GCC makefile不接受-std = c99 -lm

Question

我在使用gcc編譯器時遇到了我的makefile問題。如果我直接使用gcc：

gcc -std=c99 -lm tm.c tm_coins.c tm_options.c tm_stock.c tm_utility.c -o tm -Wall -pedantic 

一切工作正常。我需要-std-c99和-lm。

但是，我被告知使用makefile。這裏是我的make文件：

CFLAGS=-ansi -Wall -pedantic 
LFLAGS=-std=c99 -lm 
CC=gcc 
all:tm 
tm:tm.o tm_coins.o tm_options.o tm_stock.o tm_utility.o 
    $(CC) $(LFLAGS) tm.o tm_coins.o tm_options.o tm_stock.o tm_utility.o -o tm $(CFLAGS) 

tm.o: tm.h tm.c 
    $(CC) $(LFLAGS) $(CFLAGS) -c tm.c 

tm_coins.o:tm_coins.h tm_coins.c 
    $(CC) $(LFLAGS) $(CFLAGS) -c tm_coins.c 

tm_options:tm_options.h tm_options.c 
    $(CC) $(LFLAGS) $(CFLAGS) -c tm_options.c 

tm_stock:tm_stock.h tm_stock.c 
    $(CC) $(LFLAGS) $(CFLAGS) -c tm_stock.c 

tm_utility:tm_utility.h tm_utility.c 
    $(CC) $(LFLAGS) $(CFLAGS) -c tm_utility.c 

有了上面的makefile，我得到了下面的錯誤。我的理解是-std = c99和-lm不起作用。 （看看下面的第一道防線。-std = C99和-lm不存在）

gcc -ansi -Wall -pedantic -c -o tm_options.o tm_options.c 
tm_options.c: In function ‘purchase_ticket’: 
tm_options.c:37: error: expected expression before ‘/’ token 
tm_options.c:52: error: expected expression before ‘/’ token 
tm_options.c:102: warning: ISO C90 forbids mixed declarations and code 
tm_options.c: In function ‘display_tickets’: 
tm_options.c:239: error: expected expression before ‘/’ token 
tm_options.c: In function ‘add_ticket’: 
tm_options.c:285: error: expected expression before ‘/’ token 
tm_options.c:303: error: expected expression before ‘/’ token 
tm_options.c:314: warning: ISO C90 forbids mixed declarations and code 
tm_options.c: In function ‘delete_ticket’: 
tm_options.c:387: error: expected expression before ‘/’ token 
tm_options.c:405: error: expected expression before ‘/’ token 
tm_options.c: In function ‘display_coins’: 
tm_options.c:461: error: expected expression before ‘/’ token 
tm_options.c: In function ‘restock_tickets’: 
tm_options.c:501: error: expected expression before ‘/’ token 
tm_options.c: In function ‘restock_coins’: 
tm_options.c:526: error: expected expression before ‘/’ token 
tm_options.c: In function ‘save_data’: 
tm_options.c:555: warning: ISO C90 forbids mixed declarations and code 

哪裏會出錯？提前致謝。

Answer 1

爲以下三個規則，你忘記了你的目標.o後綴：

tm_options:tm_options.h tm_options.c 
    $(CC) $(LFLAGS) $(CFLAGS) -c tm_options.c 

tm_stock:tm_stock.h tm_stock.c 
    $(CC) $(LFLAGS) $(CFLAGS) -c tm_stock.c 

tm_utility:tm_utility.h tm_utility.c 
    $(CC) $(LFLAGS) $(CFLAGS) -c tm_utility.c 

這就是爲什麼你寫的規則並不適用。取而代之的是，它回落到將.c源文件編譯爲.o的默認規則。

你的意思是包括它，就像這樣：

tm_options.o:tm_options.h tm_options.c 
    $(CC) $(LFLAGS) $(CFLAGS) -c tm_options.c 

tm_stock.o:tm_stock.h tm_stock.c 
    $(CC) $(LFLAGS) $(CFLAGS) -c tm_stock.c 

tm_utility.o:tm_utility.h tm_utility.c 
    $(CC) $(LFLAGS) $(CFLAGS) -c tm_utility.c 

---

我建議重構你的makefile，所以你必須編譯一個通用的規則.c到.o：

%.o: %.c 
    $(CC) $(CFLAGS) -o %@ -c %< 

然後，您只需指定文件的相關性：

tm_options.o: tm_options.h tm_options.c 
tm_stock.o: tm_stock.h tm_stock.c 
tm_utility.o: tm_utility.h tm_utility.c 

並自動應用上述規則。重構你的makefile這將使它更容易發現錯誤:)

Answer 2

你不想在編譯命令LFLAGS無論如何 - 在CFLAGS把-std=c99 - makefile文件應該更多這樣的：

CFLAGS = -ansi -Wall -pedantic -std=c99 
LFLAGS = -lm 
CC = gcc 

all: tm 

tm: tm.o tm_coins.o tm_options.o tm_stock.o tm_utility.o 
    $(CC) $(LFLAGS) tm.o tm_coins.o tm_options.o tm_stock.o tm_utility.o -o tm 

tm.o: tm.h tm.c 
    $(CC) $(CFLAGS) -c tm.c 

tm_coins.o: tm_coins.h tm_coins.c 
    $(CC) $(CFLAGS) -c tm_coins.c 

tm_options.o: tm_options.h tm_options.c 
    $(CC) $(CFLAGS) -c tm_options.c 

tm_stock.o: tm_stock.h tm_stock.c 
    $(CC) $(CFLAGS) -c tm_stock.c 

tm_utility.o: tm_utility.h tm_utility.c 
    $(CC) $(CFLAGS) -c tm_utility.c 

（我還添加了Magnus指出的丟失的.o後綴。）