2 files changed, 233 insertions, 1 deletions

diff --git a/llvm/lib/MC/ELFObjectWriter.cpp b/llvm/lib/MC/ELFObjectWriter.cpp
index 6a48d62c8e1..9490a9941ac 100644
--- a/llvm/lib/MC/ELFObjectWriter.cpp
+++ b/llvm/lib/MC/ELFObjectWriter.cpp
@@ -532,6 +532,41 @@ void ELFObjectWriter::ExecutePostLayoutBinding(MCAssembler &Asm,
   }
 }
 
+static uint8_t mergeTypeForSet(uint8_t origType, uint8_t newType) {
+  uint8_t Type = newType;
+
+  // Propagation rules:
+  // IFUNC > FUNC > OBJECT > NOTYPE
+  // TLS_OBJECT > OBJECT > NOTYPE
+  //
+  // dont let the new type degrade the old type
+  switch (origType) {
+  default:
+    break;
+  case ELF::STT_GNU_IFUNC:
+    if (Type == ELF::STT_FUNC || Type == ELF::STT_OBJECT ||
+        Type == ELF::STT_NOTYPE || Type == ELF::STT_TLS)
+      Type = ELF::STT_GNU_IFUNC;
+    break;
+  case ELF::STT_FUNC:
+    if (Type == ELF::STT_OBJECT || Type == ELF::STT_NOTYPE ||
+        Type == ELF::STT_TLS)
+      Type = ELF::STT_FUNC;
+    break;
+  case ELF::STT_OBJECT:
+    if (Type == ELF::STT_NOTYPE)
+      Type = ELF::STT_OBJECT;
+    break;
+  case ELF::STT_TLS:
+    if (Type == ELF::STT_OBJECT || Type == ELF::STT_NOTYPE ||
+        Type == ELF::STT_GNU_IFUNC || Type == ELF::STT_FUNC)
+      Type = ELF::STT_TLS;
+    break;
+  }
+
+  return Type;
+}
+
 void ELFObjectWriter::WriteSymbol(MCDataFragment *SymtabF,
                                   MCDataFragment *ShndxF,
                                   ELFSymbolData &MSD,
@@ -545,7 +580,7 @@ void ELFObjectWriter::WriteSymbol(MCDataFragment *SymtabF,
 
   // Binding and Type share the same byte as upper and lower nibbles
   uint8_t Binding = MCELF::GetBinding(OrigData);
-  uint8_t Type = MCELF::GetType(Data);
+  uint8_t Type = mergeTypeForSet(MCELF::GetType(OrigData), MCELF::GetType(Data));
   uint8_t Info = (Binding << ELF_STB_Shift) | (Type << ELF_STT_Shift);
 
   // Other and Visibility share the same byte with Visibility using the lower
diff --git a/llvm/test/MC/ELF/type.s b/llvm/test/MC/ELF/type.s
index c2f3631ec43..638d8286991 100644
--- a/llvm/test/MC/ELF/type.s
+++ b/llvm/test/MC/ELF/type.s
@@ -41,6 +41,95 @@ tls_upper_case:
         .global tls_upper_case
         .type tls_upper_case,STT_TLS
 
