From f30ff2240932d4d03984bd16cc8b9bb2b5427a53 Mon Sep 17 00:00:00 2001
From: tomsmeding <tom.smeding@gmail.com>
Date: Sat, 13 Aug 2016 18:30:01 +0200
Subject: Better error handling, flushing, optimisation

---
 bfcomp.c | 96 ++++++++++++++++++++++++++++++++++++++++++++++++++++------------
 o.bf     |  1 +
 2 files changed, 79 insertions(+), 18 deletions(-)
 create mode 100644 o.bf

diff --git a/bfcomp.c b/bfcomp.c
index 95a43f3..5c4db60 100644
--- a/bfcomp.c
+++ b/bfcomp.c
@@ -8,9 +8,13 @@
 
 #define DBGTIME(tag,block) \
 	do { \
-		clock_t start; \
+		clock_t start=clock(); \
+		DBGTIMESTART(start,tag,block); \
+	} while(0)
+
+#define DBGTIMESTART(start,tag,block) \
+	do { \
 		if(params.verbose){ \
-			start=clock(); \
 			fprintf(stderr,"%s",(tag)); \
 		} \
 		{block} \
@@ -20,6 +24,11 @@
 	} while(0)
 
 
+__attribute__((noreturn)) void outofmem(void){
+	fprintf(stderr,"Memory allocation error!\n");
+	exit(1);
+}
+
 int uniqid(void){
 	static int i=0;
 	return i++;
@@ -85,8 +94,12 @@ void parseargs(int argc,char **argv){
 }
 
 int runcmd(const char *cmd/*,int in,int out*/){
+	clock_t start=clock();
 	pid_t pid=fork();
-	assert(pid>=0);
+	if(pid<0){
+		fprintf(stderr,"Cannot fork!\n");
+		exit(1);
+	}
 	if(pid==0){
 		/*dup2(in,0);
 		dup2(out,1);*/
@@ -94,7 +107,7 @@ int runcmd(const char *cmd/*,int in,int out*/){
 		__builtin_unreachable();
 	} else {
 		int statloc;
-		DBGTIME(cmd,{
+		DBGTIMESTART(start,cmd,{
 			while(true){
 				waitpid(pid,&statloc,0);
 				if(WIFEXITED(statloc))break;
@@ -107,16 +120,18 @@ int runcmd(const char *cmd/*,int in,int out*/){
 FILE* gettempfilew(char name[20]){
 	memcpy(name,"/tmp/tmp.XXXXXXXXXX",20);
 	int fd=mkstemp(name);
-	assert(fd>=0);
+	if(fd<0){
+		fprintf(stderr,"Cannot create temp file!\n");
+		exit(1);
+	}
 	FILE *f=fdopen(fd,"w");
-	assert(f);
+	if(!f)outofmem();
 	return f;
 }
 
 int compilechain(const char *asmfname,const char *dstfname){
 	char ofname[20];
 	FILE *f=gettempfilew(ofname);
-	if(params.verbose)fprintf(stderr,"o -> %s\n",ofname);
 	assert(strlen(ofname)==19);
 	fclose(f);
 	char buf[25+19+1+strlen(asmfname)+1];
@@ -138,8 +153,11 @@ void writeprologue(FILE *asmf){
 		"extern _malloc\n"
 		"extern _free\n"
 		"extern _printf\n"
+		"extern _getchar\n"
 		"extern _putchar\n"
 		"extern _write\n"
+		"extern ___stdoutp\n"
+		"extern _fflush\n"
 		"\n"
 		"default rel\n"
 		"\n"
@@ -167,7 +185,6 @@ void writeprogram(char *source,FILE *asmf){
 	int i=0;
 	do {
 		char c=source[i];
-		if(c&&strchr("+-><[].,",c)==NULL)continue;
 		if(addc&&c!='+'&&c!='-'){
 			addc=(addc%256)+256%256;
 			if(addc==1)fprintf(asmf,"\tinc byte [rbx]  ; 1 +\n");
@@ -200,7 +217,7 @@ void writeprogram(char *source,FILE *asmf){
 
 			case '[':{
 				struct stackitem *ls=malloc(sizeof(struct stackitem));
-				assert(ls);
+				if(!ls)outofmem();
 				ls->id=uniqid();
 				ls->next=loopstack;
 				loopstack=ls;
@@ -214,7 +231,10 @@ void writeprogram(char *source,FILE *asmf){
 			}
 
