Deduplicate S_CONSTANTs in LLD.
Summary: Deduplicate S_CONSTANTS when linking, if they have the same value.
Reviewers: rnk
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63151
git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@363089 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/COFF/Inputs/pdb-global-constants-a.s b/test/COFF/Inputs/pdb-global-constants-a.s
new file mode 100644
index 0000000..7b1d34c
--- /dev/null
+++ b/test/COFF/Inputs/pdb-global-constants-a.s
@@ -0,0 +1,214 @@
+ .text
+ .def @feat.00;
+ .scl 3;
+ .type 0;
+ .endef
+ .globl @feat.00
+.set @feat.00, 0
+ .file "t.cpp"
+ .def main;
+ .scl 2;
+ .type 32;
+ .endef
+ .globl main # -- Begin function main
+ .p2align 4, 0x90
+main: # @main
+.Lfunc_begin0:
+ .cv_func_id 0
+ .cv_file 1 "C:\\src\\testing\\t.cpp" "D28AB0CC784E17E5DF9BBB49CB629C81" 1
+ .cv_loc 0 1 4 0 # t.cpp:4:0
+.seh_proc main
+# %bb.0: # %entry
+ pushq %rax
+ .seh_stackalloc 8
+ .seh_endprologue
+ movl $0, 4(%rsp)
+.Ltmp0:
+ movl $83, %eax
+ popq %rcx
+ retq
+.Ltmp1:
+.Lfunc_end0:
+ .seh_handlerdata
+ .text
+ .seh_endproc
+ # -- End function
+ .section .debug$S,"dr"
+ .p2align 2
+ .long 4 # Debug section magic
+ .long 241
+ .long .Ltmp3-.Ltmp2 # Subsection size
+.Ltmp2:
+ .short .Ltmp5-.Ltmp4 # Record length
+.Ltmp4:
+ .short 4412 # Record kind: S_COMPILE3
+ .long 1 # Flags and language
+ .short 208 # CPUType
+ .short 9 # Frontend version
+ .short 0
+ .short 0
+ .short 0
+ .short 9000 # Backend version
+ .short 0
+ .short 0
+ .short 0
+ .asciz "clang version 9.0.0 (https://github.com/llvm/llvm-project.git ad522e17b285b1f2667163d52da5abf0968ec650)" # Null-terminated compiler version string
+ .p2align 2
+.Ltmp5:
+.Ltmp3:
+ .p2align 2
+ .long 241 # Symbol subsection for main
+ .long .Ltmp7-.Ltmp6 # Subsection size
+.Ltmp6:
+ .short .Ltmp9-.Ltmp8 # Record length
+.Ltmp8:
+ .short 4423 # Record kind: S_GPROC32_ID
+ .long 0 # PtrParent
+ .long 0 # PtrEnd
+ .long 0 # PtrNext
+ .long .Lfunc_end0-main # Code size
+ .long 0 # Offset after prologue
+ .long 0 # Offset before epilogue
+ .long 4098 # Function type index
+ .secrel32 main # Function section relative address
+ .secidx main # Function section index
+ .byte 0 # Flags
+ .asciz "main" # Function name
+ .p2align 2
+.Ltmp9:
+ .short .Ltmp11-.Ltmp10 # Record length
+.Ltmp10:
+ .short 4114 # Record kind: S_FRAMEPROC
+ .long 8 # FrameSize
+ .long 0 # Padding
+ .long 0 # Offset of padding
+ .long 0 # Bytes of callee saved registers
