[WebAssembly][Object] Record section start offsets at start of payload (#76188)

LLVM ObjectFile currently records the start offsets of sections as the
start of the section header, whereas most other tools (WABT, emscripten,
wasm-tools) record it as the start of the section content, after the
header. This affects binutils tools such as objdump and nm, but not
compilation/assembly (since that is driven by symbols and assembler
labels which already have their values inside the section payload rather
in the header. This patch updates LLVM to match the other tools.

7 files changed, 58 insertions, 58 deletions

diff --git a/llvm/lib/Object/WasmObjectFile.cpp b/llvm/lib/Object/WasmObjectFile.cpp
index 05bd7302c497..dfe86a45df32 100644
--- a/llvm/lib/Object/WasmObjectFile.cpp
+++ b/llvm/lib/Object/WasmObjectFile.cpp
@@ -265,7 +265,6 @@ static wasm::WasmTableType readTableType(WasmObjectFile::ReadContext &Ctx) {
 
 static Error readSection(WasmSection &Section, WasmObjectFile::ReadContext &Ctx,
                          WasmSectionOrderChecker &Checker) {
-  Section.Offset = Ctx.Ptr - Ctx.Start;
   Section.Type = readUint8(Ctx);
   LLVM_DEBUG(dbgs() << "readSection type=" << Section.Type << "\n");
   // When reading the section's size, store the size of the LEB used to encode
@@ -273,6 +272,7 @@ static Error readSection(WasmSection &Section, WasmObjectFile::ReadContext &Ctx,
   const uint8_t *PreSizePtr = Ctx.Ptr;
   uint32_t Size = readVaruint32(Ctx);
   Section.HeaderSecSizeEncodingLen = Ctx.Ptr - PreSizePtr;
+  Section.Offset = Ctx.Ptr - Ctx.Start;
   if (Size == 0)
     return make_error<StringError>("zero length section",
                                    object_error::parse_failed);
diff --git a/llvm/test/MC/WebAssembly/custom-sections.ll b/llvm/test/MC/WebAssembly/custom-sections.ll
index cf2d7098ae4b..ba669716c934 100644
--- a/llvm/test/MC/WebAssembly/custom-sections.ll
+++ b/llvm/test/MC/WebAssembly/custom-sections.ll
@@ -15,18 +15,18 @@ target triple = "wasm32-unknown-unknown"
 ; CHECK:  Section {
 ; CHECK:    Type: CUSTOM (0x0)
 ; CHECK:    Size: 3
-; CHECK:    Offset: 38
+; CHECK:    Offset: 44
 ; CHECK:    Name: red
 ; CHECK:  }
 ; CHECK:  Section {
 ; CHECK:    Type: CUSTOM (0x0)
 ; CHECK:    Size: 6
-; CHECK:    Offset: 51
+; CHECK:    Offset: 57
 ; CHECK:    Name: green
 ; CHECK:  }
 ; CHECK:  Section {
 ; CHECK:    Type: CUSTOM (0x0)
 ; CHECK:    Size: 25
-; CHECK:    Offset: 84
+; CHECK:    Offset: 90