 			case ']':{
-				assert(loopstack);
+				if(!loopstack){
+					fprintf(stderr,"Excess ']' in source\n");
+					exit(1);
+				}
 				fprintf(asmf,
 					"\tcmp byte [rbx], 0  ; ]\n"
 					"\tjnz loop%d_body\n"
@@ -230,7 +250,9 @@ void writeprogram(char *source,FILE *asmf){
 				fprintf(asmf,
 					"\tmov edi, 0  ; .\n"
 					"\tmov dil, byte [rbx]\n"
-					"\tcall _putchar\n");
+					"\tcall _putchar\n"
+					"\txor edi, edi\n"
+					"\tcall _fflush\n");
 				break;
 
 			case ',':
@@ -239,11 +261,18 @@ void writeprogram(char *source,FILE *asmf){
 					"\tmov byte [rbx], al\n");
 				break;
 
+			case '0':
+				fprintf(asmf,"\tmov byte [rbx], 0\n");
+				break;
+
 			default:
-				if(c)assert(false);
+				if(c)assert(false); //should've been stripped
 		}
 	} while(source[i++]);
-	assert(!loopstack);
+	if(loopstack){
+		fprintf(stderr,"Excess '[' in source\n");
+		exit(1);
+	}
 }
 
 void writeepilogue(FILE *asmf){
@@ -280,11 +309,11 @@ void writeepilogue(FILE *asmf){
 		"\n"
 		"nomemstr: db \"Out of memory!\"\n"
 		".len: equ $-nomemstr\n"
-		"\n"
+		/*"\n"
 		"formatstr: db \"Last cell reached: %%d\", 10, 0\n"
 		"\n"
 		"align 8, db 0\n"
-		"maxp: dq 0\n"
+		"maxp: dq 0\n"*/
 		"\n"
 		"\n"
 		"section .bss\n"
@@ -296,13 +325,13 @@ void writeepilogue(FILE *asmf){
 void readsource(FILE *f,char **sourcep){
 	int sz=1024;
 	char *source=malloc(sz);
-	assert(source);
+	if(!source)outofmem();
 	int i=0;
 	while(true){
 		if(i==sz-1){
 			sz*=2;
 			source=realloc(source,sz);
-			assert(source);
+			if(!source)outofmem();
 		}
 		char c=fgetc(f);
 		if(feof(f))break;
@@ -313,11 +342,36 @@ void readsource(FILE *f,char **sourcep){
 	*sourcep=source;
 }
 
+void optimise(char *source){
+	int j=0;
+#define COPY do {if(j<i)source[j]=source[i]; j++;} while(0)
+	for(int i=0;source[i];i++){
+		switch(source[i]){
+			case '[':
+				if(source[i+1]=='-'&&source[i+2]==']'){
+					source[j++]='0';
+					i+=2;
+				} else COPY;
+				break;
+
+			default:
+				COPY;
+				break;
+		}
+	}
+	source[j]='\0';
+#undef COPY
+}
+
 int main(int argc,char **argv){
+	fflush(stdout);
 	parseargs(argc,argv);
 
 	FILE *srcf=fopen(params.srcfname,"r");
-	assert(srcf);
+	if(!srcf){
+		fprintf(stderr,"Cannot open file '%s'\n",params.srcfname);
+		return 1;
+	}
 
 	char *source;
 	readsource(srcf,&source);
@@ -325,6 +379,8 @@ int main(int argc,char **argv){
 
 	fclose(srcf);
 
+	optimise(source);
+
 	char asmfname[20];
 	FILE *asmf=gettempfilew(asmfname);
 	if(params.verbose)fprintf(stderr,"asm -> %s\n",asmfname);
@@ -335,6 +391,10 @@ int main(int argc,char **argv){
 
 	fclose(asmf);
 
+	/*char *b;
+	asprintf(&b,"cat -n %s",asmfname);
+	runcmd(b);
+	free(b);*/
 	int ret=compilechain(asmfname,params.dstfname);
 	unlink(asmfname);
 	if(params.verbose)fprintf(stderr,"unlink(%s)  (asmfname)\n",asmfname);
diff --git a/o.bf b/o.bf
new file mode 100644
index 0000000..dd5b852
--- /dev/null
+++ b/o.bf
@@ -0,0 +1 @@
+++++++++++[>+++++++++++<-]>+.
-- 
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