+ .long 0 # Exception handler offset
+ .short 0 # Exception handler section
+ .long 81920 # Flags (defines frame register)
+ .p2align 2
+.Ltmp11:
+ .short 2 # Record length
+ .short 4431 # Record kind: S_PROC_ID_END
+.Ltmp7:
+ .p2align 2
+ .cv_linetable 0, main, .Lfunc_end0
+ .long 241 # Symbol subsection for globals
+ .long .Ltmp13-.Ltmp12 # Subsection size
+.Ltmp12:
+ .short .Ltmp15-.Ltmp14 # Record length
+.Ltmp14:
+ .short 4359 # Record kind: S_CONSTANT
+ .long 4099 # Type
+ .byte 0x29, 0x00 # Value
+ .asciz "Foo" # Name
+ .p2align 2
+.Ltmp15:
+ .short .Ltmp17-.Ltmp16 # Record length
+.Ltmp16:
+ .short 4359 # Record kind: S_CONSTANT
+ .long 4099 # Type
+ .byte 0x2a, 0x00 # Value
+ .asciz "Bar" # Name
+ .p2align 2
+.Ltmp17:
+.Ltmp13:
+ .p2align 2
+ .cv_filechecksums # File index to string table offset subsection
+ .cv_stringtable # String table
+ .long 241
+ .long .Ltmp19-.Ltmp18 # Subsection size
+.Ltmp18:
+ .short .Ltmp21-.Ltmp20 # Record length
+.Ltmp20:
+ .short 4428 # Record kind: S_BUILDINFO
+ .long 4102 # LF_BUILDINFO index
+ .p2align 2
+.Ltmp21:
+.Ltmp19:
+ .p2align 2
+ .section .debug$T,"dr"
+ .p2align 2
+ .long 4 # Debug section magic
+ # ArgList (0x1000) {
+ # TypeLeafKind: LF_ARGLIST (0x1201)
+ # NumArgs: 0
+ # Arguments [
+ # ]
+ # }
+ .byte 0x06, 0x00, 0x01, 0x12
+ .byte 0x00, 0x00, 0x00, 0x00
+ # Procedure (0x1001) {
+ # TypeLeafKind: LF_PROCEDURE (0x1008)
+ # ReturnType: int (0x74)
+ # CallingConvention: NearC (0x0)
+ # FunctionOptions [ (0x0)
+ # ]
+ # NumParameters: 0
+ # ArgListType: () (0x1000)
+ # }
+ .byte 0x0e, 0x00, 0x08, 0x10
+ .byte 0x74, 0x00, 0x00, 0x00
+ .byte 0x00, 0x00, 0x00, 0x00
+ .byte 0x00, 0x10, 0x00, 0x00
+ # FuncId (0x1002) {
+ # TypeLeafKind: LF_FUNC_ID (0x1601)
+ # ParentScope: 0x0
+ # FunctionType: int () (0x1001)
+ # Name: main
+ # }
+ .byte 0x12, 0x00, 0x01, 0x16
+ .byte 0x00, 0x00, 0x00, 0x00
+ .byte 0x01, 0x10, 0x00, 0x00
+ .byte 0x6d, 0x61, 0x69, 0x6e
+ .byte 0x00, 0xf3, 0xf2, 0xf1
+ # Modifier (0x1003) {
+ # TypeLeafKind: LF_MODIFIER (0x1001)
+ # ModifiedType: int (0x74)
+ # Modifiers [ (0x1)
+ # Const (0x1)
+ # ]
+ # }
+ .byte 0x0a, 0x00, 0x01, 0x10
+ .byte 0x74, 0x00, 0x00, 0x00
+ .byte 0x01, 0x00, 0xf2, 0xf1
+ # StringId (0x1004) {
+ # TypeLeafKind: LF_STRING_ID (0x1605)
+ # Id: 0x0
+ # StringData: C:\src\testing
+ # }
+ .byte 0x16, 0x00, 0x05, 0x16
+ .byte 0x00, 0x00, 0x00, 0x00
+ .byte 0x43, 0x3a, 0x5c, 0x73
+ .byte 0x72, 0x63, 0x5c, 0x74
