LTO: Verify the input even if optimize() isn't called

Clients may call writeMergedModules before calling optimize, or call
compileOptimized without calling optimize.  Make sure they don't sneak
past the verifier.  This adds LTOCodeGenerator::verifyMergedModuleOnce,
and calls it from writeMergedModule, optimize, and codegenOptimized.

I couldn't find a good way to test this.  I tried writing broken IR to
send into llvm-lto, but LTOCodeGenerator doesn't understand textual IR,
and assembler runs the verifier itself anyway.  Checking in
valid-but-doesn't-verify bitcode here doesn't seem valuable.

llvm-svn: 266894

1 files changed, 24 insertions, 2 deletions

diff --git a/llvm/lib/LTO/LTOCodeGenerator.cpp b/llvm/lib/LTO/LTOCodeGenerator.cpp
index e06903ca37b..64d708ec2b0 100644
--- a/llvm/lib/LTO/LTOCodeGenerator.cpp
+++ b/llvm/lib/LTO/LTOCodeGenerator.cpp
@@ -131,6 +131,9 @@ bool LTOCodeGenerator::addModule(LTOModule *Mod) {
   for (int i = 0, e = undefs.size(); i != e; ++i)
     AsmUndefinedRefs[undefs[i]] = 1;
 
+  // We've just changed the input, so let's make sure we verify it.
+  HasVerifiedInput = false;
+
   return !ret;
 }
 
@@ -146,6 +149,9 @@ void LTOCodeGenerator::setModule(std::unique_ptr<LTOModule> Mod) {
   const std::vector<const char*> &Undefs = Mod->getAsmUndefinedRefs();
   for (int I = 0, E = Undefs.size(); I != E; ++I)
     AsmUndefinedRefs[Undefs[I]] = 1;
+
+  // We've just changed the input, so let's make sure we verify it.
+  HasVerifiedInput = false;
 }
 
 void LTOCodeGenerator::setTargetOptions(TargetOptions Options) {
@@ -187,6 +193,9 @@ bool LTOCodeGenerator::writeMergedModules(const char *Path) {
   if (!determineTarget())
     return false;
 
+  // We always run the verifier once on the merged module.
+  verifyMergedModuleOnce();
+
   // mark which symbols can not be internalized
   applyScopeRestrictions();
 
@@ -413,6 +422,16 @@ void LTOCodeGenerator::restoreLinkageForExternals() {
                 externalize);
 }
 
+void LTOCodeGenerator::verifyMergedModuleOnce() {
+  // Only run on the first call.
+  if (HasVerifiedInput)
+    return;
+  HasVerifiedInput = true;
+
+  if (verifyModule(*MergedModule, &dbgs()))
+    report_fatal_error("Broken module found, compilation aborted!");
+}
+
 /// Optimize merged modules using various IPO passes
 bool LTOCodeGenerator::optimize(bool DisableVerify, bool DisableInline,
                                 bool DisableGVNLoadPRE,
@@ -422,8 +441,7 @@ bool LTOCodeGenerator::optimize(bool DisableVerify, bool DisableInline,
 
   // We always run the verifier once on the merged module, the `DisableVerify`
   // parameter only applies to subsequent verify.
-  if (verifyModule(*MergedModule, &dbgs()))
-    report_fatal_error("Broken module found, compilation aborted!");
+  verifyMergedModuleOnce();
 
   // Mark which symbols can not be internalized
   this->applyScopeRestrictions();
@@ -461,6 +479,10 @@ bool LTOCodeGenerator::compileOptimized(ArrayRef<raw_pwrite_stream *> Out) {
   if (!this->determineTarget())
     return false;
 
+  // We always run the verifier once on the merged module.  If it has already
+  // been called in optimize(), this call will return early.
+  verifyMergedModuleOnce();
+
   legacy::PassManager preCodeGenPasses;
 
   // If the bitcode files contain ARC code and were compiled with optimization,