Reapply r183552. This time, use a standard type for the option to avoid template
instantiation issue with non-standard type.
Add a backend option to warn on a given stack size limit.
Option: -mllvm -warn-stack-size=<limit>
Output (if limit is exceeded):
warning: Stack size limit exceeded (<actual size>) in <functionName>.
The longer term plan is to hook that to a clang warning.
PR:4072
<rdar://problem/13987214>.
llvm-svn: 183595
diff --git a/llvm/lib/CodeGen/PrologEpilogInserter.cpp b/llvm/lib/CodeGen/PrologEpilogInserter.cpp
index 959dd7d..4b301d8 100644
--- a/llvm/lib/CodeGen/PrologEpilogInserter.cpp
+++ b/llvm/lib/CodeGen/PrologEpilogInserter.cpp
@@ -35,6 +35,7 @@
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetFrameLowering.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetMachine.h"
@@ -46,6 +47,11 @@
char PEI::ID = 0;
char &llvm::PrologEpilogCodeInserterID = PEI::ID;
+static cl::opt<unsigned>
+WarnStackSize("warn-stack-size", cl::Hidden, cl::init((unsigned)-1),
+ cl::desc("Warn for stack size bigger than the given"
+ " number"));
+
INITIALIZE_PASS_BEGIN(PEI, "prologepilog",
"Prologue/Epilogue Insertion", false, false)
INITIALIZE_PASS_DEPENDENCY(MachineLoopInfo)
@@ -128,6 +134,13 @@
// Clear any vregs created by virtual scavenging.
Fn.getRegInfo().clearVirtRegs();
+ // Warn on stack size when we exceeds the given limit.
+ MachineFrameInfo *MFI = Fn.getFrameInfo();
+ if (WarnStackSize.getNumOccurrences() > 0 &&
+ WarnStackSize < MFI->getStackSize())
+ errs() << "warning: Stack size limit exceeded (" << MFI->getStackSize()
+ << ") in " << Fn.getName() << ".\n";
+
delete RS;
clearAllSets();
return true;
diff --git a/llvm/test/CodeGen/ARM/warn-stack.ll b/llvm/test/CodeGen/ARM/warn-stack.ll
new file mode 100644
index 0000000..9538bbf
--- /dev/null
+++ b/llvm/test/CodeGen/ARM/warn-stack.ll
@@ -0,0 +1,24 @@
+; RUN: llc -mtriple thumbv7-apple-ios3.0.0 -warn-stack-size=80 < %s 2>&1 >/dev/null | FileCheck %s
+; Check the internal option that warns when the stack size exceeds the
+; given amount.
+; <rdar://13987214>
+
+; CHECK-NOT: nowarn
+define void @nowarn() nounwind ssp {
+entry:
+ %buffer = alloca [12 x i8], align 1
+ %arraydecay = getelementptr inbounds [12 x i8]* %buffer, i64 0, i64 0
+ call void @doit(i8* %arraydecay) nounwind
+ ret void
+}
+
+; CHECK: warning: Stack size limit exceeded (96) in warn.
+define void @warn() nounwind ssp {
+entry:
+ %buffer = alloca [80 x i8], align 1
+ %arraydecay = getelementptr inbounds [80 x i8]* %buffer, i64 0, i64 0
+ call void @doit(i8* %arraydecay) nounwind
+ ret void
+}
+
+declare void @doit(i8*)
diff --git a/llvm/test/CodeGen/X86/warn-stack.ll b/llvm/test/CodeGen/X86/warn-stack.ll
new file mode 100644
index 0000000..5979f45
--- /dev/null
+++ b/llvm/test/CodeGen/X86/warn-stack.ll
@@ -0,0 +1,24 @@
+; RUN: llc -mtriple x86_64-apple-macosx10.8.0 -warn-stack-size=80 < %s 2>&1 >/dev/null | FileCheck %s
+; Check the internal option that warns when the stack size exceeds the
+; given amount.
+; <rdar://13987214>
+
+; CHECK-NOT: nowarn
+define void @nowarn() nounwind ssp {
+entry:
+ %buffer = alloca [12 x i8], align 1
+ %arraydecay = getelementptr inbounds [12 x i8]* %buffer, i64 0, i64 0
+ call void @doit(i8* %arraydecay) nounwind
+ ret void
+}
+
+; CHECK: warning: Stack size limit exceeded (104) in warn.
+define void @warn() nounwind ssp {
+entry:
+ %buffer = alloca [80 x i8], align 1
+ %arraydecay = getelementptr inbounds [80 x i8]* %buffer, i64 0, i64 0
+ call void @doit(i8* %arraydecay) nounwind
+ ret void
+}
+
+declare void @doit(i8*)