 ; CHECK:    Name: producers
 ; CHECK:  }
diff --git a/llvm/test/MC/WebAssembly/debug-info.ll b/llvm/test/MC/WebAssembly/debug-info.ll
index c8ab7a93165f..a65ce0ee8392 100644
--- a/llvm/test/MC/WebAssembly/debug-info.ll
+++ b/llvm/test/MC/WebAssembly/debug-info.ll
@@ -7,37 +7,37 @@
 ; CHECK-NEXT:  Section {
 ; CHECK-NEXT:    Type: TYPE (0x1)
 ; CHECK-NEXT:    Size: 4
-; CHECK-NEXT:    Offset: 8
+; CHECK-NEXT:    Offset: 14
 ; CHECK-NEXT:  }
 ; CHECK-NEXT:  Section {
 ; CHECK-NEXT:    Type: IMPORT (0x2)
 ; CHECK-NEXT:    Size: 81
-; CHECK-NEXT:    Offset: 18
+; CHECK-NEXT:    Offset: 24
 ; CHECK-NEXT:  }
 ; CHECK-NEXT:  Section {
 ; CHECK-NEXT:    Type: FUNCTION (0x3)
 ; CHECK-NEXT:    Size: 2
-; CHECK-NEXT:    Offset: 105
+; CHECK-NEXT:    Offset: 111
 ; CHECK-NEXT:  }
 ; CHECK-NEXT:  Section {
 ; CHECK-NEXT:    Type: ELEM (0x9)
 ; CHECK-NEXT:    Size: 7
-; CHECK-NEXT:    Offset: 113
+; CHECK-NEXT:    Offset: 119
 ; CHECK-NEXT:  }
 ; CHECK-NEXT:  Section {
 ; CHECK-NEXT:    Type: DATACOUNT (0xC)
 ; CHECK-NEXT:    Size: 1
-; CHECK-NEXT:    Offset: 126
+; CHECK-NEXT:    Offset: 132
 ; CHECK-NEXT:  }
 ; CHECK-NEXT:  Section {
 ; CHECK-NEXT:    Type: CODE (0xA)
 ; CHECK-NEXT:    Size: 4
-; CHECK-NEXT:    Offset: 133
+; CHECK-NEXT:    Offset: 139
 ; CHECK-NEXT:  }
 ; CHECK-NEXT:  Section {
 ; CHECK-NEXT:    Type: DATA (0xB)
 ; CHECK-NEXT:    Size: 19
-; CHECK-NEXT:    Offset: 143
+; CHECK-NEXT:    Offset: 149
 ; CHECK-NEXT:    Segments [
 ; CHECK-NEXT:      Segment {
 ; CHECK-NEXT:        Name: .data.foo
@@ -54,91 +54,91 @@
 ; CHECK-NEXT:  Section {
 ; CHECK-NEXT:    Type: CUSTOM (0x0)
 ; CHECK-NEXT:    Size: 86
-; CHECK-NEXT:    Offset: 168
+; CHECK-NEXT:    Offset: 174
 ; CHECK-NEXT:    Name: .debug_abbrev
 ; CHECK-NEXT:  }
 ; CHECK-NEXT:  Section {
 ; CHECK-NEXT:    Type: CUSTOM (0x0)
 ; CHECK-NEXT:    Size: 114
-; CHECK-NEXT:    Offset: 274
+; CHECK-NEXT:    Offset: 280
 ; CHECK-NEXT:    Name: .debug_info
 ; CHECK-NEXT:  }
 ; CHECK-NEXT:  Section {
 ; CHECK-NEXT:    Type: CUSTOM (0x0)
 ; CHECK-NEXT:    Size: 48
-; CHECK-NEXT:    Offset: 406
+; CHECK-NEXT:    Offset: 412
 ; CHECK-NEXT:    Name: .debug_aranges
 ; CHECK-NEXT:  }
 ; CHECK-NEXT:  Section {
 ; CHECK-NEXT:    Type: CUSTOM (0x0)
 ; CHECK-NEXT:    Size: 121
-; CHECK-NEXT:    Offset: 475
+; CHECK-NEXT:    Offset: 481
 ; CHECK-NEXT:    Name: .debug_str
 ; CHECK-NEXT:  }
 ; CHECK-NEXT:  Section {
 ; CHECK-NEXT:    Type: CUSTOM (0x0)
 ; CHECK-NEXT:    Size: 42
-; CHECK-NEXT:    Offset: 613