+// Test that .set doesnt downgrade the type:
+// IFUNC > FUNC > OBJECT > NOTYPE
+// TLS_OBJECT > OBJECT > NOTYPE
+// also TLS_OBJECT is incompatible with IFUNC and FUNC
+
+        .global sym1
+        .type sym1, @gnu_indirect_function
+alias1:
+        .global alias1
+        .type alias1, @function
+        .set sym1, alias1
+
+        .global sym2
+        .type sym2, @gnu_indirect_function
+alias2:
+        .global alias2
+        .type alias2, @object
+        .set sym2, alias2
+
+        .global sym3
+        .type sym3, @gnu_indirect_function
+alias3:
+        .global alias3
+        .type alias3, @notype
+        .set sym3, alias3
+
+        .global sym4
+        .type sym4, @function
+alias4:
+        .global alias4
+        .type alias4, @object
+        .set sym4, alias4
+
+        .global sym5
+        .type sym5, @function
+alias5:
+        .global alias5
+        .type alias5, @notype
+        .set sym5, alias5
+
+        .global sym6
+        .type sym6, @object
+alias6:
+        .global alias6
+        .type alias6, @notype
+        .set sym6, alias6
+
+        .global sym7
+        .type sym7, @gnu_indirect_function
+alias7:
+        .global alias7
+        .type alias7, @tls_object
+        .set sym7, alias7
+
+        .global sym8
+        .type sym8, @function
+        .global alias8
+alias8:
+        .type alias8, @tls_object
+        .set sym8, alias8
+
+        .global sym9
+        .type sym9, @tls_object
+alias9:
+        .global alias9
+        .type alias9, @object
+        .set sym9, alias9
+
+        .global sym10
+        .type sym10, @tls_object
+alias10:
+        .global alias10
+        .type alias10, @notype
+        .set sym10, alias10
+
+        .global sym11
+        .type sym11, @tls_object
+alias11:
+        .global alias11
+        .type alias11, @gnu_indirect_function
+        .set sym11, alias11
+
+        .global sym12
+        .type sym12, @tls_object
+alias12:        
+        .global alias12
+        .type alias12, @function
+        .set sym12, alias12
+
 // CHECK:        Symbol {
 // CHECK:          Name: bar
 // CHECK-NEXT:     Value: 0x0
@@ -86,6 +175,114 @@ tls_upper_case:
 // CHECK-NEXT:     Other: 0
 // CHECK-NEXT:     Section: .text (0x1)
 // CHECK-NEXT:   }
+// CHECK-NEXT:  Symbol {
+// CHECK-NEXT:    Name: sym1 (54)
+// CHECK-NEXT:    Value: 0x0
+// CHECK-NEXT:    Size: 0
+// CHECK-NEXT:    Binding: Global (0x1)
+// CHECK-NEXT:    Type: GNU_IFunc (0xA)
+// CHECK-NEXT:    Other: 0
+// CHECK-NEXT:    Section: .text (0x1)
+// CHECK-NEXT:  }
+// CHECK-NEXT:  Symbol {
+// CHECK-NEXT:    Name: sym10 (162)
+// CHECK-NEXT:    Value: 0x0
+// CHECK-NEXT:    Size: 0
+// CHECK-NEXT:    Binding: Global (0x1)
+// CHECK-NEXT:    Type: TLS (0x6)
+// CHECK-NEXT:    Other: 0
+// CHECK-NEXT:    Section: .text (0x1)
+// CHECK-NEXT:  }
+// CHECK-NEXT:  Symbol {
+// CHECK-NEXT:    Name: sym11 (176)