+ .byte 0x65, 0x73, 0x74, 0x69
+ .byte 0x6e, 0x67, 0x00, 0xf1
+ # StringId (0x1005) {
+ # TypeLeafKind: LF_STRING_ID (0x1605)
+ # Id: 0x0
+ # StringData: t.cpp
+ # }
+ .byte 0x0e, 0x00, 0x05, 0x16
+ .byte 0x00, 0x00, 0x00, 0x00
+ .byte 0x74, 0x2e, 0x63, 0x70
+ .byte 0x70, 0x00, 0xf2, 0xf1
+ # BuildInfo (0x1006) {
+ # TypeLeafKind: LF_BUILDINFO (0x1603)
+ # NumArgs: 5
+ # Arguments [
+ # ArgType: C:\src\testing (0x1004)
+ # ArgType: 0x0
+ # ArgType: t.cpp (0x1005)
+ # ArgType: 0x0
+ # ArgType: 0x0
+ # ]
+ # }
+ .byte 0x1a, 0x00, 0x03, 0x16
+ .byte 0x05, 0x00, 0x04, 0x10
+ .byte 0x00, 0x00, 0x00, 0x00
+ .byte 0x00, 0x00, 0x05, 0x10
+ .byte 0x00, 0x00, 0x00, 0x00
+ .byte 0x00, 0x00, 0x00, 0x00
+ .byte 0x00, 0x00, 0xf2, 0xf1
+
+ .addrsig
diff --git a/test/COFF/Inputs/pdb-global-constants-b.s b/test/COFF/Inputs/pdb-global-constants-b.s
new file mode 100644
index 0000000..1d987a5
--- /dev/null
+++ b/test/COFF/Inputs/pdb-global-constants-b.s
@@ -0,0 +1,204 @@
+ .text
+ .def @feat.00;
+ .scl 3;
+ .type 0;
+ .endef
+ .globl @feat.00
+.set @feat.00, 0
+ .file "t2.cpp"
+ .def "?foobar@@YAHXZ";
+ .scl 2;
+ .type 32;
+ .endef
+ .globl "?foobar@@YAHXZ" # -- Begin function ?foobar@@YAHXZ
+ .p2align 4, 0x90
+"?foobar@@YAHXZ": # @"?foobar@@YAHXZ"
+.Lfunc_begin0:
+ .cv_func_id 0
+# %bb.0: # %entry
+ .cv_file 1 "C:\\src\\testing\\t2.cpp" "C9D7AF07363FDE8EC16D73EC30039C5B" 1
+ .cv_loc 0 1 5 0 # t2.cpp:5:0
+ movl $84, %eax
+ retq
+.Ltmp0:
+.Lfunc_end0:
+ # -- End function
+ .section .debug$S,"dr"
+ .p2align 2
+ .long 4 # Debug section magic
+ .long 241
+ .long .Ltmp2-.Ltmp1 # Subsection size
+.Ltmp1:
+ .short .Ltmp4-.Ltmp3 # Record length
+.Ltmp3:
+ .short 4412 # Record kind: S_COMPILE3
+ .long 1 # Flags and language
+ .short 208 # CPUType
+ .short 9 # Frontend version
+ .short 0
+ .short 0
+ .short 0
+ .short 9000 # Backend version
+ .short 0
+ .short 0
+ .short 0
+ .asciz "clang version 9.0.0 (https://github.com/llvm/llvm-project.git ad522e17b285b1f2667163d52da5abf0968ec650)" # Null-terminated compiler version string
+ .p2align 2
+.Ltmp4:
+.Ltmp2:
+ .p2align 2
+ .long 241 # Symbol subsection for foobar
+ .long .Ltmp6-.Ltmp5 # Subsection size
+.Ltmp5:
+ .short .Ltmp8-.Ltmp7 # Record length
+.Ltmp7:
+ .short 4423 # Record kind: S_GPROC32_ID
+ .long 0 # PtrParent
+ .long 0 # PtrEnd
+ .long 0 # PtrNext
+ .long .Lfunc_end0-"?foobar@@YAHXZ" # Code size
+ .long 0 # Offset after prologue
+ .long 0 # Offset before epilogue
