[lld] c7579bf - [ELF] -o -: suppress output if disableOutput

[Fangrui Song via llvm-commits]

Author: Fangrui Song
Date: 2025-01-25T15:50:29-08:00
New Revision: c7579bfba5969377f7fb4239cc05d6cd4a077957

URL: https://github.com/llvm/llvm-project/commit/c7579bfba5969377f7fb4239cc05d6cd4a077957
DIFF: https://github.com/llvm/llvm-project/commit/c7579bfba5969377f7fb4239cc05d6cd4a077957.diff

LOG: [ELF] -o -: suppress output if disableOutput

So that LLD_IN_TEST=2 ld.lld -o - a.o only writes the output once.

Added: 
    

Modified: 
    lld/ELF/Writer.cpp
    lld/test/ELF/stdout.s

Removed: 
    


################################################################################
diff  --git a/lld/ELF/Writer.cpp b/lld/ELF/Writer.cpp
index fe4a0a15ae835d..b7c4790655e8a0 100644
--- a/lld/ELF/Writer.cpp
+++ b/lld/ELF/Writer.cpp
@@ -381,9 +381,11 @@ template <class ELFT> void Writer<ELFT>::run() {
     if (errCount(ctx))
       return;
 
-    if (auto e = buffer->commit())
-      Err(ctx) << "failed to write output '" << buffer->getPath()
-               << "': " << std::move(e);
+    if (!ctx.e.disableOutput) {
+      if (auto e = buffer->commit())
+        Err(ctx) << "failed to write output '" << buffer->getPath()
+                 << "': " << std::move(e);
+    }
 
     if (!ctx.arg.cmseOutputLib.empty())
       writeARMCmseImportLib<ELFT>(ctx);

diff  --git a/lld/test/ELF/stdout.s b/lld/test/ELF/stdout.s
index 64cf64a72b4b62..b5ec07cfabfe92 100644
--- a/lld/test/ELF/stdout.s
+++ b/lld/test/ELF/stdout.s
@@ -1,7 +1,8 @@
 # REQUIRES: x86
 
 # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
-# RUN: ld.lld %t.o -o - > %t1
+## Test that we only write to "-" once.
+# RUN: LLD_IN_TEST=2 ld.lld %t.o -o - > %t1
 # RUN: llvm-objdump -d %t1 | FileCheck %s
 
 # CHECK: nop