Is the IDE open source? An IDE that is packaged separately and uses the TCC compiler could be useful.
On Sun, Mar 10, 2024 at 1:01 PM Robert Schlicht <tin...@rschlicht.eu> wrote: > At our university we offer a course where we program simple spatial > simulations in various programming languages, one of them being C, for > illustrating close-to-the-machine programming concepts. We here need a C > implementation that is small (since it’s accessed over a network), works > out of the box on Windows computers (since our students are beginners) and > runs fast (so compiler errors are available instantaneously). We do not > need advanced developer tools, and code running three times slower is > acceptable because that is still faster than scripting languages. > > TCC is obviously a good option here, and for our course starting in April > of this year, I put together a package https://rschlicht.eu/tc-ide.zip > that includes a minimalist IDE running TCC and a very basic form of a C > standard library, all contained in a standalone executable tc-ide.exe. The > library is just headers that directly access the Windows API (no runtime > needed) and should satisfy the requirements of a conforming freestanding > implementation, while also including common memory, file, math and the > printf family of functions. (If anyone finds this useful, I’ll gladly > contribute it to the TCC project.) > > The executable is compiled by itself, although this currently requires a > few hacks and workarounds to get it working as desired. I list these here > as suggestions for improving TCC: > > (1) For using TCC as a library, it would be nice if it did a more thorough > cleanup: > – In a few places exit() is called in case of failure, but terminating the > program is not very user-friendly; cleanly propagating failure or even some > longjmp hacks might provide a better solution. [tc-ide does the latter, > while patching function calls to keep track of memory and open files.] > – Another problem I encountered is that TCC does not always properly > restore the state of the global variables; compiling the following code > fragment the first time produces an error message (as it should), but the > second time it causes an exception (which I assume is a bug): > void nothing(void) {for ( ; ; ) break;} void garbage(void) {switch > [The workaround in tc-ide is ugly but straightforward: Make a copy of the > memory block containing all global variables, and restore this block after > TCC returns.] > > (2) I really appreciate that TCC can directly link to functions in Windows > DLLs with no auxiliary .lib file and that it even supports directives like > #pragma comment(lib,"kernel32"). The current implementation of the DLL > lookup with a huge number of lseek & read calls (via read_mem() in tccpe.c) > may be inefficient on some file systems. [tc-ide avoids this issue by > creating file mappings in memory and redirecting lseek and read to those > memory buffers, which it has to deal with anyway to access the embedded > headers.] > > (3) The C23 preprocessor directive #embed would be of help for embedding > headers and other files as byte arrays in the program. [tc-ide currently > does this by providing a non-standard feature with a custom notation like > #include "stdlib.h#".] > > (4) TCC uses fixed buffer sizes for file paths in certain places. For > example, libtcc.c has 260(=MAX_PATH) in config_tccdir_w32() and > _fullpath(), 1000 in tcc_add_systemdir() and 1024 in > tcc_add_library_internal(), while tccelf.c has 1024 in getcwd(). Windows > has been supporting long file paths for quite a while now, so it might be > better to allocate those buffers dynamically: > https://learn.microsoft.com/en-us/windows/win32/fileio/maximum-file-path-limitation > > (5) Some rarely used C library functions could perhaps be replaced to make > the code less dependent on such features. Examples are the single use of > alloca() in libtcc.c to set up a buffer and the use of scanf() in tccpp.c > to convert the TCC version string into a number. [tc-ide here provides > stubs.] > > (6) It would be useful to allow the user to set the entry point symbol > (either the one called by the OS or the one called by the startup code), > like other compilers do. [tc-ide provides its own version of _start(), > which simply calls main().] > > (7) Additional observations: > – In tcc_new() (tcclib.c), checking the return value of tcc_mallocz is > probably redundant. > – In tcc_close() (tcclib.c), I do not understand why the test is ">0" > instead of ">=0". Typically 0 is stdin, but maybe the code should not rely > on that. > – The protection of InitializeCriticalSection() in tcc.h is not > thread-safe and can lead to a race condition. > – In Windows, the semicolon ';' can appear in file names and is therefore > perhaps not an ideal PATHSEP path separator character (despite that fact > that it is still used in that function in the Path environment variable); a > double null-terminated string could be a better choice. > > Let me conclude with a question on the licenses. As I understand it, TCC > is licensed under LGPL, although there is also a more permissive > RELICENSING statement, but I assume this is irrelevant due to the various > contributions by authors not listed there. Is that so, or am I missing > something? > > Robert > > _______________________________________________ > Tinycc-devel mailing list > Tinycc-devel@nongnu.org > https://lists.nongnu.org/mailman/listinfo/tinycc-devel >
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