+; CHECK-NEXT:    Offset: 619
 ; CHECK-NEXT:    Name: .debug_pubnames
 ; CHECK-NEXT:  }
 ; CHECK-NEXT:  Section {
 ; CHECK-NEXT:    Type: CUSTOM (0x0)
 ; CHECK-NEXT:    Size: 26
-; CHECK-NEXT:    Offset: 677
+; CHECK-NEXT:    Offset: 683
 ; CHECK-NEXT:    Name: .debug_pubtypes
 ; CHECK-NEXT:  }
 ; CHECK-NEXT:  Section {
 ; CHECK-NEXT:    Type: CUSTOM (0x0)
 ; CHECK-NEXT:    Size: 56
-; CHECK-NEXT:    Offset: 725
+; CHECK-NEXT:    Offset: 731
 ; CHECK-NEXT:    Name: .debug_line
 ; CHECK-NEXT:  }
 ; CHECK-NEXT:  Section {
 ; CHECK-NEXT:    Type: CUSTOM (0x0)
 ; CHECK-NEXT:    Size: 91
-; CHECK-NEXT:    Offset: 799
+; CHECK-NEXT:    Offset: 805
 ; CHECK-NEXT:    Name: linking
 ; CHECK-NEXT:  }
 ; CHECK-NEXT:  Section {
 ; CHECK-NEXT:    Type: CUSTOM (0x0)
 ; CHECK-NEXT:    Size: 9
-; CHECK-NEXT:    Offset: 904
+; CHECK-NEXT:    Offset: 910
 ; CHECK-NEXT:    Name: reloc.DATA
 ; CHECK-NEXT:  }
 ; CHECK-NEXT:  Section {
 ; CHECK-NEXT:    Type: CUSTOM (0x0)
 ; CHECK-NEXT:    Size: 61
-; CHECK-NEXT:    Offset: 930
+; CHECK-NEXT:    Offset: 936
 ; CHECK-NEXT:    Name: reloc..debug_info
 ; CHECK-NEXT:  }
 ; CHECK-NEXT:  Section {
 ; CHECK-NEXT:    Type: CUSTOM (0x0)
 ; CHECK-NEXT:    Size: 18
-; CHECK-NEXT:    Offset: 1015
+; CHECK-NEXT:    Offset: 1021
 ; CHECK-NEXT:    Name: reloc..debug_aranges
 ; CHECK-NEXT:  }
 ; CHECK-NEXT:  Section {
 ; CHECK-NEXT:    Type: CUSTOM (0x0)
 ; CHECK-NEXT:    Size: 6
-; CHECK-NEXT:    Offset: 1060
+; CHECK-NEXT:    Offset: 1066
 ; CHECK-NEXT:    Name: reloc..debug_pubnames
 ; CHECK-NEXT:  }
 ; CHECK-NEXT:  Section {
 ; CHECK-NEXT:    Type: CUSTOM (0x0)
 ; CHECK-NEXT:    Size: 6
-; CHECK-NEXT:    Offset: 1094
+; CHECK-NEXT:    Offset: 1100
 ; CHECK-NEXT:    Name: reloc..debug_pubtypes
 ; CHECK-NEXT:  }
 ; CHECK-NEXT:  Section {
 ; CHECK-NEXT:    Type: CUSTOM (0x0)
 ; CHECK-NEXT:    Size: 6
-; CHECK-NEXT:    Offset: 1128
+; CHECK-NEXT:    Offset: 1134
 ; CHECK-NEXT:    Name: reloc..debug_line
 ; CHECK-NEXT:  }
 ; CHECK-NEXT:  Section {
 ; CHECK-NEXT:    Type: CUSTOM (0x0)
 ; CHECK-NEXT:    Size: 77
-; CHECK-NEXT:    Offset: 1158
+; CHECK-NEXT:    Offset: 1164
 ; CHECK-NEXT:    Name: producers
 ; CHECK-NEXT:  }
 ; CHECK-NEXT:]
diff --git a/llvm/test/MC/WebAssembly/debug-info64.ll b/llvm/test/MC/WebAssembly/debug-info64.ll
index a63200c908b7..d0081164d73e 100644
--- a/llvm/test/MC/WebAssembly/debug-info64.ll
+++ b/llvm/test/MC/WebAssembly/debug-info64.ll
@@ -7,37 +7,37 @@
 ; CHECK-NEXT:   Section {
