[PATCH] D70507: Fix PR44093: use of stale error stream when linking

[Thomas Preud'homme via Phabricator via llvm-commits]

thopre created this revision.
thopre added reviewers: blackhole12, grimar, MaskRay, espindola.
Herald added subscribers: aheejin, arichardson, sbc100, emaste.
Herald added a project: LLVM.

llvm::lld::link() calls llvm::lld::enableColors() before initializing
the streams llvm::lld::stdoutOS and llvm::lld::stderrOS. This is a
problem because enableColors() uses stderrOS indirectly via a call to
lld::errs(). It can lead to random behavior if the lifetime of the
object passed as stderrOS in link() expires before a subsequent
invocation of link().


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D70507

Files:
  lld/COFF/Driver.cpp
  lld/ELF/Driver.cpp
  lld/MinGW/Driver.cpp
  lld/lib/Driver/DarwinLdDriver.cpp
  lld/wasm/Driver.cpp


Index: lld/wasm/Driver.cpp
===================================================================
--- lld/wasm/Driver.cpp
+++ lld/wasm/Driver.cpp
@@ -84,10 +84,10 @@
   errorHandler().errorLimitExceededMsg =
       "too many errors emitted, stopping now (use "
       "-error-limit=0 to see all errors)";
-  enableColors(stderrOS.has_colors());
 
   lld::stdoutOS = &stdoutOS;
   lld::stderrOS = &stderrOS;
+  enableColors(stderrOS.has_colors());
 
   config = make<Configuration>();
   symtab = make<SymbolTable>();
Index: lld/lib/Driver/DarwinLdDriver.cpp
===================================================================
--- lld/lib/Driver/DarwinLdDriver.cpp
+++ lld/lib/Driver/DarwinLdDriver.cpp
@@ -1150,10 +1150,10 @@
       "too many errors emitted, stopping now (use "
       "'-error-limit 0' to see all errors)";
   errorHandler().exitEarly = CanExitEarly;
-  enableColors(StderrOS.has_colors());
 
   lld::stdoutOS = &StdoutOS;
   lld::stderrOS = &StderrOS;
+  enableColors(StderrOS.has_colors());
 
   MachOLinkingContext ctx;
   if (!parse(args, ctx))
Index: lld/MinGW/Driver.cpp
===================================================================
--- lld/MinGW/Driver.cpp
+++ lld/MinGW/Driver.cpp
@@ -161,9 +161,9 @@
 // then call coff::link.
 bool mingw::link(ArrayRef<const char *> argsArr, bool canExitEarly,
                  raw_ostream &stdoutOS, raw_ostream &stderrOS) {
-  enableColors(stderrOS.has_colors());
   lld::stdoutOS = &stdoutOS;
   lld::stderrOS = &stderrOS;
+  enableColors(stderrOS.has_colors());
 
   MinGWOptTable parser;
   opt::InputArgList args = parser.parse(argsArr.slice(1));
Index: lld/ELF/Driver.cpp
===================================================================
--- lld/ELF/Driver.cpp
+++ lld/ELF/Driver.cpp
@@ -82,10 +82,10 @@
       "too many errors emitted, stopping now (use "
       "-error-limit=0 to see all errors)";
   errorHandler().exitEarly = canExitEarly;
-  enableColors(stderrOS.has_colors());
 
   lld::stdoutOS = &stdoutOS;
   lld::stderrOS = &stderrOS;
+  enableColors(stderrOS.has_colors());
 
   inputSections.clear();
   outputSections.clear();
Index: lld/COFF/Driver.cpp
===================================================================
--- lld/COFF/Driver.cpp
+++ lld/COFF/Driver.cpp
@@ -69,10 +69,10 @@
       "too many errors emitted, stopping now"
       " (use /errorlimit:0 to see all errors)";
   errorHandler().exitEarly = canExitEarly;
-  enableColors(stderrOS.has_colors());
 
   lld::stdoutOS = &stdoutOS;
   lld::stderrOS = &stderrOS;
+  enableColors(stderrOS.has_colors());
 
   config = make<Configuration>();
   symtab = make<SymbolTable>();


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