nickdesaulniers created this revision.
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Otherwise, this causes issues when building with LTO for object files
that use different values.
Link: https://github.com/ClangBuiltLinux/linux/issues/1395
Signed-off-by: Nick Desaulniers <ndesaulni...@google.com>
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D104342
Files:
clang/lib/CodeGen/CodeGenFunction.cpp
clang/lib/CodeGen/CodeGenModule.cpp
clang/test/Frontend/fwarn-stack-size.c
llvm/docs/LangRef.rst
llvm/include/llvm/IR/Module.h
llvm/lib/CodeGen/PrologEpilogInserter.cpp
llvm/lib/IR/Module.cpp
llvm/test/CodeGen/ARM/warn-stack.ll
llvm/test/CodeGen/X86/warn-stack.ll
llvm/test/Linker/warn-stack-frame.ll
Index: llvm/test/Linker/warn-stack-frame.ll
===================================================================
--- llvm/test/Linker/warn-stack-frame.ll
+++ /dev/null
@@ -1,16 +0,0 @@
-; RUN: split-file %s %t
-; RUN: llvm-link %t/main.ll %t/match.ll
-; RUN: not llvm-link %t/main.ll %t/mismatch.ll 2>&1 | \
-; RUN: FileCheck --check-prefix=CHECK-MISMATCH %s
-
-; CHECK-MISMATCH: error: linking module flags 'warn-stack-size': IDs have conflicting values
-
-;--- main.ll
-!llvm.module.flags = !{!0}
-!0 = !{i32 1, !"warn-stack-size", i32 80}
-;--- match.ll
-!llvm.module.flags = !{!0}
-!0 = !{i32 1, !"warn-stack-size", i32 80}
-;--- mismatch.ll
-!llvm.module.flags = !{!0}
-!0 = !{i32 1, !"warn-stack-size", i32 81}
Index: llvm/test/CodeGen/X86/warn-stack.ll
===================================================================
--- llvm/test/CodeGen/X86/warn-stack.ll
+++ llvm/test/CodeGen/X86/warn-stack.ll
@@ -4,7 +4,7 @@
; <rdar://13987214>
; CHECK-NOT: nowarn
-define void @nowarn() nounwind ssp {
+define void @nowarn() nounwind ssp "warn-stack-size"="80" {
entry:
%buffer = alloca [12 x i8], align 1
%arraydecay = getelementptr inbounds [12 x i8], [12 x i8]* %buffer, i64 0, i64 0
@@ -13,7 +13,7 @@
}
; CHECK: warning: stack size limit exceeded (88) in warn
-define void @warn() nounwind ssp {
+define void @warn() nounwind ssp "warn-stack-size"="80" {
entry:
%buffer = alloca [80 x i8], align 1
%arraydecay = getelementptr inbounds [80 x i8], [80 x i8]* %buffer, i64 0, i64 0
@@ -22,6 +22,3 @@
}
declare void @doit(i8*)
-
-!llvm.module.flags = !{!0}
-!0 = !{i32 1, !"warn-stack-size", i32 80}
Index: llvm/test/CodeGen/ARM/warn-stack.ll
===================================================================
--- llvm/test/CodeGen/ARM/warn-stack.ll
+++ llvm/test/CodeGen/ARM/warn-stack.ll
@@ -4,7 +4,7 @@
; <rdar://13987214>
; CHECK-NOT: nowarn
-define void @nowarn() nounwind ssp "frame-pointer"="all" {
+define void @nowarn() nounwind ssp "frame-pointer"="all" "warn-stack-size"="80" {
entry:
%buffer = alloca [12 x i8], align 1
%arraydecay = getelementptr inbounds [12 x i8], [12 x i8]* %buffer, i64 0, i64 0
@@ -13,7 +13,7 @@
}
; CHECK: warning: stack size limit exceeded (92) in warn
-define void @warn() nounwind ssp "frame-pointer"="all" {
+define void @warn() nounwind ssp "frame-pointer"="all" "warn-stack-size"="80" {
entry:
%buffer = alloca [80 x i8], align 1
%arraydecay = getelementptr inbounds [80 x i8], [80 x i8]* %buffer, i64 0, i64 0
@@ -22,6 +22,3 @@
}
declare void @doit(i8*)
-
-!llvm.module.flags = !{!0}
-!0 = !{i32 1, !"warn-stack-size", i32 80}
Index: llvm/lib/IR/Module.cpp
===================================================================
--- llvm/lib/IR/Module.cpp
+++ llvm/lib/IR/Module.cpp
@@ -732,17 +732,6 @@
addModuleFlag(ModFlagBehavior::Error, "override-stack-alignment", Align);
}
-unsigned Module::getWarnStackSize() const {
- Metadata *MD = getModuleFlag("warn-stack-size");
- if (auto *CI = mdconst::dyn_extract_or_null<ConstantInt>(MD))
- return CI->getZExtValue();
- return UINT_MAX;
-}
-
-void Module::setWarnStackSize(unsigned Threshold) {
