[Debug-Info] handle DW_CC_pass_by_value/DW_CC_pass_by_reference under strict DWARF.

Summary: When -strict-dwarf=true is specified, the calling convention info
    DW_CC_pass_by_value or DW_CC_pass_by_reference can only be generated at DWARF5.

Reviewed By: shchenz, dblaikie

Differential Revision: https://reviews.llvm.org/D103300

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
index a28dbb3..82dbb8a 100644 (file)
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -939,14 +939,17 @@ void DwarfUnit::constructTypeDIE(DIE &Buffer, const DICompositeType *CTy) {
       addFlag(Buffer, dwarf::DW_AT_APPLE_objc_complete_type);
 
     // Add the type's non-standard calling convention.
-    uint8_t CC = 0;
-    if (CTy->isTypePassByValue())
-      CC = dwarf::DW_CC_pass_by_value;
-    else if (CTy->isTypePassByReference())
-      CC = dwarf::DW_CC_pass_by_reference;
-    if (CC)
-      addUInt(Buffer, dwarf::DW_AT_calling_convention, dwarf::DW_FORM_data1,
-              CC);
+    // DW_CC_pass_by_value/DW_CC_pass_by_reference are introduced in DWARF 5.
+    if (!Asm->TM.Options.DebugStrictDwarf || DD->getDwarfVersion() >= 5) {
+      uint8_t CC = 0;
+      if (CTy->isTypePassByValue())
+        CC = dwarf::DW_CC_pass_by_value;
+      else if (CTy->isTypePassByReference())
+        CC = dwarf::DW_CC_pass_by_reference;
+      if (CC)
+        addUInt(Buffer, dwarf::DW_AT_calling_convention, dwarf::DW_FORM_data1,
+                CC);
+    }
     break;
   }
   default:

diff --git a/llvm/test/DebugInfo/Generic/pass-by-value.ll b/llvm/test/DebugInfo/Generic/pass-by-value.ll
index ce8647e..6faf5f2 100644 (file)
--- a/llvm/test/DebugInfo/Generic/pass-by-value.ll
+++ b/llvm/test/DebugInfo/Generic/pass-by-value.ll
@@ -1,4 +1,6 @@
 ; RUN: %llc_dwarf -O0 -filetype=obj < %s | llvm-dwarfdump -debug-info - | FileCheck %s
+; RUN: %llc_dwarf -O0 -filetype=obj < %s -strict-dwarf=true | llvm-dwarfdump -debug-info - \
+; RUN:   | FileCheck %s --check-prefix=STRICT --implicit-check-not DW_AT_calling_convention
 ;
 ; // S is not trivially copyable.
 ; struct S {
@@ -20,6 +22,12 @@
 ; CHECK: DW_TAG_structure_type
 ; CHECK-NEXT: DW_AT_calling_convention (DW_CC_pass_by_value)
 ; CHECK-NEXT: DW_AT_name       ("T")
+;
+; STRICT: DW_TAG_structure_type
+; STRICT-NEXT: DW_AT_name      ("S")
+;
+; STRICT: DW_TAG_structure_type
+; STRICT-NEXT: DW_AT_name      ("T")
 
 %struct.S = type { i8 }
 %struct.T = type { i8 }