http://blog.gmane.org/gmane.comp.gcc.help hourly 1 1901-01-01T00:00+00:00 http://gmane.org/img/gmane-25t.png http://gmane.org http://comments.gmane.org/gmane.comp.gcc.help/44773 <pre>Hi, I'm having trouble building GCC. I've decompressed GCC 4.7.2 source into a directory and binutils 2.21.1 into a directory in parallel with symbolic links to all subdirectories. I ran the contrib script to get all other dependencies and then ran GCC's configure in a parallel directory, following all installation instructions. It builds just fine but when I install it AR seems to be missing. Any idea what happened to it and how to get it? Looks like it's supposed to be built with binutils and I'm getting other tools from it like LD just not that one. There is a program called gcc-ar that seems to exist but not sure if it's the same tool? It may appear if I build binutils by itself but I'm trying to build them together so that I can get -flto optimization to work, as apparently GCC balks at using the linker plugin if they weren't built together. Thanks! </pre> Uri Moszkowicz 2013-06-18T20:07:49 http://comments.gmane.org/gmane.comp.gcc.help/44763 <pre> Greetings. I'm using -Wold-style-casts on my project, and I've found that I get warnings in my code when certain macros are expanded. These macros are defined in headers under /usr/include; my reading of the manual is that these ought to get some immunity from some warnings: "Macros defined in a system header are immune to a few warnings wherever they are expanded. This immunity is granted on an ad-hoc basis, when we find that a warning generates lots of false positives because of code in macros defined in system headers." -- http://gcc.gnu.org/onlinedocs/cpp/System-Headers.html But it seems there is some degree of judgment ("ad-hoc basis") involved -- it's not clear whether that's regarding the header files, individual macros, or individual warnings. The case I hit today was from zlib.h, which has the following macro definition: #define deflateInit(strm, level) \ deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream)) When expanded into my sample code: // https://gist.github.com/tkil/5806218 #include &lt;string.h&gt; #include &lt;zlib.h&gt; int main() { z_stream_s strm; memset( &amp;strm, 0, sizeof( strm ) ); const int rc = deflateInit( &amp;strm, Z_DEFAULT_COMPRESSION ); return rc; } I got: $ g++ -Wold-style-cast -o g++-warnings-check g++-warnings-check.cpp -lz g++-warnings-check.cpp: In function ‘int main()’: g++-warnings-check.cpp:49:20: warning: use of old-style cast [-Wold-style-cast] A few months ago, I ran into this &lt;sys/select.h&gt; as well; in that case, I could easily enough rewrite the needed operations for private use, so I did so. I'm aware that I can disable that warning for the single file, or even for a single region in the file using pragmas, but I would like to understand why g++ isn't applying the "system header" rule to that macro. Best regards, Anthony Foiani </pre> Anthony Foiani 2013-06-18T16:14:48 http://comments.gmane.org/gmane.comp.gcc.help/44762 <pre>Hello all Can someone please specify the pass related to if-conversion optimization? Best regards Abdul </pre> Abdul Wahid Memon 2013-06-18T15:30:46 http://comments.gmane.org/gmane.comp.gcc.help/44759 <pre>Hi, I'm curious about what is causing this reordering (prologue with the function parameters): # gcc structs.c -o structs -m32 -O1 -fschedule-insns2 (gdb) disas main Dump of assembler code for function main: 0x0804868c &lt;+0&gt;: push %ebp 0x0804868d &lt;+1&gt;: mov $0x3,%edx 0x08048692 &lt;+6&gt;: mov %esp,%ebp 0x08048694 &lt;+8&gt;: