add -fbounds-checking option.
When enabled, clang generates bounds checks for array and pointers dereferences. Work to follow in LLVM's backend.
OK'ed by Chad; thanks for the review.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@156431 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Basic/LangOptions.def b/include/clang/Basic/LangOptions.def
index d2ce7c0..a795c57 100644
--- a/include/clang/Basic/LangOptions.def
+++ b/include/clang/Basic/LangOptions.def
@@ -157,6 +157,7 @@
"maximum constexpr call depth")
BENIGN_LANGOPT(NumLargeByValueCopy, 32, 0,
"if non-zero, warn about parameter or return Warn if parameter/return value is larger in bytes than this setting. 0 is no check.")
+BENIGN_LANGOPT(BoundsChecking , 8, 0, "if non-zero, add run-time bounds checking code")
VALUE_LANGOPT(MSCVersion, 32, 0,
"version of Microsoft Visual C/C++")
diff --git a/include/clang/Driver/Options.td b/include/clang/Driver/Options.td
index 5d20e21..1868a70 100644
--- a/include/clang/Driver/Options.td
+++ b/include/clang/Driver/Options.td
@@ -315,6 +315,10 @@
def fbootclasspath_EQ : Joined<"-fbootclasspath=">, Group<f_Group>;
def fborland_extensions : Flag<"-fborland-extensions">, Group<f_Group>, Flags<[CC1Option]>,
HelpText<"Accept non-standard constructs supported by the Borland compiler">;
+def fbounds_checking : Flag<"-fbounds-checking">, Group<f_Group>,
+ HelpText<"Enable run-time bounds checks.">;
+def fbounds_checking_EQ : Joined<"-fbounds-checking=">, Flags<[CC1Option]>,
+ Group<f_Group>;
def fbuiltin_strcat : Flag<"-fbuiltin-strcat">, Group<f_Group>;
def fbuiltin_strcpy : Flag<"-fbuiltin-strcpy">, Group<f_Group>;
def fbuiltin : Flag<"-fbuiltin">, Group<f_Group>;
diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index f977f55..19ee428 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -517,7 +517,7 @@
}
void CodeGenFunction::EmitCheck(llvm::Value *Address, unsigned Size) {
- if (!CatchUndefined)
+ if (BoundsChecking <= 0)
return;
// This needs to be to the standard address space.
diff --git a/lib/CodeGen/CodeGenFunction.cpp b/lib/CodeGen/CodeGenFunction.cpp
index dfb04b4..5d108be 100644
--- a/lib/CodeGen/CodeGenFunction.cpp
+++ b/lib/CodeGen/CodeGenFunction.cpp
@@ -41,6 +41,7 @@
CXXVTTValue(0), OutermostConditional(0), TerminateLandingPad(0),
TerminateHandler(0), TrapBB(0) {
+ BoundsChecking = getContext().getLangOpts().BoundsChecking;
CatchUndefined = getContext().getLangOpts().CatchUndefined;
CGM.getCXXABI().getMangleContext().startNewFunction();
}
diff --git a/lib/CodeGen/CodeGenFunction.h b/lib/CodeGen/CodeGenFunction.h
index a25b02a..8d48a0b 100644
--- a/lib/CodeGen/CodeGenFunction.h
+++ b/lib/CodeGen/CodeGenFunction.h
@@ -591,6 +591,11 @@
/// we prefer to insert allocas.
llvm::AssertingVH<llvm::Instruction> AllocaInsertPt;
+ /// BoundsChecking - Emit run-time bounds checks. Higher values mean
+ /// potentially higher performance penalties.
+ unsigned char BoundsChecking;
+
+ /// CatchUndefined - Emit run-time checks to catch undefined behaviors.
bool CatchUndefined;
/// In ARC, whether we should autorelease the return value.
diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 90a9f0c..1ccba75 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -2025,6 +2025,15 @@
CmdArgs.push_back("-Wlarge-by-value-copy=64"); // default value
}
+ if (Arg *A = Args.getLastArg(options::OPT_fbounds_checking,
+ options::OPT_fbounds_checking_EQ)) {
+ if (A->getNumValues()) {
+ StringRef val = A->getValue(Args);
+ CmdArgs.push_back(Args.MakeArgString("-fbounds-checking=" + val));
+ } else
+ CmdArgs.push_back("-fbounds-checking=1");
+ }
+
if (Args.hasArg(options::OPT__relocatable_pch))
CmdArgs.push_back("-relocatable-pch");
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 0635be6..3a7efbc 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -675,6 +675,8 @@
Res.push_back("-fno-operator-names");
if (Opts.PascalStrings)
Res.push_back("-fpascal-strings");
+ if (Opts.BoundsChecking > 0)
+ Res.push_back("-fbounds-checking=" + llvm::utostr(Opts.BoundsChecking));
if (Opts.CatchUndefined)
Res.push_back("-fcatch-undefined-behavior");
if (Opts.AddressSanitizer)
@@ -1953,7 +1955,11 @@
Opts.ObjCNonFragileABI2 = true;
Opts.ObjCDefaultSynthProperties =
Args.hasArg(OPT_fobjc_default_synthesize_properties);
- Opts.CatchUndefined = Args.hasArg(OPT_fcatch_undefined_behavior);
+ Opts.BoundsChecking = 0;
+ if ((Opts.CatchUndefined = Args.hasArg(OPT_fcatch_undefined_behavior)))
+ Opts.BoundsChecking = 5;
+ Opts.BoundsChecking = Args.getLastArgIntValue(OPT_fbounds_checking_EQ,
+ Opts.BoundsChecking, Diags);
Opts.EmitAllDecls = Args.hasArg(OPT_femit_all_decls);
Opts.PackStruct = Args.getLastArgIntValue(OPT_fpack_struct_EQ, 0, Diags);
Opts.PICLevel = Args.getLastArgIntValue(OPT_pic_level, 0, Diags);
diff --git a/test/Driver/bounds-checking.c b/test/Driver/bounds-checking.c
new file mode 100644
index 0000000..95bb8af
--- /dev/null
+++ b/test/Driver/bounds-checking.c
@@ -0,0 +1,7 @@
+// RUN: %clang -target x86_64-apple-darwin10 -fbounds-checking -### -fsyntax-only %s 2> %t
+// RUN: FileCheck < %t %s
+// RUN: %clang -target x86_64-apple-darwin10 -fbounds-checking=3 -### -fsyntax-only %s 2> %t
+// RUN: FileCheck -check-prefix=CHECK2 < %t %s
+
+// CHECK: "-fbounds-checking=1"
+// CHECK2: "-fbounds-checking=3"