[lld] dbbc8d8 - [lld/mac] Don't crash on absolute symbols in unwind info generation

[Nico Weber via llvm-commits]

Author: Nico Weber
Date: 2021-06-23T14:25:34-04:00
New Revision: dbbc8d8333f29cf4ad6f4793da1adf71bbfdac69

URL: https://github.com/llvm/llvm-project/commit/dbbc8d8333f29cf4ad6f4793da1adf71bbfdac69
DIFF: https://github.com/llvm/llvm-project/commit/dbbc8d8333f29cf4ad6f4793da1adf71bbfdac69.diff

LOG: [lld/mac] Don't crash on absolute symbols in unwind info generation

Fixes a regression from d6565a2dbcbe and PR50820.

Added: 
    

Modified: 
    lld/MachO/UnwindInfoSection.cpp
    lld/test/MachO/compact-unwind.s

Removed: 
    


################################################################################
diff  --git a/lld/MachO/UnwindInfoSection.cpp b/lld/MachO/UnwindInfoSection.cpp
index 13be8565e861d..e1e8d30937135 100644
--- a/lld/MachO/UnwindInfoSection.cpp
+++ b/lld/MachO/UnwindInfoSection.cpp
@@ -297,7 +297,9 @@ static void addEntriesForFunctionsWithoutUnwindInfo(
   // Add explicit "has no unwind info" entries for all global and local symbols
   // without unwind info.
   auto markNoUnwindInfo = [&cuVector, &hasUnwindInfo](const Defined *d) {
-    if (d->isLive() && isCodeSection(d->isec)) {
+    // FIXME: The d->isec null check might be incorrect for symbols
+    // from LTO files.
+    if (d->isLive() && d->isec && isCodeSection(d->isec)) {
       Ptr ptr = d->getVA();
       if (!hasUnwindInfo.count(ptr))
         cuVector.push_back({ptr, 0, 0, 0, 0});

diff  --git a/lld/test/MachO/compact-unwind.s b/lld/test/MachO/compact-unwind.s
index 72aeaf85ffcba..075bb326fd55e 100644
--- a/lld/test/MachO/compact-unwind.s
+++ b/lld/test/MachO/compact-unwind.s
@@ -110,6 +110,9 @@ _main:
 _quux:
   ret
 
+.globl _abs
+_abs = 4
+
 .p2align 2
 _baz:
   .cfi_startproc