How to add an attribute group to a function call in LLVM?












2















When compiling a program with clang I observe the following in the LLVM IR:



Given the following function declaration:



declare i32 @atoi(i8*) #2


Which has the following attributes:



attributes #2 = { nounwind readonly "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "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" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }


I can see that when the function is called:



%26 = call i32 @atoi(i8* %25) #5


More attributes get defined/re-defined for it:



attributes #5 = { nounwind readonly }


I know that the #2 attribute group contains "Function attributes" that can be added to a Function with the addFnAttr(Attribute Attr) method. I also know that there are "Return attributes" that I can add to a CallInst with addAttribute(0, Attribute Attr) as well as "Parameter attributes" that I can add with the same method or with an AttributeList/Set. This gives me, for example, %26 = call nounwind i32 @atoi(i8* nounwind %25).



But how are the attributes in the #5 attribute group added? What are they called? Are they different from the other kinds of attributes? Are they redundant in this case?










share|improve this question





























    2















    When compiling a program with clang I observe the following in the LLVM IR:



    Given the following function declaration:



    declare i32 @atoi(i8*) #2


    Which has the following attributes:



    attributes #2 = { nounwind readonly "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "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" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }


    I can see that when the function is called:



    %26 = call i32 @atoi(i8* %25) #5


    More attributes get defined/re-defined for it:



    attributes #5 = { nounwind readonly }


    I know that the #2 attribute group contains "Function attributes" that can be added to a Function with the addFnAttr(Attribute Attr) method. I also know that there are "Return attributes" that I can add to a CallInst with addAttribute(0, Attribute Attr) as well as "Parameter attributes" that I can add with the same method or with an AttributeList/Set. This gives me, for example, %26 = call nounwind i32 @atoi(i8* nounwind %25).



    But how are the attributes in the #5 attribute group added? What are they called? Are they different from the other kinds of attributes? Are they redundant in this case?










    share|improve this question



























      2












      2








      2


      2






      When compiling a program with clang I observe the following in the LLVM IR:



      Given the following function declaration:



      declare i32 @atoi(i8*) #2


      Which has the following attributes:



      attributes #2 = { nounwind readonly "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "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" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }


      I can see that when the function is called:



      %26 = call i32 @atoi(i8* %25) #5


      More attributes get defined/re-defined for it:



      attributes #5 = { nounwind readonly }


      I know that the #2 attribute group contains "Function attributes" that can be added to a Function with the addFnAttr(Attribute Attr) method. I also know that there are "Return attributes" that I can add to a CallInst with addAttribute(0, Attribute Attr) as well as "Parameter attributes" that I can add with the same method or with an AttributeList/Set. This gives me, for example, %26 = call nounwind i32 @atoi(i8* nounwind %25).



      But how are the attributes in the #5 attribute group added? What are they called? Are they different from the other kinds of attributes? Are they redundant in this case?










      share|improve this question
















      When compiling a program with clang I observe the following in the LLVM IR:



      Given the following function declaration:



      declare i32 @atoi(i8*) #2


      Which has the following attributes:



      attributes #2 = { nounwind readonly "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "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" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }


      I can see that when the function is called:



      %26 = call i32 @atoi(i8* %25) #5


      More attributes get defined/re-defined for it:



      attributes #5 = { nounwind readonly }


      I know that the #2 attribute group contains "Function attributes" that can be added to a Function with the addFnAttr(Attribute Attr) method. I also know that there are "Return attributes" that I can add to a CallInst with addAttribute(0, Attribute Attr) as well as "Parameter attributes" that I can add with the same method or with an AttributeList/Set. This gives me, for example, %26 = call nounwind i32 @atoi(i8* nounwind %25).



      But how are the attributes in the #5 attribute group added? What are they called? Are they different from the other kinds of attributes? Are they redundant in this case?







      llvm llvm-clang






      share|improve this question















      share|improve this question













      share|improve this question




      share|improve this question








      edited Nov 19 '18 at 17:14







      vasilyrud

















      asked Nov 19 '18 at 16:39









      vasilyrudvasilyrud

      5482411




      5482411
























          0






          active

          oldest

          votes











          Your Answer






          StackExchange.ifUsing("editor", function () {
          StackExchange.using("externalEditor", function () {
          StackExchange.using("snippets", function () {
          StackExchange.snippets.init();
          });
          });
          }, "code-snippets");

          StackExchange.ready(function() {
          var channelOptions = {
          tags: "".split(" "),
          id: "1"
          };
          initTagRenderer("".split(" "), "".split(" "), channelOptions);

          StackExchange.using("externalEditor", function() {
          // Have to fire editor after snippets, if snippets enabled
          if (StackExchange.settings.snippets.snippetsEnabled) {
          StackExchange.using("snippets", function() {
          createEditor();
          });
          }
          else {
          createEditor();
          }
          });

          function createEditor() {
          StackExchange.prepareEditor({
          heartbeatType: 'answer',
          autoActivateHeartbeat: false,
          convertImagesToLinks: true,
          noModals: true,
          showLowRepImageUploadWarning: true,
          reputationToPostImages: 10,
          bindNavPrevention: true,
          postfix: "",
          imageUploader: {
          brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
          contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
          allowUrls: true
          },
          onDemand: true,
          discardSelector: ".discard-answer"
          ,immediatelyShowMarkdownHelp:true
          });


          }
          });














          draft saved

          draft discarded


















          StackExchange.ready(
          function () {
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53379088%2fhow-to-add-an-attribute-group-to-a-function-call-in-llvm%23new-answer', 'question_page');
          }
          );

          Post as a guest















          Required, but never shown

























          0






          active

          oldest

          votes








          0






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes
















          draft saved

          draft discarded




















































          Thanks for contributing an answer to Stack Overflow!


          • Please be sure to answer the question. Provide details and share your research!

          But avoid



          • Asking for help, clarification, or responding to other answers.

          • Making statements based on opinion; back them up with references or personal experience.


          To learn more, see our tips on writing great answers.




          draft saved


          draft discarded














          StackExchange.ready(
          function () {
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53379088%2fhow-to-add-an-attribute-group-to-a-function-call-in-llvm%23new-answer', 'question_page');
          }
          );

          Post as a guest















          Required, but never shown





















































          Required, but never shown














          Required, but never shown












          Required, but never shown







          Required, but never shown

































          Required, but never shown














          Required, but never shown












          Required, but never shown







          Required, but never shown







          Popular posts from this blog

          Guess what letter conforming each word

          Port of Spain

          Run scheduled task as local user group (not BUILTIN)