[MC] Produce proper section relative relocations for COFF in .debug_frame

The third parameter to Streamer.EmitSymbolValue() is "bool
IsSectionRelative = false".

For ELF, these debug sections are mapped to address zero, so a normal,
absolute address relocation works just fine, but COFF needs a section
relative relocation, and COFF is the only target where
needsDwarfSectionOffsetDirective() returns true. This matches how
EmitSymbolValue is called elsewhere in the same source file.

Differential Revision: https://reviews.llvm.org/D70661

diff --git a/llvm/lib/MC/MCDwarf.cpp b/llvm/lib/MC/MCDwarf.cpp
index bcc7c45..b4b3c99 100644 (file)
--- a/llvm/lib/MC/MCDwarf.cpp
+++ b/llvm/lib/MC/MCDwarf.cpp
@@ -1701,7 +1701,8 @@ void FrameEmitterImpl::EmitFDE(const MCSymbol &cieStart,
         MakeStartMinusEndExpr(Streamer, SectionStart, cieStart, 0);
     emitAbsValue(Streamer, offset, 4);
   } else {
-    Streamer.EmitSymbolValue(&cieStart, 4);
+    Streamer.EmitSymbolValue(&cieStart, 4,
+                             asmInfo->needsDwarfSectionOffsetDirective());
   }
 
   // PC Begin

diff --git a/llvm/test/MC/COFF/cfi-sections.s b/llvm/test/MC/COFF/cfi-sections.s
new file mode 100644 (file)
index 0000000..00a8d74
--- /dev/null
+++ b/llvm/test/MC/COFF/cfi-sections.s
@@ -0,0 +1,26 @@
+// RUN: llvm-mc -filetype=obj -triple x86_64-mingw32 %s -o - | llvm-objdump -r - | FileCheck --check-prefix=COFF_X86_64 %s
+// RUN: llvm-mc -filetype=obj -triple i686-mingw32 %s -o - | llvm-objdump -r - | FileCheck --check-prefix=COFF_I686 %s
+
+.cfi_sections .debug_frame
+
+f1:
+        .cfi_startproc
+        nop
+        .cfi_endproc
+
+f2:
+        .cfi_startproc
+        nop
+        .cfi_endproc
+
+// COFF_X86_64: RELOCATION RECORDS FOR [.debug_frame]:
+// COFF_X86_64-NEXT: {{.*}} IMAGE_REL_AMD64_SECREL .debug_frame
+// COFF_X86_64-NEXT: {{.*}} IMAGE_REL_AMD64_ADDR64 .text
+// COFF_X86_64-NEXT: {{.*}} IMAGE_REL_AMD64_SECREL .debug_frame
+// COFF_X86_64-NEXT: {{.*}} IMAGE_REL_AMD64_ADDR64 .text
+
+// COFF_I686: RELOCATION RECORDS FOR [.debug_frame]:
+// COFF_I686-NEXT: {{.*}} IMAGE_REL_I386_SECREL .debug_frame
+// COFF_I686-NEXT: {{.*}} IMAGE_REL_I386_DIR32 .text
+// COFF_I686-NEXT: {{.*}} IMAGE_REL_I386_SECREL .debug_frame
+// COFF_I686-NEXT: {{.*}} IMAGE_REL_I386_DIR32 .text