- addModuleFlag(ModFlagBehavior::Error, "warn-stack-size", Threshold);
-}
-
void Module::setSDKVersion(const VersionTuple &V) {
SmallVector<unsigned, 3> Entries;
Entries.push_back(V.getMajor());
Index: llvm/lib/CodeGen/PrologEpilogInserter.cpp
===================================================================
--- llvm/lib/CodeGen/PrologEpilogInserter.cpp
+++ llvm/lib/CodeGen/PrologEpilogInserter.cpp
@@ -274,7 +274,12 @@
MachineFrameInfo &MFI = MF.getFrameInfo();
uint64_t StackSize = MFI.getStackSize();
- unsigned Threshold = MF.getFunction().getParent()->getWarnStackSize();
+ unsigned Threshold = UINT_MAX;
+ if (MF.getFunction().hasFnAttribute("warn-stack-size"))
+ MF.getFunction()
+ .getFnAttribute("warn-stack-size")
+ .getValueAsString()
+ .getAsInteger(0, Threshold);
if (StackSize > Threshold) {
DiagnosticInfoStackSize DiagStackSize(F, StackSize);
F.getContext().diagnose(DiagStackSize);
Index: llvm/include/llvm/IR/Module.h
===================================================================
--- llvm/include/llvm/IR/Module.h
+++ llvm/include/llvm/IR/Module.h
@@ -913,10 +913,6 @@
unsigned getOverrideStackAlignment() const;
void setOverrideStackAlignment(unsigned Align);
- /// Get/set the stack frame size threshold to warn on.
- unsigned getWarnStackSize() const;
- void setWarnStackSize(unsigned Threshold);
-
/// @name Utility functions for querying and setting the build SDK version
/// @{
Index: llvm/docs/LangRef.rst
===================================================================
--- llvm/docs/LangRef.rst
+++ llvm/docs/LangRef.rst
@@ -2048,6 +2048,11 @@
function does not satisfy this contract, the behavior is undefined. This
attribute does not apply transitively to callees, but does apply to call
sites within the function. Note that `willreturn` implies `mustprogress`.
+``"warn-stack-size"="<threshold>"``
+ This attribute sets a threshold to emit diagnostics for once the frame size
+ is known should the frame size exceed the specified value. It takes one
+ required integer value, which should be greater than or equal to 0, and
+ less than `UINT_MAX`.
``vscale_range(<min>[, <max>])``
This attribute indicates the minimum and maximum vscale value for the given
function. A value of 0 means unbounded. If the optional max value is omitted
Index: clang/test/Frontend/fwarn-stack-size.c
===================================================================
--- /dev/null
+++ clang/test/Frontend/fwarn-stack-size.c
@@ -0,0 +1,4 @@
+// RUN: %clang_cc1 -fwarn-stack-size=42 -emit-llvm -o - %s | FileCheck %s
+void foo(void) {}
+// CHECK: define {{.*}} @foo() [[ATTR:#[0-9]+]] {
+// CHECK: attributes [[ATTR]] = {{.*}} "warn-stack-size"="42"
Index: clang/lib/CodeGen/CodeGenModule.cpp
===================================================================
--- clang/lib/CodeGen/CodeGenModule.cpp
+++ clang/lib/CodeGen/CodeGenModule.cpp
@@ -787,8 +787,6 @@
getCodeGenOpts().StackProtectorGuardOffset);
if (getCodeGenOpts().StackAlignment)
getModule().setOverrideStackAlignment(getCodeGenOpts().StackAlignment);
- if (getCodeGenOpts().WarnStackSize != UINT_MAX)
- getModule().setWarnStackSize(getCodeGenOpts().WarnStackSize);
getTargetCodeGenInfo().emitTargetMetadata(*this, MangledDeclNames);
Index: clang/lib/CodeGen/CodeGenFunction.cpp
===================================================================
--- clang/lib/CodeGen/CodeGenFunction.cpp
+++ clang/lib/CodeGen/CodeGenFunction.cpp
@@ -1050,6 +1050,10 @@
Fn->addFnAttr("packed-stack");
}
+ if (CGM.getCodeGenOpts().WarnStackSize != UINT_MAX)
+ Fn->addFnAttr("warn-stack-size",
+ std::to_string(CGM.getCodeGenOpts().WarnStackSize));
+
if (RetTy->isVoidType()) {
// Void type; nothing to return.
ReturnValue = Address::invalid();
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