[CIR][Dialect] Add SourceLangAttr #152511

seven-mile · 2025-08-07T14:14:40Z

This patch upstreams SourceLangAttr and its CodeGen logic in the CGM, which encodes the source language in CIR.

llvmbot · 2025-08-07T14:15:11Z

@llvm/pr-subscribers-clang

Author: 7mile (seven-mile)

Changes

This patch upstreams SourceLangAttr and its CodeGen logic in the CGM, which encodes the source language in CIR.

Full diff: https://github.com/llvm/llvm-project/pull/152511.diff

8 Files Affected:

(modified) clang/include/clang/CIR/Dialect/IR/CIRAttrs.td (+37)
(modified) clang/include/clang/CIR/Dialect/IR/CIRDialect.td (+1)
(modified) clang/lib/CIR/CodeGen/CIRGenModule.cpp (+24)
(modified) clang/lib/CIR/CodeGen/CIRGenModule.h (+3)
(added) clang/test/CIR/CodeGen/lang-c.c (+8)
(added) clang/test/CIR/CodeGen/lang-cpp.cpp (+8)
(added) clang/test/CIR/IR/invalid-lang-attr.cir (+5)
(added) clang/test/CIR/IR/module.cir (+12)

diff --git a/clang/include/clang/CIR/Dialect/IR/CIRAttrs.td b/clang/include/clang/CIR/Dialect/IR/CIRAttrs.td
index 588fb0d74a509..2040109298ad1 100644
--- a/clang/include/clang/CIR/Dialect/IR/CIRAttrs.td
+++ b/clang/include/clang/CIR/Dialect/IR/CIRAttrs.td
@@ -50,6 +50,43 @@ class CIR_UnitAttr<string name, string attrMnemonic, list<Trait> traits = []>
   let isOptional = 1;
 }
 
+//===----------------------------------------------------------------------===//
+// SourceLanguageAttr
+//===----------------------------------------------------------------------===//
+
+def CIR_SourceLanguage : CIR_I32EnumAttr<"SourceLanguage", "source language", [
+  I32EnumAttrCase<"C", 1, "c">,
+  I32EnumAttrCase<"CXX", 2, "cxx">
+]> {
+  // The enum attr class is defined in `CIR_SourceLanguageAttr` below,
+  // so that it can define extra class methods.
+  let genSpecializedAttr = 0;
+}
+
+def CIR_SourceLanguageAttr : CIR_EnumAttr<CIR_SourceLanguage, "lang"> {
+
+  let summary = "Module source language";
+  let description = [{
+    Represents the source language used to generate the module.
+
+    Example:
+    ```
+    // Module compiled from C.
+    module attributes {cir.lang = cir.lang<c>} {}
+    // Module compiled from C++.
+    module attributes {cir.lang = cir.lang<cxx>} {}
+    ```
+
+    Module source language attribute name is `cir.lang` is defined by
+    `getSourceLanguageAttrName` method in CIRDialect class.
+  }];
+
+  let extraClassDeclaration = [{
+    bool isC() const { return getValue() == SourceLanguage::C; }
+    bool isCXX() const { return getValue() == SourceLanguage::CXX; }
+  }];
+}
+
 //===----------------------------------------------------------------------===//
 // OptInfoAttr
 //===----------------------------------------------------------------------===//
diff --git a/clang/include/clang/CIR/Dialect/IR/CIRDialect.td b/clang/include/clang/CIR/Dialect/IR/CIRDialect.td
index 3fdbf65573b36..c62d63ad42725 100644
--- a/clang/include/clang/CIR/Dialect/IR/CIRDialect.td
+++ b/clang/include/clang/CIR/Dialect/IR/CIRDialect.td
@@ -35,6 +35,7 @@ def CIR_Dialect : Dialect {
   let hasConstantMaterializer = 1;
 
   let extraClassDeclaration = [{
+    static llvm::StringRef getSourceLanguageAttrName() { return "cir.lang"; }
     static llvm::StringRef getTripleAttrName() { return "cir.triple"; }
     static llvm::StringRef getOptInfoAttrName() { return "cir.opt_info"; }
     static llvm::StringRef getCalleeAttrName() { return "callee"; }
diff --git a/clang/lib/CIR/CodeGen/CIRGenModule.cpp b/clang/lib/CIR/CodeGen/CIRGenModule.cpp
index 425250db87da6..19f4858a7848a 100644
--- a/clang/lib/CIR/CodeGen/CIRGenModule.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenModule.cpp
@@ -102,6 +102,9 @@ CIRGenModule::CIRGenModule(mlir::MLIRContext &mlirContext,
   PtrDiffTy =
       cir::IntType::get(&getMLIRContext(), sizeTypeSize, /*isSigned=*/true);
 
