout(Record);
- HI.Offset = Layout.getFieldOffset(FD->getFieldIndex()) / 8;
- if (auto Size = Ctx.getTypeSizeInCharsIfKnown(FD->getType())) {
- HI.Size = FD->isZeroSize(Ctx) ? 0 : Size->getQuantity();
+ HI.Offset = Layout.getFieldOffset(FD->getFieldIndex());
+ if (FD->isBitField())
+ HI.Size = FD->getBitWidthValue(Ctx);
+ else if (auto Size = Ctx.getTypeSizeInCharsIfKnown(FD->getType()))
+ HI.Size = FD->isZeroSize(Ctx) ? 0 : Size->getQuantity() * 8;
+ if (HI.Size) {
unsigned EndOfField = *HI.Offset + *HI.Size;
// Calculate padding following the field.
if (!Record->isUnion() &&
FD->getFieldIndex() + 1 < Layout.getFieldCount()) {
// Measure padding up to the next class field.
- unsigned NextOffset =
- Layout.getFieldOffset(FD->getFieldIndex() + 1) / 8;
+ unsigned NextOffset = Layout.getFieldOffset(FD->getFieldIndex() + 1);
if (NextOffset >= EndOfField) // next field could be a bitfield!
HI.Padding = NextOffset - EndOfField;
} else {
// Measure padding up to the end of the object.
- HI.Padding = Layout.getSize().getQuantity() - EndOfField;
+ HI.Padding = Layout.getSize().getQuantity() * 8 - EndOfField;
}
}
// Offset in a union is always zero, so not really useful to report.
@@ -1401,6 +1402,24 @@ std::optional<HoverInfo> getHover(ParsedAST &AST, Position Pos,
return HI;
}
+// Sizes (and padding) are shown in bytes if possible, otherwise in bits.
+static std::string formatSize(uint64_t SizeInBits) {
+ uint64_t Value = SizeInBits % 8 == 0 ? SizeInBits / 8 : SizeInBits;
+ const char *Unit = Value != 0 && Value == SizeInBits ? "bit" : "byte";
+ return llvm::formatv("{0} {1}{2}", Value, Unit, Value == 1 ? "" : "s").str();
+}
+
+// Offsets are shown in bytes + bits, so offsets of
diff erent fields
+// can always be easily compared.
+static std::string formatOffset(uint64_t OffsetInBits) {
+ const auto Bytes = OffsetInBits / 8;
+ const auto Bits = OffsetInBits % 8;
+ auto Offset = formatSize(Bytes * 8);
+ if (Bits != 0)
+ Offset += " and " + formatSize(Bits);
+ return Offset;
+}
+
markup::Document HoverInfo::present() const {
markup::Document Output;
@@ -1464,14 +1483,13 @@ markup::Document HoverInfo::present() const {
}
if (Offset)
- Output.addParagraph().appendText(
- llvm::formatv("Offset: {0} byte{1}", *Offset, *Offset == 1 ? "" : "s")
- .str());
+ Output.addParagraph().appendText("Offset: " + formatOffset(*Offset));
if (Size) {
- auto &P = Output.addParagraph().appendText(
- llvm::formatv("Size: {0} byte{1}", *Size, *Size == 1 ? "" : "s").str());
- if (Padding && *Padding != 0)
- P.appendText(llvm::formatv(" (+{0} padding)", *Padding).str());
+ auto &P = Output.addParagraph().appendText("Size: " + formatSize(*Size));
+ if (Padding && *Padding != 0) {
+ P.appendText(
+ llvm::formatv(" (+{0} padding)", formatSize(*Padding)).str());
+ }
}
if (CalleeArgInfo) {
diff --git a/clang-tools-extra/clangd/Hover.h b/clang-tools-extra/clangd/Hover.h
index 891a9d9ec5546..6a61100912918 100644
--- a/clang-tools-extra/clangd/Hover.h
+++ b/clang-tools-extra/clangd/Hover.h
@@ -91,7 +91,7 @@ struct HoverInfo {
std::optional<std::vector<Param>> TemplateParameters;
/// Contains the evaluated value of the symbol if available.
std::optional<std::string> Value;
- /// Contains the byte-size of fields and types where it's interesting.