+ .long 4098 # Function type index
+ .secrel32 "?foobar@@YAHXZ" # Function section relative address
+ .secidx "?foobar@@YAHXZ" # Function section index
+ .byte 0 # Flags
+ .asciz "foobar" # Function name
+ .p2align 2
+.Ltmp8:
+ .short .Ltmp10-.Ltmp9 # Record length
+.Ltmp9:
+ .short 4114 # Record kind: S_FRAMEPROC
+ .long 0 # FrameSize
+ .long 0 # Padding
+ .long 0 # Offset of padding
+ .long 0 # Bytes of callee saved registers
+ .long 0 # Exception handler offset
+ .short 0 # Exception handler section
+ .long 0 # Flags (defines frame register)
+ .p2align 2
+.Ltmp10:
+ .short 2 # Record length
+ .short 4431 # Record kind: S_PROC_ID_END
+.Ltmp6:
+ .p2align 2
+ .cv_linetable 0, "?foobar@@YAHXZ", .Lfunc_end0
+ .long 241 # Symbol subsection for globals
+ .long .Ltmp12-.Ltmp11 # Subsection size
+.Ltmp11:
+ .short .Ltmp14-.Ltmp13 # Record length
+.Ltmp13:
+ .short 4359 # Record kind: S_CONSTANT
+ .long 4099 # Type
+ .byte 0x2a, 0x00 # Value
+ .asciz "Foo" # Name
+ .p2align 2
+.Ltmp14:
+ .short .Ltmp16-.Ltmp15 # Record length
+.Ltmp15:
+ .short 4359 # Record kind: S_CONSTANT
+ .long 4099 # Type
+ .byte 0x2a, 0x00 # Value
+ .asciz "Bar" # Name
+ .p2align 2
+.Ltmp16:
+.Ltmp12:
+ .p2align 2
+ .cv_filechecksums # File index to string table offset subsection
+ .cv_stringtable # String table
+ .long 241
+ .long .Ltmp18-.Ltmp17 # Subsection size
+.Ltmp17:
+ .short .Ltmp20-.Ltmp19 # Record length
+.Ltmp19:
+ .short 4428 # Record kind: S_BUILDINFO
+ .long 4102 # LF_BUILDINFO index
+ .p2align 2
+.Ltmp20:
+.Ltmp18:
+ .p2align 2
+ .section .debug$T,"dr"
+ .p2align 2
+ .long 4 # Debug section magic
+ # ArgList (0x1000) {
+ # TypeLeafKind: LF_ARGLIST (0x1201)
+ # NumArgs: 0
+ # Arguments [
+ # ]
+ # }
+ .byte 0x06, 0x00, 0x01, 0x12
+ .byte 0x00, 0x00, 0x00, 0x00
+ # Procedure (0x1001) {
+ # TypeLeafKind: LF_PROCEDURE (0x1008)
+ # ReturnType: int (0x74)
+ # CallingConvention: NearC (0x0)
+ # FunctionOptions [ (0x0)
+ # ]
+ # NumParameters: 0
+ # ArgListType: () (0x1000)
+ # }
+ .byte 0x0e, 0x00, 0x08, 0x10
+ .byte 0x74, 0x00, 0x00, 0x00
+ .byte 0x00, 0x00, 0x00, 0x00
+ .byte 0x00, 0x10, 0x00, 0x00
+ # FuncId (0x1002) {
+ # TypeLeafKind: LF_FUNC_ID (0x1601)
+ # ParentScope: 0x0
+ # FunctionType: int () (0x1001)
+ # Name: foobar
+ # }
+ .byte 0x12, 0x00, 0x01, 0x16
+ .byte 0x00, 0x00, 0x00, 0x00
+ .byte 0x01, 0x10, 0x00, 0x00
+ .byte 0x66, 0x6f, 0x6f, 0x62
+ .byte 0x61, 0x72, 0x00, 0xf1
+ # Modifier (0x1003) {