+  theModule->setAttr(
+      cir::CIRDialect::getSourceLanguageAttrName(),
+      cir::SourceLanguageAttr::get(&mlirContext, getCIRSourceLanguage()));
   theModule->setAttr(cir::CIRDialect::getTripleAttrName(),
                      builder.getStringAttr(getTriple().str()));
 
@@ -495,6 +498,27 @@ void CIRGenModule::setNonAliasAttributes(GlobalDecl gd, mlir::Operation *op) {
   assert(!cir::MissingFeatures::setTargetAttributes());
 }
 
+cir::SourceLanguage CIRGenModule::getCIRSourceLanguage() const {
+  using ClangStd = clang::LangStandard;
+  using CIRLang = cir::SourceLanguage;
+  auto opts = getLangOpts();
+
+  if (opts.OpenCL && !opts.OpenCLCPlusPlus)
+    llvm_unreachable("NYI");
+
+  if (opts.CPlusPlus || opts.CPlusPlus11 || opts.CPlusPlus14 ||
+      opts.CPlusPlus17 || opts.CPlusPlus20 || opts.CPlusPlus23 ||
+      opts.CPlusPlus26)
+    return CIRLang::CXX;
+  if (opts.C99 || opts.C11 || opts.C17 || opts.C23 ||
+      opts.LangStd == ClangStd::lang_c89 ||
+      opts.LangStd == ClangStd::lang_gnu89)
+    return CIRLang::C;
+
+  // TODO(cir): support remaining source languages.
+  llvm_unreachable("CIR does not yet support the given source language");
+}
+
 static void setLinkageForGV(cir::GlobalOp &gv, const NamedDecl *nd) {
   // Set linkage and visibility in case we never see a definition.
   LinkageInfo lv = nd->getLinkageAndVisibility();
diff --git a/clang/lib/CIR/CodeGen/CIRGenModule.h b/clang/lib/CIR/CodeGen/CIRGenModule.h
index 5d07d38012318..cad5afaa92615 100644
--- a/clang/lib/CIR/CodeGen/CIRGenModule.h
+++ b/clang/lib/CIR/CodeGen/CIRGenModule.h
@@ -423,6 +423,9 @@ class CIRGenModule : public CIRGenTypeCache {
   void replacePointerTypeArgs(cir::FuncOp oldF, cir::FuncOp newF);
 
   void setNonAliasAttributes(GlobalDecl gd, mlir::Operation *op);
+
+  /// Map source language used to a CIR attribute.
+  cir::SourceLanguage getCIRSourceLanguage() const;
 };
 } // namespace CIRGen
 