mov $0x2,%ecx 0x08048699 &lt;+13&gt;: and $0xfffffff0,%esp 0x0804869c &lt;+16&gt;: call 0x804845c &lt;funcao&gt; The code: __attribute__((fastcall)) void funcao(int i, int a) { ... int main() { int i, a; i = 2; i = 3; funcao(i, a); ... When I remove one of them (fastcall or schedule-insns2), the binary is generated in logic order: (gdb) disas main Dump of assembler code for function main: 0x08048340 &lt;+0&gt;: push %ebp 0x08048341 &lt;+1&gt;: mov %esp,%ebp 0x08048343 &lt;+3&gt;: and $0xfffffff0,%esp 0x08048346 &lt;+6&gt;: sub $0x10,%esp 0x08048349 &lt;+9&gt;: movl $0x3,0x4(%esp) 0x08048351 &lt;+17&gt;: movl $0x2,(%esp) 0x08048358 &lt;+24&gt;: call 0x8048450 &lt;funcao&gt; ... or (gdb) disas main Dump of assembler code for function main: 0x0804868c &lt;+0&gt;: push %ebp 0x0804868d &lt;+1&gt;: mov %esp,%ebp 0x0804868f &lt;+3&gt;: and $0xfffffff0,%esp 0x08048692 &lt;+6&gt;: mov $0x3,%edx 0x08048697 &lt;+11&gt;: mov $0x2,%ecx 0x0804869c &lt;+16&gt;: call 0x804845c &lt;funcao&gt; Someone knows something about the combined use of the fastcall attribute and schedule-insns2 option? Is there an issue? Regards. Geyslan Gregório Bem http://hackingbits.com &lt; at &gt;geyslangb br.linkedin.com/in/geyslan </pre> Geyslan Gregório Bem 2013-06-18T14:24:52 http://comments.gmane.org/gmane.comp.gcc.help/44755 <pre>Hi! I'm trying to reduce the amount of debug info in my binaries. What kind of debug info will I loose in case of using -femit-struct-debug-reduced or -femit-struct-debug-baseonly? And what is still available? /* With optimism, Evgeny Gavrin email : evgeny.gavrin&lt; at &gt;hotmail.com */ </pre> Evgeny Gavrin 2013-06-18T11:40:00 http://comments.gmane.org/gmane.comp.gcc.help/44754 <pre>I'm inspecting a static library with nm, and I see that the tool provides me with the unresolved symbols of a file foo.o even though those symbols are defined in file zoo.o and both are included in the static library (ar rcs libmy.a zoo.o foo.o). How can I ask nm to resolve these symbols if they can be found within the files of the archive and just report me about the other not resolved? Thanks R </pre> Riccardo Manfrin 2013-06-18T10:40:03 http://comments.gmane.org/gmane.comp.gcc.help/44751 <pre>If I compile my embedded program with options "-g -O1" I obtain an elf file with debug information. I can objcopy the elf file to a binary or hex file that can be loaded to flash, effectively striping out the debug information leaving only the optimized code in ROM. But if I re-build with options the same except omit the -g option, obviously I will have no symbols in the elf file making debugging impossible or at least more difficult. However, when I object copy this elf to a binary or hex file they are different somewhat than the binary or hex produced with options -g present. At least with 4.7.3 the main difference, as seen with objdump, is in the prologue to certain function calls with only a few bytes different in total code length on a fairly large embedded application (arm). So -g has some effect on the actual code produced it appears. Is this difference expected? Should -g cause changes in the actual code generated and not just add debug symbols to the elf? Possibly it is related to the optimization level? I have not checked to see if the results differ with higher or lower levels than -O1. I have seen several opinions regarding this but no authoritative answer. The gcc manual also does not really answer this. Thanks, -gene </pre> Gene Smith 2013-06-18T05:21:28 http://comments.gmane.org/gmane.comp.gcc.help/44749 <pre>I tried to ask in gcc and was redirected here. So, I've read