[cfe-dev] exc_bad_instruction on arm

[Anton Smirnov]

hi.

i'm trying to compile (seems to be sucessfully) and execute code on arm
(ios apple ipad air) and i'm having *exc_bad_instruction
(code=exc_arm_undefined, subcode=0x8458b00)* exception.

source code:

int main(int count, const char **args) {
  const char *c = "hello world";
  return 1 + 5;
}

generate bit-code cmd:

const char *cmd[] = {
        "clang",
        "-cc1",
        "-triple",
            "arm-apple-macosx10.10.0", //"thumbv7-apple-ios7.1.0",
//"arm-apple-macosx10.10.0", // "i386-apple-macosx10.10.0",
        "-emit-llvm",
        "-disable-free",
        "-main-file-name",
            [cppShortFile UTF8String],
        "-mrelocation-model",
            "pic",
        "-pic-level",
            "2",
        "-mdisable-fp-elim",
        "-masm-verbose",
        "-target-cpu",
            "cortex-a8", //"yonah",
        "-target-linker-version",
            "236.3",
        "-v",
        "-coverage-file",
            [llFile UTF8String],
//"/private/var/mobile/Applications/175ECA7F-3175-4AC9-971C-85272F5492C4/tmp/hw.ll"
        "-resource-dir",
            [[[ASPathHolder sharedHolder] tempFolder] UTF8String],
        "-stdlib=libc++",
        "-fdeprecated-macro",
        "-fdebug-compilation-dir",
            [[[ASPathHolder sharedHolder] tempFolder] UTF8String],
        "-ferror-limit",
            "19",
        "-fmessage-length",
            "0",
        //"-I",
        //    [[[[ASPathHolder sharedHolder] includeFolder]
stringByAppendingString:@"/libc"] UTF8String], // libc include folder
        //"-I",
        //    [[[[ASPathHolder sharedHolder] includeFolder]
stringByAppendingString:@"/libcxx"] UTF8String], // libc++ include folder
        "-stack-protector",
            "1",
        "-mstackrealign",
        //"-fblocks", // Apple "blocks" extensions
        //"-fobjc-runtime=macosx-fragile-10.10.0", // object-c runtime
        //"-fobjc-subscripting-legacy-runtime",
        "-fencode-extended-block-signature",
        "-fcxx-exceptions",
        "-fexceptions",
        "-fdiagnostics-show-option",
        "-vectorize-slp",
        "-target-feature",
            "+soft-float-abi",
        "-target-abi",
            "apcs-gnu",
        "-mfloat-abi",
            "soft",
        "-o",
            [llFile UTF8String], //
/private/var/mobile/Applications/175ECA7F-3175-4AC9-971C-85272F5492C4/tmp/hw.ll
        "-x",
        "c++",
            [cppFile UTF8String]
//"/private/var/mobile/Applications/175ECA7F-3175-4AC9-971C-85272F5492C4/tmp/hw.cpp"
    };

i'm not sure i'm using correct triple, target cpu and target features but i
used xcodes ones (when targeting ios device).

compilation was successfull and i'm having .ll file:
; ModuleID =
'/var/mobile/Applications/53D60D11-DF93-4129-AD97-B96424D165B5/Documents/projects/calc/calc.cpp'
target datalayout =
"e-p:32:32:32-i1:8:32-i8:8:32-i16:16:32-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:32:64-v128:32:128-a0:0:32-n32-S32"
target triple = "thumbv7-apple-ios7.1.0"

@.str = private unnamed_addr constant [12 x i8] c"hello world\00", align 1

; Function Attrs: nounwind ssp
define i32 @main(i32 %count, i8** %args) #0 {
entry:
  %retval = alloca i32, align 4
  %count.addr = alloca i32, align 4
  %args.addr = alloca i8**, align 4
  %c = alloca i8*, align 4
  store i32 0, i32* %retval
  store i32 %count, i32* %count.addr, align 4
  store i8** %args, i8*** %args.addr, align 4
  store i8* getelementptr inbounds ([12 x i8]* @.str, i32 0, i32 0), i8**
%c, align 4
  ret i32 6
}

attributes #0 = { nounwind ssp "less-precise-fpmad"="false"
"no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf"
"no-infs-fp-math"="false" "no-nans-fp-math"="false"
"stack-protector-buffer-size"="8" "unsafe-fp-math"="false"
"use-soft-float"="false" }

!llvm.ident = !{!0}

!0 = metadata !{metadata !"clang version 3.4 (tags/RELEASE_34/final
212412)"}

is it correct or can you see obvious errors?

then i'm trying to interpret .ll file.
i've copied lli tool source code and launching it from my ios app (created
static lib instead of executable) with default arguments (like triple and
cpu and so on - this can probably be wrong!).

Then i'm having exception in ExecutionEngine.cpp in line:

return runFunction(Fn, GVArgs).IntVal.getZExtValue();

*exc_bad_instruction (code=exc_arm_undefined, subcode=0x8458b00)*

Any thoughts? What does this subcode mean?

Any help is highly appreciated.

Regards, Anton.
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