diff --git a/clang/test/CIR/CodeGen/lang-c.c b/clang/test/CIR/CodeGen/lang-c.c
new file mode 100644
index 0000000000000..cae9d23059bd9
--- /dev/null
+++ b/clang/test/CIR/CodeGen/lang-c.c
@@ -0,0 +1,8 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir -emit-cir %s -o %t.cir
+// RUN: FileCheck --check-prefix=CIR --input-file=%t.cir %s
+
+// CIR: module attributes {{{.*}}cir.lang = #cir.lang<c>{{.*}}}
+
+int main() {
+  return 0;
+}
diff --git a/clang/test/CIR/CodeGen/lang-cpp.cpp b/clang/test/CIR/CodeGen/lang-cpp.cpp
new file mode 100644
index 0000000000000..561d8b66ab967
--- /dev/null
+++ b/clang/test/CIR/CodeGen/lang-cpp.cpp
@@ -0,0 +1,8 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir -emit-cir %s -o %t.cir
+// RUN: FileCheck --check-prefix=CIR --input-file=%t.cir %s
+
+// CIR: module attributes {{{.*}}cir.lang = #cir.lang<cxx>{{.*}}}
+
+int main() {
+  return 0;
+}
diff --git a/clang/test/CIR/IR/invalid-lang-attr.cir b/clang/test/CIR/IR/invalid-lang-attr.cir
new file mode 100644
index 0000000000000..ffe523b1ad401
--- /dev/null
+++ b/clang/test/CIR/IR/invalid-lang-attr.cir
@@ -0,0 +1,5 @@
+// RUN: cir-opt %s -verify-diagnostics
+
+// expected-error@below {{expected ::cir::SourceLanguage to be one of}}
+// expected-error@below {{failed to parse CIR_SourceLanguageAttr parameter 'value'}}
+module attributes {cir.lang = #cir.lang<dummy>} { }
diff --git a/clang/test/CIR/IR/module.cir b/clang/test/CIR/IR/module.cir
new file mode 100644
index 0000000000000..7ce2c0ba21cb0
--- /dev/null
+++ b/clang/test/CIR/IR/module.cir
@@ -0,0 +1,12 @@
+// RUN: cir-opt %s -split-input-file -o %t.cir
+// RUN: FileCheck --input-file=%t.cir %s
+
+// Should parse and print C source language attribute.
+module attributes {cir.lang = #cir.lang<c>} { }
+// CHECK: module attributes {cir.lang = #cir.lang<c>}
+
+// -----
+
+// Should parse and print C++ source language attribute.
+module attributes {cir.lang = #cir.lang<cxx>} { }
+// CHECK: module attributes {cir.lang = #cir.lang<cxx>}

llvmbot · 2025-08-07T14:15:12Z

@llvm/pr-subscribers-clangir

Author: 7mile (seven-mile)

Changes

This patch upstreams SourceLangAttr and its CodeGen logic in the CGM, which encodes the source language in CIR.

Full diff: https://github.com/llvm/llvm-project/pull/152511.diff

8 Files Affected:

(modified) clang/include/clang/CIR/Dialect/IR/CIRAttrs.td (+37)
(modified) clang/include/clang/CIR/Dialect/IR/CIRDialect.td (+1)
(modified) clang/lib/CIR/CodeGen/CIRGenModule.cpp (+24)
(modified) clang/lib/CIR/CodeGen/CIRGenModule.h (+3)
(added) clang/test/CIR/CodeGen/lang-c.c (+8)
(added) clang/test/CIR/CodeGen/lang-cpp.cpp (+8)
(added) clang/test/CIR/IR/invalid-lang-attr.cir (+5)
(added) clang/test/CIR/IR/module.cir (+12)

diff --git a/clang/include/clang/CIR/Dialect/IR/CIRAttrs.td b/clang/include/clang/CIR/Dialect/IR/CIRAttrs.td
index 588fb0d74a509..2040109298ad1 100644
--- a/clang/include/clang/CIR/Dialect/IR/CIRAttrs.td
+++ b/clang/include/clang/CIR/Dialect/IR/CIRAttrs.td
@@ -50,6 +50,43 @@ class CIR_UnitAttr<string name, string attrMnemonic, list<Trait> traits = []>
   let isOptional = 1;
 }
 
