dev: capture compiler diagnostics under DOS

Every fec error message was written to stderr, and COMMAND.COM can only
redirect handle 1 -- ">" is the whole vocabulary, "2>" is not parsed at all.
So a failing compile recorded exit code 1 and a zero-byte log, and the actual
message went to a screen nobody reads. Confirmed directly: `FEC.EXE --check`
on a fixture that must fail produced rc=1 and 0 bytes of stdout.

That is why an unexpected compiler failure was undiagnosable. It also means
the M6 reject cases have only ever asserted "exit code was nonzero" -- the
error text they nominally check has never been observable to the runner.

Add fe_diag_stream(), which resolves once to stdout when FE_DIAG_STDOUT is set
and stderr otherwise, and route diag.c and driver.c through it. The default is
unchanged, so interactive use keeps writing to stderr; the runner sets the
variable in RUN.BAT. The stderr references in check.c and emit_c.c are the
Ferro language's own std.io.stderr writer and are deliberately untouched.

Verified in DOSBox-X: 155 passed. A rejecting compile now records its message,
source excerpt and caret in RESULTS\<key>.LOG.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BScg8CF1sAAM2zVHAu5zvW
This commit is contained in:
2026-08-16 23:09:30 +09:00
co-authored by Claude Opus 5
parent 8b7d6a8d09
commit 86bff9a06d
4 changed files with 39 additions and 20 deletions
+6 -6
View File
@@ -8,7 +8,7 @@
static char *read_file(const char *name, unsigned long *size)
{
FILE *f; long n; char *p;
f=fopen(name,"rb"); if(!f){fprintf(stderr,"fec: cannot open %s\n",name);return 0;}
f=fopen(name,"rb"); if(!f){fprintf(fe_diag_stream(),"fec: cannot open %s\n",name);return 0;}
if(fseek(f,0L,SEEK_END)!=0){fclose(f);return 0;} n=ftell(f); if(n<0){fclose(f);return 0;} rewind(f);
p=(char *)malloc((unsigned long)n+1); if(!p){fclose(f);return 0;}
if(n && fread(p,1,(size_t)n,f)!=(size_t)n){free(p);fclose(f);return 0;} fclose(f);p[n]='\0';*size=(unsigned long)n;return p;
@@ -54,7 +54,7 @@ int main(int argc, char **argv)
else if(strcmp(argv[i],"--dump-tokens")==0) dump_tok=1;
else if(strcmp(argv[i],"--check")==0) check_only=1;
else if(strcmp(argv[i],"--emit-c")==0) emit=1;
else if(strcmp(argv[i],"-o")==0){if(i+1>=argc){fprintf(stderr,"fec: -o needs a path\n");return 2;}outname=argv[++i];}
else if(strcmp(argv[i],"-o")==0){if(i+1>=argc){fprintf(fe_diag_stream(),"fec: -o needs a path\n");return 2;}outname=argv[++i];}
else if(strncmp(argv[i],"-o",2)==0 && argv[i][2]) outname=argv[i]+2;
else if(strncmp(argv[i],"--target=bits16",15)==0) pointer_bits=16;
else if(strncmp(argv[i],"--target=bits32",15)==0) pointer_bits=32;
@@ -62,13 +62,13 @@ int main(int argc, char **argv)
else if(strncmp(argv[i],"--target=",9)==0 || strncmp(argv[i],"--model=",8)==0 || strcmp(argv[i],"--strip-error-names")==0) { }
else if(argv[i][0]!='-') file=argv[i];
else if(strcmp(argv[i],"--help")==0){usage();return 0;}
else {fprintf(stderr,"fec: unknown option %s\n",argv[i]);return 2;}
else {fprintf(fe_diag_stream(),"fec: unknown option %s\n",argv[i]);return 2;}
}
if((dump?1:0)+(dump_tok?1:0)+(check_only?1:0)+(emit?1:0)>1){
fprintf(stderr,"fec: choose only one output mode\n");
fprintf(fe_diag_stream(),"fec: choose only one output mode\n");
return 2;
}
if(!file){fprintf(stderr,"fec: no input file\n");return 2;}
if(!file){fprintf(fe_diag_stream(),"fec: no input file\n");return 2;}
src=read_file(file,&n);
if(!src)return 2;
fe_diags_init(&d,src,n);
@@ -98,7 +98,7 @@ int main(int argc, char **argv)
return 0;
}
out=outname?fopen(outname,"w"):stdout;
if(!out){fprintf(stderr,"fec: cannot create %s\n",outname);fe_ast_destroy(&ast);free(src);return 2;}
if(!out){fprintf(fe_diag_stream(),"fec: cannot create %s\n",outname);fe_ast_destroy(&ast);free(src);return 2;}
fe_emit_c_init(&emitter,out,&check,pointer_bits,no_checks);
fe_emit_c_program(&emitter);
if(outname)fclose(out);