How to get the string representation of an instruction?

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1

Hi,

I don't see a way to convert an Instruction to a string or const char
*, although '<<' works on it.

http://llvm.org/doxygen/classllvm_1_1Instruction.html

How to figure this out? Thanks.

2

Is Value::getName() not what you want?

3

he probably means text representation like in text IR

Zhang

4

Yes. Something like "store i32 %4, i32* @u.3, align 4, !dbg !22".

5

Value::print(…)?

6

Create a raw_string_ostream object and use << to print to it. The underlying string will contain the textual representation.

-Krzysztof

7

Create a raw_string_ostream object and use << to print to it. The
underlying string will contain the textual representation.

This is cumbersome. There is not a way to directly get the std::string
or char * representation of IR text?

8

> Create a raw_string_ostream object and use << to print to it. The
> underlying string will contain the textual representation.

This is cumbersome. There is not a way to directly get the std::string
or char * representation of IR text?

Directly? No. Take a look at AssemblyWriter::printInstruction() in
AsmWriter.cpp. There is a lot of logic involved in generating an
accurate, IR-parse-able representation of an instruction. Each operand
must be generated in string form which have their own complexities. A
string representation of an instruction could perhaps be cached with
it, but it would need to be updated every time the instruction is
modified -- and not every application of an instruction necessitates
having a text version of it.

9

> Create a raw_string_ostream object and use << to print to it. The
> underlying string will contain the textual representation.

This is cumbersome. There is not a way to directly get the std::string
or char * representation of IR text?

Were .dump() functions mentioned already?

--
Regards,
Peng

Roman.

10

I don't see a way to convert an Instruction to a string or const char
*, although '<<' works on it.
LLVM: llvm::Instruction Class Reference
How to figure this out? Thanks.

Create a raw_string_ostream object and use << to print to it. The underlying string will contain the textual representation.

llvm/Support/ScopedPrinter.h has a to_string() template which does this.