the spec about extension The `[index]' or `.fieldname' is known as a designator. You can also use a designator (or the obsolete colon syntax) when initializing a union, to specify which element of the union should be used. For example, union foo { int i; double d; }; union foo f = { .d = 4 }; will convert 4 to a double to store it in the union using the second element. By contrast, casting 4 to type union foo would store it into the union as the integer i, since it is an integer. (See Cast to Union.) and wrote the following test: union foo { int i; double d; }; int main(int argc, char **argv) { union foo f = { .d = 4 }; ASSERT_EQ(0, f.i); ASSERT_FEQ(4.0, f.d); return 0; } ASSERT_EQ and ASSERT_FEQ are some macros which checks the value and gives some error messages. But it fails on sparc. I guess int should be equal 0x40100000 since bytes are in reverse order. As I know now, this extension is not bi-endian. So the question is: what shall I do? Does it mean that I just shall forget about that extension usage on sparc? Sergey </pre> Sergey Kljopov 2013-06-17T11:21:46 http://comments.gmane.org/gmane.comp.gcc.help/44733 <pre>Hello, I've tried to build GCC 4.8.1 numerous times without any luck. Build, host, and target system: i686-pc-mingw32. I'm using MinGW Shell, gcc -v 4.6.2 ; g++ -v 4.7.2 Configure goes fine, then building starts: it builds all required libraries and other built-in libraries, and ./gcc folder. Then it starts to build ./i686-pc-mingw32/libgcc folder, and that's when it crashes. Configure: ../gcc-*/configure --enable-languages=c,c++ Make: make Every time I got to this point, shell showed following error: checking how to run the C preprocessor... /lib/cpp configure: error: in `/y/Downloads/gcc481d/i686-pc-mingw32/libgcc` configure: error: C preprocessor "/lib/cpp" fails sanity check See `config.log` for more details. make[2]: *** [configure-stage1-target-libgcc] Error1 make[2]: Leaving directory /y/Downloads/gcc481d make[1]: *** [stage1-bubble] Error 2 make[1]: Leaving directory /y/Downloads/gcc481d make: *** [all] Error 2 I've attached config.log. Any ideas how to fix this? Thanks. </pre> Ignas 2013-06-14T09:31:12 http://comments.gmane.org/gmane.comp.gcc.help/44732 <pre>Hi, i'm not a c++/template guru and i can't decide if this is really a valid code or i have encountered a gcc bug: ------------------------------ template &lt;class T&gt; struct A { void *p; }; template &lt;class T&gt; struct B : A&lt;T&gt; { void *foo() { return p; } }; ------------------------------ g++ says "error: 'p' was not declared in this scope". microsoft's compiler is happy with the same code. Can anyone help? </pre> Luchezar Belev 2013-06-14T09:30:56 http://comments.gmane.org/gmane.comp.gcc.help/44724 <pre>Hi there, For the below simple case, I think poly1[i] should be hoisted to outermost loop to avoid loading from innermost loop at each iteration. But for arm-none-eabi target like cortex-m4, gcc fails to do so. Is this a normal case or a missing optimization? Please advise. void PolyMul (float *poly1, unsigned int n1, float *poly2, unsigned int n2, float *polymul, unsigned int *nmul) { unsigned int i, j; for (i = 0; i &lt;= n1; i++) for (j = 0; j &lt;= n2; j++) polymul[i+j] += poly1[i] * poly2[j]; } Thanks. BR, Terry </pre> Terry Guo 2013-06-13T10:13:23 http://comments.gmane.org/gmane.comp.gcc.help/44723 <pre>Hi, Im trying to implement a dynamic linker for M4 mcu's. But the generated code from gcc seems incorrect to me: im compiling using arm-none-eabi-gcc: -mcpu=cortex-m4 -mthumb -O2 -ggdb -Wstrict-prototypes -Wunused-parameter -lmylib main.c -o test Ive