There is no output when I use command clang -cc1 -analyze -analyzer-checker=debug.ViewExplodedGraph test.c to dump the ExplodedGraph of test.c

[for-just-we]

When I use this command, shell output is Warning: viewing graph requires assertions, What does that means? And there is no any .dot file output. What should I do to view the ExplodedGraph of test.c.

The LLVM version I use is 12.0.0,I directly downloaded the released package instead of compiling from source code, the graphviz version I use is 2.40.1.

[Snape3058]

llvm-project/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp

Line 3222 in d97f997

llvm::errs() << "Warning: viewing graph requires assertions" << "\n";

llvm-project/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp

Line 3232 in d97f997

llvm::errs() << "Warning: viewing graph requires assertions" << "\n";

These two lines are wrapped with macro NDEBUG. If this macro is defined, it will only output this warning and exit directly.
You need to re-compile your tool with assertions enabled.
Although debug checkers are available in release build, such functionality is disabled if assertions are disabled.

[for-just-we]

Thank you, may I ask where could I enable this assertion?

[Snape3058]

You need to re-compile your clang to enable this.
For debug build (CMAKE_BUILD_TYPE is Debug), it is enabled by default.
For release build (CMAKE_BUILD_TYPE is Release/RelWithDebInfo/MinSizeRel), you need to add -DLLVM_ENABLE_ASSERTIONS=ON during cmake.

[steakhal]

Proposed fix: https://reviews.llvm.org/D124442

[xhslyx]

Please tell me how to solve the following problem when I recompile：
-- clang project is enabled CMake Error at CMakeLists.txt:100 (message): LLVM_ENABLE_PROJECTS requests clang but directory not found: /home/zzh/llvm-source-code/llvm/../clang
This is the command I used：
zzh@server:~/llvm-source-code/build$ cmake -G "Unix Makefiles" ../llvm -DCMAKE_BUILD_TYPE=Debug -DLLVM_ENABLE_ASSERTIONS=ON -DLLVM_ENABLE_PROJECTS="clang;clang-tools-extra"
I've installed clang before and want to recompile it

[steakhal]

I don't understand your problem. Could you please provide more details?
What is the observed behavior and what did you expect instead?

[xhslyx]

OK, THANKS.
I previously installed clang by way of release, but ViewCFG this function does not work properly, I saw the previous issue can be solved by recompiling the method to specify -DLLCM_ENABLE_ASSERTIONS=ON.
However, I encountered the above problem when recompiling and it did not compile successfully, the above is the error message given and the compile command I used

[steakhal]

However, I encountered the above problem when recompiling and it did not compile successfully, the above is the error message given and the compile command I used the above is the error message given and the compile command I used.

Okay, it seems like something really messed up. What version (commit hash) of llvm-project do you try to compile?
There should be a clang directory at the same level where the llvm directory is.

PS: I was really confused since you mentioned that you got some error during build time, but it seems like cmake configure failed.

[xhslyx]

However, I encountered the above problem when recompiling and it did not compile successfully, the above is the error message given and the compile command I used the above is the error message given and the compile command I used.

Okay, it seems like something really messed up. What version (commit hash) of llvm-project do you try to compile? There should be a clang directory at the same level where the llvm directory is.

PS: I was really confused since you mentioned that you got some error during build time, but it seems like cmake configure failed.

Thank you for your answer.
It's my expression wrong, my error happened in the cmake phase, not in the build phase, sorry。
The version i try to compile is clang version 10.0.0 llvm 10.0.0
I have no clang directory at the asme level where the llvm directory is, the directory is source code/llvm/tools/clang

[steakhal]

I would recommend using the monorepo version where clang and llvm are in a merged repository.
I cannot support the old repository structure. Let me know if using the monorepo worked.

[xhslyx]

ok, i'll rebuild in monorepo version. Thanks:)