 ; CHECK-NEXT:     Type: TYPE (0x1)
 ; CHECK-NEXT:     Size: 4
-; CHECK-NEXT:     Offset: 8
+; CHECK-NEXT:     Offset: 14
 ; CHECK-NEXT:   }
 ; CHECK-NEXT:   Section {
 ; CHECK-NEXT:     Type: IMPORT (0x2)
 ; CHECK-NEXT:     Size: 81
-; CHECK-NEXT:     Offset: 18
+; CHECK-NEXT:     Offset: 24
 ; CHECK-NEXT:   }
 ; CHECK-NEXT:   Section {
 ; CHECK-NEXT:     Type: FUNCTION (0x3)
 ; CHECK-NEXT:     Size: 2
-; CHECK-NEXT:     Offset: 105
+; CHECK-NEXT:     Offset: 111
 ; CHECK-NEXT:   }
 ; CHECK-NEXT:   Section {
 ; CHECK-NEXT:     Type: ELEM (0x9)
 ; CHECK-NEXT:     Size: 7
-; CHECK-NEXT:     Offset: 113
+; CHECK-NEXT:     Offset: 119
 ; CHECK-NEXT:   }
 ; CHECK-NEXT:   Section {
 ; CHECK-NEXT:     Type: DATACOUNT (0xC)
 ; CHECK-NEXT:     Size: 1
-; CHECK-NEXT:     Offset: 126
+; CHECK-NEXT:     Offset: 132
 ; CHECK-NEXT:   }
 ; CHECK-NEXT:   Section {
 ; CHECK-NEXT:     Type: CODE (0xA)
 ; CHECK-NEXT:     Size: 4
-; CHECK-NEXT:     Offset: 133
+; CHECK-NEXT:     Offset: 139
 ; CHECK-NEXT:   }
 ; CHECK-NEXT:   Section {
 ; CHECK-NEXT:     Type: DATA (0xB)
 ; CHECK-NEXT:     Size: 27
-; CHECK-NEXT:     Offset: 143
+; CHECK-NEXT:     Offset: 149
 ; CHECK-NEXT:     Segments [
 ; CHECK-NEXT:       Segment {
 ; CHECK-NEXT:         Name: .data.foo
@@ -54,97 +54,97 @@
 ; CHECK-NEXT:   Section {
 ; CHECK-NEXT:     Type: CUSTOM (0x0)
 ; CHECK-NEXT:     Size: 86
-; CHECK-NEXT:     Offset: 176
+; CHECK-NEXT:     Offset: 182
 ; CHECK-NEXT:     Name: .debug_abbrev
 ; CHECK-NEXT:   }
 ; CHECK-NEXT:   Section {
 ; CHECK-NEXT:     Type: CUSTOM (0x0)
 ; CHECK-NEXT:     Size: 130
-; CHECK-NEXT:     Offset: 282
+; CHECK-NEXT:     Offset: 288
 ; CHECK-NEXT:     Name: .debug_info
 ; CHECK-NEXT:   }
 ; CHECK-NEXT:   Section {
 ; CHECK-NEXT:     Type: CUSTOM (0x0)
 ; CHECK-NEXT:     Size: 80
-; CHECK-NEXT:     Offset: 430
+; CHECK-NEXT:     Offset: 436
 ; CHECK-NEXT:     Name: .debug_aranges
 ; CHECK-NEXT:   }
 ; CHECK-NEXT:   Section {
 ; CHECK-NEXT:     Type: CUSTOM (0x0)
 ; CHECK-NEXT:     Size: 121
-; CHECK-NEXT:     Offset: 531
+; CHECK-NEXT:     Offset: 537
 ; CHECK-NEXT:     Name: .debug_str
 ; CHECK-NEXT:   }
 ; CHECK-NEXT:   Section {
 ; CHECK-NEXT:     Type: CUSTOM (0x0)
 ; CHECK-NEXT:     Size: 42
-; CHECK-NEXT:     Offset: 669
+; CHECK-NEXT:     Offset: 675
 ; CHECK-NEXT:     Name: .debug_pubnames
 ; CHECK-NEXT:   }
 ; CHECK-NEXT:   Section {
 ; CHECK-NEXT:     Type: CUSTOM (0x0)
 ; CHECK-NEXT:     Size: 26
-; CHECK-NEXT:     Offset: 733