created the following program dynamically linked: ----main.c--------- int main() { test(); return 1; } On target I have the function -------mylib.c----------- int test() { return 1; } arm-none-eabi-gcc -fPIC -mcpu=cortex-m4 -mthumb -O2 -ggdb -Wstrict-prototypes -Wunused-parameter -lmylib mylib.c -o mylib.so ------linker script----- OUTPUT_FORMAT("elf32-littlearm") OUTPUT_ARCH(arm) ENTRY(_start) PHDRS { headers PT_PHDR PHDRS ; interp PT_INTERP ; text PT_LOAD FILEHDR PHDRS ; data PT_LOAD ; got PT_LOAD; dynamic PT_DYNAMIC ; } SECTIONS { . = SIZEOF_HEADERS; .interp : { *(.interp) } :text :interp .hash : { *(.hash) } .text : { *(.text) } :text .rodata : { *(.rodata) } /* defaults to :text */ .dynsym : { *(.dynsym) } .dynstr : { *(.dynstr) } .rel.dyn : { *(.rel.text .rel.text.* .rel.gnu.linkonce.t.*) *(.rel.got) } .rela.dyn : { *(.rela.text .rela.text.* .rela.gnu.linkonce.t.*) *(.rela.rodata .rela.rodata.* .rela.gnu.linkonce.r.*) *(.rela.data .rela.data.* .rela.gnu.linkonce.d.*) *(.rela.got) } .rel.plt : { *(.rel.plt) } .rela.plt : { *(.rela.plt) } .init_array : { PROVIDE_HIDDEN (__init_array_start = .); KEEP (*(SORT(.init_array.*))) KEEP (*(.init_array)) PROVIDE_HIDDEN (__init_array_end = .); } .fini_array : { PROVIDE_HIDDEN (__fini_array_start = .); KEEP (*(SORT(.fini_array.*))) KEEP (*(.fini_array)) PROVIDE_HIDDEN (__fini_array_end = .); } .jcr : { KEEP (*(.jcr)) } .init : { KEEP (*(.init)) } =0 .plt : { *(.plt) } .dynamic : { *(.dynamic) } :data :dynamic .got : { *(.got.plt) *(.igot.plt) *(.got) *(.igot) } :got .data : { *(.data) } :data } the machine generated code for main looks as follows (objdump -D): 0000015c &lt;main&gt;: 15c: b508 push {r3, lr} 15e: f000 e888 blx 270 &lt;__libc_fini_array+0xfc&gt; 162: 2001 movs r0, #1 164: bd08 pop {r3, pc} 166: bf00 nop instruction at 15e: seems incorrect to me, since M4 only branches using a register blx{cond} Rm, (M3 seems to be ok with label aswell.) Anyone who can tell me what is wrong and if there is a workaround for this ? Ive tried to use -mlong-calls, and it produces: 00000164 &lt;main&gt;: 164: b508 push {r3, lr} 166: f240 237c movw r3, #636 ; 0x27c 16a: f2c0 0300 movt r3, #0 16e: 4798 blx r3 170: 2001 movs r0, #1 172: bd08 pop {r3, pc} This looks OK except for the address in R3 not being rellative, since it's absolute it's not correct either (or am I missing something) BR Matias </pre> matti h 2013-06-13T09:25:11 http://comments.gmane.org/gmane.comp.gcc.help/44716 <pre>Hello, From DWARF standard I read that basic block info can also be stored in DWARF line number tables so that a DWARF consumer can match basic blocks with the machine code addresses. And I found in gcc 3.x there is an option "-a" to support output basic block information. However, in gcc 4.x this option is no longer available and I cannot find any basic lock info in line number tables through dwarfdump. Do gcc still record this information? What command line option is needed to enable this? Thanks, Yue Liu </pre> Yuë Liu 2013-06-13T00:07:02 http://comments.gmane.org/gmane.comp.gcc.help/44715 <pre>Hi, I'm trying to build GCC 4.7.2 with binutils 2.23.1 and am getting a compile error: dwarf.o: In function `get_TAG_name': /w/umoszkow/gcc/x86_64/binutils/../../gcc-4.7.2/binutils/dwarf.c:662: undefined reference to `get_DW_TAG_name' dwarf.o: In function `get_FORM_name': /w/umoszkow/gcc/x86_64/binutils/../../gcc-4.7.2/binutils/dwarf.c:678: undefined reference to `get_DW_FORM_name' dwarf.o: In function `get_AT_name': /w/umoszkow/gcc/x86_64/binutils/../../gcc-4.7.2/binutils/dwarf.c:1867: undefined reference to `get_DW_AT_name' collect2: error: ld returned 1 exit status Any idea how to get around this build problem? My arch is x86_64 and my OS is RHEL4u8WS. Thanks! </pre> Uri Moszkowicz 2013-06-12T20:52:02 http://comments.gmane.org/gmane.comp.gcc.help/44705 <pre>Hi, I'm having trouble with link time optimization in my application. It is a large application that uses only basic C++ (no exceptions, no templates, no STL, no floating point, etc). Like many applications, the source files are compiled separately into object files. Some of those are combined into shared libraries. The shared libraries are then statically linked with the remaining object files to produce the final application, which is about 100MB big. We are using GCC 4.7.2 with a non-GOLD 2.23.1 binutils. I simply added "-flto" to the GCC command to create object files: g++ -Wall -pipe -O3 -flto -fno-strict-aliasing -mtune=generic --no-exceptions -fPIC -c some.cc I then added "-flto" to the final link command but not the shared libraries: g++ -o exec -Xlinker some1.o some2.o -static some1.a some2.a -Wl,--wrap,open -flto I ran a benchmark of tests and the resulting execution time is now about 7% higher than it was without "-flto" added. Any suggestions for how to improve this result or why it may have gotten slower? If it helps, when I add "-fuse-linker-plugin" I get this error: g++: error: -fuse-linker-plugin is not supported in this configuration Thanks! </pre> Uri Moszkowicz 2013-06-11T21:48:17 http://comments.gmane.org/gmane.comp.gcc.help/44704 <pre>Hi list, I use gcc 4.8.1 + newlib on a cortex-m3. I'm trying to link my app with libc and a library "libtlc.a" that I created out of a bunch of object files (init.o, tlc.o, cpu.o) as follows: arm-none-eabi-ar rcs build/libtlc.a build/core_cm3.o build/cpu.o build/startup.o build/init.o build/tlc.o Within tlc.o I have the stubs implementation for _exit _sbrk ... I can see the assembly with objdump ether in the .o and in the libtlc.a library. I try linking with this command arm-none-eabi-g++ -W -Wall -mcpu=cortex-m3 -mthumb -march=armv7-m -nostartfiles -Wl,-Map=maketest.map -Wl,-Tlinkerscript.ld main.o -lc -lstdc++ -lgcc -ltlc -o maketest.elf but fail with these errors ... abort.c:63: undefined reference to `_exit' (same error for _sbrk, _getpid and _kill). On the contrary, if I use the object file "tlc.o" in the linking phase, I'm able to produce the elf app: arm-none-eabi-g++ -W -Wall -mcpu=cortex-m3 -mthumb -march=armv7-m -nostartfiles -Wl,-Map=maketest.map -Wl,-Tlinkerscript.ld main.o tlc.o -lc -lstdc++ -lgcc -ltlc -o maketest.elf What is the difference? The functions defs are in either tlc.o as well as in libtlc.o, but I'm able to produce the binary app only with the object file, not with the library. Thanks, RM </pre> Riccardo Manfrin 2013-06-11T21:36:20 http://comments.gmane.org/gmane.comp.gcc.help/44701 <pre>Hello, Does the below code look like valid C++, or is it a G++ bug? 5.2.7 has &lt;...&gt; The dynamic_cast operator shall not cast away constness (5.2.11). The other compilers I could check quickly (clang, icc, msvc) all reject the code, GCCs 3.3, 4.6, 4.7 and 4.8 accept the code. Andrey class A { }; class B : public A { }; int main() { A* a; B* b = new B(); a = dynamic_cast&lt;const A*&gt;(b); return 0; } </pre> Andrey Belevantsev 2013-06-11T11:30:17 http://comments.gmane.org/gmane.comp.gcc.help/44699 <pre>si te gusta la fortuna de san carlos. dale me gusta a nuestro sitio en fb https://www.facebook.com/fortunacostarica?ref=tn_tnmn &lt;https://www.facebook.com/fortunacostarica?ref=nf&gt; La Fortuna Costa Rica &lt;https://www.facebook.com/fortunacostarica&gt; aqui estaremos