+// CHECK-NEXT:    Value: 0x0
+// CHECK-NEXT:    Size: 0
+// CHECK-NEXT:    Binding: Global (0x1)
+// CHECK-NEXT:    Type: TLS (0x6)
+// CHECK-NEXT:    Other: 0
+// CHECK-NEXT:    Section: .text (0x1)
+// CHECK-NEXT:  }
+// CHECK-NEXT:  Symbol {
+// CHECK-NEXT:    Name: sym12 (190)
+// CHECK-NEXT:    Value: 0x0
+// CHECK-NEXT:    Size: 0
+// CHECK-NEXT:    Binding: Global (0x1)
+// CHECK-NEXT:    Type: TLS (0x6)
+// CHECK-NEXT:    Other: 0
+// CHECK-NEXT:    Section: .text (0x1)
+// CHECK-NEXT:  }
+// CHECK-NEXT:  Symbol {
+// CHECK-NEXT:    Name: sym2 (66)
+// CHECK-NEXT:    Value: 0x0
+// CHECK-NEXT:    Size: 0
+// CHECK-NEXT:    Binding: Global (0x1)
+// CHECK-NEXT:    Type: GNU_IFunc (0xA)
+// CHECK-NEXT:    Other: 0
+// CHECK-NEXT:    Section: .text (0x1)
+// CHECK-NEXT:  }
+// CHECK-NEXT:  Symbol {
+// CHECK-NEXT:    Name: sym3 (78)
+// CHECK-NEXT:    Value: 0x0
+// CHECK-NEXT:    Size: 0
+// CHECK-NEXT:    Binding: Global (0x1)
+// CHECK-NEXT:    Type: GNU_IFunc (0xA)
+// CHECK-NEXT:    Other: 0
+// CHECK-NEXT:    Section: .text (0x1)
+// CHECK-NEXT:  }
+// CHECK-NEXT:  Symbol {
+// CHECK-NEXT:    Name: sym4 (90)
+// CHECK-NEXT:    Value: 0x0
+// CHECK-NEXT:    Size: 0
+// CHECK-NEXT:    Binding: Global (0x1)
+// CHECK-NEXT:    Type: Function (0x2)
+// CHECK-NEXT:    Other: 0
+// CHECK-NEXT:    Section: .text (0x1)
+// CHECK-NEXT:  }
+// CHECK-NEXT:  Symbol {
+// CHECK-NEXT:    Name: sym5 (102)
+// CHECK-NEXT:    Value: 0x0
+// CHECK-NEXT:    Size: 0
+// CHECK-NEXT:    Binding: Global (0x1)
+// CHECK-NEXT:    Type: Function (0x2)
+// CHECK-NEXT:    Other: 0
+// CHECK-NEXT:    Section: .text (0x1)
+// CHECK-NEXT:  }
+// CHECK-NEXT:  Symbol {
+// CHECK-NEXT:    Name: sym6 (114)
+// CHECK-NEXT:    Value: 0x0
+// CHECK-NEXT:    Size: 0
+// CHECK-NEXT:    Binding: Global (0x1)
+// CHECK-NEXT:    Type: Object (0x1)
+// CHECK-NEXT:    Other: 0
+// CHECK-NEXT:    Section: .text (0x1)
+// CHECK-NEXT:  }
+// CHECK-NEXT:  Symbol {
+// CHECK-NEXT:    Name: sym7 (126)
+// CHECK-NEXT:    Value: 0x0
+// CHECK-NEXT:    Size: 0
+// CHECK-NEXT:    Binding: Global (0x1)
+// CHECK-NEXT:    Type: GNU_IFunc (0xA)
+// CHECK-NEXT:    Other: 0
+// CHECK-NEXT:    Section: .text (0x1)
+// CHECK-NEXT:  }
+// CHECK-NEXT:  Symbol {
+// CHECK-NEXT:    Name: sym8 (138)
+// CHECK-NEXT:    Value: 0x0
+// CHECK-NEXT:    Size: 0
+// CHECK-NEXT:    Binding: Global (0x1)
+// CHECK-NEXT:    Type: Function (0x2)
+// CHECK-NEXT:    Other: 0
+// CHECK-NEXT:    Section: .text (0x1)
+// CHECK-NEXT:  }
+// CHECK-NEXT:  Symbol {
+// CHECK-NEXT:    Name: sym9 (150)
+// CHECK-NEXT:    Value: 0x0
+// CHECK-NEXT:    Size: 0
+// CHECK-NEXT:    Binding: Global (0x1)
+// CHECK-NEXT:    Type: TLS (0x6)
+// CHECK-NEXT:    Other: 0
+// CHECK-NEXT:    Section: .text (0x1)
+// CHECK-NEXT:  }
 // CHECK-NEXT:   Symbol {
 // CHECK-NEXT:     Name: tls
 // CHECK-NEXT:     Value: 0x0