+; CHECK-NEXT:     Offset: 739
 ; CHECK-NEXT:     Name: .debug_pubtypes
 ; CHECK-NEXT:   }
 ; CHECK-NEXT:   Section {
 ; CHECK-NEXT:     Type: CUSTOM (0x0)
 ; CHECK-NEXT:     Size: 60
-; CHECK-NEXT:     Offset: 781
+; CHECK-NEXT:     Offset: 787
 ; CHECK-NEXT:     Name: .debug_line
 ; CHECK-NEXT:   }
 ; CHECK-NEXT:   Section {
 ; CHECK-NEXT:     Type: CUSTOM (0x0)
 ; CHECK-NEXT:     Size: 91
-; CHECK-NEXT:     Offset: 859
+; CHECK-NEXT:     Offset: 865
 ; CHECK-NEXT:     Name: linking
 ; CHECK-NEXT:   }
 ; CHECK-NEXT:   Section {
 ; CHECK-NEXT:     Type: CUSTOM (0x0)
 ; CHECK-NEXT:     Size: 9
-; CHECK-NEXT:     Offset: 964
+; CHECK-NEXT:     Offset: 970
 ; CHECK-NEXT:     Name: reloc.DATA
 ; CHECK-NEXT:   }
 ; CHECK-NEXT:   Section {
 ; CHECK-NEXT:     Type: CUSTOM (0x0)
 ; CHECK-NEXT:     Size: 61
-; CHECK-NEXT:     Offset: 990
+; CHECK-NEXT:     Offset: 996
 ; CHECK-NEXT:     Name: reloc..debug_info
 ; CHECK-NEXT:   }
 ; CHECK-NEXT:   Section {
 ; CHECK-NEXT:     Type: CUSTOM (0x0)
 ; CHECK-NEXT:     Size: 18
-; CHECK-NEXT:     Offset: 1075
+; CHECK-NEXT:     Offset: 1081
 ; CHECK-NEXT:     Name: reloc..debug_aranges
 ; CHECK-NEXT:   }
 ; CHECK-NEXT:   Section {
 ; CHECK-NEXT:     Type: CUSTOM (0x0)
 ; CHECK-NEXT:     Size: 6
-; CHECK-NEXT:     Offset: 1120
+; CHECK-NEXT:     Offset: 1126
 ; CHECK-NEXT:     Name: reloc..debug_pubnames
 ; CHECK-NEXT:   }
 ; CHECK-NEXT:   Section {
 ; CHECK-NEXT:     Type: CUSTOM (0x0)
 ; CHECK-NEXT:     Size: 6
-; CHECK-NEXT:     Offset: 1154
+; CHECK-NEXT:     Offset: 1160
 ; CHECK-NEXT:     Name: reloc..debug_pubtypes
 ; CHECK-NEXT:   }
 ; CHECK-NEXT:   Section {
 ; CHECK-NEXT:     Type: CUSTOM (0x0)
 ; CHECK-NEXT:     Size: 6
-; CHECK-NEXT:     Offset: 1188
+; CHECK-NEXT:     Offset: 1194
 ; CHECK-NEXT:     Name: reloc..debug_line
 ; CHECK-NEXT:   }
 ; CHECK-NEXT:   Section {
 ; CHECK-NEXT:     Type: CUSTOM (0x0)
 ; CHECK-NEXT:     Size: 77
-; CHECK-NEXT:     Offset: 1218
+; CHECK-NEXT:     Offset: 1224
 ; CHECK-NEXT:     Name: producers
 ; CHECK-NEXT:   }
 ; CHECK-NEXT:   Section {
 ; CHECK-NEXT:     Type: CUSTOM (0x0)
 ; CHECK-NEXT:     Size: 11
-; CHECK-NEXT:     Offset: 1311
+; CHECK-NEXT:     Offset: 1317
 ; CHECK-NEXT:     Name: target_features
 ; CHECK-NEXT:   }
 ; CHECK-NEXT: ]
diff --git a/llvm/test/MC/WebAssembly/tag-section.ll b/llvm/test/MC/WebAssembly/tag-section.ll
index c40e132e36f0..56738ec80c8d 100644
--- a/llvm/test/MC/WebAssembly/tag-section.ll