+//===----------------------------------------------------------------------===//
+// SourceLanguageAttr
+//===----------------------------------------------------------------------===//
+
+def CIR_SourceLanguage : CIR_I32EnumAttr<"SourceLanguage", "source language", [
+  I32EnumAttrCase<"C", 1, "c">,
+  I32EnumAttrCase<"CXX", 2, "cxx">
+]> {
+  // The enum attr class is defined in `CIR_SourceLanguageAttr` below,
+  // so that it can define extra class methods.
+  let genSpecializedAttr = 0;
+}
+
+def CIR_SourceLanguageAttr : CIR_EnumAttr<CIR_SourceLanguage, "lang"> {
+
+  let summary = "Module source language";
+  let description = [{
+    Represents the source language used to generate the module.
+
+    Example:
+    ```
+    // Module compiled from C.
+    module attributes {cir.lang = cir.lang<c>} {}
+    // Module compiled from C++.
+    module attributes {cir.lang = cir.lang<cxx>} {}
+    ```
+
+    Module source language attribute name is `cir.lang` is defined by
+    `getSourceLanguageAttrName` method in CIRDialect class.
+  }];
+
+  let extraClassDeclaration = [{
+    bool isC() const { return getValue() == SourceLanguage::C; }
+    bool isCXX() const { return getValue() == SourceLanguage::CXX; }
+  }];
+}
+
 //===----------------------------------------------------------------------===//
 // OptInfoAttr
 //===----------------------------------------------------------------------===//
diff --git a/clang/include/clang/CIR/Dialect/IR/CIRDialect.td b/clang/include/clang/CIR/Dialect/IR/CIRDialect.td
index 3fdbf65573b36..c62d63ad42725 100644
--- a/clang/include/clang/CIR/Dialect/IR/CIRDialect.td
+++ b/clang/include/clang/CIR/Dialect/IR/CIRDialect.td
@@ -35,6 +35,7 @@ def CIR_Dialect : Dialect {
   let hasConstantMaterializer = 1;
 
   let extraClassDeclaration = [{
+    static llvm::StringRef getSourceLanguageAttrName() { return "cir.lang"; }
     static llvm::StringRef getTripleAttrName() { return "cir.triple"; }
     static llvm::StringRef getOptInfoAttrName() { return "cir.opt_info"; }
     static llvm::StringRef getCalleeAttrName() { return "callee"; }
diff --git a/clang/lib/CIR/CodeGen/CIRGenModule.cpp b/clang/lib/CIR/CodeGen/CIRGenModule.cpp
index 425250db87da6..19f4858a7848a 100644
--- a/clang/lib/CIR/CodeGen/CIRGenModule.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenModule.cpp
@@ -102,6 +102,9 @@ CIRGenModule::CIRGenModule(mlir::MLIRContext &mlirContext,
   PtrDiffTy =
       cir::IntType::get(&getMLIRContext(), sizeTypeSize, /*isSigned=*/true);
 
+  theModule->setAttr(
+      cir::CIRDialect::getSourceLanguageAttrName(),
+      cir::SourceLanguageAttr::get(&mlirContext, getCIRSourceLanguage()));
   theModule->setAttr(cir::CIRDialect::getTripleAttrName(),
                      builder.getStringAttr(getTriple().str()));
 
@@ -495,6 +498,27 @@ void CIRGenModule::setNonAliasAttributes(GlobalDecl gd, mlir::Operation *op) {
   assert(!cir::MissingFeatures::setTargetAttributes());
 }
 
+cir::SourceLanguage CIRGenModule::getCIRSourceLanguage() const {
+  using ClangStd = clang::LangStandard;
+  using CIRLang = cir::SourceLanguage;
+  auto opts = getLangOpts();
+
+  if (opts.OpenCL && !opts.OpenCLCPlusPlus)
+    llvm_unreachable("NYI");
+
+  if (opts.CPlusPlus || opts.CPlusPlus11 || opts.CPlusPlus14 ||
+      opts.CPlusPlus17 || opts.CPlusPlus20 || opts.CPlusPlus23 ||
+      opts.CPlusPlus26)
+    return CIRLang::CXX;
+  if (opts.C99 || opts.C11 || opts.C17 || opts.C23 ||
+      opts.LangStd == ClangStd::lang_c89 ||
+      opts.LangStd == ClangStd::lang_gnu89)
+    return CIRLang::C;
+
+  // TODO(cir): support remaining source languages.
+  llvm_unreachable("CIR does not yet support the given source language");
+}
+
 static void setLinkageForGV(cir::GlobalOp &gv, const NamedDecl *nd) {
   // Set linkage and visibility in case we never see a definition.
   LinkageInfo lv = nd->getLinkageAndVisibility();
diff --git a/clang/lib/CIR/CodeGen/CIRGenModule.h b/clang/lib/CIR/CodeGen/CIRGenModule.h
index 5d07d38012318..cad5afaa92615 100644
--- a/clang/lib/CIR/CodeGen/CIRGenModule.h
+++ b/clang/lib/CIR/CodeGen/CIRGenModule.h
@@ -423,6 +423,9 @@ class CIRGenModule : public CIRGenTypeCache {
   void replacePointerTypeArgs(cir::FuncOp oldF, cir::FuncOp newF);
 