publicando las mejores ofertas, tal como la que publicamos en nuestro muro, oferta del Hotel Linda Vista a precio super rebajado gracias Esta correspondencia no contiene fines de venta directa. Nuestro deseo es mantenerle informado sobre los movimientos, servicios y oportunidades que se brindan para su crecimiento profesional y personal. Si usted est</pre> info< at >ticosviajando.com 2013-06-11T01:00:16 http://comments.gmane.org/gmane.comp.gcc.help/44689 <pre>Hi, I'm trying to do a simple register read through ARM inline assembly. If I embed the asm in the function directly, it works ... eg: #define BAD 0xBAADBAAD #define GOOD 0x600D600D #define RESET 0x00000000 #define NVIC_ISER0 0xE000E100 volatile int nvic_iser_status = 0xFFFFFFFF; function () { ... asm volatile( "ldr r2, =8 /* number of register */ \n\t" "ldr r1, =%0 /* load the nvic_iser* register */ \n\t" "read_nvic_iser:\n\t" "sub r2, r2, #1\n\t" "ldr r0, [r1]\n\t" "add r1, r1, #4 /* go to the next register */ \n\t" "cmp r0, %1\n\t" "beq read_nvic_iser_ok\n\t" "ldr r3, =%2\n\t" "str r3, [%4] /* update status flag */\n\t" "read_nvic_iser_ok:\n\t" "cmp r2, #0\n\t" "bne read_nvic_iser\n\t" "ldr r3, =%3\n\t" "str r3, [%4] /* update status flag */\n\t" : : "i" (NVIC_ISER0), "i" (RESET), "i" (BAD), "i" (GOOD), "r" (&amp;nvic_iser_status) : "r0", "r1", "r2", "r3" ); .. } But, if I want to call the asm through another function, I get errors .. eg: function (){ ... reg_read(NVIC_ISER0, RESET, nvic_iser_status) .. } reg_read(int addr, int reset, int status){ asm volatile( "ldr r2, =8 /* number of register */ \n\t" "ldr r1, =%0 /* load the nvic_iser* register */ \n\t" "read_reg:\n\t" "sub r2, r2, #1\n\t" "ldr r0, [r1]\n\t" "add r1, r1, #4 /* go to the next register */ \n\t" "cmp r0, %1\n\t" "beq read_reg_ok\n\t" "ldr r3, =%2\n\t" "str r3, [%4] /* update status flag */\n\t" "read_reg_ok:\n\t" "cmp r2, #0\n\t" "bne read_reg\n\t" "ldr r3, =%3\n\t" "str r3, [%4] /* update status flag */\n\t" : : "r" (addr), "r" (reset), "r" (BAD), "r" (GOOD), "r" (status) : "r0", "r1", "r2", "r3" //: ); } I see the following errors: /tmp/ccYu7aUS.ltrans0.ltrans.o: In function `read_reg_ok': ccYu7aUS.ltrans0.o:(.text.check_reset_value.4010+0x60): undefined reference to `r6' ccYu7aUS.ltrans0.o:(.text.check_reset_value.4010+0x64): undefined reference to `r4' ccYu7aUS.ltrans0.o:(.text.check_reset_value.4010+0x68): undefined reference to `r5' collect2: error: ld returned 1 exit status What am I doing wrong? thanks, Kalai </pre> Kalai Rajah N 2013-06-10T21:41:47 http://comments.gmane.org/gmane.comp.gcc.help/44685 <pre>I'm getting an error at compile time. All the variables are declared and my glob sruct is declared like this: struct glob_t globualation I though I might use wordexp instead since it would be more suited to what I'm doing but that fails with the same error exept it's wordexp's structure that is the problem. I also tried this to no avail. Gcc complains that the struct size is unknown. -- View this message in context: http://gcc.1065356.n5.nabble.com/trouble-using-glob-and-wordexp-tp945091.html Sent from the gcc - Help mailing list archive at Nabble.com. </pre> ballsystemlord 2013-06-10T15:59:19 http://comments.gmane.org/gmane.comp.gcc.help/44682 <pre>Is there a conditional define that expands to a string of the full gcc command-line used to compile the given .c/.cc file? I'd like to embed in the executable the exact compilation options used to build it. Thanks for help, ilya </pre> Ilya Shlyakhter 2013-06-09T22:29:08 Search the mailing list at Gmane query http://search.gmane.org/?group=$group=gmane.comp.gcc.help