+++ b/llvm/test/MC/WebAssembly/tag-section.ll
@@ -53,4 +53,4 @@ define i32 @test_throw1(ptr %p) {
 
 ; SEC:          Type: TAG (0xD)
 ; SEC-NEXT:     Size: 3
-; SEC-NEXT:     Offset: 63
+; SEC-NEXT:     Offset: 69
diff --git a/llvm/test/tools/llvm-readobj/wasm/globals.test b/llvm/test/tools/llvm-readobj/wasm/globals.test
index 4e9f6403c267..0dff18dc5d96 100644
--- a/llvm/test/tools/llvm-readobj/wasm/globals.test
+++ b/llvm/test/tools/llvm-readobj/wasm/globals.test
@@ -19,7 +19,7 @@ Sections:
 # CHECK:      Section {
 # CHECK-NEXT:     Type: DATA (0xB)
 # CHECK-NEXT:     Size: 7
-# CHECK-NEXT:     Offset: 8
+# CHECK-NEXT:     Offset: 14
 # CHECK-NEXT:     Segments [
 # CHECK-NEXT:       Segment {
 # CHECK-NEXT:         Size: 1
diff --git a/llvm/test/tools/llvm-readobj/wasm/sections.test b/llvm/test/tools/llvm-readobj/wasm/sections.test
index 8b8a526295eb..1a4aadad392f 100644
--- a/llvm/test/tools/llvm-readobj/wasm/sections.test
+++ b/llvm/test/tools/llvm-readobj/wasm/sections.test
@@ -6,27 +6,27 @@
 # CHECK-NEXT:   Section {
 # CHECK-NEXT:     Type: TYPE (0x1)
 # CHECK-NEXT:     Size: 17
-# CHECK-NEXT:     Offset: 8
+# CHECK-NEXT:     Offset: 14
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Section {
 # CHECK-NEXT:     Type: IMPORT (0x2)
 # CHECK-NEXT:     Size: 93
-# CHECK-NEXT:     Offset: 31
+# CHECK-NEXT:     Offset: 37
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Section {
 # CHECK-NEXT:     Type: FUNCTION (0x3)
 # CHECK-NEXT:     Size: 3
-# CHECK-NEXT:     Offset: 130
+# CHECK-NEXT:     Offset: 136
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Section {
 # CHECK-NEXT:     Type: CODE (0xA)
 # CHECK-NEXT:     Size: 36
-# CHECK-NEXT:     Offset: 139
+# CHECK-NEXT:     Offset: 145
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Section {
 # CHECK-NEXT:     Type: DATA (0xB)
 # CHECK-NEXT:     Size: 19
-# CHECK-NEXT:     Offset: 181
+# CHECK-NEXT:     Offset: 187
 # CHECK-NEXT:     Segments [
 # CHECK-NEXT:       Segment {
 # CHECK-NEXT:         Name: .rodata..L.str
@@ -38,13 +38,13 @@
 # CHECK-NEXT:   Section {
 # CHECK-NEXT:     Type: CUSTOM (0x0)
 # CHECK-NEXT:     Size: 89
-# CHECK-NEXT:     Offset: 206
+# CHECK-NEXT:     Offset: 212
 # CHECK-NEXT:     Name: linking
 # CHECK-NEXT:   }
 # CHECK-NEXT:   Section {
 # CHECK-NEXT:     Type: CUSTOM (0x0)
 # CHECK-NEXT:     Size: 15
-# CHECK-NEXT:     Offset: 309
+# CHECK-NEXT:     Offset: 315
 # CHECK-NEXT:     Name: reloc.CODE
 # CHECK-NEXT:   }
 # CHECK-NEXT: ]