   void setNonAliasAttributes(GlobalDecl gd, mlir::Operation *op);
+
+  /// Map source language used to a CIR attribute.
+  cir::SourceLanguage getCIRSourceLanguage() const;
 };
 } // namespace CIRGen
 
diff --git a/clang/test/CIR/CodeGen/lang-c.c b/clang/test/CIR/CodeGen/lang-c.c
new file mode 100644
index 0000000000000..cae9d23059bd9
--- /dev/null
+++ b/clang/test/CIR/CodeGen/lang-c.c
@@ -0,0 +1,8 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir -emit-cir %s -o %t.cir
+// RUN: FileCheck --check-prefix=CIR --input-file=%t.cir %s
+
+// CIR: module attributes {{{.*}}cir.lang = #cir.lang<c>{{.*}}}
+
+int main() {
+  return 0;
+}
diff --git a/clang/test/CIR/CodeGen/lang-cpp.cpp b/clang/test/CIR/CodeGen/lang-cpp.cpp
new file mode 100644
index 0000000000000..561d8b66ab967
--- /dev/null
+++ b/clang/test/CIR/CodeGen/lang-cpp.cpp
@@ -0,0 +1,8 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir -emit-cir %s -o %t.cir
+// RUN: FileCheck --check-prefix=CIR --input-file=%t.cir %s
+
+// CIR: module attributes {{{.*}}cir.lang = #cir.lang<cxx>{{.*}}}
+
+int main() {
+  return 0;
+}
diff --git a/clang/test/CIR/IR/invalid-lang-attr.cir b/clang/test/CIR/IR/invalid-lang-attr.cir
new file mode 100644
index 0000000000000..ffe523b1ad401
--- /dev/null
+++ b/clang/test/CIR/IR/invalid-lang-attr.cir
@@ -0,0 +1,5 @@
+// RUN: cir-opt %s -verify-diagnostics
+
+// expected-error@below {{expected ::cir::SourceLanguage to be one of}}
+// expected-error@below {{failed to parse CIR_SourceLanguageAttr parameter 'value'}}
+module attributes {cir.lang = #cir.lang<dummy>} { }
diff --git a/clang/test/CIR/IR/module.cir b/clang/test/CIR/IR/module.cir
new file mode 100644
index 0000000000000..7ce2c0ba21cb0
--- /dev/null
+++ b/clang/test/CIR/IR/module.cir
@@ -0,0 +1,12 @@
+// RUN: cir-opt %s -split-input-file -o %t.cir
+// RUN: FileCheck --input-file=%t.cir %s
+
+// Should parse and print C source language attribute.
+module attributes {cir.lang = #cir.lang<c>} { }
+// CHECK: module attributes {cir.lang = #cir.lang<c>}
+
+// -----
+
+// Should parse and print C++ source language attribute.
+module attributes {cir.lang = #cir.lang<cxx>} { }
+// CHECK: module attributes {cir.lang = #cir.lang<cxx>}

clang/include/clang/CIR/Dialect/IR/CIRAttrs.td

clang/lib/CIR/CodeGen/CIRGenModule.cpp

clang/include/clang/CIR/Dialect/IR/CIRAttrs.td

bcardosolopes

LGTM

clang/include/clang/CIR/Dialect/IR/CIRAttrs.td

[CIR][Dialect] Add SourceLangAttr

f501e18

seven-mile requested review from lanza, bcardosolopes, xlauko and andykaylor as code owners August 7, 2025 14:14

llvmbot added clang Clang issues not falling into any other category ClangIR Anything related to the ClangIR project labels Aug 7, 2025

bcardosolopes reviewed Aug 7, 2025

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seven-mile added 2 commits August 8, 2025 01:06

use errorNYI and add missing feature flag

6fe6b00

adjust todo position

1a04b37

bcardosolopes approved these changes Aug 12, 2025

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[CIR][Dialect] Add SourceLangAttr #152511

[CIR][Dialect] Add SourceLangAttr #152511

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