+ # TypeLeafKind: LF_MODIFIER (0x1001)
+ # ModifiedType: int (0x74)
+ # Modifiers [ (0x1)
+ # Const (0x1)
+ # ]
+ # }
+ .byte 0x0a, 0x00, 0x01, 0x10
+ .byte 0x74, 0x00, 0x00, 0x00
+ .byte 0x01, 0x00, 0xf2, 0xf1
+ # StringId (0x1004) {
+ # TypeLeafKind: LF_STRING_ID (0x1605)
+ # Id: 0x0
+ # StringData: C:\src\testing
+ # }
+ .byte 0x16, 0x00, 0x05, 0x16
+ .byte 0x00, 0x00, 0x00, 0x00
+ .byte 0x43, 0x3a, 0x5c, 0x73
+ .byte 0x72, 0x63, 0x5c, 0x74
+ .byte 0x65, 0x73, 0x74, 0x69
+ .byte 0x6e, 0x67, 0x00, 0xf1
+ # StringId (0x1005) {
+ # TypeLeafKind: LF_STRING_ID (0x1605)
+ # Id: 0x0
+ # StringData: t2.cpp
+ # }
+ .byte 0x0e, 0x00, 0x05, 0x16
+ .byte 0x00, 0x00, 0x00, 0x00
+ .byte 0x74, 0x32, 0x2e, 0x63
+ .byte 0x70, 0x70, 0x00, 0xf1
+ # BuildInfo (0x1006) {
+ # TypeLeafKind: LF_BUILDINFO (0x1603)
+ # NumArgs: 5
+ # Arguments [
+ # ArgType: C:\src\testing (0x1004)
+ # ArgType: 0x0
+ # ArgType: t2.cpp (0x1005)
+ # ArgType: 0x0
+ # ArgType: 0x0
+ # ]
+ # }
+ .byte 0x1a, 0x00, 0x03, 0x16
+ .byte 0x05, 0x00, 0x04, 0x10
+ .byte 0x00, 0x00, 0x00, 0x00
+ .byte 0x00, 0x00, 0x05, 0x10
+ .byte 0x00, 0x00, 0x00, 0x00
+ .byte 0x00, 0x00, 0x00, 0x00
+ .byte 0x00, 0x00, 0xf2, 0xf1
+
+ .addrsig
diff --git a/test/COFF/pdb-global-constants.test b/test/COFF/pdb-global-constants.test
new file mode 100644
index 0000000..b646fc9
--- /dev/null
+++ b/test/COFF/pdb-global-constants.test
@@ -0,0 +1,28 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj %S/Inputs/pdb-global-constants-a.s -o %t-a.obj -triple x86_64-windows-msvc
+# RUN: llvm-mc -filetype=obj %S/Inputs/pdb-global-constants-b.s -o %t-b.obj -triple x86_64-windows-msvc
+# RUN: lld-link -entry:main -nodefaultlib %t-a.obj %t-b.obj -out:%t.exe -pdb:%t.pdb -debug
+# RUN: llvm-pdbutil dump -globals %t.pdb | FileCheck %s
+
+# Test that lld deduplicates S_CONSTANT records with the same name and value.
+#
+# Compiled from this C code, using
+# clang t.cpp -g -gcodeview -S
+#
+# %t-a.cpp:
+# const int Foo = 41;
+# const int Bar = 42;
+# int main() { return Foo + Bar; }
+#
+# %t-b.cpp:
+# const int Foo = 42;
+# const int Bar = 42;
+# int foobar() { return Foo + Bar; }
+
+CHECK: Global Symbols
+CHECK: 88 | S_CONSTANT [size = 16] `Bar`
+CHECK-NEXT: type = 0x1002 (const int), value = 42
+CHECK-NEXT: 72 | S_CONSTANT [size = 16] `Foo`
+CHECK-NEXT: type = 0x1002 (const int), value = 41
+CHECK-NEXT: 128 | S_CONSTANT [size = 16] `Foo`
+CHECK-NEXT: type = 0x1002 (const int), value = 42