+ /// Contains the bit-size of fields and types where it's interesting.
std::optional<uint64_t> Size;
/// Contains the offset of fields within the enclosing class.
std::optional<uint64_t> Offset;
diff --git a/clang-tools-extra/clangd/unittests/HoverTests.cpp b/clang-tools-extra/clangd/unittests/HoverTests.cpp
index 135fdfc4c23bc..583310f29b63f 100644
--- a/clang-tools-extra/clangd/unittests/HoverTests.cpp
+++ b/clang-tools-extra/clangd/unittests/HoverTests.cpp
@@ -89,8 +89,8 @@ TEST(Hover, Structured) {
HI.Definition = "char bar";
HI.Type = "char";
HI.Offset = 0;
- HI.Size = 1;
- HI.Padding = 7;
+ HI.Size = 8;
+ HI.Padding = 56;
HI.AccessSpecifier = "private";
}},
// Union field
@@ -107,8 +107,8 @@ TEST(Hover, Structured) {
HI.Kind = index::SymbolKind::Field;
HI.Definition = "char bar";
HI.Type = "char";
- HI.Size = 1;
- HI.Padding = 15;
+ HI.Size = 8;
+ HI.Padding = 120;
HI.AccessSpecifier = "public";
}},
// Bitfield
@@ -125,6 +125,8 @@ TEST(Hover, Structured) {
HI.Kind = index::SymbolKind::Field;
HI.Definition = "int x : 1";
HI.Type = "int";
+ HI.Offset = 0;
+ HI.Size = 1;
HI.AccessSpecifier = "public";
}},
// Local to class method.
@@ -188,7 +190,7 @@ TEST(Hover, Structured) {
HI.Definition = "char bar";
HI.Type = "char";
HI.Offset = 0;
- HI.Size = 1;
+ HI.Size = 8;
HI.AccessSpecifier = "public";
}},
// Struct definition shows size.
@@ -200,7 +202,7 @@ TEST(Hover, Structured) {
HI.Name = "X";
HI.Kind = index::SymbolKind::Struct;
HI.Definition = "struct X {}";
- HI.Size = 1;
+ HI.Size = 8;
}},
// Variable with template type
{R"cpp(
@@ -1285,6 +1287,26 @@ class Foo final {})cpp";
HI.Kind = index::SymbolKind::Field;
HI.Definition = "m_int arr[Size]";
HI.Type = {"m_int[Size]", "int[Size]"};
+ }},
+ {// Bitfield offset, size and padding
+ R"cpp(
+ struct Foo {
+ char x;
+ char [[^y]] : 1;
+ int z;
+ };
+ )cpp",
+ [](HoverInfo &HI) {
+ HI.NamespaceScope = "";
+ HI.LocalScope = "Foo::";
+ HI.Name = "y";
+ HI.Kind = index::SymbolKind::Field;
+ HI.Definition = "char y : 1";
+ HI.Type = "char";
+ HI.Offset = 8;
+ HI.Size = 1;
+ HI.Padding = 23;
+ HI.AccessSpecifier = "public";
}}};
for (const auto &Case : Cases) {
SCOPED_TRACE(Case.Code);
@@ -1508,7 +1530,7 @@ TEST(Hover, All) {
{"auto s = ^[[\"Hello, world!\"]]; // string literal",
[](HoverInfo &HI) {
HI.Name = "string-literal";
- HI.Size = 14;
+ HI.Size = 112;
HI.Type = "const char[14]";
}},
{
@@ -3218,7 +3240,7 @@ TEST(Hover, Present) {
{
[](HoverInfo &HI) {
HI.Kind = index::SymbolKind::Class;
- HI.Size = 10;
+ HI.Size = 80;
HI.TemplateParameters = {
{{"typename"}, std::string("T"), std::nullopt},
{{"typename"}, std::string("C"), std::string("bool")},
@@ -3274,16 +3296,38 @@ template <typename T, typename C = bool> class Foo {})",
HI.Name = "foo";
HI.Type = {"type", "can_type"};
HI.Definition = "def";
- HI.Size = 4;
- HI.Offset = 12;
- HI.Padding = 4;
+ HI.Size = 32;
+ HI.Offset = 96;
+ HI.Padding = 32;
},
R"(field foo
Type: type (aka can_type)
Value = value
Offset: 12 bytes
-Size: 4 bytes (+4 padding)
+Size: 4 bytes (+4 bytes padding)
+
+// In test::Bar
+def)",
+ },
+ {
+ [](HoverInfo &HI) {
+ HI.Kind = index::SymbolKind::Field;
+ HI.LocalScope = "test::Bar::";
+ HI.Value = "value";
+ HI.Name = "foo";
+ HI.Type = {"type", "can_type"};
+ HI.Definition = "def";
+ HI.Size = 25;
+ HI.Offset = 35;
+ HI.Padding = 4;
+ },
+ R"(field foo
+
+Type: type (aka can_type)
+Value = value
+Offset: 4 bytes and 3 bits
+Size: 25 bits (+4 bits padding)
// In test::Bar
def)",
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